| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell2010 |
ElectrsClient.Import.External
Synopsis
- (++) :: [a] -> [a] -> [a]
- seq :: forall {r :: RuntimeRep} a (b :: TYPE r). a -> b -> b
- filter :: (a -> Bool) -> [a] -> [a]
- zip :: [a] -> [b] -> [(a, b)]
- fst :: (a, b) -> a
- snd :: (a, b) -> b
- otherwise :: Bool
- ($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- coerce :: forall {k :: RuntimeRep} (a :: TYPE k) (b :: TYPE k). Coercible a b => a -> b
- fromIntegral :: (Integral a, Num b) => a -> b
- realToFrac :: (Real a, Fractional b) => a -> b
- guard :: Alternative f => Bool -> f ()
- join :: Monad m => m (m a) -> m a
- class Bounded a where
- class Enum a where
- succ :: a -> a
- pred :: a -> a
- toEnum :: Int -> a
- fromEnum :: a -> Int
- enumFrom :: a -> [a]
- enumFromThen :: a -> a -> [a]
- enumFromTo :: a -> a -> [a]
- enumFromThenTo :: a -> a -> a -> [a]
- class Eq a where
- class Fractional a => Floating a where
- class Num a => Fractional a where
- (/) :: a -> a -> a
- recip :: a -> a
- fromRational :: Rational -> a
- class (Real a, Enum a) => Integral a where
- class Applicative m => Monad (m :: Type -> Type) where
- class Functor (f :: Type -> Type) where
- class Num a where
- class Eq a => Ord a where
- class Read a
- class (Num a, Ord a) => Real a where
- toRational :: a -> Rational
- class (Real a, Fractional a) => RealFrac a where
- class Show a
- class Typeable (a :: k)
- class Monad m => MonadFail (m :: Type -> Type) where
- class IsString a where
- fromString :: String -> a
- class Functor f => Applicative (f :: Type -> Type) where
- class Foldable (t :: Type -> Type)
- class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where
- traverse :: Applicative f => (a -> f b) -> t a -> f (t b)
- sequenceA :: Applicative f => t (f a) -> f (t a)
- mapM :: Monad m => (a -> m b) -> t a -> m (t b)
- sequence :: Monad m => t (m a) -> m (t a)
- class Generic a
- class KnownNat (n :: Nat)
- class IsLabel (x :: Symbol) a where
- fromLabel :: a
- class Semigroup a where
- class Semigroup a => Monoid a where
- data Bool
- type String = [Char]
- data Char
- data Double = D# Double#
- data Float = F# Float#
- data Int
- data Int8
- data Int16
- data Int32
- data Int64
- data Integer
- data Natural
- data Maybe a
- data Ordering
- data Ratio a = !a :% !a
- type Rational = Ratio Integer
- data IO a
- data Word
- data Word8
- data Word16
- data Word32
- data Word64
- data Ptr a
- data FunPtr a
- data Either a b
- type Type = Type
- data Constraint
- data Nat
- type family CmpNat (a :: Nat) (b :: Nat) :: Ordering where ...
- class a ~R# b => Coercible (a :: k) (b :: k)
- data CallStack
- class Out a where
- data ByteString
- class Hashable a where
- hashWithSalt :: Int -> a -> Int
- (<$>) :: Functor f => (a -> b) -> f a -> f b
- data Text
- const :: a -> b -> a
- (.) :: (b -> c) -> (a -> b) -> a -> c
- id :: a -> a
- data HashMap k v
- data Map k a
- class ToJSON a
- fromJSON :: FromJSON a => Value -> Result a
- genericParseJSON :: (Generic a, GFromJSON Zero (Rep a)) => Options -> Value -> Parser a
- class FromJSON a where
- class FromJSONKey a where
- camelTo2 :: Char -> String -> String
- defaultOptions :: Options
- data Options
- stdout :: Handle
- (<**>) :: Applicative f => f a -> f (a -> b) -> f b
- data Handle
- class Bifunctor (p :: Type -> Type -> Type) where
- class Applicative f => Alternative (f :: Type -> Type) where
- class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type) where
- newtype Compose (f :: k -> Type) (g :: k1 -> k) (a :: k1) = Compose {
- getCompose :: f (g a)
- data Void
- vacuous :: Functor f => f Void -> f a
- absurd :: Void -> a
- data WrappedMonoid m
- newtype Option a = Option {}
- mtimesDefault :: (Integral b, Monoid a) => b -> a -> a
- cycle1 :: Semigroup m => m -> m
- sortWith :: Ord b => (a -> b) -> [a] -> [a]
- tail :: NonEmpty a -> [a]
- nonEmpty :: [a] -> Maybe (NonEmpty a)
- last :: NonEmpty a -> a
- init :: NonEmpty a -> [a]
- head :: NonEmpty a -> a
- showStackTrace :: IO (Maybe String)
- getStackTrace :: IO (Maybe [Location])
- class Monad m => MonadIO (m :: Type -> Type) where
- zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m ()
- zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c]
- unless :: Applicative f => Bool -> f () -> f ()
- replicateM_ :: Applicative m => Int -> m a -> m ()
- replicateM :: Applicative m => Int -> m a -> m [a]
- mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a
- mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])
- forever :: Applicative f => f a -> f b
- foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m ()
- foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b
- filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a]
- (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
- (<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c
- (<$!>) :: Monad m => (a -> b) -> m a -> m b
- mapAccumR :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)
- mapAccumL :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)
- forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b)
- foldMapDefault :: (Traversable t, Monoid m) => (a -> m) -> t a -> m
- fmapDefault :: Traversable t => (a -> b) -> t a -> t b
- newtype ZipList a = ZipList {
- getZipList :: [a]
- optional :: Alternative f => f a -> f (Maybe a)
- (&&&) :: Arrow a => a b c -> a b c' -> a b (c, c')
- newtype Identity a = Identity {
- runIdentity :: a
- stdin :: Handle
- stderr :: Handle
- withFrozenCallStack :: HasCallStack => (HasCallStack => a) -> a
- callStack :: HasCallStack => CallStack
- data TVar a
- data STM a
- writeTVar :: TVar a -> a -> STM ()
- readTVar :: TVar a -> STM a
- newTVar :: a -> STM (TVar a)
- data IORef a
- type FilePath = String
- prettySrcLoc :: SrcLoc -> String
- prettyCallStack :: CallStack -> String
- class (Typeable e, Show e) => Exception e where
- toException :: e -> SomeException
- fromException :: SomeException -> Maybe e
- displayException :: e -> String
- newtype Const a (b :: k) = Const {
- getConst :: a
- foldrM :: (Foldable t, Monad m) => (a -> b -> m b) -> b -> t a -> m b
- foldlM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b
- concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
- concat :: Foldable t => t [a] -> [a]
- unfoldr :: (b -> Maybe (a, b)) -> b -> [a]
- transpose :: [[a]] -> [[a]]
- tails :: [a] -> [[a]]
- subsequences :: [a] -> [[a]]
- sortOn :: Ord b => (a -> b) -> [a] -> [a]
- sortBy :: (a -> a -> Ordering) -> [a] -> [a]
- sort :: Ord a => [a] -> [a]
- permutations :: [a] -> [[a]]
- isPrefixOf :: Eq a => [a] -> [a] -> Bool
- intersperse :: a -> [a] -> [a]
- intercalate :: [a] -> [[a]] -> [a]
- inits :: [a] -> [[a]]
- group :: Eq a => [a] -> [[a]]
- genericTake :: Integral i => i -> [a] -> [a]
- genericSplitAt :: Integral i => i -> [a] -> ([a], [a])
- genericReplicate :: Integral i => i -> a -> [a]
- genericLength :: Num i => [a] -> i
- genericDrop :: Integral i => i -> [a] -> [a]
- newtype Last a = Last {}
- newtype First a = First {}
- newtype Sum a = Sum {
- getSum :: a
- newtype Product a = Product {
- getProduct :: a
- newtype Endo a = Endo {
- appEndo :: a -> a
- newtype Dual a = Dual {
- getDual :: a
- newtype Any = Any {}
- newtype Alt (f :: k -> Type) (a :: k) = Alt {
- getAlt :: f a
- newtype All = All {}
- stimesMonoid :: (Integral b, Monoid a) => b -> a -> a
- stimesIdempotent :: Integral b => b -> a -> a
- newtype Down a = Down {
- getDown :: a
- comparing :: Ord a => (b -> a) -> b -> b -> Ordering
- data SomeNat = KnownNat n => SomeNat (Proxy n)
- someNatVal :: Natural -> SomeNat
- natVal :: forall (n :: Nat) proxy. KnownNat n => proxy n -> Natural
- reads :: Read a => ReadS a
- readMaybe :: Read a => String -> Maybe a
- rights :: [Either a b] -> [b]
- partitionEithers :: [Either a b] -> ([a], [b])
- lefts :: [Either a b] -> [a]
- isRight :: Either a b -> Bool
- isLeft :: Either a b -> Bool
- either :: (a -> c) -> (b -> c) -> Either a b -> c
- data Proxy (t :: k) = Proxy
- data IOMode
- byteSwap64 :: Word64 -> Word64
- byteSwap32 :: Word32 -> Word32
- byteSwap16 :: Word16 -> Word16
- xor :: Bits a => a -> a -> a
- underflowError :: a
- reduce :: Integral a => a -> a -> Ratio a
- ratioZeroDenominatorError :: a
- ratioPrec1 :: Int
- ratioPrec :: Int
- overflowError :: a
- odd :: Integral a => a -> Bool
- numericEnumFromTo :: (Ord a, Fractional a) => a -> a -> [a]
- numericEnumFromThenTo :: (Ord a, Fractional a) => a -> a -> a -> [a]
- numericEnumFromThen :: Fractional a => a -> a -> [a]
- numericEnumFrom :: Fractional a => a -> [a]
- numerator :: Ratio a -> a
- notANumber :: Rational
- naturalFromInt :: Int -> Natural
- lcm :: Integral a => a -> a -> a
- integralEnumFromTo :: Integral a => a -> a -> [a]
- integralEnumFromThenTo :: Integral a => a -> a -> a -> [a]
- integralEnumFromThen :: (Integral a, Bounded a) => a -> a -> [a]
- integralEnumFrom :: (Integral a, Bounded a) => a -> [a]
- infinity :: Rational
- gcd :: Integral a => a -> a -> a
- even :: Integral a => a -> Bool
- divZeroError :: a
- denominator :: Ratio a -> a
- (^^%^^) :: Integral a => Rational -> a -> Rational
- (^^) :: (Fractional a, Integral b) => a -> b -> a
- (^%^) :: Integral a => Rational -> a -> Rational
- (^) :: (Num a, Integral b) => a -> b -> a
- boundedEnumFromThen :: (Enum a, Bounded a) => a -> a -> [a]
- boundedEnumFrom :: (Enum a, Bounded a) => a -> [a]
- chr :: Int -> Char
- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
- zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
- unzip3 :: [(a, b, c)] -> ([a], [b], [c])
- unzip :: [(a, b)] -> ([a], [b])
- takeWhile :: (a -> Bool) -> [a] -> [a]
- take :: Int -> [a] -> [a]
- splitAt :: Int -> [a] -> ([a], [a])
- scanr :: (a -> b -> b) -> b -> [a] -> [b]
- scanl :: (b -> a -> b) -> b -> [a] -> [b]
- reverse :: [a] -> [a]
- replicate :: Int -> a -> [a]
- repeat :: a -> [a]
- iterate :: (a -> a) -> a -> [a]
- dropWhile :: (a -> Bool) -> [a] -> [a]
- drop :: Int -> [a] -> [a]
- cycle :: [a] -> [a]
- break :: (a -> Bool) -> [a] -> ([a], [a])
- maybeToList :: Maybe a -> [a]
- maybe :: b -> (a -> b) -> Maybe a -> b
- mapMaybe :: (a -> Maybe b) -> [a] -> [b]
- listToMaybe :: [a] -> Maybe a
- isNothing :: Maybe a -> Bool
- isJust :: Maybe a -> Bool
- fromMaybe :: a -> Maybe a -> a
- catMaybes :: [Maybe a] -> [a]
- bool :: a -> a -> Bool -> a
- fix :: (a -> a) -> a
- (&) :: a -> (a -> b) -> b
- void :: Functor f => f a -> f ()
- (<&>) :: Functor f => f a -> (a -> b) -> f b
- ($>) :: Functor f => f a -> b -> f b
- uncurry :: (a -> b -> c) -> (a, b) -> c
- curry :: ((a, b) -> c) -> a -> b -> c
- data MVar a
- subtract :: Num a => a -> a -> a
- currentCallStack :: IO [String]
- data NonEmpty a = a :| [a]
- when :: Applicative f => Bool -> f () -> f ()
- ord :: Char -> Int
- minInt :: Int
- maxInt :: Int
- liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r
- liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r
- liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r
- liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r
- liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d
- flip :: (a -> b -> c) -> b -> a -> c
- asTypeOf :: a -> a -> a
- ap :: Monad m => m (a -> b) -> m a -> m b
- (=<<) :: Monad m => (a -> m b) -> m a -> m b
- type HasCallStack = ?callStack :: CallStack
- getCallStack :: CallStack -> [([Char], SrcLoc)]
- stimesIdempotentMonoid :: (Integral b, Monoid a) => b -> a -> a
- data SomeException = Exception e => SomeException e
- (&&) :: Bool -> Bool -> Bool
- not :: Bool -> Bool
- (||) :: Bool -> Bool -> Bool
- decodeUtf8' :: ByteString -> Either UnicodeException Text
- data IdentityT (f :: k -> Type) (a :: k)
- newtype StateT s (m :: Type -> Type) a = StateT {
- runStateT :: s -> m (a, s)
- newtype ReaderT r (m :: Type -> Type) a = ReaderT {
- runReaderT :: r -> m a
- newtype MaybeT (m :: Type -> Type) a = MaybeT {}
- newtype ExceptT e (m :: Type -> Type) a = ExceptT (m (Either e a))
- class MonadIO m => MonadUnliftIO (m :: Type -> Type) where
- withRunInIO :: ((forall a. m a -> IO a) -> IO b) -> m b
- class MonadTrans (t :: (Type -> Type) -> Type -> Type) where
- class Monad m => MonadThrow (m :: Type -> Type)
- data IntMap a
- data IntSet
- data Seq a
- data Set a
- class NFData a where
- rnf :: a -> ()
- force :: NFData a => a -> a
- deepseq :: NFData a => a -> b -> b
- ($!!) :: NFData a => (a -> b) -> a -> b
- class MonadThrow m => MonadCatch (m :: Type -> Type)
- class MonadCatch m => MonadMask (m :: Type -> Type) where
- mask :: ((forall a. m a -> m a) -> m b) -> m b
- uninterruptibleMask :: ((forall a. m a -> m a) -> m b) -> m b
- generalBracket :: m a -> (a -> ExitCase b -> m c) -> (a -> m b) -> m (b, c)
- class Monad m => MonadState s (m :: Type -> Type) | m -> s where
- (^?) :: s -> Getting (First a) s a -> Maybe a
- (^..) :: s -> Getting (Endo [a]) s a -> [a]
- (^.) :: s -> Getting a s a -> a
- (.~) :: ASetter s t a b -> b -> s -> t
- over :: ASetter s t a b -> (a -> b) -> s -> t
- (%~) :: ASetter s t a b -> (a -> b) -> s -> t
- _1 :: Field1 s t a b => Lens s t a b
- _2 :: Field2 s t a b => Lens s t a b
- _3 :: Field3 s t a b => Lens s t a b
- _4 :: Field4 s t a b => Lens s t a b
- _5 :: Field5 s t a b => Lens s t a b
- type Lens s t a b = forall (f :: Type -> Type). Functor f => (a -> f b) -> s -> f t
- type Lens' s a = Lens s s a a
- type Traversal s t a b = forall (f :: Type -> Type). Applicative f => (a -> f b) -> s -> f t
- type Traversal' s a = Traversal s s a a
- modify :: MonadState s m => (s -> s) -> m ()
- gets :: MonadState s m => (s -> a) -> m a
- asks :: MonadReader r m => (r -> a) -> m a
- class Monad m => MonadReader r (m :: Type -> Type) | m -> r where
- type Reader r = ReaderT r Identity
- preuse :: MonadState s m => Getting (First a) s a -> m (Maybe a)
- use :: MonadState s m => Getting a s a -> m a
- preview :: MonadReader s m => Getting (First a) s a -> m (Maybe a)
- view :: MonadReader s m => Getting a s a -> m a
- modify' :: MonadState s m => (s -> s) -> m ()
- runExceptT :: ExceptT e m a -> m (Either e a)
- withExceptT :: forall (m :: Type -> Type) e e' a. Functor m => (e -> e') -> ExceptT e m a -> ExceptT e' m a
- runReader :: Reader r a -> r -> a
- type State s = StateT s Identity
- runState :: State s a -> s -> (a, s)
- evalState :: State s a -> s -> a
- execState :: State s a -> s -> s
- withState :: (s -> s) -> State s a -> State s a
- evalStateT :: Monad m => StateT s m a -> s -> m a
- execStateT :: Monad m => StateT s m a -> s -> m s
- bracketOnError :: MonadMask m => m a -> (a -> m b) -> (a -> m c) -> m c
- bracket_ :: MonadMask m => m a -> m b -> m c -> m c
- onException :: MonadMask m => m a -> m b -> m a
- tryAny :: MonadCatch m => m a -> m (Either SomeException a)
- try :: (MonadCatch m, Exception e) => m a -> m (Either e a)
- handleAny :: MonadCatch m => (SomeException -> m a) -> m a -> m a
- catchAny :: MonadCatch m => m a -> (SomeException -> m a) -> m a
- catch :: (MonadCatch m, Exception e) => m a -> (e -> m a) -> m a
- throwM :: (MonadThrow m, Exception e) => e -> m a
- modifyTVar' :: TVar a -> (a -> a) -> STM ()
- fromStrict :: Text -> Text
- toStrict :: Text -> Text
- unwords :: [Text] -> Text
- unlines :: [Text] -> Text
- lines :: Text -> [Text]
- words :: Text -> [Text]
- pack :: String -> Text
- decodeUtf8With :: OnDecodeError -> ByteString -> Text
- unpack :: Text -> String
- lenientDecode :: OnDecodeError
- strictDecode :: OnDecodeError
- type OnError a b = String -> Maybe a -> Maybe b
- type OnDecodeError = OnError Word8 Char
- data UnicodeException
- exceptToMaybeT :: forall (m :: Type -> Type) e a. Functor m => ExceptT e m a -> MaybeT m a
- maybeToExceptT :: forall (m :: Type -> Type) e a. Functor m => e -> MaybeT m a -> ExceptT e m a
- catchE :: forall (m :: Type -> Type) e a e'. Monad m => ExceptT e m a -> (e -> ExceptT e' m a) -> ExceptT e' m a
- throwE :: forall (m :: Type -> Type) e a. Monad m => e -> ExceptT e m a
- except :: forall (m :: Type -> Type) e a. Monad m => Either e a -> ExceptT e m a
- class SuperComposition a b c | a b -> c where
- (...) :: a -> b -> c
- type ($) (f :: k1 -> k) (a :: k1) = f a
- type family Each (c :: [k -> Constraint]) (as :: [k]) where ...
- type With (a :: [k -> Constraint]) (b :: k) = a <+> b
- readEither :: (ToString a, Read b) => a -> Either Text b
- type LText = Text
- type LByteString = ByteString
- class ConvertUtf8 a b where
- encodeUtf8 :: a -> b
- decodeUtf8 :: b -> a
- decodeUtf8Strict :: b -> Either UnicodeException a
- class ToText a where
- class ToLText a where
- class ToString a where
- undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a
- traceId :: Text -> Text
- traceM :: Monad m => Text -> m ()
- traceShowM :: (Show a, Monad m) => a -> m ()
- traceShowIdWith :: Show s => (a -> s) -> a -> a
- traceIdWith :: (a -> Text) -> a -> a
- traceShowId :: Show a => a -> a
- traceShow :: Show a => a -> b -> b
- error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => Text -> a
- trace :: Text -> a -> a
- data Undefined = Undefined
- putLTextLn :: MonadIO m => Text -> m ()
- putLText :: MonadIO m => Text -> m ()
- putTextLn :: MonadIO m => Text -> m ()
- putText :: MonadIO m => Text -> m ()
- hPrint :: (MonadIO m, Show a) => Handle -> a -> m ()
- putStrLn :: (Print a, MonadIO m) => a -> m ()
- putStr :: (Print a, MonadIO m) => a -> m ()
- hPutStrLn :: (Print a, MonadIO m) => Handle -> a -> m ()
- hPutStr :: (Print a, MonadIO m) => Handle -> a -> m ()
- class Print a
- unstableNub :: (Eq a, Hashable a) => [a] -> [a]
- sortNub :: Ord a => [a] -> [a]
- hashNub :: (Eq a, Hashable a) => [a] -> [a]
- ordNub :: Ord a => [a] -> [a]
- guardM :: MonadPlus m => m Bool -> m ()
- ifM :: Monad m => m Bool -> m a -> m a -> m a
- unlessM :: Monad m => m Bool -> m () -> m ()
- whenM :: Monad m => m Bool -> m () -> m ()
- evaluateNF_ :: (NFData a, MonadIO m) => a -> m ()
- evaluateNF :: (NFData a, MonadIO m) => a -> m a
- evaluateWHNF_ :: MonadIO m => a -> m ()
- evaluateWHNF :: MonadIO m => a -> m a
- note :: MonadError e m => e -> Maybe a -> m a
- bug :: (HasCallStack, Exception e) => e -> a
- pattern Exc :: Exception e => e -> SomeException
- data Bug = Bug SomeException CallStack
- maximum :: Ord a => NonEmpty a -> a
- maximumBy :: (a -> a -> Ordering) -> NonEmpty a -> a
- minimum :: Ord a => NonEmpty a -> a
- minimumBy :: (a -> a -> Ordering) -> NonEmpty a -> a
- foldr1 :: (a -> a -> a) -> NonEmpty a -> a
- foldl1 :: (a -> a -> a) -> NonEmpty a -> a
- whenNotNullM :: Monad m => m [a] -> (NonEmpty a -> m ()) -> m ()
- whenNotNull :: Applicative f => [a] -> (NonEmpty a -> f ()) -> f ()
- uncons :: [a] -> Maybe (a, [a])
- anyM :: (Container f, Monad m) => (Element f -> m Bool) -> f -> m Bool
- allM :: (Container f, Monad m) => (Element f -> m Bool) -> f -> m Bool
- orM :: (Container f, Element f ~ m Bool, Monad m) => f -> m Bool
- andM :: (Container f, Element f ~ m Bool, Monad m) => f -> m Bool
- concatForM :: (Applicative f, Monoid m, Container (l m), Element (l m) ~ m, Traversable l) => l a -> (a -> f m) -> f m
- concatMapM :: (Applicative f, Monoid m, Container (l m), Element (l m) ~ m, Traversable l) => (a -> f m) -> l a -> f m
- asum :: (Container t, Alternative f, Element t ~ f a) => t -> f a
- sequence_ :: (Container t, Monad m, Element t ~ m a) => t -> m ()
- sequenceA_ :: (Container t, Applicative f, Element t ~ f a) => t -> f ()
- forM_ :: (Container t, Monad m) => t -> (Element t -> m b) -> m ()
- mapM_ :: (Container t, Monad m) => (Element t -> m b) -> t -> m ()
- for_ :: (Container t, Applicative f) => t -> (Element t -> f b) -> f ()
- traverse_ :: (Container t, Applicative f) => (Element t -> f b) -> t -> f ()
- product :: (Container t, Num (Element t)) => t -> Element t
- sum :: (Container t, Num (Element t)) => t -> Element t
- flipfoldl' :: (Container t, Element t ~ a) => (a -> b -> b) -> b -> t -> b
- type family Val t
- type family Key t
- class ToPairs t where
- type family FromListC l
- type family ListElement l
- class FromList l where
- type ListElement l
- type FromListC l
- fromList :: [ListElement l] -> l
- type family Element t
- class Container t where
- type Element t
- toList :: t -> [Element t]
- null :: t -> Bool
- foldr :: (Element t -> b -> b) -> b -> t -> b
- foldl :: (b -> Element t -> b) -> b -> t -> b
- foldl' :: (b -> Element t -> b) -> b -> t -> b
- length :: t -> Int
- elem :: Element t -> t -> Bool
- foldMap :: Monoid m => (Element t -> m) -> t -> m
- fold :: t -> Element t
- foldr' :: (Element t -> b -> b) -> b -> t -> b
- notElem :: Element t -> t -> Bool
- all :: (Element t -> Bool) -> t -> Bool
- any :: (Element t -> Bool) -> t -> Bool
- and :: t -> Bool
- or :: t -> Bool
- find :: (Element t -> Bool) -> t -> Maybe (Element t)
- safeHead :: t -> Maybe (Element t)
- safeMaximum :: t -> Maybe (Element t)
- safeMinimum :: t -> Maybe (Element t)
- safeFoldr1 :: (Element t -> Element t -> Element t) -> t -> Maybe (Element t)
- safeFoldl1 :: (Element t -> Element t -> Element t) -> t -> Maybe (Element t)
- type family OneItem x
- class One x where
- maybeToMonoid :: Monoid m => Maybe m -> m
- hoistEither :: forall (m :: Type -> Type) e a. Applicative m => Either e a -> ExceptT e m a
- hoistMaybe :: forall (m :: Type -> Type) a. Applicative m => Maybe a -> MaybeT m a
- executingState :: s -> State s a -> s
- executingStateT :: Functor f => s -> StateT s f a -> f s
- evaluatingState :: s -> State s a -> a
- evaluatingStateT :: Functor f => s -> StateT s f a -> f a
- usingState :: s -> State s a -> (a, s)
- usingStateT :: s -> StateT s m a -> m (a, s)
- usingReader :: r -> Reader r a -> a
- usingReaderT :: r -> ReaderT r m a -> m a
- whenRightM :: Monad m => m (Either l r) -> (r -> m ()) -> m ()
- whenRight :: Applicative f => Either l r -> (r -> f ()) -> f ()
- whenLeftM :: Monad m => m (Either l r) -> (l -> m ()) -> m ()
- whenLeft :: Applicative f => Either l r -> (l -> f ()) -> f ()
- maybeToLeft :: r -> Maybe l -> Either l r
- maybeToRight :: l -> Maybe r -> Either l r
- rightToMaybe :: Either l r -> Maybe r
- leftToMaybe :: Either l r -> Maybe l
- fromRight :: b -> Either a b -> b
- fromLeft :: a -> Either a b -> a
- whenNothingM_ :: Monad m => m (Maybe a) -> m () -> m ()
- whenNothingM :: Monad m => m (Maybe a) -> m a -> m a
- whenNothing_ :: Applicative f => Maybe a -> f () -> f ()
- whenNothing :: Applicative f => Maybe a -> f a -> f a
- whenJustM :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()
- whenJust :: Applicative f => Maybe a -> (a -> f ()) -> f ()
- (?:) :: Maybe a -> a -> a
- atomicWriteIORef :: MonadIO m => IORef a -> a -> m ()
- atomicModifyIORef' :: MonadIO m => IORef a -> (a -> (a, b)) -> m b
- atomicModifyIORef :: MonadIO m => IORef a -> (a -> (a, b)) -> m b
- modifyIORef' :: MonadIO m => IORef a -> (a -> a) -> m ()
- modifyIORef :: MonadIO m => IORef a -> (a -> a) -> m ()
- writeIORef :: MonadIO m => IORef a -> a -> m ()
- readIORef :: MonadIO m => IORef a -> m a
- newIORef :: MonadIO m => a -> m (IORef a)
- withFile :: (MonadIO m, MonadMask m) => FilePath -> IOMode -> (Handle -> m a) -> m a
- hClose :: MonadIO m => Handle -> m ()
- openFile :: MonadIO m => FilePath -> IOMode -> m Handle
- writeFile :: MonadIO m => FilePath -> Text -> m ()
- readFile :: MonadIO m => FilePath -> m Text
- getLine :: MonadIO m => m Text
- appendFile :: MonadIO m => FilePath -> Text -> m ()
- die :: MonadIO m => String -> m a
- exitSuccess :: MonadIO m => m a
- exitFailure :: MonadIO m => m a
- exitWith :: MonadIO m => ExitCode -> m a
- updateTVar' :: TVar s -> StateT s STM a -> STM a
- updateMVar' :: MonadIO m => MVar s -> StateT s IO a -> m a
- readTVarIO :: MonadIO m => TVar a -> m a
- newTVarIO :: MonadIO m => a -> m (TVar a)
- tryTakeMVar :: MonadIO m => MVar a -> m (Maybe a)
- tryReadMVar :: MonadIO m => MVar a -> m (Maybe a)
- tryPutMVar :: MonadIO m => MVar a -> a -> m Bool
- takeMVar :: MonadIO m => MVar a -> m a
- swapMVar :: MonadIO m => MVar a -> a -> m a
- readMVar :: MonadIO m => MVar a -> m a
- putMVar :: MonadIO m => MVar a -> a -> m ()
- newMVar :: MonadIO m => a -> m (MVar a)
- newEmptyMVar :: MonadIO m => m (MVar a)
- (<<$>>) :: (Functor f, Functor g) => (a -> b) -> f (g a) -> f (g b)
- map :: Functor f => (a -> b) -> f a -> f b
- ($!) :: (a -> b) -> a -> b
- someNE :: Alternative f => f a -> f (NonEmpty a)
- pass :: Applicative f => f ()
- data Vector a
- data HashSet a
- newtype UnliftIO (m :: Type -> Type) = UnliftIO {}
- askRunInIO :: MonadUnliftIO m => m (m a -> IO a)
- withUnliftIO :: MonadUnliftIO m => (UnliftIO m -> IO a) -> m a
- race :: MonadUnliftIO m => m a -> m b -> m (Either a b)
- finally :: MonadUnliftIO m => m a -> m b -> m a
- bracket :: MonadUnliftIO m => m a -> (a -> m b) -> (a -> m c) -> m c
Documentation
(++) :: [a] -> [a] -> [a] infixr 5 #
Append two lists, i.e.,
[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn] [x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]
If the first list is not finite, the result is the first list.
seq :: forall {r :: RuntimeRep} a (b :: TYPE r). a -> b -> b infixr 0 #
The value of seq a b is bottom if a is bottom, and
otherwise equal to b. In other words, it evaluates the first
argument a to weak head normal form (WHNF). seq is usually
introduced to improve performance by avoiding unneeded laziness.
A note on evaluation order: the expression seq a b does
not guarantee that a will be evaluated before b.
The only guarantee given by seq is that the both a
and b will be evaluated before seq returns a value.
In particular, this means that b may be evaluated before
a. If you need to guarantee a specific order of evaluation,
you must use the function pseq from the "parallel" package.
filter :: (a -> Bool) -> [a] -> [a] #
\(\mathcal{O}(n)\). filter, applied to a predicate and a list, returns
the list of those elements that satisfy the predicate; i.e.,
filter p xs = [ x | x <- xs, p x]
>>>filter odd [1, 2, 3][1,3]
zip :: [a] -> [b] -> [(a, b)] #
\(\mathcal{O}(\min(m,n))\). zip takes two lists and returns a list of
corresponding pairs.
>>>zip [1, 2] ['a', 'b'][(1, 'a'), (2, 'b')]
If one input list is shorter than the other, excess elements of the longer list are discarded, even if one of the lists is infinite:
>>>zip [1] ['a', 'b'][(1, 'a')]>>>zip [1, 2] ['a'][(1, 'a')]>>>zip [] [1..][]>>>zip [1..] [][]
zip is right-lazy:
>>>zip [] _|_[]>>>zip _|_ []_|_
zip is capable of list fusion, but it is restricted to its
first list argument and its resulting list.
($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0 #
Application operator. This operator is redundant, since ordinary
application (f x) means the same as (f . However, $ x)$ has
low, right-associative binding precedence, so it sometimes allows
parentheses to be omitted; for example:
f $ g $ h x = f (g (h x))
It is also useful in higher-order situations, such as map ($ 0) xszipWith ($) fs xs
Note that ( is levity-polymorphic in its result type, so that
$)foo where $ Truefoo :: Bool -> Int# is well-typed.
coerce :: forall {k :: RuntimeRep} (a :: TYPE k) (b :: TYPE k). Coercible a b => a -> b #
The function coerce allows you to safely convert between values of
types that have the same representation with no run-time overhead. In the
simplest case you can use it instead of a newtype constructor, to go from
the newtype's concrete type to the abstract type. But it also works in
more complicated settings, e.g. converting a list of newtypes to a list of
concrete types.
This function is runtime-representation polymorphic, but the
RuntimeRep type argument is marked as Inferred, meaning
that it is not available for visible type application. This means
the typechecker will accept coerce @Int @Age 42.
fromIntegral :: (Integral a, Num b) => a -> b #
general coercion from integral types
realToFrac :: (Real a, Fractional b) => a -> b #
general coercion to fractional types
guard :: Alternative f => Bool -> f () #
Conditional failure of Alternative computations. Defined by
guard True =pure() guard False =empty
Examples
Common uses of guard include conditionally signaling an error in
an error monad and conditionally rejecting the current choice in an
Alternative-based parser.
As an example of signaling an error in the error monad Maybe,
consider a safe division function safeDiv x y that returns
Nothing when the denominator y is zero and Just (x `div`
y)
>>> safeDiv 4 0 Nothing >>> safeDiv 4 2 Just 2
A definition of safeDiv using guards, but not guard:
safeDiv :: Int -> Int -> Maybe Int
safeDiv x y | y /= 0 = Just (x `div` y)
| otherwise = Nothing
A definition of safeDiv using guard and Monad do-notation:
safeDiv :: Int -> Int -> Maybe Int safeDiv x y = do guard (y /= 0) return (x `div` y)
join :: Monad m => m (m a) -> m a #
The join function is the conventional monad join operator. It
is used to remove one level of monadic structure, projecting its
bound argument into the outer level.
'join bssdo expression
do bs <- bss bs
Examples
A common use of join is to run an IO computation returned from
an STM transaction, since STM transactions
can't perform IO directly. Recall that
atomically :: STM a -> IO a
is used to run STM transactions atomically. So, by
specializing the types of atomically and join to
atomically:: STM (IO b) -> IO (IO b)join:: IO (IO b) -> IO b
we can compose them as
join.atomically:: STM (IO b) -> IO b
The Bounded class is used to name the upper and lower limits of a
type. Ord is not a superclass of Bounded since types that are not
totally ordered may also have upper and lower bounds.
The Bounded class may be derived for any enumeration type;
minBound is the first constructor listed in the data declaration
and maxBound is the last.
Bounded may also be derived for single-constructor datatypes whose
constituent types are in Bounded.
Instances
| Bounded All | Since: base-2.1 |
| Bounded Any | Since: base-2.1 |
| Bounded Associativity | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded Int16 | Since: base-2.1 |
| Bounded Int32 | Since: base-2.1 |
| Bounded Int64 | Since: base-2.1 |
| Bounded Int8 | Since: base-2.1 |
| Bounded Word16 | Since: base-2.1 |
| Bounded Word32 | Since: base-2.1 |
| Bounded Word64 | Since: base-2.1 |
| Bounded Extension | |
| Bounded Ordering | Since: base-2.1 |
| Bounded IPv4 | |
| Bounded IPv6 | |
| Bounded PortNumber | |
Defined in Network.Socket.Types | |
| Bounded Undefined | |
| Bounded CompressionStrategy | |
Defined in Codec.Compression.Zlib.Stream | |
| Bounded Format | |
| Bounded Method | |
| Bounded Word8 | Since: base-2.1 |
| Bounded () | Since: base-2.1 |
| Bounded Bool | Since: base-2.1 |
| Bounded Char | Since: base-2.1 |
| Bounded Int | Since: base-2.1 |
| Bounded VecCount | Since: base-4.10.0.0 |
| Bounded VecElem | Since: base-4.10.0.0 |
| Bounded Word | Since: base-2.1 |
| Bounded a => Bounded (Identity a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Down a) | Swaps Since: base-4.14.0.0 |
| Bounded a => Bounded (First a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Last a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Max a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Min a) | Since: base-4.9.0.0 |
| Bounded m => Bounded (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| Bounded a => Bounded (Dual a) | Since: base-2.1 |
| Bounded a => Bounded (Product a) | Since: base-2.1 |
| Bounded a => Bounded (Sum a) | Since: base-2.1 |
| Bounded (Proxy t) | Since: base-4.7.0.0 |
| (Bounded a, Bounded b) => Bounded (Pair a b) | |
| (Bounded a, Bounded b) => Bounded (a, b) | Since: base-2.1 |
| Bounded a => Bounded (Const a b) | Since: base-4.9.0.0 |
| (Applicative f, Bounded a) => Bounded (Ap f a) | Since: base-4.12.0.0 |
| Bounded b => Bounded (Tagged s b) | |
| (Bounded a, Bounded b, Bounded c) => Bounded (a, b, c) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g) => Bounded (a, b, c, d, e, f, g) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h) => Bounded (a, b, c, d, e, f, g, h) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i) => Bounded (a, b, c, d, e, f, g, h, i) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j) => Bounded (a, b, c, d, e, f, g, h, i, j) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k) => Bounded (a, b, c, d, e, f, g, h, i, j, k) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | Since: base-2.1 |
Class Enum defines operations on sequentially ordered types.
The enumFrom... methods are used in Haskell's translation of
arithmetic sequences.
Instances of Enum may be derived for any enumeration type (types
whose constructors have no fields). The nullary constructors are
assumed to be numbered left-to-right by fromEnum from 0 through n-1.
See Chapter 10 of the Haskell Report for more details.
For any type that is an instance of class Bounded as well as Enum,
the following should hold:
- The calls
succmaxBoundpredminBound fromEnumandtoEnumshould give a runtime error if the result value is not representable in the result type. For example,toEnum7 ::BoolenumFromandenumFromThenshould be defined with an implicit bound, thus:
enumFrom x = enumFromTo x maxBound
enumFromThen x y = enumFromThenTo x y bound
where
bound | fromEnum y >= fromEnum x = maxBound
| otherwise = minBoundMethods
the successor of a value. For numeric types, succ adds 1.
the predecessor of a value. For numeric types, pred subtracts 1.
Convert from an Int.
Convert to an Int.
It is implementation-dependent what fromEnum returns when
applied to a value that is too large to fit in an Int.
Used in Haskell's translation of [n..] with [n..] = enumFrom n,
a possible implementation being enumFrom n = n : enumFrom (succ n).
For example:
enumFrom 4 :: [Integer] = [4,5,6,7,...]
enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]
enumFromThen :: a -> a -> [a] #
Used in Haskell's translation of [n,n'..]
with [n,n'..] = enumFromThen n n', a possible implementation being
enumFromThen n n' = n : n' : worker (f x) (f x n'),
worker s v = v : worker s (s v), x = fromEnum n' - fromEnum n and
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y
For example:
enumFromThen 4 6 :: [Integer] = [4,6,8,10...]
enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]
enumFromTo :: a -> a -> [a] #
Used in Haskell's translation of [n..m] with
[n..m] = enumFromTo n m, a possible implementation being
enumFromTo n m
| n <= m = n : enumFromTo (succ n) m
| otherwise = [].
For example:
enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
enumFromTo 42 1 :: [Integer] = []
enumFromThenTo :: a -> a -> a -> [a] #
Used in Haskell's translation of [n,n'..m] with
[n,n'..m] = enumFromThenTo n n' m, a possible implementation
being enumFromThenTo n n' m = worker (f x) (c x) n m,
x = fromEnum n' - fromEnum n, c x = bool (>=) ((x 0)
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y and
worker s c v m
| c v m = v : worker s c (s v) m
| otherwise = []
For example:
enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]
enumFromThenTo 6 8 2 :: [Int] = []
Instances
The Eq class defines equality (==) and inequality (/=).
All the basic datatypes exported by the Prelude are instances of Eq,
and Eq may be derived for any datatype whose constituents are also
instances of Eq.
The Haskell Report defines no laws for Eq. However, == is customarily
expected to implement an equivalence relationship where two values comparing
equal are indistinguishable by "public" functions, with a "public" function
being one not allowing to see implementation details. For example, for a
type representing non-normalised natural numbers modulo 100, a "public"
function doesn't make the difference between 1 and 201. It is expected to
have the following properties:
Instances
| Eq DotNetTime | |
Defined in Data.Aeson.Types.Internal | |
| Eq JSONPathElement | |
Defined in Data.Aeson.Types.Internal Methods (==) :: JSONPathElement -> JSONPathElement -> Bool # (/=) :: JSONPathElement -> JSONPathElement -> Bool # | |
| Eq SumEncoding | |
Defined in Data.Aeson.Types.Internal | |
| Eq Value | |
| Eq More | |
| Eq Pos | |
| Eq All | Since: base-2.1 |
| Eq Any | Since: base-2.1 |
| Eq SomeTypeRep | |
Defined in Data.Typeable.Internal | |
| Eq Version | Since: base-2.1 |
| Eq Void | Since: base-4.8.0.0 |
| Eq BlockReason | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync | |
| Eq ThreadId | Since: base-4.2.0.0 |
| Eq ThreadStatus | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync | |
| Eq ErrorCall | Since: base-4.7.0.0 |
| Eq ArithException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods (==) :: ArithException -> ArithException -> Bool # (/=) :: ArithException -> ArithException -> Bool # | |
| Eq SpecConstrAnnotation | Since: base-4.3.0.0 |
Defined in GHC.Exts Methods (==) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool # (/=) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool # | |
| Eq Associativity | Since: base-4.6.0.0 |
Defined in GHC.Generics Methods (==) :: Associativity -> Associativity -> Bool # (/=) :: Associativity -> Associativity -> Bool # | |
| Eq DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: DecidedStrictness -> DecidedStrictness -> Bool # (/=) :: DecidedStrictness -> DecidedStrictness -> Bool # | |
| Eq Fixity | Since: base-4.6.0.0 |
| Eq SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: SourceStrictness -> SourceStrictness -> Bool # (/=) :: SourceStrictness -> SourceStrictness -> Bool # | |
| Eq SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # | |
| Eq MaskingState | Since: base-4.3.0.0 |
Defined in GHC.IO | |
| Eq ArrayException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods (==) :: ArrayException -> ArrayException -> Bool # (/=) :: ArrayException -> ArrayException -> Bool # | |
| Eq AsyncException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods (==) :: AsyncException -> AsyncException -> Bool # (/=) :: AsyncException -> AsyncException -> Bool # | |
| Eq ExitCode | |
| Eq IOErrorType | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception | |
| Eq IOException | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception | |
| Eq BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
| Eq Handle | Since: base-4.1.0.0 |
| Eq Newline | Since: base-4.2.0.0 |
| Eq NewlineMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
| Eq IOMode | Since: base-4.2.0.0 |
| Eq Int16 | Since: base-2.1 |
| Eq Int32 | Since: base-2.1 |
| Eq Int64 | Since: base-2.1 |
| Eq Int8 | Since: base-2.1 |
| Eq IoSubSystem | |
Defined in GHC.RTS.Flags | |
| Eq SrcLoc | Since: base-4.9.0.0 |
| Eq SomeSymbol | Since: base-4.7.0.0 |
Defined in GHC.TypeLits | |
| Eq SomeNat | Since: base-4.7.0.0 |
| Eq Word16 | Since: base-2.1 |
| Eq Word32 | Since: base-2.1 |
| Eq Word64 | Since: base-2.1 |
| Eq ByteString | |
Defined in Data.ByteString.Internal | |
| Eq ByteString | |
Defined in Data.ByteString.Lazy.Internal | |
| Eq ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods (==) :: ShortByteString -> ShortByteString -> Bool # (/=) :: ShortByteString -> ShortByteString -> Bool # | |
| Eq IntSet | |
| Eq Relation | |
| Eq BlockHeader Source # | |
Defined in ElectrsClient.Rpc | |
| Eq BlkHeight Source # | |
| Eq RpcError Source # | |
| Eq Error | |
| Eq ForeignSrcLang | |
Defined in GHC.ForeignSrcLang.Type Methods (==) :: ForeignSrcLang -> ForeignSrcLang -> Bool # (/=) :: ForeignSrcLang -> ForeignSrcLang -> Bool # | |
| Eq Extension | |
| Eq Module | |
| Eq Ordering | |
| Eq TrName | |
| Eq TyCon | |
| Eq ConnHost | |
| Eq ConnKey | |
| Eq Proxy | |
| Eq ProxySecureMode | |
Defined in Network.HTTP.Client.Types Methods (==) :: ProxySecureMode -> ProxySecureMode -> Bool # (/=) :: ProxySecureMode -> ProxySecureMode -> Bool # | |
| Eq ResponseTimeout | |
Defined in Network.HTTP.Client.Types Methods (==) :: ResponseTimeout -> ResponseTimeout -> Bool # (/=) :: ResponseTimeout -> ResponseTimeout -> Bool # | |
| Eq StatusHeaders | |
Defined in Network.HTTP.Client.Types Methods (==) :: StatusHeaders -> StatusHeaders -> Bool # (/=) :: StatusHeaders -> StatusHeaders -> Bool # | |
| Eq StreamFileStatus | |
Defined in Network.HTTP.Client.Types Methods (==) :: StreamFileStatus -> StreamFileStatus -> Bool # (/=) :: StreamFileStatus -> StreamFileStatus -> Bool # | |
| Eq IP | Equality over IP addresses. Correctly compare IPv4 and IPv4-embedded-in-IPv6 addresses.
|
| Eq IPv4 | |
| Eq IPv6 | |
| Eq IPRange | |
| Eq MsgFlag | |
| Eq AddrInfo | |
| Eq AddrInfoFlag | |
Defined in Network.Socket.Info | |
| Eq NameInfoFlag | |
Defined in Network.Socket.Info | |
| Eq SocketOption | |
Defined in Network.Socket.Options | |
| Eq StructLinger | |
Defined in Network.Socket.Options | |
| Eq Cmsg | |
| Eq CmsgId | |
| Eq IPv4PktInfo | |
Defined in Network.Socket.Posix.Cmsg | |
| Eq IPv4TOS | |
| Eq IPv4TTL | |
| Eq IPv6HopLimit | |
Defined in Network.Socket.Posix.Cmsg | |
| Eq IPv6PktInfo | |
Defined in Network.Socket.Posix.Cmsg | |
| Eq IPv6TClass | |
Defined in Network.Socket.Posix.Cmsg | |
| Eq Family | |
| Eq PortNumber | |
Defined in Network.Socket.Types | |
| Eq SockAddr | |
| Eq Socket | |
| Eq SocketType | |
Defined in Network.Socket.Types | |
| Eq Block | |
| Eq BlockChainInfo | |
| Eq BlockVerbose | |
| Eq OutputInfo | |
| Eq OutputSetInfo | |
| Eq BitcoinRpcError | |
| Eq BlockTemplate | |
| Eq CoinBaseAux | |
| Eq HashData | |
| Eq MiningInfo | |
| Eq Transaction | |
| Eq AddNodeCommand | |
| Eq PeerInfo | |
| Eq BlockInfo | |
| Eq DecodedPsbt | |
| Eq DecodedRawTransaction | |
| Eq RawTransactionInfo | |
| Eq ScriptPubKey | |
| Eq ScriptSig | |
| Eq TxIn | |
| Eq TxOut | |
| Eq TxnOutputType | |
| Eq UnspentTransaction | |
| Eq BitcoinException | |
| Eq TransactionID | |
| Eq AddrInfo | |
| Eq AddressInfo | |
| Eq BitcoindInfo | |
| Eq DetailedTransaction | |
| Eq DetailedTransactionDetails | |
| Eq EstimationMode | |
| Eq ReceivedByAccount | |
| Eq ReceivedByAddress | |
| Eq ScrPubKey | |
| Eq SimpleTransaction | |
| Eq SinceBlock | |
| Eq TransactionCategory | |
| Eq URI | |
| Eq URIAuth | |
| Eq Mode | |
| Eq Style | |
| Eq TextDetails | |
Defined in Text.PrettyPrint.Annotated.HughesPJ | |
| Eq Doc | |
| Eq ByteArray | Since: primitive-0.6.3.0 |
| Eq StdGen | |
| Eq Scientific | Scientific numbers can be safely compared for equality. No magnitude |
Defined in Data.Scientific | |
| Eq CompactSig | |
Defined in Crypto.Secp256k1 | |
| Eq Msg | |
| Eq PubKey | |
| Eq SecKey | |
| Eq Sig | |
| Eq Tweak | |
| Eq AnnLookup | |
| Eq AnnTarget | |
| Eq Bang | |
| Eq Body | |
| Eq Bytes | |
| Eq Callconv | |
| Eq Clause | |
| Eq Con | |
| Eq Dec | |
| Eq DecidedStrictness | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: DecidedStrictness -> DecidedStrictness -> Bool # (/=) :: DecidedStrictness -> DecidedStrictness -> Bool # | |
| Eq DerivClause | |
Defined in Language.Haskell.TH.Syntax | |
| Eq DerivStrategy | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: DerivStrategy -> DerivStrategy -> Bool # (/=) :: DerivStrategy -> DerivStrategy -> Bool # | |
| Eq Exp | |
| Eq FamilyResultSig | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: FamilyResultSig -> FamilyResultSig -> Bool # (/=) :: FamilyResultSig -> FamilyResultSig -> Bool # | |
| Eq Fixity | |
| Eq FixityDirection | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: FixityDirection -> FixityDirection -> Bool # (/=) :: FixityDirection -> FixityDirection -> Bool # | |
| Eq Foreign | |
| Eq FunDep | |
| Eq Guard | |
| Eq Info | |
| Eq InjectivityAnn | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: InjectivityAnn -> InjectivityAnn -> Bool # (/=) :: InjectivityAnn -> InjectivityAnn -> Bool # | |
| Eq Inline | |
| Eq Lit | |
| Eq Loc | |
| Eq Match | |
| Eq ModName | |
| Eq Module | |
| Eq ModuleInfo | |
Defined in Language.Haskell.TH.Syntax | |
| Eq Name | |
| Eq NameFlavour | |
Defined in Language.Haskell.TH.Syntax | |
| Eq NameSpace | |
| Eq OccName | |
| Eq Overlap | |
| Eq Pat | |
| Eq PatSynArgs | |
Defined in Language.Haskell.TH.Syntax | |
| Eq PatSynDir | |
| Eq Phases | |
| Eq PkgName | |
| Eq Pragma | |
| Eq Range | |
| Eq Role | |
| Eq RuleBndr | |
| Eq RuleMatch | |
| Eq Safety | |
| Eq SourceStrictness | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: SourceStrictness -> SourceStrictness -> Bool # (/=) :: SourceStrictness -> SourceStrictness -> Bool # | |
| Eq SourceUnpackedness | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # | |
| Eq Specificity | |
Defined in Language.Haskell.TH.Syntax | |
| Eq Stmt | |
| Eq TyLit | |
| Eq TySynEqn | |
| Eq Type | |
| Eq TypeFamilyHead | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (/=) :: TypeFamilyHead -> TypeFamilyHead -> Bool # | |
| Eq CodePoint | |
| Eq DecoderState | |
| Eq UnicodeException | |
Defined in Data.Text.Encoding.Error Methods (==) :: UnicodeException -> UnicodeException -> Bool # (/=) :: UnicodeException -> UnicodeException -> Bool # | |
| Eq Day | |
| Eq AbsoluteTime | |
Defined in Data.Time.Clock.Internal.AbsoluteTime | |
| Eq UTCTime | |
| Eq UniversalTime | |
Defined in Data.Time.Clock.Internal.UniversalTime Methods (==) :: UniversalTime -> UniversalTime -> Bool # (/=) :: UniversalTime -> UniversalTime -> Bool # | |
| Eq LocalTime | |
| Eq Undefined | |
| Eq StringException | Since: unliftio-0.2.19 |
Defined in UnliftIO.Exception Methods (==) :: StringException -> StringException -> Bool # (/=) :: StringException -> StringException -> Bool # | |
| Eq ConcException | |
Defined in UnliftIO.Internals.Async Methods (==) :: ConcException -> ConcException -> Bool # (/=) :: ConcException -> ConcException -> Bool # | |
| Eq UUID | |
| Eq UnpackedUUID | |
| Eq CompressionLevel | |
Defined in Codec.Compression.Zlib.Stream Methods (==) :: CompressionLevel -> CompressionLevel -> Bool # (/=) :: CompressionLevel -> CompressionLevel -> Bool # | |
| Eq CompressionStrategy | |
Defined in Codec.Compression.Zlib.Stream Methods (==) :: CompressionStrategy -> CompressionStrategy -> Bool # (/=) :: CompressionStrategy -> CompressionStrategy -> Bool # | |
| Eq DictionaryHash | |
| Eq Format | |
| Eq MemoryLevel | |
Defined in Codec.Compression.Zlib.Stream | |
| Eq Method | |
| Eq WindowBits | |
Defined in Codec.Compression.Zlib.Stream | |
| Eq Word8 | Since: base-2.1 |
| Eq Integer | |
| Eq Natural | |
| Eq () | |
| Eq Bool | |
| Eq Char | |
| Eq Double | Note that due to the presence of
Also note that
|
| Eq Float | Note that due to the presence of
Also note that
|
| Eq Int | |
| Eq Word | |
| Eq (Digest t) | |
| Eq (Encoding' a) | |
| Eq a => Eq (IResult a) | |
| Eq a => Eq (Result a) | |
| Eq a => Eq (ZipList a) | Since: base-4.7.0.0 |
| Eq a => Eq (Complex a) | Since: base-2.1 |
| Eq a => Eq (Identity a) | Since: base-4.8.0.0 |
| Eq a => Eq (First a) | Since: base-2.1 |
| Eq a => Eq (Last a) | Since: base-2.1 |
| Eq a => Eq (Down a) | Since: base-4.6.0.0 |
| Eq a => Eq (First a) | Since: base-4.9.0.0 |
| Eq a => Eq (Last a) | Since: base-4.9.0.0 |
| Eq a => Eq (Max a) | Since: base-4.9.0.0 |
| Eq a => Eq (Min a) | Since: base-4.9.0.0 |
| Eq a => Eq (Option a) | Since: base-4.9.0.0 |
| Eq m => Eq (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods (==) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (/=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # | |
| Eq a => Eq (Dual a) | Since: base-2.1 |
| Eq a => Eq (Product a) | Since: base-2.1 |
| Eq a => Eq (Sum a) | Since: base-2.1 |
| Eq a => Eq (NonEmpty a) | Since: base-4.9.0.0 |
| Eq (TVar a) | Since: base-4.8.0.0 |
| Eq p => Eq (Par1 p) | Since: base-4.7.0.0 |
| Eq (IORef a) | Pointer equality. Since: base-4.0.0.0 |
| Eq (MVar a) | Since: base-4.1.0.0 |
| Eq (FunPtr a) | |
| Eq (Ptr a) | Since: base-2.1 |
| Eq a => Eq (Ratio a) | Since: base-2.1 |
| Eq a => Eq (Flush a) | |
| Eq a => Eq (IntMap a) | |
| Eq a => Eq (Seq a) | |
| Eq a => Eq (ViewL a) | |
| Eq a => Eq (ViewR a) | |
| Eq a => Eq (Set a) | |
| Eq a => Eq (Tree a) | |
| Eq1 f => Eq (Fix f) | |
| (Functor f, Eq1 f) => Eq (Mu f) | |
| (Functor f, Eq1 f) => Eq (Nu f) | |
| Eq a => Eq (DNonEmpty a) | |
| Eq a => Eq (DList a) | |
| Eq (OnChainAddress mrel) Source # | |
Defined in ElectrsClient.Type Methods (==) :: OnChainAddress mrel -> OnChainAddress mrel -> Bool # (/=) :: OnChainAddress mrel -> OnChainAddress mrel -> Bool # | |
| Eq a => Eq (Hashed a) | Uses precomputed hash to detect inequality faster |
| Eq a => Eq (AddrRange a) | |
| Eq a => Eq (BitcoinRpcResponse a) | |
| (Eq (Key record), Eq record) => Eq (Entity record) | |
| Eq a => Eq (AnnotDetails a) | |
Defined in Text.PrettyPrint.Annotated.HughesPJ Methods (==) :: AnnotDetails a -> AnnotDetails a -> Bool # (/=) :: AnnotDetails a -> AnnotDetails a -> Bool # | |
| Eq (Doc a) | |
| Eq a => Eq (Span a) | |
| Eq a => Eq (Array a) | |
| Eq (MutableByteArray s) | |
Defined in Data.Primitive.ByteArray Methods (==) :: MutableByteArray s -> MutableByteArray s -> Bool # (/=) :: MutableByteArray s -> MutableByteArray s -> Bool # | |
| (Eq a, Prim a) => Eq (PrimArray a) | Since: primitive-0.6.4.0 |
| Eq a => Eq (SmallArray a) | |
Defined in Data.Primitive.SmallArray | |
| Eq g => Eq (StateGen g) | |
| Eq g => Eq (AtomicGen g) | |
| Eq g => Eq (IOGen g) | |
| Eq g => Eq (STGen g) | |
| Eq g => Eq (TGen g) | |
| Eq a => Eq (Maybe a) | |
| Eq flag => Eq (TyVarBndr flag) | |
| Eq a => Eq (HashSet a) | Note that, in the presence of hash collisions, equal
In general, the lack of substitutivity can be observed with any function that depends on the key ordering, such as folds and traversals. |
| Eq a => Eq (Vector a) | |
| (Prim a, Eq a) => Eq (Vector a) | |
| (Storable a, Eq a) => Eq (Vector a) | |
| Eq a => Eq (Maybe a) | Since: base-2.1 |
| Eq a => Eq [a] | |
| (Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 |
| Eq (Proxy s) | Since: base-4.7.0.0 |
| Eq a => Eq (Arg a b) | Since: base-4.9.0.0 |
| Eq (TypeRep a) | Since: base-2.1 |
| Eq (U1 p) | Since: base-4.9.0.0 |
| Eq (V1 p) | Since: base-4.9.0.0 |
| (Eq k, Eq a) => Eq (Map k a) | |
| Eq (MutableArray s a) | |
Defined in Data.Primitive.Array Methods (==) :: MutableArray s a -> MutableArray s a -> Bool # (/=) :: MutableArray s a -> MutableArray s a -> Bool # | |
| Eq (MutablePrimArray s a) | |
Defined in Data.Primitive.PrimArray Methods (==) :: MutablePrimArray s a -> MutablePrimArray s a -> Bool # (/=) :: MutablePrimArray s a -> MutablePrimArray s a -> Bool # | |
| Eq (SmallMutableArray s a) | |
Defined in Data.Primitive.SmallArray Methods (==) :: SmallMutableArray s a -> SmallMutableArray s a -> Bool # (/=) :: SmallMutableArray s a -> SmallMutableArray s a -> Bool # | |
| (Eq a, Eq b) => Eq (Either a b) | |
| (Eq a, Eq b) => Eq (These a b) | |
| (Eq a, Eq b) => Eq (Pair a b) | |
| (Eq a, Eq b) => Eq (These a b) | |
| (Eq1 m, Eq a) => Eq (MaybeT m a) | |
| (Eq k, Eq v) => Eq (HashMap k v) | Note that, in the presence of hash collisions, equal
In general, the lack of substitutivity can be observed with any function that depends on the key ordering, such as folds and traversals. |
| (Eq k, Eq v) => Eq (Leaf k v) | |
| (Eq a, Eq b) => Eq (a, b) | |
| Eq a => Eq (Const a b) | Since: base-4.9.0.0 |
| Eq (f a) => Eq (Ap f a) | Since: base-4.12.0.0 |
| Eq (f a) => Eq (Alt f a) | Since: base-4.8.0.0 |
| Eq (f p) => Eq (Rec1 f p) | Since: base-4.7.0.0 |
| Eq (URec (Ptr ()) p) | Since: base-4.9.0.0 |
| Eq (URec Char p) | Since: base-4.9.0.0 |
| Eq (URec Double p) | Since: base-4.9.0.0 |
| Eq (URec Float p) | |
| Eq (URec Int p) | Since: base-4.9.0.0 |
| Eq (URec Word p) | Since: base-4.9.0.0 |
| Eq b => Eq (Tagged s b) | |
| (Eq1 f, Eq1 g, Eq a) => Eq (These1 f g a) | |
| (Eq e, Eq1 m, Eq a) => Eq (ErrorT e m a) | |
| (Eq e, Eq1 m, Eq a) => Eq (ExceptT e m a) | |
| (Eq1 f, Eq a) => Eq (IdentityT f a) | |
| (Eq a, Eq b, Eq c) => Eq (a, b, c) | |
| (Eq1 f, Eq1 g, Eq a) => Eq (Product f g a) | Since: base-4.9.0.0 |
| (Eq1 f, Eq1 g, Eq a) => Eq (Sum f g a) | Since: base-4.9.0.0 |
| (Eq (f p), Eq (g p)) => Eq ((f :*: g) p) | Since: base-4.7.0.0 |
| (Eq (f p), Eq (g p)) => Eq ((f :+: g) p) | Since: base-4.7.0.0 |
| Eq c => Eq (K1 i c p) | Since: base-4.7.0.0 |
| (Eq a, Eq b, Eq c, Eq d) => Eq (a, b, c, d) | |
| (Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a) | Since: base-4.9.0.0 |
| Eq (f (g p)) => Eq ((f :.: g) p) | Since: base-4.7.0.0 |
| Eq (f p) => Eq (M1 i c f p) | Since: base-4.7.0.0 |
| Eq (p b a) => Eq (Flip p a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e) => Eq (a, b, c, d, e) | |
| (Eq (f a b), Eq (g a b)) => Eq (Product f g a b) | |
| (Eq (p a b), Eq (q a b)) => Eq (Sum p q a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f) | |
| Eq (f (p a b)) => Eq (Tannen f p a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g) => Eq (a, b, c, d, e, f, g) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h) => Eq (a, b, c, d, e, f, g, h) | |
| Eq (p (f a) (g b)) => Eq (Biff p f g a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i) => Eq (a, b, c, d, e, f, g, h, i) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j) => Eq (a, b, c, d, e, f, g, h, i, j) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k) => Eq (a, b, c, d, e, f, g, h, i, j, k) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l) => Eq (a, b, c, d, e, f, g, h, i, j, k, l) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n, Eq o) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | |
class Fractional a => Floating a where #
Trigonometric and hyperbolic functions and related functions.
The Haskell Report defines no laws for Floating. However, (, +)(
and *)exp are customarily expected to define an exponential field and have
the following properties:
exp (a + b)=exp a * exp bexp (fromInteger 0)=fromInteger 1
Minimal complete definition
pi, exp, log, sin, cos, asin, acos, atan, sinh, cosh, asinh, acosh, atanh
Instances
class Num a => Fractional a where #
Fractional numbers, supporting real division.
The Haskell Report defines no laws for Fractional. However, ( and
+)( are customarily expected to define a division ring and have the
following properties:*)
recipgives the multiplicative inversex * recip x=recip x * x=fromInteger 1
Note that it isn't customarily expected that a type instance of
Fractional implement a field. However, all instances in base do.
Minimal complete definition
fromRational, (recip | (/))
Methods
Fractional division.
Reciprocal fraction.
fromRational :: Rational -> a #
Conversion from a Rational (that is Ratio IntegerfromRational
to a value of type Rational, so such literals have type
(.Fractional a) => a
Instances
| Fractional Scientific | WARNING:
|
Defined in Data.Scientific Methods (/) :: Scientific -> Scientific -> Scientific # recip :: Scientific -> Scientific # fromRational :: Rational -> Scientific # | |
| RealFloat a => Fractional (Complex a) | Since: base-2.1 |
| Fractional a => Fractional (Identity a) | Since: base-4.9.0.0 |
| Fractional a => Fractional (Down a) | Since: base-4.14.0.0 |
| Integral a => Fractional (Ratio a) | Since: base-2.0.1 |
| Fractional a => Fractional (Const a b) | Since: base-4.9.0.0 |
| Fractional a => Fractional (Tagged s a) | |
class (Real a, Enum a) => Integral a where #
Integral numbers, supporting integer division.
The Haskell Report defines no laws for Integral. However, Integral
instances are customarily expected to define a Euclidean domain and have the
following properties for the div/mod and quot/rem pairs, given
suitable Euclidean functions f and g:
x=y * quot x y + rem x ywithrem x y=fromInteger 0org (rem x y)<g yx=y * div x y + mod x ywithmod x y=fromInteger 0orf (mod x y)<f y
An example of a suitable Euclidean function, for Integer's instance, is
abs.
Methods
quot :: a -> a -> a infixl 7 #
integer division truncated toward zero
integer remainder, satisfying
(x `quot` y)*y + (x `rem` y) == x
integer division truncated toward negative infinity
integer modulus, satisfying
(x `div` y)*y + (x `mod` y) == x
conversion to Integer
Instances
class Applicative m => Monad (m :: Type -> Type) where #
The Monad class defines the basic operations over a monad,
a concept from a branch of mathematics known as category theory.
From the perspective of a Haskell programmer, however, it is best to
think of a monad as an abstract datatype of actions.
Haskell's do expressions provide a convenient syntax for writing
monadic expressions.
Instances of Monad should satisfy the following:
- Left identity
returna>>=k = k a- Right identity
m>>=return= m- Associativity
m>>=(\x -> k x>>=h) = (m>>=k)>>=h
Furthermore, the Monad and Applicative operations should relate as follows:
The above laws imply:
and that pure and (<*>) satisfy the applicative functor laws.
The instances of Monad for lists, Maybe and IO
defined in the Prelude satisfy these laws.
Minimal complete definition
Methods
(>>=) :: m a -> (a -> m b) -> m b infixl 1 #
Sequentially compose two actions, passing any value produced by the first as an argument to the second.
'as ' can be understood as the >>= bsdo expression
do a <- as bs a
(>>) :: m a -> m b -> m b infixl 1 #
Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.
'as ' can be understood as the >> bsdo expression
do as bs
Inject a value into the monadic type.
Instances
| Monad IResult | |
| Monad Parser | |
| Monad Result | |
| Monad Complex | Since: base-4.9.0.0 |
| Monad Identity | Since: base-4.8.0.0 |
| Monad First | Since: base-4.8.0.0 |
| Monad Last | Since: base-4.8.0.0 |
| Monad Down | Since: base-4.11.0.0 |
| Monad First | Since: base-4.9.0.0 |
| Monad Last | Since: base-4.9.0.0 |
| Monad Max | Since: base-4.9.0.0 |
| Monad Min | Since: base-4.9.0.0 |
| Monad Option | Since: base-4.9.0.0 |
| Monad Dual | Since: base-4.8.0.0 |
| Monad Product | Since: base-4.8.0.0 |
| Monad Sum | Since: base-4.8.0.0 |
| Monad NonEmpty | Since: base-4.9.0.0 |
| Monad STM | Since: base-4.3.0.0 |
| Monad Par1 | Since: base-4.9.0.0 |
| Monad P | Since: base-2.1 |
| Monad ReadP | Since: base-2.1 |
| Monad ReadPrec | Since: base-2.1 |
| Monad Seq | |
| Monad Tree | |
| Monad DNonEmpty | |
| Monad DList | |
| Monad IO | Since: base-2.1 |
| Monad Array | |
| Monad SmallArray | |
Defined in Data.Primitive.SmallArray Methods (>>=) :: SmallArray a -> (a -> SmallArray b) -> SmallArray b # (>>) :: SmallArray a -> SmallArray b -> SmallArray b # return :: a -> SmallArray a # | |
| Monad Q | |
| Monad Vector | |
| Monad Stream | |
| Monad Maybe | Since: base-2.1 |
| Monad Solo | Since: base-4.15 |
| Monad [] | Since: base-2.1 |
| Monad (Parser i) | |
| Monad m => Monad (WrappedMonad m) | Since: base-4.7.0.0 |
Defined in Control.Applicative Methods (>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b # (>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # return :: a -> WrappedMonad m a # | |
| ArrowApply a => Monad (ArrowMonad a) | Since: base-2.1 |
Defined in Control.Arrow Methods (>>=) :: ArrowMonad a a0 -> (a0 -> ArrowMonad a b) -> ArrowMonad a b # (>>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # return :: a0 -> ArrowMonad a a0 # | |
| Monad (Either e) | Since: base-4.4.0.0 |
| Monad (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Monad (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monad m => Monad (ResourceT m) | |
| Semigroup a => Monad (These a) | |
| Semigroup a => Monad (These a) | |
| Monad m => Monad (MaybeT m) | |
| Monoid a => Monad ((,) a) | Since: base-4.9.0.0 |
| Monad m => Monad (Kleisli m a) | Since: base-4.14.0.0 |
| Monad f => Monad (Ap f) | Since: base-4.12.0.0 |
| Monad f => Monad (Alt f) | Since: base-4.8.0.0 |
| Monad f => Monad (Rec1 f) | Since: base-4.9.0.0 |
| (Applicative f, Monad f) => Monad (WhenMissing f x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMissing f x a -> (a -> WhenMissing f x b) -> WhenMissing f x b # (>>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # return :: a -> WhenMissing f x a # | |
| Monad m => Monad (StateT s m) | |
| Monad (Tagged s) | |
| (Monad m, Error e) => Monad (ErrorT e m) | |
| Monad m => Monad (ExceptT e m) | |
| Monad m => Monad (IdentityT m) | |
| Monad m => Monad (ReaderT r m) | |
| Monad m => Monad (StateT s m) | |
| Monad m => Monad (StateT s m) | |
| (Monoid a, Monoid b) => Monad ((,,) a b) | Since: base-4.14.0.0 |
| (Monad f, Monad g) => Monad (Product f g) | Since: base-4.9.0.0 |
| (Monad f, Monad g) => Monad (f :*: g) | Since: base-4.9.0.0 |
| Monad (ConduitT i o m) | |
| (Monad f, Applicative f) => Monad (WhenMatched f x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMatched f x y a -> (a -> WhenMatched f x y b) -> WhenMatched f x y b # (>>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # return :: a -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Monad (WhenMissing f k x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMissing f k x a -> (a -> WhenMissing f k x b) -> WhenMissing f k x b # (>>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # return :: a -> WhenMissing f k x a # | |
| (Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c) | Since: base-4.14.0.0 |
| Monad ((->) r) | Since: base-2.1 |
| Monad f => Monad (M1 i c f) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Monad (WhenMatched f k x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMatched f k x y a -> (a -> WhenMatched f k x y b) -> WhenMatched f k x y b # (>>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # return :: a -> WhenMatched f k x y a # | |
| Monad m => Monad (Pipe l i o u m) | |
class Functor (f :: Type -> Type) where #
A type f is a Functor if it provides a function fmap which, given any types a and b
lets you apply any function from (a -> b) to turn an f a into an f b, preserving the
structure of f. Furthermore f needs to adhere to the following:
Note, that the second law follows from the free theorem of the type fmap and
the first law, so you need only check that the former condition holds.
Minimal complete definition
Methods
fmap :: (a -> b) -> f a -> f b #
fmap is used to apply a function of type (a -> b) to a value of type f a,
where f is a functor, to produce a value of type f b.
Note that for any type constructor with more than one parameter (e.g., Either),
only the last type parameter can be modified with fmap (e.g., b in `Either a b`).
Some type constructors with two parameters or more have a Bifunctor
Convert from a Maybe IntMaybe String
using show:
>>>fmap show NothingNothing>>>fmap show (Just 3)Just "3"
Convert from an Either Int IntEither Int String using show:
>>>fmap show (Left 17)Left 17>>>fmap show (Right 17)Right "17"
Double each element of a list:
>>>fmap (*2) [1,2,3][2,4,6]
Apply even to the second element of a pair:
>>>fmap even (2,2)(2,True)
It may seem surprising that the function is only applied to the last element of the tuple
compared to the list example above which applies it to every element in the list.
To understand, remember that tuples are type constructors with multiple type parameters:
a tuple of 3 elements `(a,b,c)` can also be written `(,,) a b c` and its Functor instance
is defined for `Functor ((,,) a b)` (i.e., only the third parameter is free to be mapped over
with fmap).
It explains why fmap can be used with tuples containing values of different types as in the
following example:
>>>fmap even ("hello", 1.0, 4)("hello",1.0,True)
Instances
| Functor FromJSONKeyFunction | Only law abiding up to interpretation |
Defined in Data.Aeson.Types.FromJSON Methods fmap :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b # (<$) :: a -> FromJSONKeyFunction b -> FromJSONKeyFunction a # | |
| Functor IResult | |
| Functor Parser | |
| Functor Result | |
| Functor ZipList | Since: base-2.1 |
| Functor Handler | Since: base-4.6.0.0 |
| Functor Complex | Since: base-4.9.0.0 |
| Functor Identity | Since: base-4.8.0.0 |
| Functor First | Since: base-4.8.0.0 |
| Functor Last | Since: base-4.8.0.0 |
| Functor Down | Since: base-4.11.0.0 |
| Functor First | Since: base-4.9.0.0 |
| Functor Last | Since: base-4.9.0.0 |
| Functor Max | Since: base-4.9.0.0 |
| Functor Min | Since: base-4.9.0.0 |
| Functor Option | Since: base-4.9.0.0 |
| Functor Dual | Since: base-4.8.0.0 |
| Functor Product | Since: base-4.8.0.0 |
| Functor Sum | Since: base-4.8.0.0 |
| Functor NonEmpty | Since: base-4.9.0.0 |
| Functor STM | Since: base-4.3.0.0 |
| Functor Par1 | Since: base-4.9.0.0 |
| Functor P | Since: base-4.8.0.0 |
Defined in Text.ParserCombinators.ReadP | |
| Functor ReadP | Since: base-2.1 |
| Functor ReadPrec | Since: base-2.1 |
| Functor Flush | |
| Functor IntMap | |
| Functor Digit | |
| Functor Elem | |
| Functor FingerTree | |
Defined in Data.Sequence.Internal Methods fmap :: (a -> b) -> FingerTree a -> FingerTree b # (<$) :: a -> FingerTree b -> FingerTree a # | |
| Functor Node | |
| Functor Seq | |
| Functor ViewL | |
| Functor ViewR | |
| Functor Tree | |
| Functor DNonEmpty | |
| Functor DList | |
| Functor IO | Since: base-2.1 |
| Functor HistoriedResponse | |
Defined in Network.HTTP.Client Methods fmap :: (a -> b) -> HistoriedResponse a -> HistoriedResponse b # (<$) :: a -> HistoriedResponse b -> HistoriedResponse a # | |
| Functor Response | |
| Functor AnnotDetails | |
Defined in Text.PrettyPrint.Annotated.HughesPJ Methods fmap :: (a -> b) -> AnnotDetails a -> AnnotDetails b # (<$) :: a -> AnnotDetails b -> AnnotDetails a # | |
| Functor Doc | |
| Functor Span | |
| Functor Array | |
| Functor SmallArray | |
Defined in Data.Primitive.SmallArray Methods fmap :: (a -> b) -> SmallArray a -> SmallArray b # (<$) :: a -> SmallArray b -> SmallArray a # | |
| Functor Maybe | |
| Functor Q | |
| Functor TyVarBndr | |
| Functor Flat | |
| Functor FlatApp | |
| Functor Vector | |
| Functor Stream | |
Defined in Codec.Compression.Zlib.Stream | |
| Functor Maybe | Since: base-2.1 |
| Functor Solo | Since: base-4.15 |
| Functor [] | Since: base-2.1 |
| Functor (Tagged2 s) | |
Defined in Data.Aeson.Types.Generic | |
| Functor (IResult i) | |
| Functor (Parser i) | |
| Monad m => Functor (WrappedMonad m) | Since: base-2.1 |
Defined in Control.Applicative Methods fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b # (<$) :: a -> WrappedMonad m b -> WrappedMonad m a # | |
| Arrow a => Functor (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in Control.Arrow Methods fmap :: (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # (<$) :: a0 -> ArrowMonad a b -> ArrowMonad a a0 # | |
| Functor (Either a) | Since: base-3.0 |
| Functor (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Functor (Arg a) | Since: base-4.9.0.0 |
| Functor (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (V1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monad m => Functor (ZipSource m) | |
| Functor (Map k) | |
| Functor (Parser e) | |
| Functor (VarF e) | |
| Monad m => Functor (Handler m) | |
| Functor m => Functor (ResourceT m) | |
| Functor (Either a) | |
| Functor (These a) | |
| Functor (Pair e) | |
| Functor (These a) | |
| Functor m => Functor (MaybeT m) | |
| Functor m => Functor (Conc m) | |
| Monad m => Functor (Concurrently m) | Since: unliftio-0.1.0.0 |
Defined in UnliftIO.Internals.Async Methods fmap :: (a -> b) -> Concurrently m a -> Concurrently m b # (<$) :: a -> Concurrently m b -> Concurrently m a # | |
| Functor (HashMap k) | |
| Functor ((,) a) | Since: base-2.1 |
| Arrow a => Functor (WrappedArrow a b) | Since: base-2.1 |
Defined in Control.Applicative Methods fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # (<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
| Functor m => Functor (Kleisli m a) | Since: base-4.14.0.0 |
| Functor (Const m :: Type -> Type) | Since: base-2.1 |
| Functor f => Functor (Ap f) | Since: base-4.12.0.0 |
| Functor f => Functor (Alt f) | Since: base-4.8.0.0 |
| Functor f => Functor (Rec1 f) | Since: base-4.9.0.0 |
| Functor (URec (Ptr ()) :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Char :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Double :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Float :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Int :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Word :: Type -> Type) | Since: base-4.9.0.0 |
| Monad m => Functor (ZipSink i m) | |
| (Applicative f, Monad f) => Functor (WhenMissing f x) | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods fmap :: (a -> b) -> WhenMissing f x a -> WhenMissing f x b # (<$) :: a -> WhenMissing f x b -> WhenMissing f x a # | |
| Functor (Bazaar a b) | |
Defined in Lens.Micro | |
| Functor m => Functor (StateT s m) | |
Defined in Lens.Micro | |
| Functor (Effect m r) | |
| Monad m => Functor (Focusing m s) | |
| Functor (k (May s)) => Functor (FocusingMay k s) | |
Defined in Lens.Micro.Mtl.Internal Methods fmap :: (a -> b) -> FocusingMay k s a -> FocusingMay k s b # (<$) :: a -> FocusingMay k s b -> FocusingMay k s a # | |
| Functor (Tagged s) | |
| (Functor f, Functor g) => Functor (These1 f g) | |
| Functor m => Functor (ErrorT e m) | |
| Functor m => Functor (ExceptT e m) | |
| Functor m => Functor (IdentityT m) | |
| Functor m => Functor (ReaderT r m) | |
| Functor m => Functor (StateT s m) | |
| Functor m => Functor (StateT s m) | |
| Functor ((,,) a b) | Since: base-4.14.0.0 |
| (Functor f, Functor g) => Functor (Product f g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (Sum f g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :*: g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :+: g) | Since: base-4.9.0.0 |
| Functor (K1 i c :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (ConduitT i o m) | |
| Functor (ZipConduit i o m) | |
Defined in Data.Conduit.Internal.Conduit Methods fmap :: (a -> b) -> ZipConduit i o m a -> ZipConduit i o m b # (<$) :: a -> ZipConduit i o m b -> ZipConduit i o m a # | |
| Functor f => Functor (WhenMatched f x y) | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods fmap :: (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b # (<$) :: a -> WhenMatched f x y b -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Functor (WhenMissing f k x) | Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods fmap :: (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # (<$) :: a -> WhenMissing f k x b -> WhenMissing f k x a # | |
| Functor (k (Err e s)) => Functor (FocusingErr e k s) | |
Defined in Lens.Micro.Mtl.Internal Methods fmap :: (a -> b) -> FocusingErr e k s a -> FocusingErr e k s b # (<$) :: a -> FocusingErr e k s b -> FocusingErr e k s a # | |
| Functor (k (f s)) => Functor (FocusingOn f k s) | |
Defined in Lens.Micro.Mtl.Internal Methods fmap :: (a -> b) -> FocusingOn f k s a -> FocusingOn f k s b # (<$) :: a -> FocusingOn f k s b -> FocusingOn f k s a # | |
| Functor (k (s, w)) => Functor (FocusingPlus w k s) | |
Defined in Lens.Micro.Mtl.Internal Methods fmap :: (a -> b) -> FocusingPlus w k s a -> FocusingPlus w k s b # (<$) :: a -> FocusingPlus w k s b -> FocusingPlus w k s a # | |
| Monad m => Functor (FocusingWith w m s) | |
Defined in Lens.Micro.Mtl.Internal Methods fmap :: (a -> b) -> FocusingWith w m s a -> FocusingWith w m s b # (<$) :: a -> FocusingWith w m s b -> FocusingWith w m s a # | |
| Functor ((,,,) a b c) | Since: base-4.14.0.0 |
| Functor ((->) r) | Since: base-2.1 |
| (Functor f, Functor g) => Functor (Compose f g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :.: g) | Since: base-4.9.0.0 |
| Functor f => Functor (M1 i c f) | Since: base-4.9.0.0 |
| Bifunctor p => Functor (Flip p a) | |
| Functor f => Functor (WhenMatched f k x y) | Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods fmap :: (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # (<$) :: a -> WhenMatched f k x y b -> WhenMatched f k x y a # | |
| Functor (EffectRWS w st m s) | |
| Monad m => Functor (Pipe l i o u m) | |
| (Functor f, Bifunctor p) => Functor (Tannen f p a) | |
| (Bifunctor p, Functor g) => Functor (Biff p f g a) | |
Basic numeric class.
The Haskell Report defines no laws for Num. However, ( and +)( are
customarily expected to define a ring and have the following properties:*)
- Associativity of
(+) (x + y) + z=x + (y + z)- Commutativity of
(+) x + y=y + xfromInteger0x + fromInteger 0=xnegategives the additive inversex + negate x=fromInteger 0- Associativity of
(*) (x * y) * z=x * (y * z)fromInteger1x * fromInteger 1=xandfromInteger 1 * x=x- Distributivity of
(with respect to*)(+) a * (b + c)=(a * b) + (a * c)and(b + c) * a=(b * a) + (c * a)
Note that it isn't customarily expected that a type instance of both Num
and Ord implement an ordered ring. Indeed, in base only Integer and
Rational do.
Methods
Unary negation.
Absolute value.
Sign of a number.
The functions abs and signum should satisfy the law:
abs x * signum x == x
For real numbers, the signum is either -1 (negative), 0 (zero)
or 1 (positive).
fromInteger :: Integer -> a #
Conversion from an Integer.
An integer literal represents the application of the function
fromInteger to the appropriate value of type Integer,
so such literals have type (.Num a) => a
Instances
| Num Pos | |
| Num Int16 | Since: base-2.1 |
| Num Int32 | Since: base-2.1 |
| Num Int64 | Since: base-2.1 |
| Num Int8 | Since: base-2.1 |
| Num Word16 | Since: base-2.1 |
| Num Word32 | Since: base-2.1 |
| Num Word64 | Since: base-2.1 |
| Num BlkHeight Source # | |
Defined in ElectrsClient.Type | |
| Num MsgFlag | |
| Num PortNumber | |
Defined in Network.Socket.Types Methods (+) :: PortNumber -> PortNumber -> PortNumber # (-) :: PortNumber -> PortNumber -> PortNumber # (*) :: PortNumber -> PortNumber -> PortNumber # negate :: PortNumber -> PortNumber # abs :: PortNumber -> PortNumber # signum :: PortNumber -> PortNumber # fromInteger :: Integer -> PortNumber # | |
| Num Scientific | WARNING: |
Defined in Data.Scientific Methods (+) :: Scientific -> Scientific -> Scientific # (-) :: Scientific -> Scientific -> Scientific # (*) :: Scientific -> Scientific -> Scientific # negate :: Scientific -> Scientific # abs :: Scientific -> Scientific # signum :: Scientific -> Scientific # fromInteger :: Integer -> Scientific # | |
| Num CodePoint | |
Defined in Data.Text.Encoding | |
| Num DecoderState | |
Defined in Data.Text.Encoding Methods (+) :: DecoderState -> DecoderState -> DecoderState # (-) :: DecoderState -> DecoderState -> DecoderState # (*) :: DecoderState -> DecoderState -> DecoderState # negate :: DecoderState -> DecoderState # abs :: DecoderState -> DecoderState # signum :: DecoderState -> DecoderState # fromInteger :: Integer -> DecoderState # | |
| Num Word8 | Since: base-2.1 |
| Num Integer | Since: base-2.1 |
| Num Natural | Note that Since: base-4.8.0.0 |
| Num Int | Since: base-2.1 |
| Num Word | Since: base-2.1 |
| RealFloat a => Num (Complex a) | Since: base-2.1 |
| Num a => Num (Identity a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Identity | |
| Num a => Num (Down a) | Since: base-4.11.0.0 |
| Num a => Num (Max a) | Since: base-4.9.0.0 |
| Num a => Num (Min a) | Since: base-4.9.0.0 |
| Num a => Num (Product a) | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| Num a => Num (Sum a) | Since: base-4.7.0.0 |
| Integral a => Num (Ratio a) | Since: base-2.0.1 |
| Num a => Num (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| (Applicative f, Num a) => Num (Ap f a) | Note that even if the underlying Commutativity:
Additive inverse:
Distributivity:
Since: base-4.12.0.0 |
| Num (f a) => Num (Alt f a) | Since: base-4.8.0.0 |
| Num a => Num (Tagged s a) | |
Defined in Data.Tagged | |
The Ord class is used for totally ordered datatypes.
Instances of Ord can be derived for any user-defined datatype whose
constituent types are in Ord. The declared order of the constructors in
the data declaration determines the ordering in derived Ord instances. The
Ordering datatype allows a single comparison to determine the precise
ordering of two objects.
The Haskell Report defines no laws for Ord. However, <= is customarily
expected to implement a non-strict partial order and have the following
properties:
- Transitivity
- if
x <= y && y <= z=True, thenx <= z=True - Reflexivity
x <= x=True- Antisymmetry
- if
x <= y && y <= x=True, thenx == y=True
Note that the following operator interactions are expected to hold:
x >= y=y <= xx < y=x <= y && x /= yx > y=y < xx < y=compare x y == LTx > y=compare x y == GTx == y=compare x y == EQmin x y == if x <= y then x else y=Truemax x y == if x >= y then x else y=True
Note that (7.) and (8.) do not require min and max to return either of
their arguments. The result is merely required to equal one of the
arguments in terms of (==).
Minimal complete definition: either compare or <=.
Using compare can be more efficient for complex types.
Methods
compare :: a -> a -> Ordering #
(<) :: a -> a -> Bool infix 4 #
(<=) :: a -> a -> Bool infix 4 #
(>) :: a -> a -> Bool infix 4 #
Instances
| Ord DotNetTime | |
Defined in Data.Aeson.Types.Internal Methods compare :: DotNetTime -> DotNetTime -> Ordering # (<) :: DotNetTime -> DotNetTime -> Bool # (<=) :: DotNetTime -> DotNetTime -> Bool # (>) :: DotNetTime -> DotNetTime -> Bool # (>=) :: DotNetTime -> DotNetTime -> Bool # max :: DotNetTime -> DotNetTime -> DotNetTime # min :: DotNetTime -> DotNetTime -> DotNetTime # | |
| Ord JSONPathElement | |
Defined in Data.Aeson.Types.Internal Methods compare :: JSONPathElement -> JSONPathElement -> Ordering # (<) :: JSONPathElement -> JSONPathElement -> Bool # (<=) :: JSONPathElement -> JSONPathElement -> Bool # (>) :: JSONPathElement -> JSONPathElement -> Bool # (>=) :: JSONPathElement -> JSONPathElement -> Bool # max :: JSONPathElement -> JSONPathElement -> JSONPathElement # min :: JSONPathElement -> JSONPathElement -> JSONPathElement # | |
| Ord Value | The ordering is total, consistent with Since: aeson-1.5.2.0 |
| Ord Pos | |
| Ord All | Since: base-2.1 |
| Ord Any | Since: base-2.1 |
| Ord SomeTypeRep | |
Defined in Data.Typeable.Internal Methods compare :: SomeTypeRep -> SomeTypeRep -> Ordering # (<) :: SomeTypeRep -> SomeTypeRep -> Bool # (<=) :: SomeTypeRep -> SomeTypeRep -> Bool # (>) :: SomeTypeRep -> SomeTypeRep -> Bool # (>=) :: SomeTypeRep -> SomeTypeRep -> Bool # max :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep # min :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep # | |
| Ord Version | Since: base-2.1 |
| Ord Void | Since: base-4.8.0.0 |
| Ord BlockReason | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync Methods compare :: BlockReason -> BlockReason -> Ordering # (<) :: BlockReason -> BlockReason -> Bool # (<=) :: BlockReason -> BlockReason -> Bool # (>) :: BlockReason -> BlockReason -> Bool # (>=) :: BlockReason -> BlockReason -> Bool # max :: BlockReason -> BlockReason -> BlockReason # min :: BlockReason -> BlockReason -> BlockReason # | |
| Ord ThreadId | Since: base-4.2.0.0 |
Defined in GHC.Conc.Sync | |
| Ord ThreadStatus | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync Methods compare :: ThreadStatus -> ThreadStatus -> Ordering # (<) :: ThreadStatus -> ThreadStatus -> Bool # (<=) :: ThreadStatus -> ThreadStatus -> Bool # (>) :: ThreadStatus -> ThreadStatus -> Bool # (>=) :: ThreadStatus -> ThreadStatus -> Bool # max :: ThreadStatus -> ThreadStatus -> ThreadStatus # min :: ThreadStatus -> ThreadStatus -> ThreadStatus # | |
| Ord ErrorCall | Since: base-4.7.0.0 |
| Ord ArithException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods compare :: ArithException -> ArithException -> Ordering # (<) :: ArithException -> ArithException -> Bool # (<=) :: ArithException -> ArithException -> Bool # (>) :: ArithException -> ArithException -> Bool # (>=) :: ArithException -> ArithException -> Bool # max :: ArithException -> ArithException -> ArithException # min :: ArithException -> ArithException -> ArithException # | |
| Ord Associativity | Since: base-4.6.0.0 |
Defined in GHC.Generics Methods compare :: Associativity -> Associativity -> Ordering # (<) :: Associativity -> Associativity -> Bool # (<=) :: Associativity -> Associativity -> Bool # (>) :: Associativity -> Associativity -> Bool # (>=) :: Associativity -> Associativity -> Bool # max :: Associativity -> Associativity -> Associativity # min :: Associativity -> Associativity -> Associativity # | |
| Ord DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: DecidedStrictness -> DecidedStrictness -> Ordering # (<) :: DecidedStrictness -> DecidedStrictness -> Bool # (<=) :: DecidedStrictness -> DecidedStrictness -> Bool # (>) :: DecidedStrictness -> DecidedStrictness -> Bool # (>=) :: DecidedStrictness -> DecidedStrictness -> Bool # max :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # min :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # | |
| Ord Fixity | Since: base-4.6.0.0 |
| Ord SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: SourceStrictness -> SourceStrictness -> Ordering # (<) :: SourceStrictness -> SourceStrictness -> Bool # (<=) :: SourceStrictness -> SourceStrictness -> Bool # (>) :: SourceStrictness -> SourceStrictness -> Bool # (>=) :: SourceStrictness -> SourceStrictness -> Bool # max :: SourceStrictness -> SourceStrictness -> SourceStrictness # min :: SourceStrictness -> SourceStrictness -> SourceStrictness # | |
| Ord SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: SourceUnpackedness -> SourceUnpackedness -> Ordering # (<) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (<=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # max :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # min :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # | |
| Ord ArrayException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods compare :: ArrayException -> ArrayException -> Ordering # (<) :: ArrayException -> ArrayException -> Bool # (<=) :: ArrayException -> ArrayException -> Bool # (>) :: ArrayException -> ArrayException -> Bool # (>=) :: ArrayException -> ArrayException -> Bool # max :: ArrayException -> ArrayException -> ArrayException # min :: ArrayException -> ArrayException -> ArrayException # | |
| Ord AsyncException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods compare :: AsyncException -> AsyncException -> Ordering # (<) :: AsyncException -> AsyncException -> Bool # (<=) :: AsyncException -> AsyncException -> Bool # (>) :: AsyncException -> AsyncException -> Bool # (>=) :: AsyncException -> AsyncException -> Bool # max :: AsyncException -> AsyncException -> AsyncException # min :: AsyncException -> AsyncException -> AsyncException # | |
| Ord ExitCode | |
Defined in GHC.IO.Exception | |
| Ord BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods compare :: BufferMode -> BufferMode -> Ordering # (<) :: BufferMode -> BufferMode -> Bool # (<=) :: BufferMode -> BufferMode -> Bool # (>) :: BufferMode -> BufferMode -> Bool # (>=) :: BufferMode -> BufferMode -> Bool # max :: BufferMode -> BufferMode -> BufferMode # min :: BufferMode -> BufferMode -> BufferMode # | |
| Ord Newline | Since: base-4.3.0.0 |
| Ord NewlineMode | Since: base-4.3.0.0 |
Defined in GHC.IO.Handle.Types Methods compare :: NewlineMode -> NewlineMode -> Ordering # (<) :: NewlineMode -> NewlineMode -> Bool # (<=) :: NewlineMode -> NewlineMode -> Bool # (>) :: NewlineMode -> NewlineMode -> Bool # (>=) :: NewlineMode -> NewlineMode -> Bool # max :: NewlineMode -> NewlineMode -> NewlineMode # min :: NewlineMode -> NewlineMode -> NewlineMode # | |
| Ord IOMode | Since: base-4.2.0.0 |
| Ord Int16 | Since: base-2.1 |
| Ord Int32 | Since: base-2.1 |
| Ord Int64 | Since: base-2.1 |
| Ord Int8 | Since: base-2.1 |
| Ord SomeSymbol | Since: base-4.7.0.0 |
Defined in GHC.TypeLits Methods compare :: SomeSymbol -> SomeSymbol -> Ordering # (<) :: SomeSymbol -> SomeSymbol -> Bool # (<=) :: SomeSymbol -> SomeSymbol -> Bool # (>) :: SomeSymbol -> SomeSymbol -> Bool # (>=) :: SomeSymbol -> SomeSymbol -> Bool # max :: SomeSymbol -> SomeSymbol -> SomeSymbol # min :: SomeSymbol -> SomeSymbol -> SomeSymbol # | |
| Ord SomeNat | Since: base-4.7.0.0 |
| Ord Word16 | Since: base-2.1 |
| Ord Word32 | Since: base-2.1 |
| Ord Word64 | Since: base-2.1 |
| Ord ByteString | |
Defined in Data.ByteString.Internal Methods compare :: ByteString -> ByteString -> Ordering # (<) :: ByteString -> ByteString -> Bool # (<=) :: ByteString -> ByteString -> Bool # (>) :: ByteString -> ByteString -> Bool # (>=) :: ByteString -> ByteString -> Bool # max :: ByteString -> ByteString -> ByteString # min :: ByteString -> ByteString -> ByteString # | |
| Ord ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods compare :: ByteString -> ByteString -> Ordering # (<) :: ByteString -> ByteString -> Bool # (<=) :: ByteString -> ByteString -> Bool # (>) :: ByteString -> ByteString -> Bool # (>=) :: ByteString -> ByteString -> Bool # max :: ByteString -> ByteString -> ByteString # min :: ByteString -> ByteString -> ByteString # | |
| Ord ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods compare :: ShortByteString -> ShortByteString -> Ordering # (<) :: ShortByteString -> ShortByteString -> Bool # (<=) :: ShortByteString -> ShortByteString -> Bool # (>) :: ShortByteString -> ShortByteString -> Bool # (>=) :: ShortByteString -> ShortByteString -> Bool # max :: ShortByteString -> ShortByteString -> ShortByteString # min :: ShortByteString -> ShortByteString -> ShortByteString # | |
| Ord IntSet | |
| Ord BlkHeight Source # | |
| Ord Extension | |
| Ord Ordering | |
Defined in GHC.Classes | |
| Ord TyCon | |
| Ord ConnHost | |
Defined in Network.HTTP.Client.Types | |
| Ord ConnKey | |
Defined in Network.HTTP.Client.Types | |
| Ord Proxy | |
| Ord ProxySecureMode | |
Defined in Network.HTTP.Client.Types Methods compare :: ProxySecureMode -> ProxySecureMode -> Ordering # (<) :: ProxySecureMode -> ProxySecureMode -> Bool # (<=) :: ProxySecureMode -> ProxySecureMode -> Bool # (>) :: ProxySecureMode -> ProxySecureMode -> Bool # (>=) :: ProxySecureMode -> ProxySecureMode -> Bool # max :: ProxySecureMode -> ProxySecureMode -> ProxySecureMode # min :: ProxySecureMode -> ProxySecureMode -> ProxySecureMode # | |
| Ord StatusHeaders | |
Defined in Network.HTTP.Client.Types Methods compare :: StatusHeaders -> StatusHeaders -> Ordering # (<) :: StatusHeaders -> StatusHeaders -> Bool # (<=) :: StatusHeaders -> StatusHeaders -> Bool # (>) :: StatusHeaders -> StatusHeaders -> Bool # (>=) :: StatusHeaders -> StatusHeaders -> Bool # max :: StatusHeaders -> StatusHeaders -> StatusHeaders # min :: StatusHeaders -> StatusHeaders -> StatusHeaders # | |
| Ord StreamFileStatus | |
Defined in Network.HTTP.Client.Types Methods compare :: StreamFileStatus -> StreamFileStatus -> Ordering # (<) :: StreamFileStatus -> StreamFileStatus -> Bool # (<=) :: StreamFileStatus -> StreamFileStatus -> Bool # (>) :: StreamFileStatus -> StreamFileStatus -> Bool # (>=) :: StreamFileStatus -> StreamFileStatus -> Bool # max :: StreamFileStatus -> StreamFileStatus -> StreamFileStatus # min :: StreamFileStatus -> StreamFileStatus -> StreamFileStatus # | |
| Ord IP | |
| Ord IPv4 | |
| Ord IPv6 | |
| Ord IPRange | |
| Ord MsgFlag | |
| Ord StructLinger | |
Defined in Network.Socket.Options Methods compare :: StructLinger -> StructLinger -> Ordering # (<) :: StructLinger -> StructLinger -> Bool # (<=) :: StructLinger -> StructLinger -> Bool # (>) :: StructLinger -> StructLinger -> Bool # (>=) :: StructLinger -> StructLinger -> Bool # max :: StructLinger -> StructLinger -> StructLinger # min :: StructLinger -> StructLinger -> StructLinger # | |
| Ord Family | |
| Ord PortNumber | |
Defined in Network.Socket.Types Methods compare :: PortNumber -> PortNumber -> Ordering # (<) :: PortNumber -> PortNumber -> Bool # (<=) :: PortNumber -> PortNumber -> Bool # (>) :: PortNumber -> PortNumber -> Bool # (>=) :: PortNumber -> PortNumber -> Bool # max :: PortNumber -> PortNumber -> PortNumber # min :: PortNumber -> PortNumber -> PortNumber # | |
| Ord SockAddr | |
Defined in Network.Socket.Types | |
| Ord SocketType | |
Defined in Network.Socket.Types Methods compare :: SocketType -> SocketType -> Ordering # (<) :: SocketType -> SocketType -> Bool # (<=) :: SocketType -> SocketType -> Bool # (>) :: SocketType -> SocketType -> Bool # (>=) :: SocketType -> SocketType -> Bool # max :: SocketType -> SocketType -> SocketType # min :: SocketType -> SocketType -> SocketType # | |
| Ord Block | |
| Ord BlockChainInfo | |
Defined in Network.Bitcoin.BlockChain Methods compare :: BlockChainInfo -> BlockChainInfo -> Ordering # (<) :: BlockChainInfo -> BlockChainInfo -> Bool # (<=) :: BlockChainInfo -> BlockChainInfo -> Bool # (>) :: BlockChainInfo -> BlockChainInfo -> Bool # (>=) :: BlockChainInfo -> BlockChainInfo -> Bool # | |
| Ord BlockVerbose | |
Defined in Network.Bitcoin.BlockChain | |
| Ord OutputInfo | |
Defined in Network.Bitcoin.BlockChain | |
| Ord OutputSetInfo | |
Defined in Network.Bitcoin.BlockChain Methods compare :: OutputSetInfo -> OutputSetInfo -> Ordering # (<) :: OutputSetInfo -> OutputSetInfo -> Bool # (<=) :: OutputSetInfo -> OutputSetInfo -> Bool # (>) :: OutputSetInfo -> OutputSetInfo -> Bool # (>=) :: OutputSetInfo -> OutputSetInfo -> Bool # | |
| Ord BitcoinRpcError | |
Defined in Network.Bitcoin.Internal Methods compare :: BitcoinRpcError -> BitcoinRpcError -> Ordering # (<) :: BitcoinRpcError -> BitcoinRpcError -> Bool # (<=) :: BitcoinRpcError -> BitcoinRpcError -> Bool # (>) :: BitcoinRpcError -> BitcoinRpcError -> Bool # (>=) :: BitcoinRpcError -> BitcoinRpcError -> Bool # max :: BitcoinRpcError -> BitcoinRpcError -> BitcoinRpcError # min :: BitcoinRpcError -> BitcoinRpcError -> BitcoinRpcError # | |
| Ord BlockTemplate | |
Defined in Network.Bitcoin.Mining Methods compare :: BlockTemplate -> BlockTemplate -> Ordering # (<) :: BlockTemplate -> BlockTemplate -> Bool # (<=) :: BlockTemplate -> BlockTemplate -> Bool # (>) :: BlockTemplate -> BlockTemplate -> Bool # (>=) :: BlockTemplate -> BlockTemplate -> Bool # | |
| Ord CoinBaseAux | |
Defined in Network.Bitcoin.Mining | |
| Ord HashData | |
Defined in Network.Bitcoin.Mining | |
| Ord MiningInfo | |
Defined in Network.Bitcoin.Mining | |
| Ord Transaction | |
Defined in Network.Bitcoin.Mining | |
| Ord PeerInfo | |
Defined in Network.Bitcoin.Net | |
| Ord BlockInfo | |
| Ord DecodedPsbt | |
Defined in Network.Bitcoin.RawTransaction | |
| Ord DecodedRawTransaction | |
Defined in Network.Bitcoin.RawTransaction Methods compare :: DecodedRawTransaction -> DecodedRawTransaction -> Ordering # (<) :: DecodedRawTransaction -> DecodedRawTransaction -> Bool # (<=) :: DecodedRawTransaction -> DecodedRawTransaction -> Bool # (>) :: DecodedRawTransaction -> DecodedRawTransaction -> Bool # (>=) :: DecodedRawTransaction -> DecodedRawTransaction -> Bool # max :: DecodedRawTransaction -> DecodedRawTransaction -> DecodedRawTransaction # min :: DecodedRawTransaction -> DecodedRawTransaction -> DecodedRawTransaction # | |
| Ord RawTransactionInfo | |
Defined in Network.Bitcoin.RawTransaction Methods compare :: RawTransactionInfo -> RawTransactionInfo -> Ordering # (<) :: RawTransactionInfo -> RawTransactionInfo -> Bool # (<=) :: RawTransactionInfo -> RawTransactionInfo -> Bool # (>) :: RawTransactionInfo -> RawTransactionInfo -> Bool # (>=) :: RawTransactionInfo -> RawTransactionInfo -> Bool # max :: RawTransactionInfo -> RawTransactionInfo -> RawTransactionInfo # min :: RawTransactionInfo -> RawTransactionInfo -> RawTransactionInfo # | |
| Ord ScriptPubKey | |
Defined in Network.Bitcoin.RawTransaction | |
| Ord ScriptSig | |
| Ord TxIn | |
| Ord TxOut | |
| Ord TxnOutputType | |
Defined in Network.Bitcoin.RawTransaction Methods compare :: TxnOutputType -> TxnOutputType -> Ordering # (<) :: TxnOutputType -> TxnOutputType -> Bool # (<=) :: TxnOutputType -> TxnOutputType -> Bool # (>) :: TxnOutputType -> TxnOutputType -> Bool # (>=) :: TxnOutputType -> TxnOutputType -> Bool # | |
| Ord BitcoinException | |
Defined in Network.Bitcoin.Types Methods compare :: BitcoinException -> BitcoinException -> Ordering # (<) :: BitcoinException -> BitcoinException -> Bool # (<=) :: BitcoinException -> BitcoinException -> Bool # (>) :: BitcoinException -> BitcoinException -> Bool # (>=) :: BitcoinException -> BitcoinException -> Bool # max :: BitcoinException -> BitcoinException -> BitcoinException # min :: BitcoinException -> BitcoinException -> BitcoinException # | |
| Ord TransactionID | |
Defined in Network.Bitcoin.Types Methods compare :: TransactionID -> TransactionID -> Ordering # (<) :: TransactionID -> TransactionID -> Bool # (<=) :: TransactionID -> TransactionID -> Bool # (>) :: TransactionID -> TransactionID -> Bool # (>=) :: TransactionID -> TransactionID -> Bool # | |
| Ord AddrInfo | |
Defined in Network.Bitcoin.Wallet | |
| Ord AddressInfo | |
Defined in Network.Bitcoin.Wallet | |
| Ord BitcoindInfo | |
Defined in Network.Bitcoin.Wallet | |
| Ord DetailedTransaction | |
Defined in Network.Bitcoin.Wallet Methods compare :: DetailedTransaction -> DetailedTransaction -> Ordering # (<) :: DetailedTransaction -> DetailedTransaction -> Bool # (<=) :: DetailedTransaction -> DetailedTransaction -> Bool # (>) :: DetailedTransaction -> DetailedTransaction -> Bool # (>=) :: DetailedTransaction -> DetailedTransaction -> Bool # max :: DetailedTransaction -> DetailedTransaction -> DetailedTransaction # min :: DetailedTransaction -> DetailedTransaction -> DetailedTransaction # | |
| Ord DetailedTransactionDetails | |
Defined in Network.Bitcoin.Wallet Methods compare :: DetailedTransactionDetails -> DetailedTransactionDetails -> Ordering # (<) :: DetailedTransactionDetails -> DetailedTransactionDetails -> Bool # (<=) :: DetailedTransactionDetails -> DetailedTransactionDetails -> Bool # (>) :: DetailedTransactionDetails -> DetailedTransactionDetails -> Bool # (>=) :: DetailedTransactionDetails -> DetailedTransactionDetails -> Bool # max :: DetailedTransactionDetails -> DetailedTransactionDetails -> DetailedTransactionDetails # min :: DetailedTransactionDetails -> DetailedTransactionDetails -> DetailedTransactionDetails # | |
| Ord ReceivedByAccount | |
Defined in Network.Bitcoin.Wallet Methods compare :: ReceivedByAccount -> ReceivedByAccount -> Ordering # (<) :: ReceivedByAccount -> ReceivedByAccount -> Bool # (<=) :: ReceivedByAccount -> ReceivedByAccount -> Bool # (>) :: ReceivedByAccount -> ReceivedByAccount -> Bool # (>=) :: ReceivedByAccount -> ReceivedByAccount -> Bool # max :: ReceivedByAccount -> ReceivedByAccount -> ReceivedByAccount # min :: ReceivedByAccount -> ReceivedByAccount -> ReceivedByAccount # | |
| Ord ReceivedByAddress | |
Defined in Network.Bitcoin.Wallet Methods compare :: ReceivedByAddress -> ReceivedByAddress -> Ordering # (<) :: ReceivedByAddress -> ReceivedByAddress -> Bool # (<=) :: ReceivedByAddress -> ReceivedByAddress -> Bool # (>) :: ReceivedByAddress -> ReceivedByAddress -> Bool # (>=) :: ReceivedByAddress -> ReceivedByAddress -> Bool # max :: ReceivedByAddress -> ReceivedByAddress -> ReceivedByAddress # min :: ReceivedByAddress -> ReceivedByAddress -> ReceivedByAddress # | |
| Ord ScrPubKey | |
| Ord SimpleTransaction | |
Defined in Network.Bitcoin.Wallet Methods compare :: SimpleTransaction -> SimpleTransaction -> Ordering # (<) :: SimpleTransaction -> SimpleTransaction -> Bool # (<=) :: SimpleTransaction -> SimpleTransaction -> Bool # (>) :: SimpleTransaction -> SimpleTransaction -> Bool # (>=) :: SimpleTransaction -> SimpleTransaction -> Bool # max :: SimpleTransaction -> SimpleTransaction -> SimpleTransaction # min :: SimpleTransaction -> SimpleTransaction -> SimpleTransaction # | |
| Ord SinceBlock | |
Defined in Network.Bitcoin.Wallet | |
| Ord TransactionCategory | |
Defined in Network.Bitcoin.Wallet Methods compare :: TransactionCategory -> TransactionCategory -> Ordering # (<) :: TransactionCategory -> TransactionCategory -> Bool # (<=) :: TransactionCategory -> TransactionCategory -> Bool # (>) :: TransactionCategory -> TransactionCategory -> Bool # (>=) :: TransactionCategory -> TransactionCategory -> Bool # max :: TransactionCategory -> TransactionCategory -> TransactionCategory # min :: TransactionCategory -> TransactionCategory -> TransactionCategory # | |
| Ord URI | |
| Ord URIAuth | |
| Ord ByteArray | Non-lexicographic ordering. This compares the lengths of the byte arrays first and uses a lexicographic ordering if the lengths are equal. Subject to change between major versions. Since: primitive-0.6.3.0 |
| Ord Scientific | Scientific numbers can be safely compared for ordering. No magnitude |
Defined in Data.Scientific Methods compare :: Scientific -> Scientific -> Ordering # (<) :: Scientific -> Scientific -> Bool # (<=) :: Scientific -> Scientific -> Bool # (>) :: Scientific -> Scientific -> Bool # (>=) :: Scientific -> Scientific -> Bool # max :: Scientific -> Scientific -> Scientific # min :: Scientific -> Scientific -> Scientific # | |
| Ord AnnLookup | |
| Ord AnnTarget | |
| Ord Bang | |
| Ord Body | |
| Ord Bytes | |
| Ord Callconv | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Clause | |
| Ord Con | |
| Ord Dec | |
| Ord DecidedStrictness | |
Defined in Language.Haskell.TH.Syntax Methods compare :: DecidedStrictness -> DecidedStrictness -> Ordering # (<) :: DecidedStrictness -> DecidedStrictness -> Bool # (<=) :: DecidedStrictness -> DecidedStrictness -> Bool # (>) :: DecidedStrictness -> DecidedStrictness -> Bool # (>=) :: DecidedStrictness -> DecidedStrictness -> Bool # max :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # min :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # | |
| Ord DerivClause | |
Defined in Language.Haskell.TH.Syntax Methods compare :: DerivClause -> DerivClause -> Ordering # (<) :: DerivClause -> DerivClause -> Bool # (<=) :: DerivClause -> DerivClause -> Bool # (>) :: DerivClause -> DerivClause -> Bool # (>=) :: DerivClause -> DerivClause -> Bool # max :: DerivClause -> DerivClause -> DerivClause # min :: DerivClause -> DerivClause -> DerivClause # | |
| Ord DerivStrategy | |
Defined in Language.Haskell.TH.Syntax Methods compare :: DerivStrategy -> DerivStrategy -> Ordering # (<) :: DerivStrategy -> DerivStrategy -> Bool # (<=) :: DerivStrategy -> DerivStrategy -> Bool # (>) :: DerivStrategy -> DerivStrategy -> Bool # (>=) :: DerivStrategy -> DerivStrategy -> Bool # max :: DerivStrategy -> DerivStrategy -> DerivStrategy # min :: DerivStrategy -> DerivStrategy -> DerivStrategy # | |
| Ord Exp | |
| Ord FamilyResultSig | |
Defined in Language.Haskell.TH.Syntax Methods compare :: FamilyResultSig -> FamilyResultSig -> Ordering # (<) :: FamilyResultSig -> FamilyResultSig -> Bool # (<=) :: FamilyResultSig -> FamilyResultSig -> Bool # (>) :: FamilyResultSig -> FamilyResultSig -> Bool # (>=) :: FamilyResultSig -> FamilyResultSig -> Bool # max :: FamilyResultSig -> FamilyResultSig -> FamilyResultSig # min :: FamilyResultSig -> FamilyResultSig -> FamilyResultSig # | |
| Ord Fixity | |
| Ord FixityDirection | |
Defined in Language.Haskell.TH.Syntax Methods compare :: FixityDirection -> FixityDirection -> Ordering # (<) :: FixityDirection -> FixityDirection -> Bool # (<=) :: FixityDirection -> FixityDirection -> Bool # (>) :: FixityDirection -> FixityDirection -> Bool # (>=) :: FixityDirection -> FixityDirection -> Bool # max :: FixityDirection -> FixityDirection -> FixityDirection # min :: FixityDirection -> FixityDirection -> FixityDirection # | |
| Ord Foreign | |
Defined in Language.Haskell.TH.Syntax | |
| Ord FunDep | |
| Ord Guard | |
| Ord Info | |
| Ord InjectivityAnn | |
Defined in Language.Haskell.TH.Syntax Methods compare :: InjectivityAnn -> InjectivityAnn -> Ordering # (<) :: InjectivityAnn -> InjectivityAnn -> Bool # (<=) :: InjectivityAnn -> InjectivityAnn -> Bool # (>) :: InjectivityAnn -> InjectivityAnn -> Bool # (>=) :: InjectivityAnn -> InjectivityAnn -> Bool # max :: InjectivityAnn -> InjectivityAnn -> InjectivityAnn # min :: InjectivityAnn -> InjectivityAnn -> InjectivityAnn # | |
| Ord Inline | |
| Ord Lit | |
| Ord Loc | |
| Ord Match | |
| Ord ModName | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Module | |
| Ord ModuleInfo | |
Defined in Language.Haskell.TH.Syntax Methods compare :: ModuleInfo -> ModuleInfo -> Ordering # (<) :: ModuleInfo -> ModuleInfo -> Bool # (<=) :: ModuleInfo -> ModuleInfo -> Bool # (>) :: ModuleInfo -> ModuleInfo -> Bool # (>=) :: ModuleInfo -> ModuleInfo -> Bool # max :: ModuleInfo -> ModuleInfo -> ModuleInfo # min :: ModuleInfo -> ModuleInfo -> ModuleInfo # | |
| Ord Name | |
| Ord NameFlavour | |
Defined in Language.Haskell.TH.Syntax Methods compare :: NameFlavour -> NameFlavour -> Ordering # (<) :: NameFlavour -> NameFlavour -> Bool # (<=) :: NameFlavour -> NameFlavour -> Bool # (>) :: NameFlavour -> NameFlavour -> Bool # (>=) :: NameFlavour -> NameFlavour -> Bool # max :: NameFlavour -> NameFlavour -> NameFlavour # min :: NameFlavour -> NameFlavour -> NameFlavour # | |
| Ord NameSpace | |
| Ord OccName | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Overlap | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Pat | |
| Ord PatSynArgs | |
Defined in Language.Haskell.TH.Syntax Methods compare :: PatSynArgs -> PatSynArgs -> Ordering # (<) :: PatSynArgs -> PatSynArgs -> Bool # (<=) :: PatSynArgs -> PatSynArgs -> Bool # (>) :: PatSynArgs -> PatSynArgs -> Bool # (>=) :: PatSynArgs -> PatSynArgs -> Bool # max :: PatSynArgs -> PatSynArgs -> PatSynArgs # min :: PatSynArgs -> PatSynArgs -> PatSynArgs # | |
| Ord PatSynDir | |
| Ord Phases | |
| Ord PkgName | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Pragma | |
| Ord Range | |
| Ord Role | |
| Ord RuleBndr | |
Defined in Language.Haskell.TH.Syntax | |
| Ord RuleMatch | |
| Ord Safety | |
| Ord SourceStrictness | |
Defined in Language.Haskell.TH.Syntax Methods compare :: SourceStrictness -> SourceStrictness -> Ordering # (<) :: SourceStrictness -> SourceStrictness -> Bool # (<=) :: SourceStrictness -> SourceStrictness -> Bool # (>) :: SourceStrictness -> SourceStrictness -> Bool # (>=) :: SourceStrictness -> SourceStrictness -> Bool # max :: SourceStrictness -> SourceStrictness -> SourceStrictness # min :: SourceStrictness -> SourceStrictness -> SourceStrictness # | |
| Ord SourceUnpackedness | |
Defined in Language.Haskell.TH.Syntax Methods compare :: SourceUnpackedness -> SourceUnpackedness -> Ordering # (<) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (<=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # max :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # min :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # | |
| Ord Specificity | |
Defined in Language.Haskell.TH.Syntax Methods compare :: Specificity -> Specificity -> Ordering # (<) :: Specificity -> Specificity -> Bool # (<=) :: Specificity -> Specificity -> Bool # (>) :: Specificity -> Specificity -> Bool # (>=) :: Specificity -> Specificity -> Bool # max :: Specificity -> Specificity -> Specificity # min :: Specificity -> Specificity -> Specificity # | |
| Ord Stmt | |
| Ord TyLit | |
| Ord TySynEqn | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Type | |
| Ord TypeFamilyHead | |
Defined in Language.Haskell.TH.Syntax Methods compare :: TypeFamilyHead -> TypeFamilyHead -> Ordering # (<) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (<=) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (>) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (>=) :: TypeFamilyHead -> TypeFamilyHead -> Bool # max :: TypeFamilyHead -> TypeFamilyHead -> TypeFamilyHead # min :: TypeFamilyHead -> TypeFamilyHead -> TypeFamilyHead # | |
| Ord Day | |
| Ord AbsoluteTime | |
Defined in Data.Time.Clock.Internal.AbsoluteTime Methods compare :: AbsoluteTime -> AbsoluteTime -> Ordering # (<) :: AbsoluteTime -> AbsoluteTime -> Bool # (<=) :: AbsoluteTime -> AbsoluteTime -> Bool # (>) :: AbsoluteTime -> AbsoluteTime -> Bool # (>=) :: AbsoluteTime -> AbsoluteTime -> Bool # max :: AbsoluteTime -> AbsoluteTime -> AbsoluteTime # min :: AbsoluteTime -> AbsoluteTime -> AbsoluteTime # | |
| Ord UTCTime | |
Defined in Data.Time.Clock.Internal.UTCTime | |
| Ord UniversalTime | |
Defined in Data.Time.Clock.Internal.UniversalTime Methods compare :: UniversalTime -> UniversalTime -> Ordering # (<) :: UniversalTime -> UniversalTime -> Bool # (<=) :: UniversalTime -> UniversalTime -> Bool # (>) :: UniversalTime -> UniversalTime -> Bool # (>=) :: UniversalTime -> UniversalTime -> Bool # max :: UniversalTime -> UniversalTime -> UniversalTime # min :: UniversalTime -> UniversalTime -> UniversalTime # | |
| Ord LocalTime | |
Defined in Data.Time.LocalTime.Internal.LocalTime | |
| Ord Undefined | |
| Ord ConcException | |
Defined in UnliftIO.Internals.Async Methods compare :: ConcException -> ConcException -> Ordering # (<) :: ConcException -> ConcException -> Bool # (<=) :: ConcException -> ConcException -> Bool # (>) :: ConcException -> ConcException -> Bool # (>=) :: ConcException -> ConcException -> Bool # max :: ConcException -> ConcException -> ConcException # min :: ConcException -> ConcException -> ConcException # | |
| Ord UUID | |
| Ord UnpackedUUID | |
Defined in Data.UUID.Types.Internal | |
| Ord CompressionStrategy | |
Defined in Codec.Compression.Zlib.Stream Methods compare :: CompressionStrategy -> CompressionStrategy -> Ordering # (<) :: CompressionStrategy -> CompressionStrategy -> Bool # (<=) :: CompressionStrategy -> CompressionStrategy -> Bool # (>) :: CompressionStrategy -> CompressionStrategy -> Bool # (>=) :: CompressionStrategy -> CompressionStrategy -> Bool # max :: CompressionStrategy -> CompressionStrategy -> CompressionStrategy # min :: CompressionStrategy -> CompressionStrategy -> CompressionStrategy # | |
| Ord DictionaryHash | |
Defined in Codec.Compression.Zlib.Stream Methods compare :: DictionaryHash -> DictionaryHash -> Ordering # (<) :: DictionaryHash -> DictionaryHash -> Bool # (<=) :: DictionaryHash -> DictionaryHash -> Bool # (>) :: DictionaryHash -> DictionaryHash -> Bool # (>=) :: DictionaryHash -> DictionaryHash -> Bool # | |
| Ord Format | |
| Ord Method | |
| Ord WindowBits | |
Defined in Codec.Compression.Zlib.Stream Methods compare :: WindowBits -> WindowBits -> Ordering # (<) :: WindowBits -> WindowBits -> Bool # (<=) :: WindowBits -> WindowBits -> Bool # (>) :: WindowBits -> WindowBits -> Bool # (>=) :: WindowBits -> WindowBits -> Bool # max :: WindowBits -> WindowBits -> WindowBits # min :: WindowBits -> WindowBits -> WindowBits # | |
| Ord Word8 | Since: base-2.1 |
| Ord Integer | |
| Ord Natural | |
| Ord () | |
| Ord Bool | |
| Ord Char | |
| Ord Double | Note that due to the presence of
Also note that, due to the same,
|
| Ord Float | Note that due to the presence of
Also note that, due to the same,
|
| Ord Int | |
| Ord Word | |
| Ord (Digest t) | |
Defined in Data.Digest.Pure.SHA | |
| Ord (Encoding' a) | |
Defined in Data.Aeson.Encoding.Internal | |
| Ord a => Ord (ZipList a) | Since: base-4.7.0.0 |
| Ord a => Ord (Identity a) | Since: base-4.8.0.0 |
Defined in Data.Functor.Identity | |
| Ord a => Ord (First a) | Since: base-2.1 |
| Ord a => Ord (Last a) | Since: base-2.1 |
| Ord a => Ord (Down a) | Since: base-4.6.0.0 |
| Ord a => Ord (First a) | Since: base-4.9.0.0 |
| Ord a => Ord (Last a) | Since: base-4.9.0.0 |
| Ord a => Ord (Max a) | Since: base-4.9.0.0 |
| Ord a => Ord (Min a) | Since: base-4.9.0.0 |
| Ord a => Ord (Option a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| Ord m => Ord (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods compare :: WrappedMonoid m -> WrappedMonoid m -> Ordering # (<) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (<=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (>) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (>=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # max :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # min :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # | |
| Ord a => Ord (Dual a) | Since: base-2.1 |
| Ord a => Ord (Product a) | Since: base-2.1 |
| Ord a => Ord (Sum a) | Since: base-2.1 |
| Ord a => Ord (NonEmpty a) | Since: base-4.9.0.0 |
| Ord p => Ord (Par1 p) | Since: base-4.7.0.0 |
| Ord (FunPtr a) | |
Defined in GHC.Ptr | |
| Ord (Ptr a) | Since: base-2.1 |
| Integral a => Ord (Ratio a) | Since: base-2.0.1 |
| Ord a => Ord (Flush a) | |
Defined in Data.Conduit.Internal.Conduit | |
| Ord a => Ord (IntMap a) | |
Defined in Data.IntMap.Internal | |
| Ord a => Ord (Seq a) | |
| Ord a => Ord (ViewL a) | |
Defined in Data.Sequence.Internal | |
| Ord a => Ord (ViewR a) | |
Defined in Data.Sequence.Internal | |
| Ord a => Ord (Set a) | |
| Ord1 f => Ord (Fix f) | |
| (Functor f, Ord1 f) => Ord (Mu f) | |
| (Functor f, Ord1 f) => Ord (Nu f) | |
| Ord a => Ord (DNonEmpty a) | |
Defined in Data.DList.DNonEmpty.Internal | |
| Ord a => Ord (DList a) | |
| Ord (OnChainAddress mrel) Source # | |
Defined in ElectrsClient.Type Methods compare :: OnChainAddress mrel -> OnChainAddress mrel -> Ordering # (<) :: OnChainAddress mrel -> OnChainAddress mrel -> Bool # (<=) :: OnChainAddress mrel -> OnChainAddress mrel -> Bool # (>) :: OnChainAddress mrel -> OnChainAddress mrel -> Bool # (>=) :: OnChainAddress mrel -> OnChainAddress mrel -> Bool # max :: OnChainAddress mrel -> OnChainAddress mrel -> OnChainAddress mrel # min :: OnChainAddress mrel -> OnChainAddress mrel -> OnChainAddress mrel # | |
| Ord a => Ord (Hashed a) | |
Defined in Data.Hashable.Class | |
| Ord a => Ord (AddrRange a) | |
Defined in Data.IP.Range | |
| Ord a => Ord (BitcoinRpcResponse a) | |
Defined in Network.Bitcoin.Internal Methods compare :: BitcoinRpcResponse a -> BitcoinRpcResponse a -> Ordering # (<) :: BitcoinRpcResponse a -> BitcoinRpcResponse a -> Bool # (<=) :: BitcoinRpcResponse a -> BitcoinRpcResponse a -> Bool # (>) :: BitcoinRpcResponse a -> BitcoinRpcResponse a -> Bool # (>=) :: BitcoinRpcResponse a -> BitcoinRpcResponse a -> Bool # max :: BitcoinRpcResponse a -> BitcoinRpcResponse a -> BitcoinRpcResponse a # min :: BitcoinRpcResponse a -> BitcoinRpcResponse a -> BitcoinRpcResponse a # | |
| (Ord (Key record), Ord record) => Ord (Entity record) | |
Defined in Database.Persist.Class.PersistEntity Methods compare :: Entity record -> Entity record -> Ordering # (<) :: Entity record -> Entity record -> Bool # (<=) :: Entity record -> Entity record -> Bool # (>) :: Entity record -> Entity record -> Bool # (>=) :: Entity record -> Entity record -> Bool # | |
| Ord a => Ord (Array a) | Lexicographic ordering. Subject to change between major versions. |
Defined in Data.Primitive.Array | |
| (Ord a, Prim a) => Ord (PrimArray a) | Lexicographic ordering. Subject to change between major versions. Since: primitive-0.6.4.0 |
Defined in Data.Primitive.PrimArray | |
| Ord a => Ord (SmallArray a) | Lexicographic ordering. Subject to change between major versions. |
Defined in Data.Primitive.SmallArray Methods compare :: SmallArray a -> SmallArray a -> Ordering # (<) :: SmallArray a -> SmallArray a -> Bool # (<=) :: SmallArray a -> SmallArray a -> Bool # (>) :: SmallArray a -> SmallArray a -> Bool # (>=) :: SmallArray a -> SmallArray a -> Bool # max :: SmallArray a -> SmallArray a -> SmallArray a # min :: SmallArray a -> SmallArray a -> SmallArray a # | |
| Ord g => Ord (StateGen g) | |
Defined in System.Random.Internal | |
| Ord g => Ord (AtomicGen g) | |
Defined in System.Random.Stateful | |
| Ord g => Ord (IOGen g) | |
Defined in System.Random.Stateful | |
| Ord g => Ord (STGen g) | |
Defined in System.Random.Stateful | |
| Ord g => Ord (TGen g) | |
| Ord a => Ord (Maybe a) | |
| Ord flag => Ord (TyVarBndr flag) | |
Defined in Language.Haskell.TH.Syntax Methods compare :: TyVarBndr flag -> TyVarBndr flag -> Ordering # (<) :: TyVarBndr flag -> TyVarBndr flag -> Bool # (<=) :: TyVarBndr flag -> TyVarBndr flag -> Bool # (>) :: TyVarBndr flag -> TyVarBndr flag -> Bool # (>=) :: TyVarBndr flag -> TyVarBndr flag -> Bool # | |
| Ord a => Ord (HashSet a) | |
| Ord a => Ord (Vector a) | |
Defined in Data.Vector | |
| (Prim a, Ord a) => Ord (Vector a) | |
Defined in Data.Vector.Primitive | |
| (Storable a, Ord a) => Ord (Vector a) | |
Defined in Data.Vector.Storable | |
| Ord a => Ord (Maybe a) | Since: base-2.1 |
| Ord a => Ord [a] | |
| (Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 |
| Ord (Proxy s) | Since: base-4.7.0.0 |
| Ord a => Ord (Arg a b) | Since: base-4.9.0.0 |
| Ord (TypeRep a) | Since: base-4.4.0.0 |
| Ord (U1 p) | Since: base-4.7.0.0 |
| Ord (V1 p) | Since: base-4.9.0.0 |
| (Ord k, Ord v) => Ord (Map k v) | |
| (Ord a, Ord b) => Ord (Either a b) | |
| (Ord a, Ord b) => Ord (These a b) | |
| (Ord a, Ord b) => Ord (Pair a b) | |
Defined in Data.Strict.Tuple | |
| (Ord a, Ord b) => Ord (These a b) | |
| (Ord1 m, Ord a) => Ord (MaybeT m a) | |
Defined in Control.Monad.Trans.Maybe | |
| (Ord k, Ord v) => Ord (HashMap k v) | The ordering is total and consistent with the |
Defined in Data.HashMap.Internal | |
| (Ord a, Ord b) => Ord (a, b) | |
| Ord a => Ord (Const a b) | Since: base-4.9.0.0 |
| Ord (f a) => Ord (Ap f a) | Since: base-4.12.0.0 |
| Ord (f a) => Ord (Alt f a) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
| Ord (f p) => Ord (Rec1 f p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
| Ord (URec (Ptr ()) p) | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: URec (Ptr ()) p -> URec (Ptr ()) p -> Ordering # (<) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (<=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # max :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p # min :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p # | |
| Ord (URec Char p) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Ord (URec Double p) | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: URec Double p -> URec Double p -> Ordering # (<) :: URec Double p -> URec Double p -> Bool # (<=) :: URec Double p -> URec Double p -> Bool # (>) :: URec Double p -> URec Double p -> Bool # (>=) :: URec Double p -> URec Double p -> Bool # | |
| Ord (URec Float p) | |
Defined in GHC.Generics | |
| Ord (URec Int p) | Since: base-4.9.0.0 |
| Ord (URec Word p) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Ord b => Ord (Tagged s b) | |
| (Ord1 f, Ord1 g, Ord a) => Ord (These1 f g a) | |
Defined in Data.Functor.These | |
| (Ord e, Ord1 m, Ord a) => Ord (ErrorT e m a) | |
Defined in Control.Monad.Trans.Error | |
| (Ord e, Ord1 m, Ord a) => Ord (ExceptT e m a) | |
Defined in Control.Monad.Trans.Except Methods compare :: ExceptT e m a -> ExceptT e m a -> Ordering # (<) :: ExceptT e m a -> ExceptT e m a -> Bool # (<=) :: ExceptT e m a -> ExceptT e m a -> Bool # (>) :: ExceptT e m a -> ExceptT e m a -> Bool # (>=) :: ExceptT e m a -> ExceptT e m a -> Bool # | |
| (Ord1 f, Ord a) => Ord (IdentityT f a) | |
Defined in Control.Monad.Trans.Identity Methods compare :: IdentityT f a -> IdentityT f a -> Ordering # (<) :: IdentityT f a -> IdentityT f a -> Bool # (<=) :: IdentityT f a -> IdentityT f a -> Bool # (>) :: IdentityT f a -> IdentityT f a -> Bool # (>=) :: IdentityT f a -> IdentityT f a -> Bool # | |
| (Ord a, Ord b, Ord c) => Ord (a, b, c) | |
| (Ord1 f, Ord1 g, Ord a) => Ord (Product f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product Methods compare :: Product f g a -> Product f g a -> Ordering # (<) :: Product f g a -> Product f g a -> Bool # (<=) :: Product f g a -> Product f g a -> Bool # (>) :: Product f g a -> Product f g a -> Bool # (>=) :: Product f g a -> Product f g a -> Bool # | |
| (Ord1 f, Ord1 g, Ord a) => Ord (Sum f g a) | Since: base-4.9.0.0 |
| (Ord (f p), Ord (g p)) => Ord ((f :*: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
| (Ord (f p), Ord (g p)) => Ord ((f :+: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
| Ord c => Ord (K1 i c p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
| (Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) | |
Defined in GHC.Classes | |
| (Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods compare :: Compose f g a -> Compose f g a -> Ordering # (<) :: Compose f g a -> Compose f g a -> Bool # (<=) :: Compose f g a -> Compose f g a -> Bool # (>) :: Compose f g a -> Compose f g a -> Bool # (>=) :: Compose f g a -> Compose f g a -> Bool # | |
| Ord (f (g p)) => Ord ((f :.: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
| Ord (f p) => Ord (M1 i c f p) | Since: base-4.7.0.0 |
| Ord (p b a) => Ord (Flip p a b) | |
Defined in Data.Bifunctor.Flip | |
| (Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e) -> (a, b, c, d, e) -> Ordering # (<) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (<=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (>=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # max :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # min :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # | |
| (Ord (f a b), Ord (g a b)) => Ord (Product f g a b) | |
Defined in Data.Bifunctor.Product Methods compare :: Product f g a b -> Product f g a b -> Ordering # (<) :: Product f g a b -> Product f g a b -> Bool # (<=) :: Product f g a b -> Product f g a b -> Bool # (>) :: Product f g a b -> Product f g a b -> Bool # (>=) :: Product f g a b -> Product f g a b -> Bool # max :: Product f g a b -> Product f g a b -> Product f g a b # min :: Product f g a b -> Product f g a b -> Product f g a b # | |
| (Ord (p a b), Ord (q a b)) => Ord (Sum p q a b) | |
Defined in Data.Bifunctor.Sum | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f) => Ord (a, b, c, d, e, f) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Ordering # (<) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # (<=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # (>) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # (>=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # max :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f) # min :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f) # | |
| Ord (f (p a b)) => Ord (Tannen f p a b) | |
Defined in Data.Bifunctor.Tannen Methods compare :: Tannen f p a b -> Tannen f p a b -> Ordering # (<) :: Tannen f p a b -> Tannen f p a b -> Bool # (<=) :: Tannen f p a b -> Tannen f p a b -> Bool # (>) :: Tannen f p a b -> Tannen f p a b -> Bool # (>=) :: Tannen f p a b -> Tannen f p a b -> Bool # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g) => Ord (a, b, c, d, e, f, g) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Ordering # (<) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # (<=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # (>) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # (>=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # max :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) # min :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h) => Ord (a, b, c, d, e, f, g, h) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Ordering # (<) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # (<=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # (>) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # (>=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # max :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) # min :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) # | |
| Ord (p (f a) (g b)) => Ord (Biff p f g a b) | |
Defined in Data.Bifunctor.Biff Methods compare :: Biff p f g a b -> Biff p f g a b -> Ordering # (<) :: Biff p f g a b -> Biff p f g a b -> Bool # (<=) :: Biff p f g a b -> Biff p f g a b -> Bool # (>) :: Biff p f g a b -> Biff p f g a b -> Bool # (>=) :: Biff p f g a b -> Biff p f g a b -> Bool # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i) => Ord (a, b, c, d, e, f, g, h, i) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # max :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) # min :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j) => Ord (a, b, c, d, e, f, g, h, i, j) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) # min :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k) => Ord (a, b, c, d, e, f, g, h, i, j, k) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) # min :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l) => Ord (a, b, c, d, e, f, g, h, i, j, k, l) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) # min :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n, Ord o) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # | |
Parsing of Strings, producing values.
Derived instances of Read make the following assumptions, which
derived instances of Show obey:
- If the constructor is defined to be an infix operator, then the
derived
Readinstance will parse only infix applications of the constructor (not the prefix form). - Associativity is not used to reduce the occurrence of parentheses, although precedence may be.
- If the constructor is defined using record syntax, the derived
Readwill parse only the record-syntax form, and furthermore, the fields must be given in the same order as the original declaration. - The derived
Readinstance allows arbitrary Haskell whitespace between tokens of the input string. Extra parentheses are also allowed.
For example, given the declarations
infixr 5 :^: data Tree a = Leaf a | Tree a :^: Tree a
the derived instance of Read in Haskell 2010 is equivalent to
instance (Read a) => Read (Tree a) where
readsPrec d r = readParen (d > app_prec)
(\r -> [(Leaf m,t) |
("Leaf",s) <- lex r,
(m,t) <- readsPrec (app_prec+1) s]) r
++ readParen (d > up_prec)
(\r -> [(u:^:v,w) |
(u,s) <- readsPrec (up_prec+1) r,
(":^:",t) <- lex s,
(v,w) <- readsPrec (up_prec+1) t]) r
where app_prec = 10
up_prec = 5Note that right-associativity of :^: is unused.
The derived instance in GHC is equivalent to
instance (Read a) => Read (Tree a) where
readPrec = parens $ (prec app_prec $ do
Ident "Leaf" <- lexP
m <- step readPrec
return (Leaf m))
+++ (prec up_prec $ do
u <- step readPrec
Symbol ":^:" <- lexP
v <- step readPrec
return (u :^: v))
where app_prec = 10
up_prec = 5
readListPrec = readListPrecDefaultWhy do both readsPrec and readPrec exist, and why does GHC opt to
implement readPrec in derived Read instances instead of readsPrec?
The reason is that readsPrec is based on the ReadS type, and although
ReadS is mentioned in the Haskell 2010 Report, it is not a very efficient
parser data structure.
readPrec, on the other hand, is based on a much more efficient ReadPrec
datatype (a.k.a "new-style parsers"), but its definition relies on the use
of the RankNTypes language extension. Therefore, readPrec (and its
cousin, readListPrec) are marked as GHC-only. Nevertheless, it is
recommended to use readPrec instead of readsPrec whenever possible
for the efficiency improvements it brings.
As mentioned above, derived Read instances in GHC will implement
readPrec instead of readsPrec. The default implementations of
readsPrec (and its cousin, readList) will simply use readPrec under
the hood. If you are writing a Read instance by hand, it is recommended
to write it like so:
instanceReadT wherereadPrec= ...readListPrec=readListPrecDefault
Instances
| Read DotNetTime | |
Defined in Data.Aeson.Types.Internal Methods readsPrec :: Int -> ReadS DotNetTime # readList :: ReadS [DotNetTime] # readPrec :: ReadPrec DotNetTime # readListPrec :: ReadPrec [DotNetTime] # | |
| Read Value | |
| Read All | Since: base-2.1 |
| Read Any | Since: base-2.1 |
| Read Version | Since: base-2.1 |
| Read Void | Reading a Since: base-4.8.0.0 |
| Read Associativity | Since: base-4.6.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS Associativity # readList :: ReadS [Associativity] # | |
| Read DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS DecidedStrictness # readList :: ReadS [DecidedStrictness] # | |
| Read Fixity | Since: base-4.6.0.0 |
| Read SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS SourceStrictness # readList :: ReadS [SourceStrictness] # | |
| Read SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS SourceUnpackedness # readList :: ReadS [SourceUnpackedness] # | |
| Read ExitCode | |
| Read BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS BufferMode # readList :: ReadS [BufferMode] # readPrec :: ReadPrec BufferMode # readListPrec :: ReadPrec [BufferMode] # | |
| Read Newline | Since: base-4.3.0.0 |
| Read NewlineMode | Since: base-4.3.0.0 |
Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS NewlineMode # readList :: ReadS [NewlineMode] # readPrec :: ReadPrec NewlineMode # readListPrec :: ReadPrec [NewlineMode] # | |
| Read IOMode | Since: base-4.2.0.0 |
| Read Int16 | Since: base-2.1 |
| Read Int32 | Since: base-2.1 |
| Read Int64 | Since: base-2.1 |
| Read Int8 | Since: base-2.1 |
| Read GCDetails | Since: base-4.10.0.0 |
| Read RTSStats | Since: base-4.10.0.0 |
| Read SomeSymbol | Since: base-4.7.0.0 |
Defined in GHC.TypeLits Methods readsPrec :: Int -> ReadS SomeSymbol # readList :: ReadS [SomeSymbol] # readPrec :: ReadPrec SomeSymbol # readListPrec :: ReadPrec [SomeSymbol] # | |
| Read SomeNat | Since: base-4.7.0.0 |
| Read GeneralCategory | Since: base-2.1 |
Defined in GHC.Read Methods readsPrec :: Int -> ReadS GeneralCategory # readList :: ReadS [GeneralCategory] # | |
| Read Word16 | Since: base-2.1 |
| Read Word32 | Since: base-2.1 |
| Read Word64 | Since: base-2.1 |
| Read Lexeme | Since: base-2.1 |
| Read ByteString | |
Defined in Data.ByteString.Internal Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] # | |
| Read ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] # | |
| Read ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods readsPrec :: Int -> ReadS ShortByteString # readList :: ReadS [ShortByteString] # | |
| Read IntSet | |
| Read Ordering | Since: base-2.1 |
| Read Cookie | |
| Read CookieJar | |
| Read Proxy | |
| Read ProxySecureMode | |
Defined in Network.HTTP.Client.Types Methods readsPrec :: Int -> ReadS ProxySecureMode # readList :: ReadS [ProxySecureMode] # | |
| Read IP | |
| Read IPv4 | |
| Read IPv6 | |
| Read IPRange | |
| Read AddrInfoFlag | |
Defined in Network.Socket.Info Methods readsPrec :: Int -> ReadS AddrInfoFlag # readList :: ReadS [AddrInfoFlag] # | |
| Read NameInfoFlag | |
Defined in Network.Socket.Info Methods readsPrec :: Int -> ReadS NameInfoFlag # readList :: ReadS [NameInfoFlag] # | |
| Read SocketOption | |
Defined in Network.Socket.Options Methods readsPrec :: Int -> ReadS SocketOption # readList :: ReadS [SocketOption] # | |
| Read CmsgId | |
| Read Family | |
| Read PortNumber | |
Defined in Network.Socket.Types Methods readsPrec :: Int -> ReadS PortNumber # readList :: ReadS [PortNumber] # readPrec :: ReadPrec PortNumber # readListPrec :: ReadPrec [PortNumber] # | |
| Read SocketType | |
Defined in Network.Socket.Types Methods readsPrec :: Int -> ReadS SocketType # readList :: ReadS [SocketType] # readPrec :: ReadPrec SocketType # readListPrec :: ReadPrec [SocketType] # | |
| Read Block | |
| Read BlockChainInfo | |
| Read BlockVerbose | |
| Read OutputInfo | |
| Read OutputSetInfo | |
| Read BitcoinRpcError | |
| Read BlockTemplate | |
| Read CoinBaseAux | |
| Read HashData | |
| Read MiningInfo | |
| Read Transaction | |
| Read AddNodeCommand | |
| Read PeerInfo | |
| Read BlockInfo | |
| Read DecodedPsbt | |
| Read DecodedRawTransaction | |
| Read RawTransactionInfo | |
| Read ScriptPubKey | |
| Read ScriptSig | |
| Read TxIn | |
| Read TxOut | |
| Read TxnOutputType | |
| Read BitcoinException | |
| Read TransactionID | |
| Read AddrInfo | |
| Read AddressInfo | |
| Read BitcoindInfo | |
| Read ReceivedByAccount | |
| Read ReceivedByAddress | |
| Read ScrPubKey | |
| Read TransactionCategory | |
| Read Scientific | Supports the skipping of parentheses and whitespaces. Example: > read " ( (( -1.0e+3 ) ))" :: Scientific -1000.0 (Note: This |
Defined in Data.Scientific Methods readsPrec :: Int -> ReadS Scientific # readList :: ReadS [Scientific] # readPrec :: ReadPrec Scientific # readListPrec :: ReadPrec [Scientific] # | |
| Read Msg | |
| Read PubKey | |
| Read SecKey | |
| Read Sig | |
| Read Tweak | |
| Read Undefined | |
| Read UUID | |
| Read UnpackedUUID | |
| Read DictionaryHash | |
| Read Word8 | Since: base-2.1 |
| Read Integer | Since: base-2.1 |
| Read Natural | Since: base-4.8.0.0 |
| Read () | Since: base-2.1 |
| Read Bool | Since: base-2.1 |
| Read Char | Since: base-2.1 |
| Read Double | Since: base-2.1 |
| Read Float | Since: base-2.1 |
| Read Int | Since: base-2.1 |
| Read Word | Since: base-4.5.0.0 |
| Read a => Read (ZipList a) | Since: base-4.7.0.0 |
| Read a => Read (Complex a) | Since: base-2.1 |
| Read a => Read (Identity a) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| Read a => Read (First a) | Since: base-2.1 |
| Read a => Read (Last a) | Since: base-2.1 |
| Read a => Read (Down a) | This instance would be equivalent to the derived instances of the
Since: base-4.7.0.0 |
| Read a => Read (First a) | Since: base-4.9.0.0 |
| Read a => Read (Last a) | Since: base-4.9.0.0 |
| Read a => Read (Max a) | Since: base-4.9.0.0 |
| Read a => Read (Min a) | Since: base-4.9.0.0 |
| Read a => Read (Option a) | Since: base-4.9.0.0 |
| Read m => Read (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (WrappedMonoid m) # readList :: ReadS [WrappedMonoid m] # readPrec :: ReadPrec (WrappedMonoid m) # readListPrec :: ReadPrec [WrappedMonoid m] # | |
| Read a => Read (Dual a) | Since: base-2.1 |
| Read a => Read (Product a) | Since: base-2.1 |
| Read a => Read (Sum a) | Since: base-2.1 |
| Read a => Read (NonEmpty a) | Since: base-4.11.0.0 |
| Read p => Read (Par1 p) | Since: base-4.7.0.0 |
| (Integral a, Read a) => Read (Ratio a) | Since: base-2.1 |
| Read e => Read (IntMap e) | |
| Read a => Read (Seq a) | |
| Read a => Read (ViewL a) | |
| Read a => Read (ViewR a) | |
| (Read a, Ord a) => Read (Set a) | |
| Read a => Read (Tree a) | |
| Read1 f => Read (Fix f) | |
| (Functor f, Read1 f) => Read (Mu f) | |
| (Functor f, Read1 f) => Read (Nu f) | |
| Read a => Read (DNonEmpty a) | |
| Read a => Read (DList a) | |
| Read (OnChainAddress mrel) Source # | |
Defined in ElectrsClient.Type Methods readsPrec :: Int -> ReadS (OnChainAddress mrel) # readList :: ReadS [OnChainAddress mrel] # readPrec :: ReadPrec (OnChainAddress mrel) # readListPrec :: ReadPrec [OnChainAddress mrel] # | |
| Read (AddrRange IPv4) | |
| Read (AddrRange IPv6) | |
| Read a => Read (BitcoinRpcResponse a) | |
| (Read (Key record), Read record) => Read (Entity record) | |
| Read a => Read (Array a) | |
| Read a => Read (SmallArray a) | |
Defined in Data.Primitive.SmallArray Methods readsPrec :: Int -> ReadS (SmallArray a) # readList :: ReadS [SmallArray a] # readPrec :: ReadPrec (SmallArray a) # readListPrec :: ReadPrec [SmallArray a] # | |
| Read a => Read (Maybe a) | |
| (Eq a, Hashable a, Read a) => Read (HashSet a) | |
| Read a => Read (Vector a) | |
| (Read a, Prim a) => Read (Vector a) | |
| (Read a, Storable a) => Read (Vector a) | |
| Read a => Read (Maybe a) | Since: base-2.1 |
| Read a => Read (a) | Since: base-4.15 |
| Read a => Read [a] | Since: base-2.1 |
| (Read a, Read b) => Read (Either a b) | Since: base-3.0 |
| Read (Proxy t) | Since: base-4.7.0.0 |
| (Read a, Read b) => Read (Arg a b) | Since: base-4.9.0.0 |
| (Ix a, Read a, Read b) => Read (Array a b) | Since: base-2.1 |
| Read (U1 p) | Since: base-4.9.0.0 |
| Read (V1 p) | Since: base-4.9.0.0 |
| (Ord k, Read k, Read e) => Read (Map k e) | |
| (Read a, Read b) => Read (Either a b) | |
| (Read a, Read b) => Read (These a b) | |
| (Read a, Read b) => Read (Pair a b) | |
| (Read a, Read b) => Read (These a b) | |
| (Read1 m, Read a) => Read (MaybeT m a) | |
| (Eq k, Hashable k, Read k, Read e) => Read (HashMap k e) | |
| (Read a, Read b) => Read (a, b) | Since: base-2.1 |
| Read a => Read (Const a b) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| Read (f a) => Read (Ap f a) | Since: base-4.12.0.0 |
| Read (f a) => Read (Alt f a) | Since: base-4.8.0.0 |
| Read (f p) => Read (Rec1 f p) | Since: base-4.7.0.0 |
| Read b => Read (Tagged s b) | |
| (Read1 f, Read1 g, Read a) => Read (These1 f g a) | |
| (Read e, Read1 m, Read a) => Read (ErrorT e m a) | |
| (Read e, Read1 m, Read a) => Read (ExceptT e m a) | |
| (Read1 f, Read a) => Read (IdentityT f a) | |
| (Read a, Read b, Read c) => Read (a, b, c) | Since: base-2.1 |
| (Read1 f, Read1 g, Read a) => Read (Product f g a) | Since: base-4.9.0.0 |
| (Read1 f, Read1 g, Read a) => Read (Sum f g a) | Since: base-4.9.0.0 |
| (Read (f p), Read (g p)) => Read ((f :*: g) p) | Since: base-4.7.0.0 |
| (Read (f p), Read (g p)) => Read ((f :+: g) p) | Since: base-4.7.0.0 |
| Read c => Read (K1 i c p) | Since: base-4.7.0.0 |
| (Read a, Read b, Read c, Read d) => Read (a, b, c, d) | Since: base-2.1 |
| (Read1 f, Read1 g, Read a) => Read (Compose f g a) | Since: base-4.9.0.0 |
| Read (f (g p)) => Read ((f :.: g) p) | Since: base-4.7.0.0 |
| Read (f p) => Read (M1 i c f p) | Since: base-4.7.0.0 |
| Read (p b a) => Read (Flip p a b) | |
| (Read a, Read b, Read c, Read d, Read e) => Read (a, b, c, d, e) | Since: base-2.1 |
| (Read (f a b), Read (g a b)) => Read (Product f g a b) | |
| (Read (p a b), Read (q a b)) => Read (Sum p q a b) | |
| (Read a, Read b, Read c, Read d, Read e, Read f) => Read (a, b, c, d, e, f) | Since: base-2.1 |
| Read (f (p a b)) => Read (Tannen f p a b) | |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g) => Read (a, b, c, d, e, f, g) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h) => Read (a, b, c, d, e, f, g, h) | Since: base-2.1 |
| Read (p (f a) (g b)) => Read (Biff p f g a b) | |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i) => Read (a, b, c, d, e, f, g, h, i) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j) => Read (a, b, c, d, e, f, g, h, i, j) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k) => Read (a, b, c, d, e, f, g, h, i, j, k) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l) => Read (a, b, c, d, e, f, g, h, i, j, k, l) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m, Read n) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m, Read n, Read o) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | Since: base-2.1 |
Defined in GHC.Read | |
class (Num a, Ord a) => Real a where #
Methods
toRational :: a -> Rational #
the rational equivalent of its real argument with full precision
Instances
| Real Int16 | Since: base-2.1 |
Defined in GHC.Int Methods toRational :: Int16 -> Rational # | |
| Real Int32 | Since: base-2.1 |
Defined in GHC.Int Methods toRational :: Int32 -> Rational # | |
| Real Int64 | Since: base-2.1 |
Defined in GHC.Int Methods toRational :: Int64 -> Rational # | |
| Real Int8 | Since: base-2.1 |
Defined in GHC.Int Methods toRational :: Int8 -> Rational # | |
| Real Word16 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word16 -> Rational # | |
| Real Word32 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word32 -> Rational # | |
| Real Word64 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word64 -> Rational # | |
| Real PortNumber | |
Defined in Network.Socket.Types Methods toRational :: PortNumber -> Rational # | |
| Real Scientific | WARNING: Avoid applying |
Defined in Data.Scientific Methods toRational :: Scientific -> Rational # | |
| Real Word8 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word8 -> Rational # | |
| Real Integer | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Integer -> Rational # | |
| Real Natural | Since: base-4.8.0.0 |
Defined in GHC.Real Methods toRational :: Natural -> Rational # | |
| Real Int | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Int -> Rational # | |
| Real Word | Since: base-2.1 |
Defined in GHC.Real Methods toRational :: Word -> Rational # | |
| Real a => Real (Identity a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Identity Methods toRational :: Identity a -> Rational # | |
| Real a => Real (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods toRational :: Down a -> Rational # | |
| Integral a => Real (Ratio a) | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Ratio a -> Rational # | |
| Real a => Real (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods toRational :: Const a b -> Rational # | |
| Real a => Real (Tagged s a) | |
Defined in Data.Tagged Methods toRational :: Tagged s a -> Rational # | |
class (Real a, Fractional a) => RealFrac a where #
Extracting components of fractions.
Minimal complete definition
Methods
properFraction :: Integral b => a -> (b, a) #
The function properFraction takes a real fractional number x
and returns a pair (n,f) such that x = n+f, and:
nis an integral number with the same sign asx; andfis a fraction with the same type and sign asx, and with absolute value less than1.
The default definitions of the ceiling, floor, truncate
and round functions are in terms of properFraction.
truncate :: Integral b => a -> b #
truncate xx between zero and x
round :: Integral b => a -> b #
round xx;
the even integer if x is equidistant between two integers
ceiling :: Integral b => a -> b #
ceiling xx
floor :: Integral b => a -> b #
floor xx
Instances
| RealFrac Scientific | WARNING: the methods of the |
Defined in Data.Scientific Methods properFraction :: Integral b => Scientific -> (b, Scientific) # truncate :: Integral b => Scientific -> b # round :: Integral b => Scientific -> b # ceiling :: Integral b => Scientific -> b # floor :: Integral b => Scientific -> b # | |
| RealFrac a => RealFrac (Identity a) | Since: base-4.9.0.0 |
| RealFrac a => RealFrac (Down a) | Since: base-4.14.0.0 |
| Integral a => RealFrac (Ratio a) | Since: base-2.0.1 |
| RealFrac a => RealFrac (Const a b) | Since: base-4.9.0.0 |
| RealFrac a => RealFrac (Tagged s a) | |
Conversion of values to readable Strings.
Derived instances of Show have the following properties, which
are compatible with derived instances of Read:
- The result of
showis a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used. - If the constructor is defined to be an infix operator, then
showsPrecwill produce infix applications of the constructor. - the representation will be enclosed in parentheses if the
precedence of the top-level constructor in
xis less thand(associativity is ignored). Thus, ifdis0then the result is never surrounded in parentheses; ifdis11it is always surrounded in parentheses, unless it is an atomic expression. - If the constructor is defined using record syntax, then
showwill produce the record-syntax form, with the fields given in the same order as the original declaration.
For example, given the declarations
infixr 5 :^: data Tree a = Leaf a | Tree a :^: Tree a
the derived instance of Show is equivalent to
instance (Show a) => Show (Tree a) where
showsPrec d (Leaf m) = showParen (d > app_prec) $
showString "Leaf " . showsPrec (app_prec+1) m
where app_prec = 10
showsPrec d (u :^: v) = showParen (d > up_prec) $
showsPrec (up_prec+1) u .
showString " :^: " .
showsPrec (up_prec+1) v
where up_prec = 5Note that right-associativity of :^: is ignored. For example,
show(Leaf 1 :^: Leaf 2 :^: Leaf 3)"Leaf 1 :^: (Leaf 2 :^: Leaf 3)".
Instances
The class Typeable allows a concrete representation of a type to
be calculated.
Minimal complete definition
typeRep#
class Monad m => MonadFail (m :: Type -> Type) where #
When a value is bound in do-notation, the pattern on the left
hand side of <- might not match. In this case, this class
provides a function to recover.
A Monad without a MonadFail instance may only be used in conjunction
with pattern that always match, such as newtypes, tuples, data types with
only a single data constructor, and irrefutable patterns (~pat).
Instances of MonadFail should satisfy the following law: fail s should
be a left zero for >>=,
fail s >>= f = fail s
If your Monad is also MonadPlus, a popular definition is
fail _ = mzero
Since: base-4.9.0.0
Instances
Class for string-like datastructures; used by the overloaded string extension (-XOverloadedStrings in GHC).
Methods
fromString :: String -> a #
Instances
class Functor f => Applicative (f :: Type -> Type) where #
A functor with application, providing operations to
A minimal complete definition must include implementations of pure
and of either <*> or liftA2. If it defines both, then they must behave
the same as their default definitions:
(<*>) =liftA2id
liftA2f x y = f<$>x<*>y
Further, any definition must satisfy the following:
- Identity
pureid<*>v = v- Composition
pure(.)<*>u<*>v<*>w = u<*>(v<*>w)- Homomorphism
puref<*>purex =pure(f x)- Interchange
u
<*>purey =pure($y)<*>u
The other methods have the following default definitions, which may be overridden with equivalent specialized implementations:
As a consequence of these laws, the Functor instance for f will satisfy
It may be useful to note that supposing
forall x y. p (q x y) = f x . g y
it follows from the above that
liftA2p (liftA2q u v) =liftA2f u .liftA2g v
If f is also a Monad, it should satisfy
(which implies that pure and <*> satisfy the applicative functor laws).
Methods
Lift a value.
(<*>) :: f (a -> b) -> f a -> f b infixl 4 #
Sequential application.
A few functors support an implementation of <*> that is more
efficient than the default one.
Example
Used in combination with (, <$>)( can be used to build a record.<*>)
>>>data MyState = MyState {arg1 :: Foo, arg2 :: Bar, arg3 :: Baz}
>>>produceFoo :: Applicative f => f Foo
>>>produceBar :: Applicative f => f Bar>>>produceBaz :: Applicative f => f Baz
>>>mkState :: Applicative f => f MyState>>>mkState = MyState <$> produceFoo <*> produceBar <*> produceBaz
liftA2 :: (a -> b -> c) -> f a -> f b -> f c #
Lift a binary function to actions.
Some functors support an implementation of liftA2 that is more
efficient than the default one. In particular, if fmap is an
expensive operation, it is likely better to use liftA2 than to
fmap over the structure and then use <*>.
This became a typeclass method in 4.10.0.0. Prior to that, it was
a function defined in terms of <*> and fmap.
Example
>>>liftA2 (,) (Just 3) (Just 5)Just (3,5)
(*>) :: f a -> f b -> f b infixl 4 #
Sequence actions, discarding the value of the first argument.
Examples
If used in conjunction with the Applicative instance for Maybe,
you can chain Maybe computations, with a possible "early return"
in case of Nothing.
>>>Just 2 *> Just 3Just 3
>>>Nothing *> Just 3Nothing
Of course a more interesting use case would be to have effectful computations instead of just returning pure values.
>>>import Data.Char>>>import Text.ParserCombinators.ReadP>>>let p = string "my name is " *> munch1 isAlpha <* eof>>>readP_to_S p "my name is Simon"[("Simon","")]
(<*) :: f a -> f b -> f a infixl 4 #
Sequence actions, discarding the value of the second argument.
Instances
| Applicative IResult | |
| Applicative Parser | |
| Applicative Result | |
| Applicative ZipList | f <$> ZipList xs1 <*> ... <*> ZipList xsN
= ZipList (zipWithN f xs1 ... xsN)where (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <*> ZipList "567" <*> ZipList [1..]
= ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..])
= ZipList {getZipList = ["a5","b6b6","c7c7c7"]}Since: base-2.1 |
| Applicative Complex | Since: base-4.9.0.0 |
| Applicative Identity | Since: base-4.8.0.0 |
| Applicative First | Since: base-4.8.0.0 |
| Applicative Last | Since: base-4.8.0.0 |
| Applicative Down | Since: base-4.11.0.0 |
| Applicative First | Since: base-4.9.0.0 |
| Applicative Last | Since: base-4.9.0.0 |
| Applicative Max | Since: base-4.9.0.0 |
| Applicative Min | Since: base-4.9.0.0 |
| Applicative Option | Since: base-4.9.0.0 |
| Applicative Dual | Since: base-4.8.0.0 |
| Applicative Product | Since: base-4.8.0.0 |
| Applicative Sum | Since: base-4.8.0.0 |
| Applicative NonEmpty | Since: base-4.9.0.0 |
| Applicative STM | Since: base-4.8.0.0 |
| Applicative Par1 | Since: base-4.9.0.0 |
| Applicative P | Since: base-4.5.0.0 |
| Applicative ReadP | Since: base-4.6.0.0 |
| Applicative ReadPrec | Since: base-4.6.0.0 |
| Applicative Seq | Since: containers-0.5.4 |
| Applicative Tree | |
| Applicative DNonEmpty | |
Defined in Data.DList.DNonEmpty.Internal | |
| Applicative DList | |
| Applicative IO | Since: base-2.1 |
| Applicative Array | |
| Applicative SmallArray | |
Defined in Data.Primitive.SmallArray Methods pure :: a -> SmallArray a # (<*>) :: SmallArray (a -> b) -> SmallArray a -> SmallArray b # liftA2 :: (a -> b -> c) -> SmallArray a -> SmallArray b -> SmallArray c # (*>) :: SmallArray a -> SmallArray b -> SmallArray b # (<*) :: SmallArray a -> SmallArray b -> SmallArray a # | |
| Applicative Q | |
| Applicative Flat | |
| Applicative FlatApp | |
| Applicative Vector | |
| Applicative Stream | |
| Applicative Maybe | Since: base-2.1 |
| Applicative Solo | Since: base-4.15 |
| Applicative [] | Since: base-2.1 |
| Applicative (Parser i) | |
| Monad m => Applicative (WrappedMonad m) | Since: base-2.1 |
Defined in Control.Applicative Methods pure :: a -> WrappedMonad m a # (<*>) :: WrappedMonad m (a -> b) -> WrappedMonad m a -> WrappedMonad m b # liftA2 :: (a -> b -> c) -> WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m c # (*>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # (<*) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m a # | |
| Arrow a => Applicative (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in Control.Arrow Methods pure :: a0 -> ArrowMonad a a0 # (<*>) :: ArrowMonad a (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # liftA2 :: (a0 -> b -> c) -> ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a c # (*>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # (<*) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a a0 # | |
| Applicative (Either e) | Since: base-3.0 |
| Applicative (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Applicative (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monad m => Applicative (ZipSource m) | |
Defined in Data.Conduit.Internal.Conduit | |
| Applicative (Parser e) | |
| Applicative m => Applicative (ResourceT m) | |
Defined in Control.Monad.Trans.Resource.Internal | |
| Semigroup a => Applicative (These a) | |
| Semigroup a => Applicative (These a) | |
| (Functor m, Monad m) => Applicative (MaybeT m) | |
| MonadUnliftIO m => Applicative (Conc m) | Since: unliftio-0.2.9.0 |
| MonadUnliftIO m => Applicative (Concurrently m) | Since: unliftio-0.1.0.0 |
Defined in UnliftIO.Internals.Async Methods pure :: a -> Concurrently m a # (<*>) :: Concurrently m (a -> b) -> Concurrently m a -> Concurrently m b # liftA2 :: (a -> b -> c) -> Concurrently m a -> Concurrently m b -> Concurrently m c # (*>) :: Concurrently m a -> Concurrently m b -> Concurrently m b # (<*) :: Concurrently m a -> Concurrently m b -> Concurrently m a # | |
| Monoid a => Applicative ((,) a) | For tuples, the ("hello ", (+15)) <*> ("world!", 2002)
("hello world!",2017)Since: base-2.1 |
| Arrow a => Applicative (WrappedArrow a b) | Since: base-2.1 |
Defined in Control.Applicative Methods pure :: a0 -> WrappedArrow a b a0 # (<*>) :: WrappedArrow a b (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # liftA2 :: (a0 -> b0 -> c) -> WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b c # (*>) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b b0 # (<*) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
| Applicative m => Applicative (Kleisli m a) | Since: base-4.14.0.0 |
Defined in Control.Arrow | |
| Monoid m => Applicative (Const m :: Type -> Type) | Since: base-2.0.1 |
| Applicative f => Applicative (Ap f) | Since: base-4.12.0.0 |
| Applicative f => Applicative (Alt f) | Since: base-4.8.0.0 |
| Applicative f => Applicative (Rec1 f) | Since: base-4.9.0.0 |
| Monad m => Applicative (ZipSink i m) | |
Defined in Data.Conduit.Internal.Conduit | |
| (Applicative f, Monad f) => Applicative (WhenMissing f x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods pure :: a -> WhenMissing f x a # (<*>) :: WhenMissing f x (a -> b) -> WhenMissing f x a -> WhenMissing f x b # liftA2 :: (a -> b -> c) -> WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x c # (*>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # (<*) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x a # | |
| Applicative (Bazaar a b) | |
Defined in Lens.Micro | |
| (Functor m, Monad m) => Applicative (StateT s m) | |
| (Monad m, Monoid r) => Applicative (Effect m r) | |
Defined in Lens.Micro.Mtl.Internal | |
| (Monad m, Monoid s) => Applicative (Focusing m s) | |
Defined in Lens.Micro.Mtl.Internal | |
| Applicative (k (May s)) => Applicative (FocusingMay k s) | |
Defined in Lens.Micro.Mtl.Internal Methods pure :: a -> FocusingMay k s a # (<*>) :: FocusingMay k s (a -> b) -> FocusingMay k s a -> FocusingMay k s b # liftA2 :: (a -> b -> c) -> FocusingMay k s a -> FocusingMay k s b -> FocusingMay k s c # (*>) :: FocusingMay k s a -> FocusingMay k s b -> FocusingMay k s b # (<*) :: FocusingMay k s a -> FocusingMay k s b -> FocusingMay k s a # | |
| Applicative (Tagged s) | |
| (Functor m, Monad m) => Applicative (ErrorT e m) | |
Defined in Control.Monad.Trans.Error | |
| (Functor m, Monad m) => Applicative (ExceptT e m) | |
Defined in Control.Monad.Trans.Except | |
| Applicative m => Applicative (IdentityT m) | |
Defined in Control.Monad.Trans.Identity | |
| Applicative m => Applicative (ReaderT r m) | |
Defined in Control.Monad.Trans.Reader | |
| (Functor m, Monad m) => Applicative (StateT s m) | |
Defined in Control.Monad.Trans.State.Lazy | |
| (Functor m, Monad m) => Applicative (StateT s m) | |
Defined in Control.Monad.Trans.State.Strict | |
| (Monoid a, Monoid b) => Applicative ((,,) a b) | Since: base-4.14.0.0 |
| (Applicative f, Applicative g) => Applicative (Product f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product | |
| (Applicative f, Applicative g) => Applicative (f :*: g) | Since: base-4.9.0.0 |
| Monoid c => Applicative (K1 i c :: Type -> Type) | Since: base-4.12.0.0 |
| Applicative (ConduitT i o m) | |
Defined in Data.Conduit.Internal.Conduit Methods pure :: a -> ConduitT i o m a # (<*>) :: ConduitT i o m (a -> b) -> ConduitT i o m a -> ConduitT i o m b # liftA2 :: (a -> b -> c) -> ConduitT i o m a -> ConduitT i o m b -> ConduitT i o m c # (*>) :: ConduitT i o m a -> ConduitT i o m b -> ConduitT i o m b # (<*) :: ConduitT i o m a -> ConduitT i o m b -> ConduitT i o m a # | |
| Monad m => Applicative (ZipConduit i o m) | |
Defined in Data.Conduit.Internal.Conduit Methods pure :: a -> ZipConduit i o m a # (<*>) :: ZipConduit i o m (a -> b) -> ZipConduit i o m a -> ZipConduit i o m b # liftA2 :: (a -> b -> c) -> ZipConduit i o m a -> ZipConduit i o m b -> ZipConduit i o m c # (*>) :: ZipConduit i o m a -> ZipConduit i o m b -> ZipConduit i o m b # (<*) :: ZipConduit i o m a -> ZipConduit i o m b -> ZipConduit i o m a # | |
| (Monad f, Applicative f) => Applicative (WhenMatched f x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods pure :: a -> WhenMatched f x y a # (<*>) :: WhenMatched f x y (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b # liftA2 :: (a -> b -> c) -> WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y c # (*>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # (<*) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Applicative (WhenMissing f k x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods pure :: a -> WhenMissing f k x a # (<*>) :: WhenMissing f k x (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # liftA2 :: (a -> b -> c) -> WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x c # (*>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # (<*) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x a # | |
| Applicative (k (Err e s)) => Applicative (FocusingErr e k s) | |
Defined in Lens.Micro.Mtl.Internal Methods pure :: a -> FocusingErr e k s a # (<*>) :: FocusingErr e k s (a -> b) -> FocusingErr e k s a -> FocusingErr e k s b # liftA2 :: (a -> b -> c) -> FocusingErr e k s a -> FocusingErr e k s b -> FocusingErr e k s c # (*>) :: FocusingErr e k s a -> FocusingErr e k s b -> FocusingErr e k s b # (<*) :: FocusingErr e k s a -> FocusingErr e k s b -> FocusingErr e k s a # | |
| Applicative (k (f s)) => Applicative (FocusingOn f k s) | |
Defined in Lens.Micro.Mtl.Internal Methods pure :: a -> FocusingOn f k s a # (<*>) :: FocusingOn f k s (a -> b) -> FocusingOn f k s a -> FocusingOn f k s b # liftA2 :: (a -> b -> c) -> FocusingOn f k s a -> FocusingOn f k s b -> FocusingOn f k s c # (*>) :: FocusingOn f k s a -> FocusingOn f k s b -> FocusingOn f k s b # (<*) :: FocusingOn f k s a -> FocusingOn f k s b -> FocusingOn f k s a # | |
| Applicative (k (s, w)) => Applicative (FocusingPlus w k s) | |
Defined in Lens.Micro.Mtl.Internal Methods pure :: a -> FocusingPlus w k s a # (<*>) :: FocusingPlus w k s (a -> b) -> FocusingPlus w k s a -> FocusingPlus w k s b # liftA2 :: (a -> b -> c) -> FocusingPlus w k s a -> FocusingPlus w k s b -> FocusingPlus w k s c # (*>) :: FocusingPlus w k s a -> FocusingPlus w k s b -> FocusingPlus w k s b # (<*) :: FocusingPlus w k s a -> FocusingPlus w k s b -> FocusingPlus w k s a # | |
| (Monad m, Monoid s, Monoid w) => Applicative (FocusingWith w m s) | |
Defined in Lens.Micro.Mtl.Internal Methods pure :: a -> FocusingWith w m s a # (<*>) :: FocusingWith w m s (a -> b) -> FocusingWith w m s a -> FocusingWith w m s b # liftA2 :: (a -> b -> c) -> FocusingWith w m s a -> FocusingWith w m s b -> FocusingWith w m s c # (*>) :: FocusingWith w m s a -> FocusingWith w m s b -> FocusingWith w m s b # (<*) :: FocusingWith w m s a -> FocusingWith w m s b -> FocusingWith w m s a # | |
| (Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c) | Since: base-4.14.0.0 |
Defined in GHC.Base | |
| Applicative ((->) r) | Since: base-2.1 |
| (Applicative f, Applicative g) => Applicative (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Applicative f, Applicative g) => Applicative (f :.: g) | Since: base-4.9.0.0 |
| Applicative f => Applicative (M1 i c f) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Applicative (WhenMatched f k x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods pure :: a -> WhenMatched f k x y a # (<*>) :: WhenMatched f k x y (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # liftA2 :: (a -> b -> c) -> WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y c # (*>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # (<*) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y a # | |
| (Monoid s, Monoid w, Monad m) => Applicative (EffectRWS w st m s) | |
Defined in Lens.Micro.Mtl.Internal Methods pure :: a -> EffectRWS w st m s a # (<*>) :: EffectRWS w st m s (a -> b) -> EffectRWS w st m s a -> EffectRWS w st m s b # liftA2 :: (a -> b -> c) -> EffectRWS w st m s a -> EffectRWS w st m s b -> EffectRWS w st m s c # (*>) :: EffectRWS w st m s a -> EffectRWS w st m s b -> EffectRWS w st m s b # (<*) :: EffectRWS w st m s a -> EffectRWS w st m s b -> EffectRWS w st m s a # | |
| Monad m => Applicative (Pipe l i o u m) | |
Defined in Data.Conduit.Internal.Pipe Methods pure :: a -> Pipe l i o u m a # (<*>) :: Pipe l i o u m (a -> b) -> Pipe l i o u m a -> Pipe l i o u m b # liftA2 :: (a -> b -> c) -> Pipe l i o u m a -> Pipe l i o u m b -> Pipe l i o u m c # (*>) :: Pipe l i o u m a -> Pipe l i o u m b -> Pipe l i o u m b # (<*) :: Pipe l i o u m a -> Pipe l i o u m b -> Pipe l i o u m a # | |
class Foldable (t :: Type -> Type) #
The Foldable class represents data structures that can be reduced to a summary value one element at a time. Strict left-associative folds are a good fit for space-efficient reduction, while lazy right-associative folds are a good fit for corecursive iteration, or for folds that short-circuit after processing an initial subsequence of the structure's elements.
Instances can be derived automatically by enabling the DeriveFoldable
extension. For example, a derived instance for a binary tree might be:
{-# LANGUAGE DeriveFoldable #-}
data Tree a = Empty
| Leaf a
| Node (Tree a) a (Tree a)
deriving FoldableA more detailed description can be found in the Overview section of Data.Foldable.
For the class laws see the Laws section of Data.Foldable.
Instances
| Foldable IResult | |
Defined in Data.Aeson.Types.Internal Methods fold :: Monoid m => IResult m -> m # foldMap :: Monoid m => (a -> m) -> IResult a -> m # foldMap' :: Monoid m => (a -> m) -> IResult a -> m # foldr :: (a -> b -> b) -> b -> IResult a -> b # foldr' :: (a -> b -> b) -> b -> IResult a -> b # foldl :: (b -> a -> b) -> b -> IResult a -> b # foldl' :: (b -> a -> b) -> b -> IResult a -> b # foldr1 :: (a -> a -> a) -> IResult a -> a # foldl1 :: (a -> a -> a) -> IResult a -> a # elem :: Eq a => a -> IResult a -> Bool # maximum :: Ord a => IResult a -> a # minimum :: Ord a => IResult a -> a # | |
| Foldable Result | |
Defined in Data.Aeson.Types.Internal Methods fold :: Monoid m => Result m -> m # foldMap :: Monoid m => (a -> m) -> Result a -> m # foldMap' :: Monoid m => (a -> m) -> Result a -> m # foldr :: (a -> b -> b) -> b -> Result a -> b # foldr' :: (a -> b -> b) -> b -> Result a -> b # foldl :: (b -> a -> b) -> b -> Result a -> b # foldl' :: (b -> a -> b) -> b -> Result a -> b # foldr1 :: (a -> a -> a) -> Result a -> a # foldl1 :: (a -> a -> a) -> Result a -> a # elem :: Eq a => a -> Result a -> Bool # maximum :: Ord a => Result a -> a # minimum :: Ord a => Result a -> a # | |
| Foldable ZipList | Since: base-4.9.0.0 |
Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # | |
| Foldable Complex | Since: base-4.9.0.0 |
Defined in Data.Complex Methods fold :: Monoid m => Complex m -> m # foldMap :: Monoid m => (a -> m) -> Complex a -> m # foldMap' :: Monoid m => (a -> m) -> Complex a -> m # foldr :: (a -> b -> b) -> b -> Complex a -> b # foldr' :: (a -> b -> b) -> b -> Complex a -> b # foldl :: (b -> a -> b) -> b -> Complex a -> b # foldl' :: (b -> a -> b) -> b -> Complex a -> b # foldr1 :: (a -> a -> a) -> Complex a -> a # foldl1 :: (a -> a -> a) -> Complex a -> a # elem :: Eq a => a -> Complex a -> Bool # maximum :: Ord a => Complex a -> a # minimum :: Ord a => Complex a -> a # | |
| Foldable Identity | Since: base-4.8.0.0 |
Defined in Data.Functor.Identity Methods fold :: Monoid m => Identity m -> m # foldMap :: Monoid m => (a -> m) -> Identity a -> m # foldMap' :: Monoid m => (a -> m) -> Identity a -> m # foldr :: (a -> b -> b) -> b -> Identity a -> b # foldr' :: (a -> b -> b) -> b -> Identity a -> b # foldl :: (b -> a -> b) -> b -> Identity a -> b # foldl' :: (b -> a -> b) -> b -> Identity a -> b # foldr1 :: (a -> a -> a) -> Identity a -> a # foldl1 :: (a -> a -> a) -> Identity a -> a # elem :: Eq a => a -> Identity a -> Bool # maximum :: Ord a => Identity a -> a # minimum :: Ord a => Identity a -> a # | |
| Foldable First | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Foldable Last | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Foldable Down | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m # foldMap :: Monoid m => (a -> m) -> Down a -> m # foldMap' :: Monoid m => (a -> m) -> Down a -> m # foldr :: (a -> b -> b) -> b -> Down a -> b # foldr' :: (a -> b -> b) -> b -> Down a -> b # foldl :: (b -> a -> b) -> b -> Down a -> b # foldl' :: (b -> a -> b) -> b -> Down a -> b # foldr1 :: (a -> a -> a) -> Down a -> a # foldl1 :: (a -> a -> a) -> Down a -> a # elem :: Eq a => a -> Down a -> Bool # maximum :: Ord a => Down a -> a # | |
| Foldable First | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Foldable Last | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Foldable Max | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Max m -> m # foldMap :: Monoid m => (a -> m) -> Max a -> m # foldMap' :: Monoid m => (a -> m) -> Max a -> m # foldr :: (a -> b -> b) -> b -> Max a -> b # foldr' :: (a -> b -> b) -> b -> Max a -> b # foldl :: (b -> a -> b) -> b -> Max a -> b # foldl' :: (b -> a -> b) -> b -> Max a -> b # foldr1 :: (a -> a -> a) -> Max a -> a # foldl1 :: (a -> a -> a) -> Max a -> a # elem :: Eq a => a -> Max a -> Bool # maximum :: Ord a => Max a -> a # | |
| Foldable Min | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Min m -> m # foldMap :: Monoid m => (a -> m) -> Min a -> m # foldMap' :: Monoid m => (a -> m) -> Min a -> m # foldr :: (a -> b -> b) -> b -> Min a -> b # foldr' :: (a -> b -> b) -> b -> Min a -> b # foldl :: (b -> a -> b) -> b -> Min a -> b # foldl' :: (b -> a -> b) -> b -> Min a -> b # foldr1 :: (a -> a -> a) -> Min a -> a # foldl1 :: (a -> a -> a) -> Min a -> a # elem :: Eq a => a -> Min a -> Bool # maximum :: Ord a => Min a -> a # | |
| Foldable Option | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Option m -> m # foldMap :: Monoid m => (a -> m) -> Option a -> m # foldMap' :: Monoid m => (a -> m) -> Option a -> m # foldr :: (a -> b -> b) -> b -> Option a -> b # foldr' :: (a -> b -> b) -> b -> Option a -> b # foldl :: (b -> a -> b) -> b -> Option a -> b # foldl' :: (b -> a -> b) -> b -> Option a -> b # foldr1 :: (a -> a -> a) -> Option a -> a # foldl1 :: (a -> a -> a) -> Option a -> a # elem :: Eq a => a -> Option a -> Bool # maximum :: Ord a => Option a -> a # minimum :: Ord a => Option a -> a # | |
| Foldable Dual | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Dual m -> m # foldMap :: Monoid m => (a -> m) -> Dual a -> m # foldMap' :: Monoid m => (a -> m) -> Dual a -> m # foldr :: (a -> b -> b) -> b -> Dual a -> b # foldr' :: (a -> b -> b) -> b -> Dual a -> b # foldl :: (b -> a -> b) -> b -> Dual a -> b # foldl' :: (b -> a -> b) -> b -> Dual a -> b # foldr1 :: (a -> a -> a) -> Dual a -> a # foldl1 :: (a -> a -> a) -> Dual a -> a # elem :: Eq a => a -> Dual a -> Bool # maximum :: Ord a => Dual a -> a # | |
| Foldable Product | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Product m -> m # foldMap :: Monoid m => (a -> m) -> Product a -> m # foldMap' :: Monoid m => (a -> m) -> Product a -> m # foldr :: (a -> b -> b) -> b -> Product a -> b # foldr' :: (a -> b -> b) -> b -> Product a -> b # foldl :: (b -> a -> b) -> b -> Product a -> b # foldl' :: (b -> a -> b) -> b -> Product a -> b # foldr1 :: (a -> a -> a) -> Product a -> a # foldl1 :: (a -> a -> a) -> Product a -> a # elem :: Eq a => a -> Product a -> Bool # maximum :: Ord a => Product a -> a # minimum :: Ord a => Product a -> a # | |
| Foldable Sum | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Sum m -> m # foldMap :: Monoid m => (a -> m) -> Sum a -> m # foldMap' :: Monoid m => (a -> m) -> Sum a -> m # foldr :: (a -> b -> b) -> b -> Sum a -> b # foldr' :: (a -> b -> b) -> b -> Sum a -> b # foldl :: (b -> a -> b) -> b -> Sum a -> b # foldl' :: (b -> a -> b) -> b -> Sum a -> b # foldr1 :: (a -> a -> a) -> Sum a -> a # foldl1 :: (a -> a -> a) -> Sum a -> a # elem :: Eq a => a -> Sum a -> Bool # maximum :: Ord a => Sum a -> a # | |
| Foldable NonEmpty | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => NonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m # foldr :: (a -> b -> b) -> b -> NonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b # foldl :: (b -> a -> b) -> b -> NonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b # foldr1 :: (a -> a -> a) -> NonEmpty a -> a # foldl1 :: (a -> a -> a) -> NonEmpty a -> a # elem :: Eq a => a -> NonEmpty a -> Bool # maximum :: Ord a => NonEmpty a -> a # minimum :: Ord a => NonEmpty a -> a # | |
| Foldable Par1 | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Par1 m -> m # foldMap :: Monoid m => (a -> m) -> Par1 a -> m # foldMap' :: Monoid m => (a -> m) -> Par1 a -> m # foldr :: (a -> b -> b) -> b -> Par1 a -> b # foldr' :: (a -> b -> b) -> b -> Par1 a -> b # foldl :: (b -> a -> b) -> b -> Par1 a -> b # foldl' :: (b -> a -> b) -> b -> Par1 a -> b # foldr1 :: (a -> a -> a) -> Par1 a -> a # foldl1 :: (a -> a -> a) -> Par1 a -> a # elem :: Eq a => a -> Par1 a -> Bool # maximum :: Ord a => Par1 a -> a # | |
| Foldable IntMap | Folds in order of increasing key. |
Defined in Data.IntMap.Internal Methods fold :: Monoid m => IntMap m -> m # foldMap :: Monoid m => (a -> m) -> IntMap a -> m # foldMap' :: Monoid m => (a -> m) -> IntMap a -> m # foldr :: (a -> b -> b) -> b -> IntMap a -> b # foldr' :: (a -> b -> b) -> b -> IntMap a -> b # foldl :: (b -> a -> b) -> b -> IntMap a -> b # foldl' :: (b -> a -> b) -> b -> IntMap a -> b # foldr1 :: (a -> a -> a) -> IntMap a -> a # foldl1 :: (a -> a -> a) -> IntMap a -> a # elem :: Eq a => a -> IntMap a -> Bool # maximum :: Ord a => IntMap a -> a # minimum :: Ord a => IntMap a -> a # | |
| Foldable Digit | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Digit m -> m # foldMap :: Monoid m => (a -> m) -> Digit a -> m # foldMap' :: Monoid m => (a -> m) -> Digit a -> m # foldr :: (a -> b -> b) -> b -> Digit a -> b # foldr' :: (a -> b -> b) -> b -> Digit a -> b # foldl :: (b -> a -> b) -> b -> Digit a -> b # foldl' :: (b -> a -> b) -> b -> Digit a -> b # foldr1 :: (a -> a -> a) -> Digit a -> a # foldl1 :: (a -> a -> a) -> Digit a -> a # elem :: Eq a => a -> Digit a -> Bool # maximum :: Ord a => Digit a -> a # minimum :: Ord a => Digit a -> a # | |
| Foldable Elem | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Elem m -> m # foldMap :: Monoid m => (a -> m) -> Elem a -> m # foldMap' :: Monoid m => (a -> m) -> Elem a -> m # foldr :: (a -> b -> b) -> b -> Elem a -> b # foldr' :: (a -> b -> b) -> b -> Elem a -> b # foldl :: (b -> a -> b) -> b -> Elem a -> b # foldl' :: (b -> a -> b) -> b -> Elem a -> b # foldr1 :: (a -> a -> a) -> Elem a -> a # foldl1 :: (a -> a -> a) -> Elem a -> a # elem :: Eq a => a -> Elem a -> Bool # maximum :: Ord a => Elem a -> a # | |
| Foldable FingerTree | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => FingerTree m -> m # foldMap :: Monoid m => (a -> m) -> FingerTree a -> m # foldMap' :: Monoid m => (a -> m) -> FingerTree a -> m # foldr :: (a -> b -> b) -> b -> FingerTree a -> b # foldr' :: (a -> b -> b) -> b -> FingerTree a -> b # foldl :: (b -> a -> b) -> b -> FingerTree a -> b # foldl' :: (b -> a -> b) -> b -> FingerTree a -> b # foldr1 :: (a -> a -> a) -> FingerTree a -> a # foldl1 :: (a -> a -> a) -> FingerTree a -> a # toList :: FingerTree a -> [a] # null :: FingerTree a -> Bool # length :: FingerTree a -> Int # elem :: Eq a => a -> FingerTree a -> Bool # maximum :: Ord a => FingerTree a -> a # minimum :: Ord a => FingerTree a -> a # sum :: Num a => FingerTree a -> a # product :: Num a => FingerTree a -> a # | |
| Foldable Node | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Node m -> m # foldMap :: Monoid m => (a -> m) -> Node a -> m # foldMap' :: Monoid m => (a -> m) -> Node a -> m # foldr :: (a -> b -> b) -> b -> Node a -> b # foldr' :: (a -> b -> b) -> b -> Node a -> b # foldl :: (b -> a -> b) -> b -> Node a -> b # foldl' :: (b -> a -> b) -> b -> Node a -> b # foldr1 :: (a -> a -> a) -> Node a -> a # foldl1 :: (a -> a -> a) -> Node a -> a # elem :: Eq a => a -> Node a -> Bool # maximum :: Ord a => Node a -> a # | |
| Foldable Seq | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Seq m -> m # foldMap :: Monoid m => (a -> m) -> Seq a -> m # foldMap' :: Monoid m => (a -> m) -> Seq a -> m # foldr :: (a -> b -> b) -> b -> Seq a -> b # foldr' :: (a -> b -> b) -> b -> Seq a -> b # foldl :: (b -> a -> b) -> b -> Seq a -> b # foldl' :: (b -> a -> b) -> b -> Seq a -> b # foldr1 :: (a -> a -> a) -> Seq a -> a # foldl1 :: (a -> a -> a) -> Seq a -> a # elem :: Eq a => a -> Seq a -> Bool # maximum :: Ord a => Seq a -> a # | |
| Foldable ViewL | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => ViewL m -> m # foldMap :: Monoid m => (a -> m) -> ViewL a -> m # foldMap' :: Monoid m => (a -> m) -> ViewL a -> m # foldr :: (a -> b -> b) -> b -> ViewL a -> b # foldr' :: (a -> b -> b) -> b -> ViewL a -> b # foldl :: (b -> a -> b) -> b -> ViewL a -> b # foldl' :: (b -> a -> b) -> b -> ViewL a -> b # foldr1 :: (a -> a -> a) -> ViewL a -> a # foldl1 :: (a -> a -> a) -> ViewL a -> a # elem :: Eq a => a -> ViewL a -> Bool # maximum :: Ord a => ViewL a -> a # minimum :: Ord a => ViewL a -> a # | |
| Foldable ViewR | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => ViewR m -> m # foldMap :: Monoid m => (a -> m) -> ViewR a -> m # foldMap' :: Monoid m => (a -> m) -> ViewR a -> m # foldr :: (a -> b -> b) -> b -> ViewR a -> b # foldr' :: (a -> b -> b) -> b -> ViewR a -> b # foldl :: (b -> a -> b) -> b -> ViewR a -> b # foldl' :: (b -> a -> b) -> b -> ViewR a -> b # foldr1 :: (a -> a -> a) -> ViewR a -> a # foldl1 :: (a -> a -> a) -> ViewR a -> a # elem :: Eq a => a -> ViewR a -> Bool # maximum :: Ord a => ViewR a -> a # minimum :: Ord a => ViewR a -> a # | |
| Foldable Set | Folds in order of increasing key. |
Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # | |
| Foldable Tree | |
Defined in Data.Tree Methods fold :: Monoid m => Tree m -> m # foldMap :: Monoid m => (a -> m) -> Tree a -> m # foldMap' :: Monoid m => (a -> m) -> Tree a -> m # foldr :: (a -> b -> b) -> b -> Tree a -> b # foldr' :: (a -> b -> b) -> b -> Tree a -> b # foldl :: (b -> a -> b) -> b -> Tree a -> b # foldl' :: (b -> a -> b) -> b -> Tree a -> b # foldr1 :: (a -> a -> a) -> Tree a -> a # foldl1 :: (a -> a -> a) -> Tree a -> a # elem :: Eq a => a -> Tree a -> Bool # maximum :: Ord a => Tree a -> a # | |
| Foldable DNonEmpty | |
Defined in Data.DList.DNonEmpty.Internal Methods fold :: Monoid m => DNonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> DNonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> DNonEmpty a -> m # foldr :: (a -> b -> b) -> b -> DNonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> DNonEmpty a -> b # foldl :: (b -> a -> b) -> b -> DNonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> DNonEmpty a -> b # foldr1 :: (a -> a -> a) -> DNonEmpty a -> a # foldl1 :: (a -> a -> a) -> DNonEmpty a -> a # toList :: DNonEmpty a -> [a] # length :: DNonEmpty a -> Int # elem :: Eq a => a -> DNonEmpty a -> Bool # maximum :: Ord a => DNonEmpty a -> a # minimum :: Ord a => DNonEmpty a -> a # | |
| Foldable DList | |
Defined in Data.DList.Internal Methods fold :: Monoid m => DList m -> m # foldMap :: Monoid m => (a -> m) -> DList a -> m # foldMap' :: Monoid m => (a -> m) -> DList a -> m # foldr :: (a -> b -> b) -> b -> DList a -> b # foldr' :: (a -> b -> b) -> b -> DList a -> b # foldl :: (b -> a -> b) -> b -> DList a -> b # foldl' :: (b -> a -> b) -> b -> DList a -> b # foldr1 :: (a -> a -> a) -> DList a -> a # foldl1 :: (a -> a -> a) -> DList a -> a # elem :: Eq a => a -> DList a -> Bool # maximum :: Ord a => DList a -> a # minimum :: Ord a => DList a -> a # | |
| Foldable Hashed | |
Defined in Data.Hashable.Class Methods fold :: Monoid m => Hashed m -> m # foldMap :: Monoid m => (a -> m) -> Hashed a -> m # foldMap' :: Monoid m => (a -> m) -> Hashed a -> m # foldr :: (a -> b -> b) -> b -> Hashed a -> b # foldr' :: (a -> b -> b) -> b -> Hashed a -> b # foldl :: (b -> a -> b) -> b -> Hashed a -> b # foldl' :: (b -> a -> b) -> b -> Hashed a -> b # foldr1 :: (a -> a -> a) -> Hashed a -> a # foldl1 :: (a -> a -> a) -> Hashed a -> a # elem :: Eq a => a -> Hashed a -> Bool # maximum :: Ord a => Hashed a -> a # minimum :: Ord a => Hashed a -> a # | |
| Foldable HistoriedResponse | |
Defined in Network.HTTP.Client Methods fold :: Monoid m => HistoriedResponse m -> m # foldMap :: Monoid m => (a -> m) -> HistoriedResponse a -> m # foldMap' :: Monoid m => (a -> m) -> HistoriedResponse a -> m # foldr :: (a -> b -> b) -> b -> HistoriedResponse a -> b # foldr' :: (a -> b -> b) -> b -> HistoriedResponse a -> b # foldl :: (b -> a -> b) -> b -> HistoriedResponse a -> b # foldl' :: (b -> a -> b) -> b -> HistoriedResponse a -> b # foldr1 :: (a -> a -> a) -> HistoriedResponse a -> a # foldl1 :: (a -> a -> a) -> HistoriedResponse a -> a # toList :: HistoriedResponse a -> [a] # null :: HistoriedResponse a -> Bool # length :: HistoriedResponse a -> Int # elem :: Eq a => a -> HistoriedResponse a -> Bool # maximum :: Ord a => HistoriedResponse a -> a # minimum :: Ord a => HistoriedResponse a -> a # sum :: Num a => HistoriedResponse a -> a # product :: Num a => HistoriedResponse a -> a # | |
| Foldable Response | |
Defined in Network.HTTP.Client.Types Methods fold :: Monoid m => Response m -> m # foldMap :: Monoid m => (a -> m) -> Response a -> m # foldMap' :: Monoid m => (a -> m) -> Response a -> m # foldr :: (a -> b -> b) -> b -> Response a -> b # foldr' :: (a -> b -> b) -> b -> Response a -> b # foldl :: (b -> a -> b) -> b -> Response a -> b # foldl' :: (b -> a -> b) -> b -> Response a -> b # foldr1 :: (a -> a -> a) -> Response a -> a # foldl1 :: (a -> a -> a) -> Response a -> a # elem :: Eq a => a -> Response a -> Bool # maximum :: Ord a => Response a -> a # minimum :: Ord a => Response a -> a # | |
| Foldable Array | |
Defined in Data.Primitive.Array Methods fold :: Monoid m => Array m -> m # foldMap :: Monoid m => (a -> m) -> Array a -> m # foldMap' :: Monoid m => (a -> m) -> Array a -> m # foldr :: (a -> b -> b) -> b -> Array a -> b # foldr' :: (a -> b -> b) -> b -> Array a -> b # foldl :: (b -> a -> b) -> b -> Array a -> b # foldl' :: (b -> a -> b) -> b -> Array a -> b # foldr1 :: (a -> a -> a) -> Array a -> a # foldl1 :: (a -> a -> a) -> Array a -> a # elem :: Eq a => a -> Array a -> Bool # maximum :: Ord a => Array a -> a # minimum :: Ord a => Array a -> a # | |
| Foldable SmallArray | |
Defined in Data.Primitive.SmallArray Methods fold :: Monoid m => SmallArray m -> m # foldMap :: Monoid m => (a -> m) -> SmallArray a -> m # foldMap' :: Monoid m => (a -> m) -> SmallArray a -> m # foldr :: (a -> b -> b) -> b -> SmallArray a -> b # foldr' :: (a -> b -> b) -> b -> SmallArray a -> b # foldl :: (b -> a -> b) -> b -> SmallArray a -> b # foldl' :: (b -> a -> b) -> b -> SmallArray a -> b # foldr1 :: (a -> a -> a) -> SmallArray a -> a # foldl1 :: (a -> a -> a) -> SmallArray a -> a # toList :: SmallArray a -> [a] # null :: SmallArray a -> Bool # length :: SmallArray a -> Int # elem :: Eq a => a -> SmallArray a -> Bool # maximum :: Ord a => SmallArray a -> a # minimum :: Ord a => SmallArray a -> a # sum :: Num a => SmallArray a -> a # product :: Num a => SmallArray a -> a # | |
| Foldable Maybe | |
Defined in Data.Strict.Maybe Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Foldable HashSet | |
Defined in Data.HashSet.Internal Methods fold :: Monoid m => HashSet m -> m # foldMap :: Monoid m => (a -> m) -> HashSet a -> m # foldMap' :: Monoid m => (a -> m) -> HashSet a -> m # foldr :: (a -> b -> b) -> b -> HashSet a -> b # foldr' :: (a -> b -> b) -> b -> HashSet a -> b # foldl :: (b -> a -> b) -> b -> HashSet a -> b # foldl' :: (b -> a -> b) -> b -> HashSet a -> b # foldr1 :: (a -> a -> a) -> HashSet a -> a # foldl1 :: (a -> a -> a) -> HashSet a -> a # elem :: Eq a => a -> HashSet a -> Bool # maximum :: Ord a => HashSet a -> a # minimum :: Ord a => HashSet a -> a # | |
| Foldable Vector | |
Defined in Data.Vector Methods fold :: Monoid m => Vector m -> m # foldMap :: Monoid m => (a -> m) -> Vector a -> m # foldMap' :: Monoid m => (a -> m) -> Vector a -> m # foldr :: (a -> b -> b) -> b -> Vector a -> b # foldr' :: (a -> b -> b) -> b -> Vector a -> b # foldl :: (b -> a -> b) -> b -> Vector a -> b # foldl' :: (b -> a -> b) -> b -> Vector a -> b # foldr1 :: (a -> a -> a) -> Vector a -> a # foldl1 :: (a -> a -> a) -> Vector a -> a # elem :: Eq a => a -> Vector a -> Bool # maximum :: Ord a => Vector a -> a # minimum :: Ord a => Vector a -> a # | |
| Foldable Maybe | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Foldable Solo | Since: base-4.15 |
Defined in Data.Foldable Methods fold :: Monoid m => Solo m -> m # foldMap :: Monoid m => (a -> m) -> Solo a -> m # foldMap' :: Monoid m => (a -> m) -> Solo a -> m # foldr :: (a -> b -> b) -> b -> Solo a -> b # foldr' :: (a -> b -> b) -> b -> Solo a -> b # foldl :: (b -> a -> b) -> b -> Solo a -> b # foldl' :: (b -> a -> b) -> b -> Solo a -> b # foldr1 :: (a -> a -> a) -> Solo a -> a # foldl1 :: (a -> a -> a) -> Solo a -> a # elem :: Eq a => a -> Solo a -> Bool # maximum :: Ord a => Solo a -> a # | |
| Foldable [] | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => [m] -> m # foldMap :: Monoid m => (a -> m) -> [a] -> m # foldMap' :: Monoid m => (a -> m) -> [a] -> m # foldr :: (a -> b -> b) -> b -> [a] -> b # foldr' :: (a -> b -> b) -> b -> [a] -> b # foldl :: (b -> a -> b) -> b -> [a] -> b # foldl' :: (b -> a -> b) -> b -> [a] -> b # foldr1 :: (a -> a -> a) -> [a] -> a # foldl1 :: (a -> a -> a) -> [a] -> a # elem :: Eq a => a -> [a] -> Bool # maximum :: Ord a => [a] -> a # | |
| Foldable (Either a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # toList :: Either a a0 -> [a0] # length :: Either a a0 -> Int # elem :: Eq a0 => a0 -> Either a a0 -> Bool # maximum :: Ord a0 => Either a a0 -> a0 # minimum :: Ord a0 => Either a a0 -> a0 # | |
| Foldable (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # | |
| Foldable (Arg a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Arg a m -> m # foldMap :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # elem :: Eq a0 => a0 -> Arg a a0 -> Bool # maximum :: Ord a0 => Arg a a0 -> a0 # minimum :: Ord a0 => Arg a a0 -> a0 # | |
| Foldable (Array i) | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Array i m -> m # foldMap :: Monoid m => (a -> m) -> Array i a -> m # foldMap' :: Monoid m => (a -> m) -> Array i a -> m # foldr :: (a -> b -> b) -> b -> Array i a -> b # foldr' :: (a -> b -> b) -> b -> Array i a -> b # foldl :: (b -> a -> b) -> b -> Array i a -> b # foldl' :: (b -> a -> b) -> b -> Array i a -> b # foldr1 :: (a -> a -> a) -> Array i a -> a # foldl1 :: (a -> a -> a) -> Array i a -> a # elem :: Eq a => a -> Array i a -> Bool # maximum :: Ord a => Array i a -> a # minimum :: Ord a => Array i a -> a # | |
| Foldable (U1 :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => U1 m -> m # foldMap :: Monoid m => (a -> m) -> U1 a -> m # foldMap' :: Monoid m => (a -> m) -> U1 a -> m # foldr :: (a -> b -> b) -> b -> U1 a -> b # foldr' :: (a -> b -> b) -> b -> U1 a -> b # foldl :: (b -> a -> b) -> b -> U1 a -> b # foldl' :: (b -> a -> b) -> b -> U1 a -> b # foldr1 :: (a -> a -> a) -> U1 a -> a # foldl1 :: (a -> a -> a) -> U1 a -> a # elem :: Eq a => a -> U1 a -> Bool # maximum :: Ord a => U1 a -> a # | |
| Foldable (UAddr :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UAddr m -> m # foldMap :: Monoid m => (a -> m) -> UAddr a -> m # foldMap' :: Monoid m => (a -> m) -> UAddr a -> m # foldr :: (a -> b -> b) -> b -> UAddr a -> b # foldr' :: (a -> b -> b) -> b -> UAddr a -> b # foldl :: (b -> a -> b) -> b -> UAddr a -> b # foldl' :: (b -> a -> b) -> b -> UAddr a -> b # foldr1 :: (a -> a -> a) -> UAddr a -> a # foldl1 :: (a -> a -> a) -> UAddr a -> a # elem :: Eq a => a -> UAddr a -> Bool # maximum :: Ord a => UAddr a -> a # minimum :: Ord a => UAddr a -> a # | |
| Foldable (UChar :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UChar m -> m # foldMap :: Monoid m => (a -> m) -> UChar a -> m # foldMap' :: Monoid m => (a -> m) -> UChar a -> m # foldr :: (a -> b -> b) -> b -> UChar a -> b # foldr' :: (a -> b -> b) -> b -> UChar a -> b # foldl :: (b -> a -> b) -> b -> UChar a -> b # foldl' :: (b -> a -> b) -> b -> UChar a -> b # foldr1 :: (a -> a -> a) -> UChar a -> a # foldl1 :: (a -> a -> a) -> UChar a -> a # elem :: Eq a => a -> UChar a -> Bool # maximum :: Ord a => UChar a -> a # minimum :: Ord a => UChar a -> a # | |
| Foldable (UDouble :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UDouble m -> m # foldMap :: Monoid m => (a -> m) -> UDouble a -> m # foldMap' :: Monoid m => (a -> m) -> UDouble a -> m # foldr :: (a -> b -> b) -> b -> UDouble a -> b # foldr' :: (a -> b -> b) -> b -> UDouble a -> b # foldl :: (b -> a -> b) -> b -> UDouble a -> b # foldl' :: (b -> a -> b) -> b -> UDouble a -> b # foldr1 :: (a -> a -> a) -> UDouble a -> a # foldl1 :: (a -> a -> a) -> UDouble a -> a # elem :: Eq a => a -> UDouble a -> Bool # maximum :: Ord a => UDouble a -> a # minimum :: Ord a => UDouble a -> a # | |
| Foldable (UFloat :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # | |
| Foldable (UInt :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UInt m -> m # foldMap :: Monoid m => (a -> m) -> UInt a -> m # foldMap' :: Monoid m => (a -> m) -> UInt a -> m # foldr :: (a -> b -> b) -> b -> UInt a -> b # foldr' :: (a -> b -> b) -> b -> UInt a -> b # foldl :: (b -> a -> b) -> b -> UInt a -> b # foldl' :: (b -> a -> b) -> b -> UInt a -> b # foldr1 :: (a -> a -> a) -> UInt a -> a # foldl1 :: (a -> a -> a) -> UInt a -> a # elem :: Eq a => a -> UInt a -> Bool # maximum :: Ord a => UInt a -> a # | |
| Foldable (UWord :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UWord m -> m # foldMap :: Monoid m => (a -> m) -> UWord a -> m # foldMap' :: Monoid m => (a -> m) -> UWord a -> m # foldr :: (a -> b -> b) -> b -> UWord a -> b # foldr' :: (a -> b -> b) -> b -> UWord a -> b # foldl :: (b -> a -> b) -> b -> UWord a -> b # foldl' :: (b -> a -> b) -> b -> UWord a -> b # foldr1 :: (a -> a -> a) -> UWord a -> a # foldl1 :: (a -> a -> a) -> UWord a -> a # elem :: Eq a => a -> UWord a -> Bool # maximum :: Ord a => UWord a -> a # minimum :: Ord a => UWord a -> a # | |
| Foldable (V1 :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => V1 m -> m # foldMap :: Monoid m => (a -> m) -> V1 a -> m # foldMap' :: Monoid m => (a -> m) -> V1 a -> m # foldr :: (a -> b -> b) -> b -> V1 a -> b # foldr' :: (a -> b -> b) -> b -> V1 a -> b # foldl :: (b -> a -> b) -> b -> V1 a -> b # foldl' :: (b -> a -> b) -> b -> V1 a -> b # foldr1 :: (a -> a -> a) -> V1 a -> a # foldl1 :: (a -> a -> a) -> V1 a -> a # elem :: Eq a => a -> V1 a -> Bool # maximum :: Ord a => V1 a -> a # | |
| Foldable (Map k) | Folds in order of increasing key. |
Defined in Data.Map.Internal Methods fold :: Monoid m => Map k m -> m # foldMap :: Monoid m => (a -> m) -> Map k a -> m # foldMap' :: Monoid m => (a -> m) -> Map k a -> m # foldr :: (a -> b -> b) -> b -> Map k a -> b # foldr' :: (a -> b -> b) -> b -> Map k a -> b # foldl :: (b -> a -> b) -> b -> Map k a -> b # foldl' :: (b -> a -> b) -> b -> Map k a -> b # foldr1 :: (a -> a -> a) -> Map k a -> a # foldl1 :: (a -> a -> a) -> Map k a -> a # elem :: Eq a => a -> Map k a -> Bool # maximum :: Ord a => Map k a -> a # minimum :: Ord a => Map k a -> a # | |
| Foldable (Either e) | |
Defined in Data.Strict.Either Methods fold :: Monoid m => Either e m -> m # foldMap :: Monoid m => (a -> m) -> Either e a -> m # foldMap' :: Monoid m => (a -> m) -> Either e a -> m # foldr :: (a -> b -> b) -> b -> Either e a -> b # foldr' :: (a -> b -> b) -> b -> Either e a -> b # foldl :: (b -> a -> b) -> b -> Either e a -> b # foldl' :: (b -> a -> b) -> b -> Either e a -> b # foldr1 :: (a -> a -> a) -> Either e a -> a # foldl1 :: (a -> a -> a) -> Either e a -> a # elem :: Eq a => a -> Either e a -> Bool # maximum :: Ord a => Either e a -> a # minimum :: Ord a => Either e a -> a # | |
| Foldable (These a) | |
Defined in Data.Strict.These Methods fold :: Monoid m => These a m -> m # foldMap :: Monoid m => (a0 -> m) -> These a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> These a a0 -> m # foldr :: (a0 -> b -> b) -> b -> These a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> These a a0 -> b # foldl :: (b -> a0 -> b) -> b -> These a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> These a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # toList :: These a a0 -> [a0] # elem :: Eq a0 => a0 -> These a a0 -> Bool # maximum :: Ord a0 => These a a0 -> a0 # minimum :: Ord a0 => These a a0 -> a0 # | |
| Foldable (Pair e) | |
Defined in Data.Strict.Tuple Methods fold :: Monoid m => Pair e m -> m # foldMap :: Monoid m => (a -> m) -> Pair e a -> m # foldMap' :: Monoid m => (a -> m) -> Pair e a -> m # foldr :: (a -> b -> b) -> b -> Pair e a -> b # foldr' :: (a -> b -> b) -> b -> Pair e a -> b # foldl :: (b -> a -> b) -> b -> Pair e a -> b # foldl' :: (b -> a -> b) -> b -> Pair e a -> b # foldr1 :: (a -> a -> a) -> Pair e a -> a # foldl1 :: (a -> a -> a) -> Pair e a -> a # elem :: Eq a => a -> Pair e a -> Bool # maximum :: Ord a => Pair e a -> a # minimum :: Ord a => Pair e a -> a # | |
| Foldable (These a) | |
Defined in Data.These Methods fold :: Monoid m => These a m -> m # foldMap :: Monoid m => (a0 -> m) -> These a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> These a a0 -> m # foldr :: (a0 -> b -> b) -> b -> These a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> These a a0 -> b # foldl :: (b -> a0 -> b) -> b -> These a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> These a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # toList :: These a a0 -> [a0] # elem :: Eq a0 => a0 -> These a a0 -> Bool # maximum :: Ord a0 => These a a0 -> a0 # minimum :: Ord a0 => These a a0 -> a0 # | |
| Foldable f => Foldable (MaybeT f) | |
Defined in Control.Monad.Trans.Maybe Methods fold :: Monoid m => MaybeT f m -> m # foldMap :: Monoid m => (a -> m) -> MaybeT f a -> m # foldMap' :: Monoid m => (a -> m) -> MaybeT f a -> m # foldr :: (a -> b -> b) -> b -> MaybeT f a -> b # foldr' :: (a -> b -> b) -> b -> MaybeT f a -> b # foldl :: (b -> a -> b) -> b -> MaybeT f a -> b # foldl' :: (b -> a -> b) -> b -> MaybeT f a -> b # foldr1 :: (a -> a -> a) -> MaybeT f a -> a # foldl1 :: (a -> a -> a) -> MaybeT f a -> a # elem :: Eq a => a -> MaybeT f a -> Bool # maximum :: Ord a => MaybeT f a -> a # minimum :: Ord a => MaybeT f a -> a # | |
| Foldable (HashMap k) | |
Defined in Data.HashMap.Internal Methods fold :: Monoid m => HashMap k m -> m # foldMap :: Monoid m => (a -> m) -> HashMap k a -> m # foldMap' :: Monoid m => (a -> m) -> HashMap k a -> m # foldr :: (a -> b -> b) -> b -> HashMap k a -> b # foldr' :: (a -> b -> b) -> b -> HashMap k a -> b # foldl :: (b -> a -> b) -> b -> HashMap k a -> b # foldl' :: (b -> a -> b) -> b -> HashMap k a -> b # foldr1 :: (a -> a -> a) -> HashMap k a -> a # foldl1 :: (a -> a -> a) -> HashMap k a -> a # toList :: HashMap k a -> [a] # length :: HashMap k a -> Int # elem :: Eq a => a -> HashMap k a -> Bool # maximum :: Ord a => HashMap k a -> a # minimum :: Ord a => HashMap k a -> a # | |
| Foldable ((,) a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (a, m) -> m # foldMap :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldMap' :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldr :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldr' :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldl :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldl' :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldr1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # foldl1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # elem :: Eq a0 => a0 -> (a, a0) -> Bool # maximum :: Ord a0 => (a, a0) -> a0 # minimum :: Ord a0 => (a, a0) -> a0 # | |
| Foldable (Const m :: Type -> Type) | Since: base-4.7.0.0 |
Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # | |
| Foldable f => Foldable (Ap f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Ap f m -> m # foldMap :: Monoid m => (a -> m) -> Ap f a -> m # foldMap' :: Monoid m => (a -> m) -> Ap f a -> m # foldr :: (a -> b -> b) -> b -> Ap f a -> b # foldr' :: (a -> b -> b) -> b -> Ap f a -> b # foldl :: (b -> a -> b) -> b -> Ap f a -> b # foldl' :: (b -> a -> b) -> b -> Ap f a -> b # foldr1 :: (a -> a -> a) -> Ap f a -> a # foldl1 :: (a -> a -> a) -> Ap f a -> a # elem :: Eq a => a -> Ap f a -> Bool # maximum :: Ord a => Ap f a -> a # | |
| Foldable f => Foldable (Alt f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m # foldMap :: Monoid m => (a -> m) -> Alt f a -> m # foldMap' :: Monoid m => (a -> m) -> Alt f a -> m # foldr :: (a -> b -> b) -> b -> Alt f a -> b # foldr' :: (a -> b -> b) -> b -> Alt f a -> b # foldl :: (b -> a -> b) -> b -> Alt f a -> b # foldl' :: (b -> a -> b) -> b -> Alt f a -> b # foldr1 :: (a -> a -> a) -> Alt f a -> a # foldl1 :: (a -> a -> a) -> Alt f a -> a # elem :: Eq a => a -> Alt f a -> Bool # maximum :: Ord a => Alt f a -> a # minimum :: Ord a => Alt f a -> a # | |
| Foldable f => Foldable (Rec1 f) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Rec1 f m -> m # foldMap :: Monoid m => (a -> m) -> Rec1 f a -> m # foldMap' :: Monoid m => (a -> m) -> Rec1 f a -> m # foldr :: (a -> b -> b) -> b -> Rec1 f a -> b # foldr' :: (a -> b -> b) -> b -> Rec1 f a -> b # foldl :: (b -> a -> b) -> b -> Rec1 f a -> b # foldl' :: (b -> a -> b) -> b -> Rec1 f a -> b # foldr1 :: (a -> a -> a) -> Rec1 f a -> a # foldl1 :: (a -> a -> a) -> Rec1 f a -> a # elem :: Eq a => a -> Rec1 f a -> Bool # maximum :: Ord a => Rec1 f a -> a # minimum :: Ord a => Rec1 f a -> a # | |
| Foldable (Tagged s) | |
Defined in Data.Tagged Methods fold :: Monoid m => Tagged s m -> m # foldMap :: Monoid m => (a -> m) -> Tagged s a -> m # foldMap' :: Monoid m => (a -> m) -> Tagged s a -> m # foldr :: (a -> b -> b) -> b -> Tagged s a -> b # foldr' :: (a -> b -> b) -> b -> Tagged s a -> b # foldl :: (b -> a -> b) -> b -> Tagged s a -> b # foldl' :: (b -> a -> b) -> b -> Tagged s a -> b # foldr1 :: (a -> a -> a) -> Tagged s a -> a # foldl1 :: (a -> a -> a) -> Tagged s a -> a # elem :: Eq a => a -> Tagged s a -> Bool # maximum :: Ord a => Tagged s a -> a # minimum :: Ord a => Tagged s a -> a # | |
| (Foldable f, Foldable g) => Foldable (These1 f g) | |
Defined in Data.Functor.These Methods fold :: Monoid m => These1 f g m -> m # foldMap :: Monoid m => (a -> m) -> These1 f g a -> m # foldMap' :: Monoid m => (a -> m) -> These1 f g a -> m # foldr :: (a -> b -> b) -> b -> These1 f g a -> b # foldr' :: (a -> b -> b) -> b -> These1 f g a -> b # foldl :: (b -> a -> b) -> b -> These1 f g a -> b # foldl' :: (b -> a -> b) -> b -> These1 f g a -> b # foldr1 :: (a -> a -> a) -> These1 f g a -> a # foldl1 :: (a -> a -> a) -> These1 f g a -> a # toList :: These1 f g a -> [a] # null :: These1 f g a -> Bool # length :: These1 f g a -> Int # elem :: Eq a => a -> These1 f g a -> Bool # maximum :: Ord a => These1 f g a -> a # minimum :: Ord a => These1 f g a -> a # | |
| Foldable f => Foldable (ErrorT e f) | |
Defined in Control.Monad.Trans.Error Methods fold :: Monoid m => ErrorT e f m -> m # foldMap :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldMap' :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldr :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldr' :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldl :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldl' :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldr1 :: (a -> a -> a) -> ErrorT e f a -> a # foldl1 :: (a -> a -> a) -> ErrorT e f a -> a # toList :: ErrorT e f a -> [a] # null :: ErrorT e f a -> Bool # length :: ErrorT e f a -> Int # elem :: Eq a => a -> ErrorT e f a -> Bool # maximum :: Ord a => ErrorT e f a -> a # minimum :: Ord a => ErrorT e f a -> a # | |
| Foldable f => Foldable (ExceptT e f) | |
Defined in Control.Monad.Trans.Except Methods fold :: Monoid m => ExceptT e f m -> m # foldMap :: Monoid m => (a -> m) -> ExceptT e f a -> m # foldMap' :: Monoid m => (a -> m) -> ExceptT e f a -> m # foldr :: (a -> b -> b) -> b -> ExceptT e f a -> b # foldr' :: (a -> b -> b) -> b -> ExceptT e f a -> b # foldl :: (b -> a -> b) -> b -> ExceptT e f a -> b # foldl' :: (b -> a -> b) -> b -> ExceptT e f a -> b # foldr1 :: (a -> a -> a) -> ExceptT e f a -> a # foldl1 :: (a -> a -> a) -> ExceptT e f a -> a # toList :: ExceptT e f a -> [a] # null :: ExceptT e f a -> Bool # length :: ExceptT e f a -> Int # elem :: Eq a => a -> ExceptT e f a -> Bool # maximum :: Ord a => ExceptT e f a -> a # minimum :: Ord a => ExceptT e f a -> a # | |
| Foldable f => Foldable (IdentityT f) | |
Defined in Control.Monad.Trans.Identity Methods fold :: Monoid m => IdentityT f m -> m # foldMap :: Monoid m => (a -> m) -> IdentityT f a -> m # foldMap' :: Monoid m => (a -> m) -> IdentityT f a -> m # foldr :: (a -> b -> b) -> b -> IdentityT f a -> b # foldr' :: (a -> b -> b) -> b -> IdentityT f a -> b # foldl :: (b -> a -> b) -> b -> IdentityT f a -> b # foldl' :: (b -> a -> b) -> b -> IdentityT f a -> b # foldr1 :: (a -> a -> a) -> IdentityT f a -> a # foldl1 :: (a -> a -> a) -> IdentityT f a -> a # toList :: IdentityT f a -> [a] # null :: IdentityT f a -> Bool # length :: IdentityT f a -> Int # elem :: Eq a => a -> IdentityT f a -> Bool # maximum :: Ord a => IdentityT f a -> a # minimum :: Ord a => IdentityT f a -> a # | |
| (Foldable f, Foldable g) => Foldable (Product f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product Methods fold :: Monoid m => Product f g m -> m # foldMap :: Monoid m => (a -> m) -> Product f g a -> m # foldMap' :: Monoid m => (a -> m) -> Product f g a -> m # foldr :: (a -> b -> b) -> b -> Product f g a -> b # foldr' :: (a -> b -> b) -> b -> Product f g a -> b # foldl :: (b -> a -> b) -> b -> Product f g a -> b # foldl' :: (b -> a -> b) -> b -> Product f g a -> b # foldr1 :: (a -> a -> a) -> Product f g a -> a # foldl1 :: (a -> a -> a) -> Product f g a -> a # toList :: Product f g a -> [a] # null :: Product f g a -> Bool # length :: Product f g a -> Int # elem :: Eq a => a -> Product f g a -> Bool # maximum :: Ord a => Product f g a -> a # minimum :: Ord a => Product f g a -> a # | |
| (Foldable f, Foldable g) => Foldable (Sum f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Sum Methods fold :: Monoid m => Sum f g m -> m # foldMap :: Monoid m => (a -> m) -> Sum f g a -> m # foldMap' :: Monoid m => (a -> m) -> Sum f g a -> m # foldr :: (a -> b -> b) -> b -> Sum f g a -> b # foldr' :: (a -> b -> b) -> b -> Sum f g a -> b # foldl :: (b -> a -> b) -> b -> Sum f g a -> b # foldl' :: (b -> a -> b) -> b -> Sum f g a -> b # foldr1 :: (a -> a -> a) -> Sum f g a -> a # foldl1 :: (a -> a -> a) -> Sum f g a -> a # elem :: Eq a => a -> Sum f g a -> Bool # maximum :: Ord a => Sum f g a -> a # minimum :: Ord a => Sum f g a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :*: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :*: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :*: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :*: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :*: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :*: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :*: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :*: g) a -> b # foldr1 :: (a -> a -> a) -> (f :*: g) a -> a # foldl1 :: (a -> a -> a) -> (f :*: g) a -> a # toList :: (f :*: g) a -> [a] # length :: (f :*: g) a -> Int # elem :: Eq a => a -> (f :*: g) a -> Bool # maximum :: Ord a => (f :*: g) a -> a # minimum :: Ord a => (f :*: g) a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :+: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :+: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldr1 :: (a -> a -> a) -> (f :+: g) a -> a # foldl1 :: (a -> a -> a) -> (f :+: g) a -> a # toList :: (f :+: g) a -> [a] # length :: (f :+: g) a -> Int # elem :: Eq a => a -> (f :+: g) a -> Bool # maximum :: Ord a => (f :+: g) a -> a # minimum :: Ord a => (f :+: g) a -> a # | |
| Foldable (K1 i c :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => K1 i c m -> m # foldMap :: Monoid m => (a -> m) -> K1 i c a -> m # foldMap' :: Monoid m => (a -> m) -> K1 i c a -> m # foldr :: (a -> b -> b) -> b -> K1 i c a -> b # foldr' :: (a -> b -> b) -> b -> K1 i c a -> b # foldl :: (b -> a -> b) -> b -> K1 i c a -> b # foldl' :: (b -> a -> b) -> b -> K1 i c a -> b # foldr1 :: (a -> a -> a) -> K1 i c a -> a # foldl1 :: (a -> a -> a) -> K1 i c a -> a # elem :: Eq a => a -> K1 i c a -> Bool # maximum :: Ord a => K1 i c a -> a # minimum :: Ord a => K1 i c a -> a # | |
| (Foldable f, Foldable g) => Foldable (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods fold :: Monoid m => Compose f g m -> m # foldMap :: Monoid m => (a -> m) -> Compose f g a -> m # foldMap' :: Monoid m => (a -> m) -> Compose f g a -> m # foldr :: (a -> b -> b) -> b -> Compose f g a -> b # foldr' :: (a -> b -> b) -> b -> Compose f g a -> b # foldl :: (b -> a -> b) -> b -> Compose f g a -> b # foldl' :: (b -> a -> b) -> b -> Compose f g a -> b # foldr1 :: (a -> a -> a) -> Compose f g a -> a # foldl1 :: (a -> a -> a) -> Compose f g a -> a # toList :: Compose f g a -> [a] # null :: Compose f g a -> Bool # length :: Compose f g a -> Int # elem :: Eq a => a -> Compose f g a -> Bool # maximum :: Ord a => Compose f g a -> a # minimum :: Ord a => Compose f g a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :.: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :.: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldr1 :: (a -> a -> a) -> (f :.: g) a -> a # foldl1 :: (a -> a -> a) -> (f :.: g) a -> a # toList :: (f :.: g) a -> [a] # length :: (f :.: g) a -> Int # elem :: Eq a => a -> (f :.: g) a -> Bool # maximum :: Ord a => (f :.: g) a -> a # minimum :: Ord a => (f :.: g) a -> a # | |
| Foldable f => Foldable (M1 i c f) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => M1 i c f m -> m # foldMap :: Monoid m => (a -> m) -> M1 i c f a -> m # foldMap' :: Monoid m => (a -> m) -> M1 i c f a -> m # foldr :: (a -> b -> b) -> b -> M1 i c f a -> b # foldr' :: (a -> b -> b) -> b -> M1 i c f a -> b # foldl :: (b -> a -> b) -> b -> M1 i c f a -> b # foldl' :: (b -> a -> b) -> b -> M1 i c f a -> b # foldr1 :: (a -> a -> a) -> M1 i c f a -> a # foldl1 :: (a -> a -> a) -> M1 i c f a -> a # elem :: Eq a => a -> M1 i c f a -> Bool # maximum :: Ord a => M1 i c f a -> a # minimum :: Ord a => M1 i c f a -> a # | |
| Bifoldable p => Foldable (Flip p a) | |
Defined in Data.Bifunctor.Flip Methods fold :: Monoid m => Flip p a m -> m # foldMap :: Monoid m => (a0 -> m) -> Flip p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Flip p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Flip p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Flip p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Flip p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Flip p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Flip p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Flip p a a0 -> a0 # toList :: Flip p a a0 -> [a0] # length :: Flip p a a0 -> Int # elem :: Eq a0 => a0 -> Flip p a a0 -> Bool # maximum :: Ord a0 => Flip p a a0 -> a0 # minimum :: Ord a0 => Flip p a a0 -> a0 # | |
| (Foldable f, Bifoldable p) => Foldable (Tannen f p a) | |
Defined in Data.Bifunctor.Tannen Methods fold :: Monoid m => Tannen f p a m -> m # foldMap :: Monoid m => (a0 -> m) -> Tannen f p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Tannen f p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Tannen f p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Tannen f p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Tannen f p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Tannen f p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Tannen f p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Tannen f p a a0 -> a0 # toList :: Tannen f p a a0 -> [a0] # null :: Tannen f p a a0 -> Bool # length :: Tannen f p a a0 -> Int # elem :: Eq a0 => a0 -> Tannen f p a a0 -> Bool # maximum :: Ord a0 => Tannen f p a a0 -> a0 # minimum :: Ord a0 => Tannen f p a a0 -> a0 # | |
| (Bifoldable p, Foldable g) => Foldable (Biff p f g a) | |
Defined in Data.Bifunctor.Biff Methods fold :: Monoid m => Biff p f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Biff p f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Biff p f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Biff p f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Biff p f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Biff p f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Biff p f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Biff p f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Biff p f g a a0 -> a0 # toList :: Biff p f g a a0 -> [a0] # null :: Biff p f g a a0 -> Bool # length :: Biff p f g a a0 -> Int # elem :: Eq a0 => a0 -> Biff p f g a a0 -> Bool # maximum :: Ord a0 => Biff p f g a a0 -> a0 # minimum :: Ord a0 => Biff p f g a a0 -> a0 # | |
class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where #
Functors representing data structures that can be transformed to
structures of the same shape by performing an Applicative (or,
therefore, Monad) action on each element from left to right.
A more detailed description of what same shape means, the various methods, how traversals are constructed, and example advanced use-cases can be found in the Overview section of Data.Traversable.
For the class laws see the Laws section of Data.Traversable.
Methods
traverse :: Applicative f => (a -> f b) -> t a -> f (t b) #
Map each element of a structure to an action, evaluate these actions
from left to right, and collect the results. For a version that ignores
the results see traverse_.
Examples
Basic usage:
In the first two examples we show each evaluated action mapping to the output structure.
>>>traverse Just [1,2,3,4]Just [1,2,3,4]
>>>traverse id [Right 1, Right 2, Right 3, Right 4]Right [1,2,3,4]
In the next examples, we show that Nothing and Left values short
circuit the created structure.
>>>traverse (const Nothing) [1,2,3,4]Nothing
>>>traverse (\x -> if odd x then Just x else Nothing) [1,2,3,4]Nothing
>>>traverse id [Right 1, Right 2, Right 3, Right 4, Left 0]Left 0
sequenceA :: Applicative f => t (f a) -> f (t a) #
Evaluate each action in the structure from left to right, and
collect the results. For a version that ignores the results
see sequenceA_.
Examples
Basic usage:
For the first two examples we show sequenceA fully evaluating a a structure and collecting the results.
>>>sequenceA [Just 1, Just 2, Just 3]Just [1,2,3]
>>>sequenceA [Right 1, Right 2, Right 3]Right [1,2,3]
The next two example show Nothing and Just will short circuit
the resulting structure if present in the input. For more context,
check the Traversable instances for Either and Maybe.
>>>sequenceA [Just 1, Just 2, Just 3, Nothing]Nothing
>>>sequenceA [Right 1, Right 2, Right 3, Left 4]Left 4
mapM :: Monad m => (a -> m b) -> t a -> m (t b) #
Map each element of a structure to a monadic action, evaluate
these actions from left to right, and collect the results. For
a version that ignores the results see mapM_.
Examples
sequence :: Monad m => t (m a) -> m (t a) #
Evaluate each monadic action in the structure from left to
right, and collect the results. For a version that ignores the
results see sequence_.
Examples
Basic usage:
The first two examples are instances where the input and
and output of sequence are isomorphic.
>>>sequence $ Right [1,2,3,4][Right 1,Right 2,Right 3,Right 4]
>>>sequence $ [Right 1,Right 2,Right 3,Right 4]Right [1,2,3,4]
The following examples demonstrate short circuit behavior
for sequence.
>>>sequence $ Left [1,2,3,4]Left [1,2,3,4]
>>>sequence $ [Left 0, Right 1,Right 2,Right 3,Right 4]Left 0
Instances
Representable types of kind *.
This class is derivable in GHC with the DeriveGeneric flag on.
A Generic instance must satisfy the following laws:
from.to≡idto.from≡id
Instances
This class gives the integer associated with a type-level natural. There are instances of the class for every concrete literal: 0, 1, 2, etc.
Since: base-4.7.0.0
Minimal complete definition
natSing
class IsLabel (x :: Symbol) a where #
Instances
| SymbolToField sym rec typ => IsLabel sym (EntityField rec typ) | This instance delegates to Since: persistent-2.11.0.0 |
Defined in Database.Persist.Class.PersistEntity Methods fromLabel :: EntityField rec typ # | |
The class of semigroups (types with an associative binary operation).
Instances should satisfy the following:
Since: base-4.9.0.0
Minimal complete definition
Methods
(<>) :: a -> a -> a infixr 6 #
An associative operation.
>>>[1,2,3] <> [4,5,6][1,2,3,4,5,6]
Reduce a non-empty list with <>
The default definition should be sufficient, but this can be overridden for efficiency.
>>>import Data.List.NonEmpty (NonEmpty (..))>>>sconcat $ "Hello" :| [" ", "Haskell", "!"]"Hello Haskell!"
stimes :: Integral b => b -> a -> a #
Repeat a value n times.
Given that this works on a Semigroup it is allowed to fail if
you request 0 or fewer repetitions, and the default definition
will do so.
By making this a member of the class, idempotent semigroups
and monoids can upgrade this to execute in \(\mathcal{O}(1)\) by
picking stimes = or stimesIdempotentstimes =
respectively.stimesIdempotentMonoid
>>>stimes 4 [1][1,1,1,1]
Instances
| Semigroup Series | |
| Semigroup More | |
| Semigroup All | Since: base-4.9.0.0 |
| Semigroup Any | Since: base-4.9.0.0 |
| Semigroup Void | Since: base-4.9.0.0 |
| Semigroup ByteString | |
Defined in Data.ByteString.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString # | |
| Semigroup ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString # | |
| Semigroup ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods (<>) :: ShortByteString -> ShortByteString -> ShortByteString # sconcat :: NonEmpty ShortByteString -> ShortByteString # stimes :: Integral b => b -> ShortByteString -> ShortByteString # | |
| Semigroup IntSet | Since: containers-0.5.7 |
| Semigroup Ordering | Since: base-4.9.0.0 |
| Semigroup CookieJar | |
| Semigroup RequestBody | |
Defined in Network.HTTP.Client.Types Methods (<>) :: RequestBody -> RequestBody -> RequestBody # sconcat :: NonEmpty RequestBody -> RequestBody # stimes :: Integral b => b -> RequestBody -> RequestBody # | |
| Semigroup MsgFlag | |
| Semigroup Doc | |
| Semigroup ByteArray | |
| Semigroup () | Since: base-4.9.0.0 |
| Semigroup (IResult a) | |
| Semigroup (Parser a) | |
| Semigroup (Result a) | |
| Semigroup a => Semigroup (Identity a) | Since: base-4.9.0.0 |
| Semigroup (First a) | Since: base-4.9.0.0 |
| Semigroup (Last a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Down a) | Since: base-4.11.0.0 |
| Semigroup (First a) | Since: base-4.9.0.0 |
| Semigroup (Last a) | Since: base-4.9.0.0 |
| Ord a => Semigroup (Max a) | Since: base-4.9.0.0 |
| Ord a => Semigroup (Min a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Option a) | Since: base-4.9.0.0 |
| Monoid m => Semigroup (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods (<>) :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # sconcat :: NonEmpty (WrappedMonoid m) -> WrappedMonoid m # stimes :: Integral b => b -> WrappedMonoid m -> WrappedMonoid m # | |
| Semigroup a => Semigroup (Dual a) | Since: base-4.9.0.0 |
| Semigroup (Endo a) | Since: base-4.9.0.0 |
| Num a => Semigroup (Product a) | Since: base-4.9.0.0 |
| Num a => Semigroup (Sum a) | Since: base-4.9.0.0 |
| Semigroup (NonEmpty a) | Since: base-4.9.0.0 |
| Semigroup p => Semigroup (Par1 p) | Since: base-4.12.0.0 |
| Semigroup (IntMap a) | Since: containers-0.5.7 |
| Semigroup (Seq a) | Since: containers-0.5.7 |
| Semigroup (MergeSet a) | |
| Ord a => Semigroup (Set a) | Since: containers-0.5.7 |
| Semigroup (DNonEmpty a) | |
| Semigroup (DList a) | |
| Semigroup a => Semigroup (IO a) | Since: base-4.10.0.0 |
| Semigroup a => Semigroup (May a) | |
| Semigroup (Doc a) | |
| Semigroup (Array a) | Since: primitive-0.6.3.0 |
| Semigroup (PrimArray a) | Since: primitive-0.6.4.0 |
| Semigroup (SmallArray a) | Since: primitive-0.6.3.0 |
Defined in Data.Primitive.SmallArray Methods (<>) :: SmallArray a -> SmallArray a -> SmallArray a # sconcat :: NonEmpty (SmallArray a) -> SmallArray a # stimes :: Integral b => b -> SmallArray a -> SmallArray a # | |
| Semigroup a => Semigroup (Maybe a) | |
| Semigroup a => Semigroup (Q a) | Since: template-haskell-2.17.0.0 |
| (Hashable a, Eq a) => Semigroup (HashSet a) | O(n+m) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| Semigroup (Vector a) | |
| Prim a => Semigroup (Vector a) | |
| Storable a => Semigroup (Vector a) | |
| Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (a) | Since: base-4.15 |
| Semigroup [a] | Since: base-4.9.0.0 |
| Semigroup (Parser i a) | |
| Semigroup (Either a b) | Since: base-4.9.0.0 |
| Semigroup (Proxy s) | Since: base-4.9.0.0 |
| Semigroup (U1 p) | Since: base-4.12.0.0 |
| Semigroup (V1 p) | Since: base-4.12.0.0 |
| Ord k => Semigroup (Map k v) | |
| Semigroup (Mod t a) | |
| Applicative f => Semigroup (Traversed a f) | |
| Semigroup a => Semigroup (Err e a) | |
| Semigroup (Either a b) | |
| (Semigroup a, Semigroup b) => Semigroup (These a b) | |
| (Semigroup a, Semigroup b) => Semigroup (Pair a b) | |
| (Semigroup a, Semigroup b) => Semigroup (These a b) | |
| (MonadUnliftIO m, Semigroup a) => Semigroup (Conc m a) | Since: unliftio-0.2.9.0 |
| (MonadUnliftIO m, Semigroup a) => Semigroup (Concurrently m a) | Only defined by Since: unliftio-0.1.0.0 |
Defined in UnliftIO.Internals.Async Methods (<>) :: Concurrently m a -> Concurrently m a -> Concurrently m a # sconcat :: NonEmpty (Concurrently m a) -> Concurrently m a # stimes :: Integral b => b -> Concurrently m a -> Concurrently m a # | |
| (Eq k, Hashable k) => Semigroup (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| Semigroup b => Semigroup (a -> b) | Since: base-4.9.0.0 |
| (Semigroup a, Semigroup b) => Semigroup (a, b) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Const a b) | Since: base-4.9.0.0 |
| (Applicative f, Semigroup a) => Semigroup (Ap f a) | Since: base-4.12.0.0 |
| Alternative f => Semigroup (Alt f a) | Since: base-4.9.0.0 |
| Semigroup (f p) => Semigroup (Rec1 f p) | Since: base-4.12.0.0 |
| (Monad m, Semigroup r) => Semigroup (Effect m r a) | |
| Semigroup a => Semigroup (Tagged s a) | |
| (Semigroup a, Semigroup b, Semigroup c) => Semigroup (a, b, c) | Since: base-4.9.0.0 |
| (Semigroup (f p), Semigroup (g p)) => Semigroup ((f :*: g) p) | Since: base-4.12.0.0 |
| Semigroup c => Semigroup (K1 i c p) | Since: base-4.12.0.0 |
| Monad m => Semigroup (ConduitT i o m ()) | |
| (Semigroup a, Semigroup b, Semigroup c, Semigroup d) => Semigroup (a, b, c, d) | Since: base-4.9.0.0 |
| Semigroup (f (g p)) => Semigroup ((f :.: g) p) | Since: base-4.12.0.0 |
| Semigroup (f p) => Semigroup (M1 i c f p) | Since: base-4.12.0.0 |
| (Semigroup a, Semigroup b, Semigroup c, Semigroup d, Semigroup e) => Semigroup (a, b, c, d, e) | Since: base-4.9.0.0 |
| Monad m => Semigroup (Pipe l i o u m ()) | |
class Semigroup a => Monoid a where #
The class of monoids (types with an associative binary operation that has an identity). Instances should satisfy the following:
- Right identity
x<>mempty= x- Left identity
mempty<>x = x- Associativity
x(<>(y<>z) = (x<>y)<>zSemigrouplaw)- Concatenation
mconcat=foldr(<>)mempty
The method names refer to the monoid of lists under concatenation, but there are many other instances.
Some types can be viewed as a monoid in more than one way,
e.g. both addition and multiplication on numbers.
In such cases we often define newtypes and make those instances
of Monoid, e.g. Sum and Product.
NOTE: Semigroup is a superclass of Monoid since base-4.11.0.0.
Minimal complete definition
Methods
Identity of mappend
>>>"Hello world" <> mempty"Hello world"
An associative operation
NOTE: This method is redundant and has the default
implementation mappend = (<>)mappend is a synonym for
(<>), it is expected that the two functions are defined the same
way. In a future GHC release mappend will be removed from Monoid.
Fold a list using the monoid.
For most types, the default definition for mconcat will be
used, but the function is included in the class definition so
that an optimized version can be provided for specific types.
>>>mconcat ["Hello", " ", "Haskell", "!"]"Hello Haskell!"
Instances
| Monoid Series | |
| Monoid More | |
| Monoid All | Since: base-2.1 |
| Monoid Any | Since: base-2.1 |
| Monoid ByteString | |
Defined in Data.ByteString.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods mappend :: ShortByteString -> ShortByteString -> ShortByteString # mconcat :: [ShortByteString] -> ShortByteString # | |
| Monoid IntSet | |
| Monoid Ordering | Since: base-2.1 |
| Monoid CookieJar | Since 1.9 |
| Monoid RequestBody | |
Defined in Network.HTTP.Client.Types Methods mempty :: RequestBody # mappend :: RequestBody -> RequestBody -> RequestBody # mconcat :: [RequestBody] -> RequestBody # | |
| Monoid MsgFlag | |
| Monoid Doc | |
| Monoid ByteArray | |
| Monoid () | Since: base-2.1 |
| Monoid (IResult a) | |
| Monoid (Parser a) | |
| Monoid (Result a) | |
| Monoid a => Monoid (Identity a) | Since: base-4.9.0.0 |
| Monoid (First a) | Since: base-2.1 |
| Monoid (Last a) | Since: base-2.1 |
| Monoid a => Monoid (Down a) | Since: base-4.11.0.0 |
| (Ord a, Bounded a) => Monoid (Max a) | Since: base-4.9.0.0 |
| (Ord a, Bounded a) => Monoid (Min a) | Since: base-4.9.0.0 |
| Semigroup a => Monoid (Option a) | Since: base-4.9.0.0 |
| Monoid m => Monoid (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods mempty :: WrappedMonoid m # mappend :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # mconcat :: [WrappedMonoid m] -> WrappedMonoid m # | |
| Monoid a => Monoid (Dual a) | Since: base-2.1 |
| Monoid (Endo a) | Since: base-2.1 |
| Num a => Monoid (Product a) | Since: base-2.1 |
| Num a => Monoid (Sum a) | Since: base-2.1 |
| Monoid p => Monoid (Par1 p) | Since: base-4.12.0.0 |
| Monoid (IntMap a) | |
| Monoid (Seq a) | |
| Monoid (MergeSet a) | |
| Ord a => Monoid (Set a) | |
| Monoid (DList a) | |
| Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
| Monoid a => Monoid (May a) | |
| Monoid (Doc a) | |
| Monoid (Array a) | |
| Monoid (PrimArray a) | Since: primitive-0.6.4.0 |
| Monoid (SmallArray a) | |
Defined in Data.Primitive.SmallArray Methods mempty :: SmallArray a # mappend :: SmallArray a -> SmallArray a -> SmallArray a # mconcat :: [SmallArray a] -> SmallArray a # | |
| Semigroup a => Monoid (Maybe a) | |
| Monoid a => Monoid (Q a) | Since: template-haskell-2.17.0.0 |
| (Hashable a, Eq a) => Monoid (HashSet a) | O(n+m) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| Monoid (Vector a) | |
| Prim a => Monoid (Vector a) | |
| Storable a => Monoid (Vector a) | |
| Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
| Monoid a => Monoid (a) | Since: base-4.15 |
| Monoid [a] | Since: base-2.1 |
| Monoid (Parser i a) | |
| Monoid (Proxy s) | Since: base-4.7.0.0 |
| Monoid (U1 p) | Since: base-4.12.0.0 |
| Ord k => Monoid (Map k v) | |
| Monoid (Mod t a) | |
| Applicative f => Monoid (Traversed a f) | |
| Monoid a => Monoid (Err e a) | |
| (Monoid a, Monoid b) => Monoid (Pair a b) | |
| (Monoid a, MonadUnliftIO m) => Monoid (Conc m a) | Since: unliftio-0.2.9.0 |
| (Semigroup a, Monoid a, MonadUnliftIO m) => Monoid (Concurrently m a) | Since: unliftio-0.1.0.0 |
Defined in UnliftIO.Internals.Async Methods mempty :: Concurrently m a # mappend :: Concurrently m a -> Concurrently m a -> Concurrently m a # mconcat :: [Concurrently m a] -> Concurrently m a # | |
| (Eq k, Hashable k) => Monoid (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| Monoid b => Monoid (a -> b) | Since: base-2.1 |
| (Monoid a, Monoid b) => Monoid (a, b) | Since: base-2.1 |
| Monoid a => Monoid (Const a b) | Since: base-4.9.0.0 |
| (Applicative f, Monoid a) => Monoid (Ap f a) | Since: base-4.12.0.0 |
| Alternative f => Monoid (Alt f a) | Since: base-4.8.0.0 |
| Monoid (f p) => Monoid (Rec1 f p) | Since: base-4.12.0.0 |
| (Monad m, Monoid r) => Monoid (Effect m r a) | |
| (Semigroup a, Monoid a) => Monoid (Tagged s a) | |
| (Monoid a, Monoid b, Monoid c) => Monoid (a, b, c) | Since: base-2.1 |
| (Monoid (f p), Monoid (g p)) => Monoid ((f :*: g) p) | Since: base-4.12.0.0 |
| Monoid c => Monoid (K1 i c p) | Since: base-4.12.0.0 |
| Monad m => Monoid (ConduitT i o m ()) | |
| (Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d) | Since: base-2.1 |
| Monoid (f (g p)) => Monoid ((f :.: g) p) | Since: base-4.12.0.0 |
| Monoid (f p) => Monoid (M1 i c f p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e) | Since: base-2.1 |
| Monad m => Monoid (Pipe l i o u m ()) | |
Instances
The character type Char is an enumeration whose values represent
Unicode (or equivalently ISO/IEC 10646) code points (i.e. characters, see
http://www.unicode.org/ for details). This set extends the ISO 8859-1
(Latin-1) character set (the first 256 characters), which is itself an extension
of the ASCII character set (the first 128 characters). A character literal in
Haskell has type Char.
To convert a Char to or from the corresponding Int value defined
by Unicode, use toEnum and fromEnum from the
Enum class respectively (or equivalently ord and
chr).
Instances
Double-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE double-precision type.
Instances
Single-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE single-precision type.
Instances
A fixed-precision integer type with at least the range [-2^29 .. 2^29-1].
The exact range for a given implementation can be determined by using
minBound and maxBound from the Bounded class.
Instances
8-bit signed integer type
Instances
16-bit signed integer type
Instances
32-bit signed integer type
Instances
64-bit signed integer type
Instances
Arbitrary precision integers. In contrast with fixed-size integral types
such as Int, the Integer type represents the entire infinite range of
integers.
Integers are stored in a kind of sign-magnitude form, hence do not expect two's complement form when using bit operations.
If the value is small (fit into an Int), IS constructor is used.
Otherwise IP and IN constructors are used to store a BigNat
representing respectively the positive or the negative value magnitude.
Instances
Natural number
Invariant: numbers <= 0xffffffffffffffff use the NS constructor
Instances
The Maybe type encapsulates an optional value. A value of type
Maybe aa (represented as Just aNothing). Using Maybe is a good way to
deal with errors or exceptional cases without resorting to drastic
measures such as error.
The Maybe type is also a monad. It is a simple kind of error
monad, where all errors are represented by Nothing. A richer
error monad can be built using the Either type.
Instances
| FromJSON1 Maybe | |
| ToJSON1 Maybe | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Maybe a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Maybe a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Maybe a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Maybe a] -> Encoding # | |
| MonadFail Maybe | Since: base-4.9.0.0 |
Defined in Control.Monad.Fail | |
| Foldable Maybe | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Eq1 Maybe | Since: base-4.9.0.0 |
| Ord1 Maybe | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read1 Maybe | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Show1 Maybe | Since: base-4.9.0.0 |
| Traversable Maybe | Since: base-2.1 |
| Alternative Maybe | Since: base-2.1 |
| Applicative Maybe | Since: base-2.1 |
| Functor Maybe | Since: base-2.1 |
| Monad Maybe | Since: base-2.1 |
| MonadPlus Maybe | Since: base-2.1 |
| NFData1 Maybe | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| MonadThrow Maybe | |
Defined in Control.Monad.Catch | |
| Hashable1 Maybe | |
Defined in Data.Hashable.Class | |
| MonadError () Maybe | Since: mtl-2.2.2 |
Defined in Control.Monad.Error.Class | |
| (Selector s, GToJSON' enc arity (K1 i (Maybe a) :: Type -> Type), KeyValuePair enc pairs, Monoid pairs) => RecordToPairs enc pairs arity (S1 s (K1 i (Maybe a) :: Type -> Type)) | |
Defined in Data.Aeson.Types.ToJSON | |
| Lift a => Lift (Maybe a :: Type) | |
| (Selector s, FromJSON a) => RecordFromJSON' arity (S1 s (K1 i (Maybe a) :: Type -> Type)) | |
Defined in Data.Aeson.Types.FromJSON | |
| Out a => Out (Maybe a) | |
| FromJSON a => FromJSON (Maybe a) | |
| ToJSON a => ToJSON (Maybe a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
| Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
| Generic (Maybe a) | |
| SingKind a => SingKind (Maybe a) | Since: base-4.9.0.0 |
Defined in GHC.Generics Associated Types type DemoteRep (Maybe a) | |
| Read a => Read (Maybe a) | Since: base-2.1 |
| Show a => Show (Maybe a) | Since: base-2.1 |
| NFData a => NFData (Maybe a) | |
Defined in Control.DeepSeq | |
| Eq a => Eq (Maybe a) | Since: base-2.1 |
| Ord a => Ord (Maybe a) | Since: base-2.1 |
| Hashable a => Hashable (Maybe a) | |
Defined in Data.Hashable.Class | |
| (TypeError (DisallowInstance "Maybe") :: Constraint) => Container (Maybe a) | |
Defined in Universum.Container.Class Methods toList :: Maybe a -> [Element (Maybe a)] # foldr :: (Element (Maybe a) -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> Element (Maybe a) -> b) -> b -> Maybe a -> b # foldl' :: (b -> Element (Maybe a) -> b) -> b -> Maybe a -> b # elem :: Element (Maybe a) -> Maybe a -> Bool # foldMap :: Monoid m => (Element (Maybe a) -> m) -> Maybe a -> m # fold :: Maybe a -> Element (Maybe a) # foldr' :: (Element (Maybe a) -> b -> b) -> b -> Maybe a -> b # notElem :: Element (Maybe a) -> Maybe a -> Bool # all :: (Element (Maybe a) -> Bool) -> Maybe a -> Bool # any :: (Element (Maybe a) -> Bool) -> Maybe a -> Bool # find :: (Element (Maybe a) -> Bool) -> Maybe a -> Maybe (Element (Maybe a)) # safeHead :: Maybe a -> Maybe (Element (Maybe a)) # safeMaximum :: Maybe a -> Maybe (Element (Maybe a)) # safeMinimum :: Maybe a -> Maybe (Element (Maybe a)) # safeFoldr1 :: (Element (Maybe a) -> Element (Maybe a) -> Element (Maybe a)) -> Maybe a -> Maybe (Element (Maybe a)) # safeFoldl1 :: (Element (Maybe a) -> Element (Maybe a) -> Element (Maybe a)) -> Maybe a -> Maybe (Element (Maybe a)) # | |
| Generic1 Maybe | |
| SingI ('Nothing :: Maybe a) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Each (Maybe a) (Maybe b) a b | |
| SingI a2 => SingI ('Just a2 :: Maybe a1) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| type DemoteRep (Maybe a) | |
Defined in GHC.Generics | |
| type Rep (Maybe a) | Since: base-4.6.0.0 |
Defined in GHC.Generics | |
| data Sing (b :: Maybe a) | |
| type Element (Maybe a) | |
Defined in Universum.Container.Class | |
| type Rep1 Maybe | Since: base-4.6.0.0 |
Instances
| FromJSON Ordering | |
| ToJSON Ordering | |
Defined in Data.Aeson.Types.ToJSON | |
| Monoid Ordering | Since: base-2.1 |
| Semigroup Ordering | Since: base-4.9.0.0 |
| Bounded Ordering | Since: base-2.1 |
| Enum Ordering | Since: base-2.1 |
| Generic Ordering | |
| Read Ordering | Since: base-2.1 |
| Show Ordering | Since: base-2.1 |
| NFData Ordering | |
Defined in Control.DeepSeq | |
| Eq Ordering | |
| Ord Ordering | |
Defined in GHC.Classes | |
| Hashable Ordering | |
Defined in Data.Hashable.Class | |
| type Rep Ordering | Since: base-4.6.0.0 |
Rational numbers, with numerator and denominator of some Integral type.
Note that Ratio's instances inherit the deficiencies from the type
parameter's. For example, Ratio Natural's Num instance has similar
problems to Natural's.
Constructors
| !a :% !a |
Instances
| Out Rational | |
| NFData1 Ratio | Available on Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Integral a => Lift (Ratio a :: Type) | |
| (FromJSON a, Integral a) => FromJSON (Ratio a) | |
| (ToJSON a, Integral a) => ToJSON (Ratio a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Storable a, Integral a) => Storable (Ratio a) | Since: base-4.8.0.0 |
| Integral a => Enum (Ratio a) | Since: base-2.0.1 |
| Integral a => Num (Ratio a) | Since: base-2.0.1 |
| (Integral a, Read a) => Read (Ratio a) | Since: base-2.1 |
| Integral a => Fractional (Ratio a) | Since: base-2.0.1 |
| Integral a => Real (Ratio a) | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Ratio a -> Rational # | |
| Integral a => RealFrac (Ratio a) | Since: base-2.0.1 |
| Show a => Show (Ratio a) | Since: base-2.0.1 |
| NFData a => NFData (Ratio a) | |
Defined in Control.DeepSeq | |
| Eq a => Eq (Ratio a) | Since: base-2.1 |
| Integral a => Ord (Ratio a) | Since: base-2.0.1 |
| Hashable a => Hashable (Ratio a) | |
Defined in Data.Hashable.Class | |
A value of type IO aa.
There is really only one way to "perform" an I/O action: bind it to
Main.main in your program. When your program is run, the I/O will
be performed. It isn't possible to perform I/O from an arbitrary
function, unless that function is itself in the IO monad and called
at some point, directly or indirectly, from Main.main.
IO is a monad, so IO actions can be combined using either the do-notation
or the >> and >>= operations from the Monad
class.
Instances
Instances
8-bit unsigned integer type
Instances
16-bit unsigned integer type
Instances
32-bit unsigned integer type
Instances
64-bit unsigned integer type
Instances
A value of type Ptr aa.
The type a will often be an instance of class
Storable which provides the marshalling operations.
However this is not essential, and you can provide your own operations
to access the pointer. For example you might write small foreign
functions to get or set the fields of a C struct.
Instances
| NFData1 Ptr | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Generic1 (URec (Ptr ()) :: k -> Type) | |
| Foldable (UAddr :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UAddr m -> m # foldMap :: Monoid m => (a -> m) -> UAddr a -> m # foldMap' :: Monoid m => (a -> m) -> UAddr a -> m # foldr :: (a -> b -> b) -> b -> UAddr a -> b # foldr' :: (a -> b -> b) -> b -> UAddr a -> b # foldl :: (b -> a -> b) -> b -> UAddr a -> b # foldl' :: (b -> a -> b) -> b -> UAddr a -> b # foldr1 :: (a -> a -> a) -> UAddr a -> a # foldl1 :: (a -> a -> a) -> UAddr a -> a # elem :: Eq a => a -> UAddr a -> Bool # maximum :: Ord a => UAddr a -> a # minimum :: Ord a => UAddr a -> a # | |
| Traversable (UAddr :: Type -> Type) | Since: base-4.9.0.0 |
| Storable (Ptr a) | Since: base-2.1 |
| Show (Ptr a) | Since: base-2.1 |
| NFData (Ptr a) | Since: deepseq-1.4.2.0 |
Defined in Control.DeepSeq | |
| Eq (Ptr a) | Since: base-2.1 |
| Ord (Ptr a) | Since: base-2.1 |
| Hashable (Ptr a) | |
Defined in Data.Hashable.Class | |
| Prim (Ptr a) | |
Defined in Data.Primitive.Types Methods alignment# :: Ptr a -> Int# # indexByteArray# :: ByteArray# -> Int# -> Ptr a # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Ptr a #) # writeByteArray# :: MutableByteArray# s -> Int# -> Ptr a -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Ptr a -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Ptr a # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Ptr a #) # writeOffAddr# :: Addr# -> Int# -> Ptr a -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Ptr a -> State# s -> State# s # | |
| Functor (URec (Ptr ()) :: Type -> Type) | Since: base-4.9.0.0 |
| Generic (URec (Ptr ()) p) | |
| Eq (URec (Ptr ()) p) | Since: base-4.9.0.0 |
| Ord (URec (Ptr ()) p) | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: URec (Ptr ()) p -> URec (Ptr ()) p -> Ordering # (<) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (<=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # max :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p # min :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p # | |
| data URec (Ptr ()) (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
| type Rep1 (URec (Ptr ()) :: k -> Type) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| type Rep (URec (Ptr ()) p) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
A value of type FunPtr aa will normally be a foreign type,
a function type with zero or more arguments where
- the argument types are marshallable foreign types,
i.e.
Char,Int,Double,Float,Bool,Int8,Int16,Int32,Int64,Word8,Word16,Word32,Word64,PtraFunPtraStablePtranewtype. - the return type is either a marshallable foreign type or has the form
IOttis a marshallable foreign type or().
A value of type FunPtr a
foreign import ccall "stdlib.h &free" p_free :: FunPtr (Ptr a -> IO ())
or a pointer to a Haskell function created using a wrapper stub
declared to produce a FunPtr of the correct type. For example:
type Compare = Int -> Int -> Bool foreign import ccall "wrapper" mkCompare :: Compare -> IO (FunPtr Compare)
Calls to wrapper stubs like mkCompare allocate storage, which
should be released with freeHaskellFunPtr when no
longer required.
To convert FunPtr values to corresponding Haskell functions, one
can define a dynamic stub for the specific foreign type, e.g.
type IntFunction = CInt -> IO () foreign import ccall "dynamic" mkFun :: FunPtr IntFunction -> IntFunction
Instances
| NFData1 FunPtr | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Storable (FunPtr a) | Since: base-2.1 |
Defined in Foreign.Storable | |
| Show (FunPtr a) | Since: base-2.1 |
| NFData (FunPtr a) | Since: deepseq-1.4.2.0 |
Defined in Control.DeepSeq | |
| Eq (FunPtr a) | |
| Ord (FunPtr a) | |
Defined in GHC.Ptr | |
| Hashable (FunPtr a) | |
Defined in Data.Hashable.Class | |
| Prim (FunPtr a) | |
Defined in Data.Primitive.Types Methods alignment# :: FunPtr a -> Int# # indexByteArray# :: ByteArray# -> Int# -> FunPtr a # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, FunPtr a #) # writeByteArray# :: MutableByteArray# s -> Int# -> FunPtr a -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> FunPtr a -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> FunPtr a # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, FunPtr a #) # writeOffAddr# :: Addr# -> Int# -> FunPtr a -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> FunPtr a -> State# s -> State# s # | |
The Either type represents values with two possibilities: a value of
type Either a bLeft aRight b
The Either type is sometimes used to represent a value which is
either correct or an error; by convention, the Left constructor is
used to hold an error value and the Right constructor is used to
hold a correct value (mnemonic: "right" also means "correct").
Examples
The type Either String IntString or an Int. The Left constructor can be used only on
Strings, and the Right constructor can be used only on Ints:
>>>let s = Left "foo" :: Either String Int>>>sLeft "foo">>>let n = Right 3 :: Either String Int>>>nRight 3>>>:type ss :: Either String Int>>>:type nn :: Either String Int
The fmap from our Functor instance will ignore Left values, but
will apply the supplied function to values contained in a Right:
>>>let s = Left "foo" :: Either String Int>>>let n = Right 3 :: Either String Int>>>fmap (*2) sLeft "foo">>>fmap (*2) nRight 6
The Monad instance for Either allows us to chain together multiple
actions which may fail, and fail overall if any of the individual
steps failed. First we'll write a function that can either parse an
Int from a Char, or fail.
>>>import Data.Char ( digitToInt, isDigit )>>>:{let parseEither :: Char -> Either String Int parseEither c | isDigit c = Right (digitToInt c) | otherwise = Left "parse error">>>:}
The following should work, since both '1' and '2' can be
parsed as Ints.
>>>:{let parseMultiple :: Either String Int parseMultiple = do x <- parseEither '1' y <- parseEither '2' return (x + y)>>>:}
>>>parseMultipleRight 3
But the following should fail overall, since the first operation where
we attempt to parse 'm' as an Int will fail:
>>>:{let parseMultiple :: Either String Int parseMultiple = do x <- parseEither 'm' y <- parseEither '2' return (x + y)>>>:}
>>>parseMultipleLeft "parse error"
Instances
data Constraint #
The kind of constraints, like Show a
type family CmpNat (a :: Nat) (b :: Nat) :: Ordering where ... #
Comparison of type-level naturals, as a function.
Since: base-4.7.0.0
class a ~R# b => Coercible (a :: k) (b :: k) #
Coercible is a two-parameter class that has instances for types a and b if
the compiler can infer that they have the same representation. This class
does not have regular instances; instead they are created on-the-fly during
type-checking. Trying to manually declare an instance of Coercible
is an error.
Nevertheless one can pretend that the following three kinds of instances exist. First, as a trivial base-case:
instance Coercible a a
Furthermore, for every type constructor there is
an instance that allows to coerce under the type constructor. For
example, let D be a prototypical type constructor (data or
newtype) with three type arguments, which have roles nominal,
representational resp. phantom. Then there is an instance of
the form
instance Coercible b b' => Coercible (D a b c) (D a b' c')
Note that the nominal type arguments are equal, the
representational type arguments can differ, but need to have a
Coercible instance themself, and the phantom type arguments can be
changed arbitrarily.
The third kind of instance exists for every newtype NT = MkNT T and
comes in two variants, namely
instance Coercible a T => Coercible a NT
instance Coercible T b => Coercible NT b
This instance is only usable if the constructor MkNT is in scope.
If, as a library author of a type constructor like Set a, you
want to prevent a user of your module to write
coerce :: Set T -> Set NT,
you need to set the role of Set's type parameter to nominal,
by writing
type role Set nominal
For more details about this feature, please refer to Safe Coercions by Joachim Breitner, Richard A. Eisenberg, Simon Peyton Jones and Stephanie Weirich.
Since: ghc-prim-4.7.0.0
CallStacks are a lightweight method of obtaining a
partial call-stack at any point in the program.
A function can request its call-site with the HasCallStack constraint.
For example, we can define
putStrLnWithCallStack :: HasCallStack => String -> IO ()
as a variant of putStrLn that will get its call-site and print it,
along with the string given as argument. We can access the
call-stack inside putStrLnWithCallStack with callStack.
putStrLnWithCallStack :: HasCallStack => String -> IO () putStrLnWithCallStack msg = do putStrLn msg putStrLn (prettyCallStack callStack)
Thus, if we call putStrLnWithCallStack we will get a formatted call-stack
alongside our string.
>>>putStrLnWithCallStack "hello"hello CallStack (from HasCallStack): putStrLnWithCallStack, called at <interactive>:2:1 in interactive:Ghci1
GHC solves HasCallStack constraints in three steps:
- If there is a
CallStackin scope -- i.e. the enclosing function has aHasCallStackconstraint -- GHC will append the new call-site to the existingCallStack. - If there is no
CallStackin scope -- e.g. in the GHCi session above -- and the enclosing definition does not have an explicit type signature, GHC will infer aHasCallStackconstraint for the enclosing definition (subject to the monomorphism restriction). - If there is no
CallStackin scope and the enclosing definition has an explicit type signature, GHC will solve theHasCallStackconstraint for the singletonCallStackcontaining just the current call-site.
CallStacks do not interact with the RTS and do not require compilation
with -prof. On the other hand, as they are built up explicitly via the
HasCallStack constraints, they will generally not contain as much
information as the simulated call-stacks maintained by the RTS.
A CallStack is a [(String, SrcLoc)]. The String is the name of
function that was called, the SrcLoc is the call-site. The list is
ordered with the most recently called function at the head.
NOTE: The intrepid user may notice that HasCallStack is just an
alias for an implicit parameter ?callStack :: CallStack. This is an
implementation detail and should not be considered part of the
CallStack API, we may decide to change the implementation in the
future.
Since: base-4.8.1.0
The class Out is the equivalent of Show
It provides conversion of values to pretty printable Pretty.Doc's.
Minimal complete definition: docPrec or doc.
Derived instances of Out have the following properties
- The result of
docPrecis a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used. - If the constructor is defined to be an infix operator, then
docPrecwill produce infix applications of the constructor. - the representation will be enclosed in parentheses if the
precedence of the top-level constructor in
xis less thand(associativity is ignored). Thus, ifdis0then the result is never surrounded in parentheses; ifdis11it is always surrounded in parentheses, unless it is an atomic expression. - If the constructor is defined using record syntax, then
docPrecwill produce the record-syntax form, with the fields given in the same order as the original declaration.
For example, given the declarations
data Tree a = Leaf a | Node (Tree a) (Tree a) deriving (Generic)
The derived instance of Out is equivalent to:
instance (Out a) => Out (Tree a) where
docPrec d (Leaf m) = Pretty.sep $ wrapParens (d > appPrec) $
text "Leaf" : [nest (constrLen + parenLen) (docPrec (appPrec+1) m)]
where appPrec = 10
constrLen = 5;
parenLen = if(d > appPrec) then 1 else 0
docPrec d (Node u v) = Pretty.sep $ wrapParens (d > appPrec) $
text "Node" :
nest (constrLen + parenLen) (docPrec (appPrec+1) u) :
[nest (constrLen + parenLen) (docPrec (appPrec+1) v)]
where appPrec = 10
constrLen = 5
parenLen = if(d > appPrec) then 1 else 0Minimal complete definition
Nothing
Methods
Arguments
| :: Int | the operator precedence of the enclosing
context (a number from |
| -> a | the value to be converted to a |
| -> Doc | the resulting Doc |
This is a specialised variant of docPrec, using precedence context zero.
docList is the equivalent of showList.
The method docList is provided to allow the programmer to
give a specialised way of showing lists of values.
For example, this is used by the predefined Out instance of
the Char type, where values of type String should be shown
in double quotes, rather than between square brackets.
Instances
| Out Rational | |
| Out Balance Source # | |
| Out BlockHeader Source # | |
Defined in ElectrsClient.Rpc Methods docPrec :: Int -> BlockHeader -> Doc # doc :: BlockHeader -> Doc # docList :: [BlockHeader] -> Doc # | |
| Out ByteStringDoc | |
| Out Integer | |
| Out () | |
| Out Bool | |
| Out Char | |
| Out Double | |
| Out Float | |
| Out Int | |
| Out a => Out (Maybe a) | |
| Out a => Out [a] | |
| (Out a, Out b) => Out (Either a b) | |
| (Out a, Out b) => Out (a, b) | |
| (Out a, Out b, Out c) => Out (a, b, c) | |
| (Out a, Out b, Out c, Out d) => Out (a, b, c, d) | |
| (Out a, Out b, Out c, Out d, Out e) => Out (a, b, c, d, e) | |
| (Out a, Out b, Out c, Out d, Out e, Out f) => Out (a, b, c, d, e, f) | |
| (Out a, Out b, Out c, Out d, Out e, Out f, Out g) => Out (a, b, c, d, e, f, g) | |
data ByteString #
A space-efficient representation of a Word8 vector, supporting many
efficient operations.
A ByteString contains 8-bit bytes, or by using the operations from
Data.ByteString.Char8 it can be interpreted as containing 8-bit
characters.
Instances
The class of types that can be converted to a hash value.
Minimal implementation: hashWithSalt.
Note: the hash is not guaranteed to be stable across library versions, operating systems or architectures. For stable hashing use named hashes: SHA256, CRC32 etc.
If you are looking for Hashable instance in time package,
check time-compat
Minimal complete definition
Nothing
Methods
hashWithSalt :: Int -> a -> Int infixl 0 #
Return a hash value for the argument, using the given salt.
The general contract of hashWithSalt is:
- If two values are equal according to the
==method, then applying thehashWithSaltmethod on each of the two values must produce the same integer result if the same salt is used in each case. - It is not required that if two values are unequal
according to the
==method, then applying thehashWithSaltmethod on each of the two values must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal values may improve the performance of hashing-based data structures. - This method can be used to compute different hash values for
the same input by providing a different salt in each
application of the method. This implies that any instance
that defines
hashWithSaltmust make use of the salt in its implementation. hashWithSaltmay return negativeIntvalues.
Instances
(<$>) :: Functor f => (a -> b) -> f a -> f b infixl 4 #
An infix synonym for fmap.
The name of this operator is an allusion to $.
Note the similarities between their types:
($) :: (a -> b) -> a -> b (<$>) :: Functor f => (a -> b) -> f a -> f b
Whereas $ is function application, <$> is function
application lifted over a Functor.
Examples
Convert from a Maybe IntMaybe
Stringshow:
>>>show <$> NothingNothing>>>show <$> Just 3Just "3"
Convert from an Either Int IntEither IntString using show:
>>>show <$> Left 17Left 17>>>show <$> Right 17Right "17"
Double each element of a list:
>>>(*2) <$> [1,2,3][2,4,6]
Apply even to the second element of a pair:
>>>even <$> (2,2)(2,True)
A space efficient, packed, unboxed Unicode text type.
Instances
const x is a unary function which evaluates to x for all inputs.
>>>const 42 "hello"42
>>>map (const 42) [0..3][42,42,42,42]
A map from keys to values. A map cannot contain duplicate keys; each key can map to at most one value.
Instances
| KeyValue Object | Constructs a singleton |
| Bifoldable HashMap | Since: unordered-containers-0.2.11 |
| Eq2 HashMap | |
| Ord2 HashMap | |
Defined in Data.HashMap.Internal | |
| Show2 HashMap | |
| NFData2 HashMap | Since: unordered-containers-0.2.14.0 |
Defined in Data.HashMap.Internal | |
| Hashable2 HashMap | |
Defined in Data.HashMap.Internal | |
| (Lift k, Lift v) => Lift (HashMap k v :: Type) | Since: unordered-containers-0.2.17.0 |
| (FromJSONKey k, Eq k, Hashable k) => FromJSON1 (HashMap k) | |
| ToJSONKey k => ToJSON1 (HashMap k) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> HashMap k a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [HashMap k a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> HashMap k a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [HashMap k a] -> Encoding # | |
| Foldable (HashMap k) | |
Defined in Data.HashMap.Internal Methods fold :: Monoid m => HashMap k m -> m # foldMap :: Monoid m => (a -> m) -> HashMap k a -> m # foldMap' :: Monoid m => (a -> m) -> HashMap k a -> m # foldr :: (a -> b -> b) -> b -> HashMap k a -> b # foldr' :: (a -> b -> b) -> b -> HashMap k a -> b # foldl :: (b -> a -> b) -> b -> HashMap k a -> b # foldl' :: (b -> a -> b) -> b -> HashMap k a -> b # foldr1 :: (a -> a -> a) -> HashMap k a -> a # foldl1 :: (a -> a -> a) -> HashMap k a -> a # toList :: HashMap k a -> [a] # length :: HashMap k a -> Int # elem :: Eq a => a -> HashMap k a -> Bool # maximum :: Ord a => HashMap k a -> a # minimum :: Ord a => HashMap k a -> a # | |
| Eq k => Eq1 (HashMap k) | |
| Ord k => Ord1 (HashMap k) | |
Defined in Data.HashMap.Internal | |
| (Eq k, Hashable k, Read k) => Read1 (HashMap k) | |
Defined in Data.HashMap.Internal | |
| Show k => Show1 (HashMap k) | |
| Traversable (HashMap k) | |
Defined in Data.HashMap.Internal | |
| Functor (HashMap k) | |
| NFData k => NFData1 (HashMap k) | Since: unordered-containers-0.2.14.0 |
Defined in Data.HashMap.Internal | |
| Hashable k => Hashable1 (HashMap k) | |
Defined in Data.HashMap.Internal | |
| (FromJSON v, FromJSONKey k, Eq k, Hashable k) => FromJSON (HashMap k v) | |
| (ToJSON v, ToJSONKey k) => ToJSON (HashMap k v) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data k, Data v, Eq k, Hashable k) => Data (HashMap k v) | |
Defined in Data.HashMap.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> HashMap k v -> c (HashMap k v) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (HashMap k v) # toConstr :: HashMap k v -> Constr # dataTypeOf :: HashMap k v -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (HashMap k v)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (HashMap k v)) # gmapT :: (forall b. Data b => b -> b) -> HashMap k v -> HashMap k v # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> HashMap k v -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> HashMap k v -> r # gmapQ :: (forall d. Data d => d -> u) -> HashMap k v -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> HashMap k v -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) # | |
| (Eq k, Hashable k) => Monoid (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| (Eq k, Hashable k) => Semigroup (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| (Eq k, Hashable k) => IsList (HashMap k v) | |
| (Eq k, Hashable k, Read k, Read e) => Read (HashMap k e) | |
| (Show k, Show v) => Show (HashMap k v) | |
| (NFData k, NFData v) => NFData (HashMap k v) | |
Defined in Data.HashMap.Internal | |
| (Eq k, Eq v) => Eq (HashMap k v) | Note that, in the presence of hash collisions, equal
In general, the lack of substitutivity can be observed with any function that depends on the key ordering, such as folds and traversals. |
| (Ord k, Ord v) => Ord (HashMap k v) | The ordering is total and consistent with the |
Defined in Data.HashMap.Internal | |
| (Hashable k, Hashable v) => Hashable (HashMap k v) | |
Defined in Data.HashMap.Internal | |
| Container (HashMap k v) | |
Defined in Universum.Container.Class Methods toList :: HashMap k v -> [Element (HashMap k v)] # foldr :: (Element (HashMap k v) -> b -> b) -> b -> HashMap k v -> b # foldl :: (b -> Element (HashMap k v) -> b) -> b -> HashMap k v -> b # foldl' :: (b -> Element (HashMap k v) -> b) -> b -> HashMap k v -> b # length :: HashMap k v -> Int # elem :: Element (HashMap k v) -> HashMap k v -> Bool # foldMap :: Monoid m => (Element (HashMap k v) -> m) -> HashMap k v -> m # fold :: HashMap k v -> Element (HashMap k v) # foldr' :: (Element (HashMap k v) -> b -> b) -> b -> HashMap k v -> b # notElem :: Element (HashMap k v) -> HashMap k v -> Bool # all :: (Element (HashMap k v) -> Bool) -> HashMap k v -> Bool # any :: (Element (HashMap k v) -> Bool) -> HashMap k v -> Bool # find :: (Element (HashMap k v) -> Bool) -> HashMap k v -> Maybe (Element (HashMap k v)) # safeHead :: HashMap k v -> Maybe (Element (HashMap k v)) # safeMaximum :: HashMap k v -> Maybe (Element (HashMap k v)) # safeMinimum :: HashMap k v -> Maybe (Element (HashMap k v)) # safeFoldr1 :: (Element (HashMap k v) -> Element (HashMap k v) -> Element (HashMap k v)) -> HashMap k v -> Maybe (Element (HashMap k v)) # safeFoldl1 :: (Element (HashMap k v) -> Element (HashMap k v) -> Element (HashMap k v)) -> HashMap k v -> Maybe (Element (HashMap k v)) # | |
| (Eq k, Hashable k) => FromList (HashMap k v) | |
Defined in Universum.Container.Class Methods fromList :: [ListElement (HashMap k v)] -> HashMap k v # | |
| Hashable k => One (HashMap k v) | |
| ToPairs (HashMap k v) | |
| type Item (HashMap k v) | |
Defined in Data.HashMap.Internal | |
| type Element (HashMap k v) | |
Defined in Universum.Container.Class | |
| type FromListC (HashMap k v) | |
Defined in Universum.Container.Class | |
| type Key (HashMap k v) | |
Defined in Universum.Container.Class | |
| type ListElement (HashMap k v) | |
Defined in Universum.Container.Class | |
| type OneItem (HashMap k v) | |
Defined in Universum.Container.Class | |
| type Val (HashMap k v) | |
Defined in Universum.Container.Class | |
A Map from keys k to values a.
The Semigroup operation for Map is union, which prefers
values from the left operand. If m1 maps a key k to a value
a1, and m2 maps the same key to a different value a2, then
their union m1 <> m2 maps k to a1.
Instances
| Bifoldable Map | Since: containers-0.6.3.1 |
| Eq2 Map | Since: containers-0.5.9 |
| Ord2 Map | Since: containers-0.5.9 |
Defined in Data.Map.Internal | |
| Show2 Map | Since: containers-0.5.9 |
| Hashable2 Map | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| (FromJSONKey k, Ord k) => FromJSON1 (Map k) | |
| ToJSONKey k => ToJSON1 (Map k) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Map k a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Map k a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Map k a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Map k a] -> Encoding # | |
| Foldable (Map k) | Folds in order of increasing key. |
Defined in Data.Map.Internal Methods fold :: Monoid m => Map k m -> m # foldMap :: Monoid m => (a -> m) -> Map k a -> m # foldMap' :: Monoid m => (a -> m) -> Map k a -> m # foldr :: (a -> b -> b) -> b -> Map k a -> b # foldr' :: (a -> b -> b) -> b -> Map k a -> b # foldl :: (b -> a -> b) -> b -> Map k a -> b # foldl' :: (b -> a -> b) -> b -> Map k a -> b # foldr1 :: (a -> a -> a) -> Map k a -> a # foldl1 :: (a -> a -> a) -> Map k a -> a # elem :: Eq a => a -> Map k a -> Bool # maximum :: Ord a => Map k a -> a # minimum :: Ord a => Map k a -> a # | |
| Eq k => Eq1 (Map k) | Since: containers-0.5.9 |
| Ord k => Ord1 (Map k) | Since: containers-0.5.9 |
Defined in Data.Map.Internal | |
| (Ord k, Read k) => Read1 (Map k) | Since: containers-0.5.9 |
Defined in Data.Map.Internal | |
| Show k => Show1 (Map k) | Since: containers-0.5.9 |
| Traversable (Map k) | Traverses in order of increasing key. |
| Functor (Map k) | |
| Hashable k => Hashable1 (Map k) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| (FromJSONKey k, Ord k, FromJSON v) => FromJSON (Map k v) | |
| (ToJSON v, ToJSONKey k) => ToJSON (Map k v) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data k, Data a, Ord k) => Data (Map k a) | |
Defined in Data.Map.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Map k a -> c (Map k a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Map k a) # toConstr :: Map k a -> Constr # dataTypeOf :: Map k a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Map k a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Map k a)) # gmapT :: (forall b. Data b => b -> b) -> Map k a -> Map k a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Map k a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Map k a -> r # gmapQ :: (forall d. Data d => d -> u) -> Map k a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Map k a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # | |
| Ord k => Monoid (Map k v) | |
| Ord k => Semigroup (Map k v) | |
| Ord k => IsList (Map k v) | Since: containers-0.5.6.2 |
| (Ord k, Read k, Read e) => Read (Map k e) | |
| (Show k, Show a) => Show (Map k a) | |
| (NFData k, NFData a) => NFData (Map k a) | |
Defined in Data.Map.Internal | |
| (Eq k, Eq a) => Eq (Map k a) | |
| (Ord k, Ord v) => Ord (Map k v) | |
| (Hashable k, Hashable v) => Hashable (Map k v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Container (Map k v) | |
Defined in Universum.Container.Class Methods toList :: Map k v -> [Element (Map k v)] # foldr :: (Element (Map k v) -> b -> b) -> b -> Map k v -> b # foldl :: (b -> Element (Map k v) -> b) -> b -> Map k v -> b # foldl' :: (b -> Element (Map k v) -> b) -> b -> Map k v -> b # elem :: Element (Map k v) -> Map k v -> Bool # foldMap :: Monoid m => (Element (Map k v) -> m) -> Map k v -> m # fold :: Map k v -> Element (Map k v) # foldr' :: (Element (Map k v) -> b -> b) -> b -> Map k v -> b # notElem :: Element (Map k v) -> Map k v -> Bool # all :: (Element (Map k v) -> Bool) -> Map k v -> Bool # any :: (Element (Map k v) -> Bool) -> Map k v -> Bool # find :: (Element (Map k v) -> Bool) -> Map k v -> Maybe (Element (Map k v)) # safeHead :: Map k v -> Maybe (Element (Map k v)) # safeMaximum :: Map k v -> Maybe (Element (Map k v)) # safeMinimum :: Map k v -> Maybe (Element (Map k v)) # safeFoldr1 :: (Element (Map k v) -> Element (Map k v) -> Element (Map k v)) -> Map k v -> Maybe (Element (Map k v)) # safeFoldl1 :: (Element (Map k v) -> Element (Map k v) -> Element (Map k v)) -> Map k v -> Maybe (Element (Map k v)) # | |
| Ord k => FromList (Map k v) | |
Defined in Universum.Container.Class Methods fromList :: [ListElement (Map k v)] -> Map k v # | |
| One (Map k v) | |
| ToPairs (Map k v) | |
| type Item (Map k v) | |
Defined in Data.Map.Internal | |
| type Element (Map k v) | |
Defined in Universum.Container.Class | |
| type FromListC (Map k v) | |
Defined in Universum.Container.Class | |
| type Key (Map k v) | |
Defined in Universum.Container.Class | |
| type ListElement (Map k v) | |
Defined in Universum.Container.Class | |
| type OneItem (Map k v) | |
Defined in Universum.Container.Class | |
| type Val (Map k v) | |
Defined in Universum.Container.Class | |
A type that can be converted to JSON.
Instances in general must specify toJSON and should (but don't need
to) specify toEncoding.
An example type and instance:
-- Allow ourselves to writeTextliterals. {-# LANGUAGE OverloadedStrings #-} data Coord = Coord { x :: Double, y :: Double } instanceToJSONCoord wheretoJSON(Coord x y) =object["x".=x, "y".=y]toEncoding(Coord x y) =pairs("x".=x<>"y".=y)
Instead of manually writing your ToJSON instance, there are two options
to do it automatically:
- Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
- The compiler can provide a default generic implementation for
toJSON.
To use the second, simply add a deriving clause to your
datatype and declare a GenericToJSON instance. If you require nothing other than
defaultOptions, it is sufficient to write (and this is the only
alternative where the default toJSON implementation is sufficient):
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics
data Coord = Coord { x :: Double, y :: Double } deriving Generic
instance ToJSON Coord where
toEncoding = genericToEncoding defaultOptions
If on the other hand you wish to customize the generic decoding, you have to implement both methods:
customOptions =defaultOptions{fieldLabelModifier=maptoUpper} instanceToJSONCoord wheretoJSON=genericToJSONcustomOptionstoEncoding=genericToEncodingcustomOptions
Previous versions of this library only had the toJSON method. Adding
toEncoding had two reasons:
- toEncoding is more efficient for the common case that the output of
toJSONis directly serialized to aByteString. Further, expressing either method in terms of the other would be non-optimal. - The choice of defaults allows a smooth transition for existing users:
Existing instances that do not define
toEncodingstill compile and have the correct semantics. This is ensured by making the default implementation oftoEncodingusetoJSON. This produces correct results, but since it performs an intermediate conversion to aValue, it will be less efficient than directly emitting anEncoding. (this also means that specifying nothing more thaninstance ToJSON Coordwould be sufficient as a generically decoding instance, but there probably exists no good reason to not specifytoEncodingin new instances.)
Instances
fromJSON :: FromJSON a => Value -> Result a #
Convert a value from JSON, failing if the types do not match.
genericParseJSON :: (Generic a, GFromJSON Zero (Rep a)) => Options -> Value -> Parser a #
A configurable generic JSON decoder. This function applied to
defaultOptions is used as the default for parseJSON when the
type is an instance of Generic.
A type that can be converted from JSON, with the possibility of failure.
In many cases, you can get the compiler to generate parsing code for you (see below). To begin, let's cover writing an instance by hand.
There are various reasons a conversion could fail. For example, an
Object could be missing a required key, an Array could be of
the wrong size, or a value could be of an incompatible type.
The basic ways to signal a failed conversion are as follows:
failyields a custom error message: it is the recommended way of reporting a failure;empty(ormzero) is uninformative: use it when the error is meant to be caught by some(;<|>)typeMismatchcan be used to report a failure when the encountered value is not of the expected JSON type;unexpectedis an appropriate alternative when more than one type may be expected, or to keep the expected type implicit.
prependFailure (or modifyFailure) add more information to a parser's
error messages.
An example type and instance using typeMismatch and prependFailure:
-- Allow ourselves to writeTextliterals. {-# LANGUAGE OverloadedStrings #-} data Coord = Coord { x :: Double, y :: Double } instanceFromJSONCoord whereparseJSON(Objectv) = Coord<$>v.:"x"<*>v.:"y" -- We do not expect a non-Objectvalue here. -- We could useemptyto fail, buttypeMismatch-- gives a much more informative error message.parseJSONinvalid =prependFailure"parsing Coord failed, " (typeMismatch"Object" invalid)
For this common case of only being concerned with a single
type of JSON value, the functions withObject, withScientific, etc.
are provided. Their use is to be preferred when possible, since
they are more terse. Using withObject, we can rewrite the above instance
(assuming the same language extension and data type) as:
instanceFromJSONCoord whereparseJSON=withObject"Coord" $ \v -> Coord<$>v.:"x"<*>v.:"y"
Instead of manually writing your FromJSON instance, there are two options
to do it automatically:
- Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
- The compiler can provide a default generic implementation for
parseJSON.
To use the second, simply add a deriving clause to your
datatype and declare a GenericFromJSON instance for your datatype without giving
a definition for parseJSON.
For example, the previous example can be simplified to just:
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics
data Coord = Coord { x :: Double, y :: Double } deriving Generic
instance FromJSON Coord
The default implementation will be equivalent to
parseJSON = ; if you need different
options, you can customize the generic decoding by defining:genericParseJSON defaultOptions
customOptions =defaultOptions{fieldLabelModifier=maptoUpper} instanceFromJSONCoord whereparseJSON=genericParseJSONcustomOptions
Minimal complete definition
Nothing
Instances
class FromJSONKey a where #
Read the docs for ToJSONKey first. This class is a conversion
in the opposite direction. If you have a newtype wrapper around Text,
the recommended way to define instances is with generalized newtype deriving:
newtype SomeId = SomeId { getSomeId :: Text }
deriving (Eq,Ord,Hashable,FromJSONKey)If you have a sum of nullary constructors, you may use the generic implementation:
data Color = Red | Green | Blue deriving Generic instanceFromJSONKeyColor wherefromJSONKey=genericFromJSONKeydefaultJSONKeyOptions
Minimal complete definition
Nothing
Methods
fromJSONKey :: FromJSONKeyFunction a #
Strategy for parsing the key of a map-like container.
fromJSONKeyList :: FromJSONKeyFunction [a] #
Instances
camelTo2 :: Char -> String -> String #
Better version of camelTo. Example where it works better:
camelTo '_' 'CamelAPICase' == "camel_apicase" camelTo2 '_' 'CamelAPICase' == "camel_api_case"
Default encoding Options:
Options{fieldLabelModifier= id ,constructorTagModifier= id ,allNullaryToStringTag= True ,omitNothingFields= False ,sumEncoding=defaultTaggedObject,unwrapUnaryRecords= False ,tagSingleConstructors= False ,rejectUnknownFields= False }
Options that specify how to encode/decode your datatype to/from JSON.
Options can be set using record syntax on defaultOptions with the fields
below.
(<**>) :: Applicative f => f a -> f (a -> b) -> f b infixl 4 #
A variant of <*> with the arguments reversed.
Haskell defines operations to read and write characters from and to files,
represented by values of type Handle. Each value of this type is a
handle: a record used by the Haskell run-time system to manage I/O
with file system objects. A handle has at least the following properties:
- whether it manages input or output or both;
- whether it is open, closed or semi-closed;
- whether the object is seekable;
- whether buffering is disabled, or enabled on a line or block basis;
- a buffer (whose length may be zero).
Most handles will also have a current I/O position indicating where the next
input or output operation will occur. A handle is readable if it
manages only input or both input and output; likewise, it is writable if
it manages only output or both input and output. A handle is open when
first allocated.
Once it is closed it can no longer be used for either input or output,
though an implementation cannot re-use its storage while references
remain to it. Handles are in the Show and Eq classes. The string
produced by showing a handle is system dependent; it should include
enough information to identify the handle for debugging. A handle is
equal according to == only to itself; no attempt
is made to compare the internal state of different handles for equality.
Instances
class Bifunctor (p :: Type -> Type -> Type) where #
A bifunctor is a type constructor that takes
two type arguments and is a functor in both arguments. That
is, unlike with Functor, a type constructor such as Either
does not need to be partially applied for a Bifunctor
instance, and the methods in this class permit mapping
functions over the Left value or the Right value,
or both at the same time.
Formally, the class Bifunctor represents a bifunctor
from Hask -> Hask.
Intuitively it is a bifunctor where both the first and second arguments are covariant.
You can define a Bifunctor by either defining bimap or by
defining both first and second.
If you supply bimap, you should ensure that:
bimapidid≡id
If you supply first and second, ensure:
firstid≡idsecondid≡id
If you supply both, you should also ensure:
bimapf g ≡firstf.secondg
These ensure by parametricity:
bimap(f.g) (h.i) ≡bimapf h.bimapg ifirst(f.g) ≡firstf.firstgsecond(f.g) ≡secondf.secondg
Since: base-4.8.0.0
Methods
bimap :: (a -> b) -> (c -> d) -> p a c -> p b d #
Map over both arguments at the same time.
bimapf g ≡firstf.secondg
Examples
>>>bimap toUpper (+1) ('j', 3)('J',4)
>>>bimap toUpper (+1) (Left 'j')Left 'J'
>>>bimap toUpper (+1) (Right 3)Right 4
Instances
| Bifunctor Either | Since: base-4.8.0.0 |
| Bifunctor Arg | Since: base-4.9.0.0 |
| Bifunctor Either | |
| Bifunctor These | |
| Bifunctor Pair | |
| Bifunctor These | |
| Bifunctor (,) | Since: base-4.8.0.0 |
| Bifunctor (Const :: Type -> Type -> Type) | Since: base-4.8.0.0 |
| Bifunctor (Tagged :: Type -> Type -> Type) | |
| Bifunctor ((,,) x1) | Since: base-4.8.0.0 |
| Bifunctor (K1 i :: Type -> Type -> Type) | Since: base-4.9.0.0 |
| Bifunctor ((,,,) x1 x2) | Since: base-4.8.0.0 |
| Bifunctor p => Bifunctor (Flip p) | |
| Bifunctor ((,,,,) x1 x2 x3) | Since: base-4.8.0.0 |
| (Bifunctor f, Bifunctor g) => Bifunctor (Product f g) | |
| (Bifunctor p, Bifunctor q) => Bifunctor (Sum p q) | |
| Bifunctor ((,,,,,) x1 x2 x3 x4) | Since: base-4.8.0.0 |
| (Functor f, Bifunctor p) => Bifunctor (Tannen f p) | |
| Bifunctor ((,,,,,,) x1 x2 x3 x4 x5) | Since: base-4.8.0.0 |
| (Bifunctor p, Functor f, Functor g) => Bifunctor (Biff p f g) | |
class Applicative f => Alternative (f :: Type -> Type) where #
A monoid on applicative functors.
If defined, some and many should be the least solutions
of the equations:
Methods
The identity of <|>
(<|>) :: f a -> f a -> f a infixl 3 #
An associative binary operation
One or more.
Zero or more.
Instances
class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type) where #
Monads that also support choice and failure.
Minimal complete definition
Nothing
Methods
The identity of mplus. It should also satisfy the equations
mzero >>= f = mzero v >> mzero = mzero
The default definition is
mzero = empty
An associative operation. The default definition is
mplus = (<|>)
Instances
newtype Compose (f :: k -> Type) (g :: k1 -> k) (a :: k1) infixr 9 #
Right-to-left composition of functors. The composition of applicative functors is always applicative, but the composition of monads is not always a monad.
Constructors
| Compose infixr 9 | |
Fields
| |
Instances
| TestEquality f => TestEquality (Compose f g :: k2 -> Type) | The deduction (via generativity) that if Since: base-4.14.0.0 |
Defined in Data.Functor.Compose | |
| Functor f => Generic1 (Compose f g :: k -> Type) | |
| Unbox (f (g a)) => Vector Vector (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: PrimMonad m => Mutable Vector (PrimState m) (Compose f g a) -> m (Vector (Compose f g a)) # basicUnsafeThaw :: PrimMonad m => Vector (Compose f g a) -> m (Mutable Vector (PrimState m) (Compose f g a)) # basicLength :: Vector (Compose f g a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Compose f g a) -> Vector (Compose f g a) # basicUnsafeIndexM :: Monad m => Vector (Compose f g a) -> Int -> m (Compose f g a) # basicUnsafeCopy :: PrimMonad m => Mutable Vector (PrimState m) (Compose f g a) -> Vector (Compose f g a) -> m () # elemseq :: Vector (Compose f g a) -> Compose f g a -> b -> b # | |
| Unbox (f (g a)) => MVector MVector (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Compose f g a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Compose f g a) -> MVector s (Compose f g a) # basicOverlaps :: MVector s (Compose f g a) -> MVector s (Compose f g a) -> Bool # basicUnsafeNew :: PrimMonad m => Int -> m (MVector (PrimState m) (Compose f g a)) # basicInitialize :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> m () # basicUnsafeReplicate :: PrimMonad m => Int -> Compose f g a -> m (MVector (PrimState m) (Compose f g a)) # basicUnsafeRead :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> Int -> m (Compose f g a) # basicUnsafeWrite :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> Int -> Compose f g a -> m () # basicClear :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> m () # basicSet :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> Compose f g a -> m () # basicUnsafeCopy :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> MVector (PrimState m) (Compose f g a) -> m () # basicUnsafeMove :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> MVector (PrimState m) (Compose f g a) -> m () # basicUnsafeGrow :: PrimMonad m => MVector (PrimState m) (Compose f g a) -> Int -> m (MVector (PrimState m) (Compose f g a)) # | |
| (FromJSON1 f, FromJSON1 g) => FromJSON1 (Compose f g) | |
| (ToJSON1 f, ToJSON1 g) => ToJSON1 (Compose f g) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Compose f g a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Compose f g a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Compose f g a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Compose f g a] -> Encoding # | |
| (Foldable f, Foldable g) => Foldable (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods fold :: Monoid m => Compose f g m -> m # foldMap :: Monoid m => (a -> m) -> Compose f g a -> m # foldMap' :: Monoid m => (a -> m) -> Compose f g a -> m # foldr :: (a -> b -> b) -> b -> Compose f g a -> b # foldr' :: (a -> b -> b) -> b -> Compose f g a -> b # foldl :: (b -> a -> b) -> b -> Compose f g a -> b # foldl' :: (b -> a -> b) -> b -> Compose f g a -> b # foldr1 :: (a -> a -> a) -> Compose f g a -> a # foldl1 :: (a -> a -> a) -> Compose f g a -> a # toList :: Compose f g a -> [a] # null :: Compose f g a -> Bool # length :: Compose f g a -> Int # elem :: Eq a => a -> Compose f g a -> Bool # maximum :: Ord a => Compose f g a -> a # minimum :: Ord a => Compose f g a -> a # | |
| (Eq1 f, Eq1 g) => Eq1 (Compose f g) | Since: base-4.9.0.0 |
| (Ord1 f, Ord1 g) => Ord1 (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Read1 f, Read1 g) => Read1 (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Compose f g a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Compose f g a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Compose f g a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Compose f g a] # | |
| (Show1 f, Show1 g) => Show1 (Compose f g) | Since: base-4.9.0.0 |
| (Traversable f, Traversable g) => Traversable (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Alternative f, Applicative g) => Alternative (Compose f g) | Since: base-4.9.0.0 |
| (Applicative f, Applicative g) => Applicative (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Functor f, Functor g) => Functor (Compose f g) | Since: base-4.9.0.0 |
| (NFData1 f, NFData1 g) => NFData1 (Compose f g) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| (Hashable1 f, Hashable1 g) => Hashable1 (Compose f g) | |
Defined in Data.Hashable.Class | |
| (FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Compose f g a) | |
| (ToJSON1 f, ToJSON1 g, ToJSON a) => ToJSON (Compose f g a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Typeable a, Typeable f, Typeable g, Typeable k1, Typeable k2, Data (f (g a))) => Data (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g0. g0 -> c g0) -> Compose f g a -> c (Compose f g a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Compose f g a) # toConstr :: Compose f g a -> Constr # dataTypeOf :: Compose f g a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Compose f g a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Compose f g a)) # gmapT :: (forall b. Data b => b -> b) -> Compose f g a -> Compose f g a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Compose f g a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Compose f g a -> r # gmapQ :: (forall d. Data d => d -> u) -> Compose f g a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Compose f g a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a) # | |
| Generic (Compose f g a) | |
| (Read1 f, Read1 g, Read a) => Read (Compose f g a) | Since: base-4.9.0.0 |
| (Show1 f, Show1 g, Show a) => Show (Compose f g a) | Since: base-4.9.0.0 |
| (NFData1 f, NFData1 g, NFData a) => NFData (Compose f g a) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| (Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a) | Since: base-4.9.0.0 |
| (Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods compare :: Compose f g a -> Compose f g a -> Ordering # (<) :: Compose f g a -> Compose f g a -> Bool # (<=) :: Compose f g a -> Compose f g a -> Bool # (>) :: Compose f g a -> Compose f g a -> Bool # (>=) :: Compose f g a -> Compose f g a -> Bool # | |
| (Hashable1 f, Hashable1 g, Hashable a) => Hashable (Compose f g a) | In general, |
Defined in Data.Hashable.Class | |
| Unbox (f (g a)) => Unbox (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 (Compose f g :: k -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| newtype MVector s (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| newtype Vector (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base | |
Uninhabited data type
Since: base-4.8.0.0
Instances
| FromJSON Void | |
| ToJSON Void | |
Defined in Data.Aeson.Types.ToJSON | |
| Data Void | Since: base-4.8.0.0 |
Defined in Data.Void Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Void -> c Void # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Void # dataTypeOf :: Void -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Void) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Void) # gmapT :: (forall b. Data b => b -> b) -> Void -> Void # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQ :: (forall d. Data d => d -> u) -> Void -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Void -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void # | |
| Semigroup Void | Since: base-4.9.0.0 |
| Exception Void | Since: base-4.8.0.0 |
Defined in Data.Void Methods toException :: Void -> SomeException # fromException :: SomeException -> Maybe Void # displayException :: Void -> String # | |
| Generic Void | |
| Ix Void | Since: base-4.8.0.0 |
| Read Void | Reading a Since: base-4.8.0.0 |
| Show Void | Since: base-4.8.0.0 |
| NFData Void | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq Void | Since: base-4.8.0.0 |
| Ord Void | Since: base-4.8.0.0 |
| Hashable Void | |
Defined in Data.Hashable.Class | |
| Lift Void | Since: template-haskell-2.15.0.0 |
| type Rep Void | Since: base-4.8.0.0 |
Since Void values logically don't exist, this witnesses the
logical reasoning tool of "ex falso quodlibet".
>>>let x :: Either Void Int; x = Right 5>>>:{case x of Right r -> r Left l -> absurd l :} 5
Since: base-4.8.0.0
data WrappedMonoid m #
Provide a Semigroup for an arbitrary Monoid.
NOTE: This is not needed anymore since Semigroup became a superclass of
Monoid in base-4.11 and this newtype be deprecated at some point in the future.
Instances
Option is effectively Maybe with a better instance of
Monoid, built off of an underlying Semigroup instead of an
underlying Monoid.
Ideally, this type would not exist at all and we would just fix the
Monoid instance of Maybe.
In GHC 8.4 and higher, the Monoid instance for Maybe has been
corrected to lift a Semigroup instance instead of a Monoid
instance. Consequently, this type is no longer useful.
Instances
| FromJSON1 Option | |
| ToJSON1 Option | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Option a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Option a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Option a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Option a] -> Encoding # | |
| MonadFix Option | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| Foldable Option | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Option m -> m # foldMap :: Monoid m => (a -> m) -> Option a -> m # foldMap' :: Monoid m => (a -> m) -> Option a -> m # foldr :: (a -> b -> b) -> b -> Option a -> b # foldr' :: (a -> b -> b) -> b -> Option a -> b # foldl :: (b -> a -> b) -> b -> Option a -> b # foldl' :: (b -> a -> b) -> b -> Option a -> b # foldr1 :: (a -> a -> a) -> Option a -> a # foldl1 :: (a -> a -> a) -> Option a -> a # elem :: Eq a => a -> Option a -> Bool # maximum :: Ord a => Option a -> a # minimum :: Ord a => Option a -> a # | |
| Traversable Option | Since: base-4.9.0.0 |
| Alternative Option | Since: base-4.9.0.0 |
| Applicative Option | Since: base-4.9.0.0 |
| Functor Option | Since: base-4.9.0.0 |
| Monad Option | Since: base-4.9.0.0 |
| MonadPlus Option | Since: base-4.9.0.0 |
| NFData1 Option | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable1 Option | Since: hashable-1.3.1.0 |
Defined in Data.Hashable.Class | |
| (Selector s, GToJSON' enc arity (K1 i (Maybe a) :: Type -> Type), KeyValuePair enc pairs, Monoid pairs) => RecordToPairs enc pairs arity (S1 s (K1 i (Option a) :: Type -> Type)) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Selector s, FromJSON a) => RecordFromJSON' arity (S1 s (K1 i (Option a) :: Type -> Type)) | |
Defined in Data.Aeson.Types.FromJSON | |
| FromJSON a => FromJSON (Option a) | |
| ToJSON a => ToJSON (Option a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (Option a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Option a -> c (Option a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Option a) # toConstr :: Option a -> Constr # dataTypeOf :: Option a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Option a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Option a)) # gmapT :: (forall b. Data b => b -> b) -> Option a -> Option a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Option a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Option a -> r # gmapQ :: (forall d. Data d => d -> u) -> Option a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Option a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Option a -> m (Option a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Option a -> m (Option a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Option a -> m (Option a) # | |
| Semigroup a => Monoid (Option a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Option a) | Since: base-4.9.0.0 |
| Generic (Option a) | |
| Read a => Read (Option a) | Since: base-4.9.0.0 |
| Show a => Show (Option a) | Since: base-4.9.0.0 |
| NFData a => NFData (Option a) | Since: deepseq-1.4.2.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Option a) | Since: base-4.9.0.0 |
| Ord a => Ord (Option a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| Hashable a => Hashable (Option a) | |
Defined in Data.Hashable.Class | |
| Generic1 Option | |
| type Rep (Option a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| type Rep1 Option | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
mtimesDefault :: (Integral b, Monoid a) => b -> a -> a #
sortWith :: Ord b => (a -> b) -> [a] -> [a] #
The sortWith function sorts a list of elements using the
user supplied function to project something out of each element
showStackTrace :: IO (Maybe String) #
Get a string representation of the current execution stack state.
getStackTrace :: IO (Maybe [Location]) #
Get a trace of the current execution stack state.
Returns Nothing if stack trace support isn't available on host machine.
class Monad m => MonadIO (m :: Type -> Type) where #
Monads in which IO computations may be embedded.
Any monad built by applying a sequence of monad transformers to the
IO monad will be an instance of this class.
Instances should satisfy the following laws, which state that liftIO
is a transformer of monads:
Methods
Lift a computation from the IO monad.
This allows us to run IO computations in any monadic stack, so long as it supports these kinds of operations
(i.e. IO is the base monad for the stack).
Example
import Control.Monad.Trans.State -- from the "transformers" library printState :: Show s => StateT s IO () printState = do state <- get liftIO $ print state
Had we omitted liftIO
• Couldn't match type ‘IO’ with ‘StateT s IO’ Expected type: StateT s IO () Actual type: IO ()
The important part here is the mismatch between StateT s IO () and IO ()
Luckily, we know of a function that takes an IO a(m a): liftIO
> evalStateT printState "hello" "hello" > evalStateT printState 3 3
Instances
| MonadIO IO | Since: base-4.9.0.0 |
Defined in Control.Monad.IO.Class | |
| MonadIO Q | |
Defined in Language.Haskell.TH.Syntax | |
| MonadIO m => MonadIO (ResourceT m) | |
Defined in Control.Monad.Trans.Resource.Internal | |
| MonadIO m => MonadIO (MaybeT m) | |
Defined in Control.Monad.Trans.Maybe | |
| (Error e, MonadIO m) => MonadIO (ErrorT e m) | |
Defined in Control.Monad.Trans.Error | |
| MonadIO m => MonadIO (ExceptT e m) | |
Defined in Control.Monad.Trans.Except | |
| MonadIO m => MonadIO (IdentityT m) | |
Defined in Control.Monad.Trans.Identity | |
| MonadIO m => MonadIO (ReaderT r m) | |
Defined in Control.Monad.Trans.Reader | |
| MonadIO m => MonadIO (StateT s m) | |
Defined in Control.Monad.Trans.State.Lazy | |
| MonadIO m => MonadIO (StateT s m) | |
Defined in Control.Monad.Trans.State.Strict | |
| MonadIO m => MonadIO (ConduitT i o m) | |
Defined in Data.Conduit.Internal.Conduit | |
| MonadIO m => MonadIO (Pipe l i o u m) | |
Defined in Data.Conduit.Internal.Pipe | |
zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m () #
zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c] #
unless :: Applicative f => Bool -> f () -> f () #
The reverse of when.
replicateM_ :: Applicative m => Int -> m a -> m () #
Like replicateM, but discards the result.
replicateM :: Applicative m => Int -> m a -> m [a] #
replicateM n actact n times,
and then returns the list of results:
Examples
>>>replicateM 3 (putStrLn "a")a a a
mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c]) #
The mapAndUnzipM function maps its first argument over a list, returning
the result as a pair of lists. This function is mainly used with complicated
data structures or a state monad.
forever :: Applicative f => f a -> f b #
Repeat an action indefinitely.
Examples
A common use of forever is to process input from network sockets,
Handles, and channels
(e.g. MVar and
Chan).
For example, here is how we might implement an echo
server, using
forever both to listen for client connections on a network socket
and to echo client input on client connection handles:
echoServer :: Socket -> IO () echoServer socket =forever$ do client <- accept socketforkFinally(echo client) (\_ -> hClose client) where echo :: Handle -> IO () echo client =forever$ hGetLine client >>= hPutStrLn client
Note that "forever" isn't necessarily non-terminating.
If the action is in a MonadPlusforevermzero, effectively short-circuiting its caller.
foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m () #
Like foldM, but discards the result.
foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b #
The foldM function is analogous to foldl, except that its result is
encapsulated in a monad. Note that foldM works from left-to-right over
the list arguments. This could be an issue where ( and the `folded
function' are not commutative.>>)
foldM f a1 [x1, x2, ..., xm] == do a2 <- f a1 x1 a3 <- f a2 x2 ... f am xm
If right-to-left evaluation is required, the input list should be reversed.
filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a] #
This generalizes the list-based filter function.
(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c infixr 1 #
Left-to-right composition of Kleisli arrows.
'(bs ' can be understood as the >=> cs) ado expression
do b <- bs a cs b
mapAccumR :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b) #
The mapAccumR function behaves like a combination of fmap
and foldr; it applies a function to each element of a structure,
passing an accumulating parameter from right to left, and returning
a final value of this accumulator together with the new structure.
Examples
Basic usage:
>>>mapAccumR (\a b -> (a + b, a)) 0 [1..10](55,[54,52,49,45,40,34,27,19,10,0])
>>>mapAccumR (\a b -> (a <> show b, a)) "0" [1..5]("054321",["05432","0543","054","05","0"])
mapAccumL :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b) #
The mapAccumL function behaves like a combination of fmap
and foldl; it applies a function to each element of a structure,
passing an accumulating parameter from left to right, and returning
a final value of this accumulator together with the new structure.
Examples
Basic usage:
>>>mapAccumL (\a b -> (a + b, a)) 0 [1..10](55,[0,1,3,6,10,15,21,28,36,45])
>>>mapAccumL (\a b -> (a <> show b, a)) "0" [1..5]("012345",["0","01","012","0123","01234"])
forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b) #
foldMapDefault :: (Traversable t, Monoid m) => (a -> m) -> t a -> m #
fmapDefault :: Traversable t => (a -> b) -> t a -> t b #
This function may be used as a value for fmap in a Functor
instance, provided that traverse is defined. (Using
fmapDefault with a Traversable instance defined only by
sequenceA will result in infinite recursion.)
fmapDefaultf ≡runIdentity.traverse(Identity. f)
Lists, but with an Applicative functor based on zipping.
Constructors
| ZipList | |
Fields
| |
Instances
| Foldable ZipList | Since: base-4.9.0.0 |
Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # | |
| Traversable ZipList | Since: base-4.9.0.0 |
| Alternative ZipList | Since: base-4.11.0.0 |
| Applicative ZipList | f <$> ZipList xs1 <*> ... <*> ZipList xsN
= ZipList (zipWithN f xs1 ... xsN)where (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <*> ZipList "567" <*> ZipList [1..]
= ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..])
= ZipList {getZipList = ["a5","b6b6","c7c7c7"]}Since: base-2.1 |
| Functor ZipList | Since: base-2.1 |
| NFData1 ZipList | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| IsList (ZipList a) | Since: base-4.15.0.0 |
| Generic (ZipList a) | |
| Read a => Read (ZipList a) | Since: base-4.7.0.0 |
| Show a => Show (ZipList a) | Since: base-4.7.0.0 |
| NFData a => NFData (ZipList a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (ZipList a) | Since: base-4.7.0.0 |
| Ord a => Ord (ZipList a) | Since: base-4.7.0.0 |
| Container (ZipList a) | |
Defined in Universum.Container.Class Methods toList :: ZipList a -> [Element (ZipList a)] # foldr :: (Element (ZipList a) -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> Element (ZipList a) -> b) -> b -> ZipList a -> b # foldl' :: (b -> Element (ZipList a) -> b) -> b -> ZipList a -> b # elem :: Element (ZipList a) -> ZipList a -> Bool # foldMap :: Monoid m => (Element (ZipList a) -> m) -> ZipList a -> m # fold :: ZipList a -> Element (ZipList a) # foldr' :: (Element (ZipList a) -> b -> b) -> b -> ZipList a -> b # notElem :: Element (ZipList a) -> ZipList a -> Bool # all :: (Element (ZipList a) -> Bool) -> ZipList a -> Bool # any :: (Element (ZipList a) -> Bool) -> ZipList a -> Bool # find :: (Element (ZipList a) -> Bool) -> ZipList a -> Maybe (Element (ZipList a)) # safeHead :: ZipList a -> Maybe (Element (ZipList a)) # safeMaximum :: ZipList a -> Maybe (Element (ZipList a)) # safeMinimum :: ZipList a -> Maybe (Element (ZipList a)) # safeFoldr1 :: (Element (ZipList a) -> Element (ZipList a) -> Element (ZipList a)) -> ZipList a -> Maybe (Element (ZipList a)) # safeFoldl1 :: (Element (ZipList a) -> Element (ZipList a) -> Element (ZipList a)) -> ZipList a -> Maybe (Element (ZipList a)) # | |
| FromList (ZipList a) | |
Defined in Universum.Container.Class Methods fromList :: [ListElement (ZipList a)] -> ZipList a # | |
| Generic1 ZipList | |
| type Item (ZipList a) | |
| type Rep (ZipList a) | Since: base-4.7.0.0 |
Defined in Control.Applicative | |
| type Element (ZipList a) | |
Defined in Universum.Container.Class | |
| type FromListC (ZipList a) | |
Defined in Universum.Container.Class | |
| type ListElement (ZipList a) | |
Defined in Universum.Container.Class | |
| type Rep1 ZipList | Since: base-4.7.0.0 |
Defined in Control.Applicative | |
optional :: Alternative f => f a -> f (Maybe a) #
One or none.
It is useful for modelling any computation that is allowed to fail.
Examples
Using the Alternative instance of Except, the following functions:
>>>canFail = throwError "it failed" :: Except String Int>>>final = return 42 :: Except String Int
Can be combined by allowing the first function to fail:
>>>runExcept $ canFail *> finalLeft "it failed">>>runExcept $ optional canFail *> finalRight 42
(&&&) :: Arrow a => a b c -> a b c' -> a b (c, c') infixr 3 #
Fanout: send the input to both argument arrows and combine their output.
The default definition may be overridden with a more efficient version if desired.
Identity functor and monad. (a non-strict monad)
Since: base-4.8.0.0
Constructors
| Identity | |
Fields
| |
Instances
withFrozenCallStack :: HasCallStack => (HasCallStack => a) -> a #
Perform some computation without adding new entries to the CallStack.
Since: base-4.9.0.0
callStack :: HasCallStack => CallStack #
Shared memory locations that support atomic memory transactions.
A monad supporting atomic memory transactions.
Instances
A mutable variable in the IO monad
Instances
| NFData1 IORef | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| NFData (IORef a) | NOTE: Only strict in the reference and not the referenced value. Since: deepseq-1.4.2.0 |
Defined in Control.DeepSeq | |
| Eq (IORef a) | Pointer equality. Since: base-4.0.0.0 |
File and directory names are values of type String, whose precise
meaning is operating system dependent. Files can be opened, yielding a
handle which can then be used to operate on the contents of that file.
prettySrcLoc :: SrcLoc -> String #
Pretty print a SrcLoc.
Since: base-4.9.0.0
prettyCallStack :: CallStack -> String #
Pretty print a CallStack.
Since: base-4.9.0.0
class (Typeable e, Show e) => Exception e where #
Any type that you wish to throw or catch as an exception must be an
instance of the Exception class. The simplest case is a new exception
type directly below the root:
data MyException = ThisException | ThatException
deriving Show
instance Exception MyExceptionThe default method definitions in the Exception class do what we need
in this case. You can now throw and catch ThisException and
ThatException as exceptions:
*Main> throw ThisException `catch` \e -> putStrLn ("Caught " ++ show (e :: MyException))
Caught ThisException
In more complicated examples, you may wish to define a whole hierarchy of exceptions:
---------------------------------------------------------------------
-- Make the root exception type for all the exceptions in a compiler
data SomeCompilerException = forall e . Exception e => SomeCompilerException e
instance Show SomeCompilerException where
show (SomeCompilerException e) = show e
instance Exception SomeCompilerException
compilerExceptionToException :: Exception e => e -> SomeException
compilerExceptionToException = toException . SomeCompilerException
compilerExceptionFromException :: Exception e => SomeException -> Maybe e
compilerExceptionFromException x = do
SomeCompilerException a <- fromException x
cast a
---------------------------------------------------------------------
-- Make a subhierarchy for exceptions in the frontend of the compiler
data SomeFrontendException = forall e . Exception e => SomeFrontendException e
instance Show SomeFrontendException where
show (SomeFrontendException e) = show e
instance Exception SomeFrontendException where
toException = compilerExceptionToException
fromException = compilerExceptionFromException
frontendExceptionToException :: Exception e => e -> SomeException
frontendExceptionToException = toException . SomeFrontendException
frontendExceptionFromException :: Exception e => SomeException -> Maybe e
frontendExceptionFromException x = do
SomeFrontendException a <- fromException x
cast a
---------------------------------------------------------------------
-- Make an exception type for a particular frontend compiler exception
data MismatchedParentheses = MismatchedParentheses
deriving Show
instance Exception MismatchedParentheses where
toException = frontendExceptionToException
fromException = frontendExceptionFromExceptionWe can now catch a MismatchedParentheses exception as
MismatchedParentheses, SomeFrontendException or
SomeCompilerException, but not other types, e.g. IOException:
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: MismatchedParentheses))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeFrontendException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeCompilerException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: IOException))
*** Exception: MismatchedParentheses
Minimal complete definition
Nothing
Methods
toException :: e -> SomeException #
fromException :: SomeException -> Maybe e #
displayException :: e -> String #
Render this exception value in a human-friendly manner.
Default implementation: show
Since: base-4.8.0.0
Instances
The Const functor.
Instances
| Generic1 (Const a :: k -> Type) | |
| Unbox a => Vector Vector (Const a b) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: PrimMonad m => Mutable Vector (PrimState m) (Const a b) -> m (Vector (Const a b)) # basicUnsafeThaw :: PrimMonad m => Vector (Const a b) -> m (Mutable Vector (PrimState m) (Const a b)) # basicLength :: Vector (Const a b) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Const a b) -> Vector (Const a b) # basicUnsafeIndexM :: Monad m => Vector (Const a b) -> Int -> m (Const a b) # basicUnsafeCopy :: PrimMonad m => Mutable Vector (PrimState m) (Const a b) -> Vector (Const a b) -> m () # | |
| Unbox a => MVector MVector (Const a b) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Const a b) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Const a b) -> MVector s (Const a b) # basicOverlaps :: MVector s (Const a b) -> MVector s (Const a b) -> Bool # basicUnsafeNew :: PrimMonad m => Int -> m (MVector (PrimState m) (Const a b)) # basicInitialize :: PrimMonad m => MVector (PrimState m) (Const a b) -> m () # basicUnsafeReplicate :: PrimMonad m => Int -> Const a b -> m (MVector (PrimState m) (Const a b)) # basicUnsafeRead :: PrimMonad m => MVector (PrimState m) (Const a b) -> Int -> m (Const a b) # basicUnsafeWrite :: PrimMonad m => MVector (PrimState m) (Const a b) -> Int -> Const a b -> m () # basicClear :: PrimMonad m => MVector (PrimState m) (Const a b) -> m () # basicSet :: PrimMonad m => MVector (PrimState m) (Const a b) -> Const a b -> m () # basicUnsafeCopy :: PrimMonad m => MVector (PrimState m) (Const a b) -> MVector (PrimState m) (Const a b) -> m () # basicUnsafeMove :: PrimMonad m => MVector (PrimState m) (Const a b) -> MVector (PrimState m) (Const a b) -> m () # basicUnsafeGrow :: PrimMonad m => MVector (PrimState m) (Const a b) -> Int -> m (MVector (PrimState m) (Const a b)) # | |
| FromJSON2 (Const :: Type -> Type -> Type) | |
Defined in Data.Aeson.Types.FromJSON | |
| ToJSON2 (Const :: Type -> Type -> Type) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> Const a b -> Value # liftToJSONList2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> [Const a b] -> Value # liftToEncoding2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> Const a b -> Encoding # liftToEncodingList2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> [Const a b] -> Encoding # | |
| Bifunctor (Const :: Type -> Type -> Type) | Since: base-4.8.0.0 |
| Eq2 (Const :: Type -> Type -> Type) | Since: base-4.9.0.0 |
| Ord2 (Const :: Type -> Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read2 (Const :: Type -> Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Const a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Const a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Const a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Const a b] # | |
| Show2 (Const :: Type -> Type -> Type) | Since: base-4.9.0.0 |
| NFData2 (Const :: Type -> Type -> Type) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable2 (Const :: Type -> Type -> Type) | |
Defined in Data.Hashable.Class | |
| FromJSON a => FromJSON1 (Const a :: Type -> Type) | |
| ToJSON a => ToJSON1 (Const a :: Type -> Type) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a0 -> Value) -> ([a0] -> Value) -> Const a a0 -> Value # liftToJSONList :: (a0 -> Value) -> ([a0] -> Value) -> [Const a a0] -> Value # liftToEncoding :: (a0 -> Encoding) -> ([a0] -> Encoding) -> Const a a0 -> Encoding # liftToEncodingList :: (a0 -> Encoding) -> ([a0] -> Encoding) -> [Const a a0] -> Encoding # | |
| Foldable (Const m :: Type -> Type) | Since: base-4.7.0.0 |
Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # | |
| Eq a => Eq1 (Const a :: Type -> Type) | Since: base-4.9.0.0 |
| Ord a => Ord1 (Const a :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read a => Read1 (Const a :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Const a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Const a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Const a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Const a a0] # | |
| Show a => Show1 (Const a :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (Const m :: Type -> Type) | Since: base-4.7.0.0 |
| Monoid m => Applicative (Const m :: Type -> Type) | Since: base-2.0.1 |
| Functor (Const m :: Type -> Type) | Since: base-2.1 |
| NFData a => NFData1 (Const a :: Type -> Type) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable a => Hashable1 (Const a :: Type -> Type) | |
Defined in Data.Hashable.Class | |
| FromJSON a => FromJSON (Const a b) | |
| (FromJSON a, FromJSONKey a) => FromJSONKey (Const a b) | |
Defined in Data.Aeson.Types.FromJSON Methods fromJSONKey :: FromJSONKeyFunction (Const a b) # fromJSONKeyList :: FromJSONKeyFunction [Const a b] # | |
| ToJSON a => ToJSON (Const a b) | |
Defined in Data.Aeson.Types.ToJSON | |
| (ToJSON a, ToJSONKey a) => ToJSONKey (Const a b) | |
Defined in Data.Aeson.Types.ToJSON | |
| Bits a => Bits (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods (.&.) :: Const a b -> Const a b -> Const a b # (.|.) :: Const a b -> Const a b -> Const a b # xor :: Const a b -> Const a b -> Const a b # complement :: Const a b -> Const a b # shift :: Const a b -> Int -> Const a b # rotate :: Const a b -> Int -> Const a b # setBit :: Const a b -> Int -> Const a b # clearBit :: Const a b -> Int -> Const a b # complementBit :: Const a b -> Int -> Const a b # testBit :: Const a b -> Int -> Bool # bitSizeMaybe :: Const a b -> Maybe Int # isSigned :: Const a b -> Bool # shiftL :: Const a b -> Int -> Const a b # unsafeShiftL :: Const a b -> Int -> Const a b # shiftR :: Const a b -> Int -> Const a b # unsafeShiftR :: Const a b -> Int -> Const a b # rotateL :: Const a b -> Int -> Const a b # | |
| FiniteBits a => FiniteBits (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods finiteBitSize :: Const a b -> Int # countLeadingZeros :: Const a b -> Int # countTrailingZeros :: Const a b -> Int # | |
| IsString a => IsString (Const a b) | Since: base-4.9.0.0 |
Defined in Data.String Methods fromString :: String -> Const a b # | |
| Storable a => Storable (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| Monoid a => Monoid (Const a b) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Const a b) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Const a b) | Since: base-4.9.0.0 |
| Enum a => Enum (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods succ :: Const a b -> Const a b # pred :: Const a b -> Const a b # fromEnum :: Const a b -> Int # enumFrom :: Const a b -> [Const a b] # enumFromThen :: Const a b -> Const a b -> [Const a b] # enumFromTo :: Const a b -> Const a b -> [Const a b] # enumFromThenTo :: Const a b -> Const a b -> Const a b -> [Const a b] # | |
| Floating a => Floating (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods exp :: Const a b -> Const a b # log :: Const a b -> Const a b # sqrt :: Const a b -> Const a b # (**) :: Const a b -> Const a b -> Const a b # logBase :: Const a b -> Const a b -> Const a b # sin :: Const a b -> Const a b # cos :: Const a b -> Const a b # tan :: Const a b -> Const a b # asin :: Const a b -> Const a b # acos :: Const a b -> Const a b # atan :: Const a b -> Const a b # sinh :: Const a b -> Const a b # cosh :: Const a b -> Const a b # tanh :: Const a b -> Const a b # asinh :: Const a b -> Const a b # acosh :: Const a b -> Const a b # atanh :: Const a b -> Const a b # log1p :: Const a b -> Const a b # expm1 :: Const a b -> Const a b # | |
| RealFloat a => RealFloat (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods floatRadix :: Const a b -> Integer # floatDigits :: Const a b -> Int # floatRange :: Const a b -> (Int, Int) # decodeFloat :: Const a b -> (Integer, Int) # encodeFloat :: Integer -> Int -> Const a b # exponent :: Const a b -> Int # significand :: Const a b -> Const a b # scaleFloat :: Int -> Const a b -> Const a b # isInfinite :: Const a b -> Bool # isDenormalized :: Const a b -> Bool # isNegativeZero :: Const a b -> Bool # | |
| Generic (Const a b) | |
| Ix a => Ix (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods range :: (Const a b, Const a b) -> [Const a b] # index :: (Const a b, Const a b) -> Const a b -> Int # unsafeIndex :: (Const a b, Const a b) -> Const a b -> Int # inRange :: (Const a b, Const a b) -> Const a b -> Bool # rangeSize :: (Const a b, Const a b) -> Int # unsafeRangeSize :: (Const a b, Const a b) -> Int # | |
| Num a => Num (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| Read a => Read (Const a b) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| Fractional a => Fractional (Const a b) | Since: base-4.9.0.0 |
| Integral a => Integral (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods quot :: Const a b -> Const a b -> Const a b # rem :: Const a b -> Const a b -> Const a b # div :: Const a b -> Const a b -> Const a b # mod :: Const a b -> Const a b -> Const a b # quotRem :: Const a b -> Const a b -> (Const a b, Const a b) # divMod :: Const a b -> Const a b -> (Const a b, Const a b) # | |
| Real a => Real (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods toRational :: Const a b -> Rational # | |
| RealFrac a => RealFrac (Const a b) | Since: base-4.9.0.0 |
| Show a => Show (Const a b) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| NFData a => NFData (Const a b) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Const a b) | Since: base-4.9.0.0 |
| Ord a => Ord (Const a b) | Since: base-4.9.0.0 |
| Hashable a => Hashable (Const a b) | |
Defined in Data.Hashable.Class | |
| Prim a => Prim (Const a b) | Since: primitive-0.6.5.0 |
Defined in Data.Primitive.Types Methods sizeOf# :: Const a b -> Int# # alignment# :: Const a b -> Int# # indexByteArray# :: ByteArray# -> Int# -> Const a b # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Const a b #) # writeByteArray# :: MutableByteArray# s -> Int# -> Const a b -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Const a b -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Const a b # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Const a b #) # writeOffAddr# :: Addr# -> Int# -> Const a b -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Const a b -> State# s -> State# s # | |
| Container (Const a b) | |
Defined in Universum.Container.Class Methods toList :: Const a b -> [Element (Const a b)] # foldr :: (Element (Const a b) -> b0 -> b0) -> b0 -> Const a b -> b0 # foldl :: (b0 -> Element (Const a b) -> b0) -> b0 -> Const a b -> b0 # foldl' :: (b0 -> Element (Const a b) -> b0) -> b0 -> Const a b -> b0 # elem :: Element (Const a b) -> Const a b -> Bool # foldMap :: Monoid m => (Element (Const a b) -> m) -> Const a b -> m # fold :: Const a b -> Element (Const a b) # foldr' :: (Element (Const a b) -> b0 -> b0) -> b0 -> Const a b -> b0 # notElem :: Element (Const a b) -> Const a b -> Bool # all :: (Element (Const a b) -> Bool) -> Const a b -> Bool # any :: (Element (Const a b) -> Bool) -> Const a b -> Bool # find :: (Element (Const a b) -> Bool) -> Const a b -> Maybe (Element (Const a b)) # safeHead :: Const a b -> Maybe (Element (Const a b)) # safeMaximum :: Const a b -> Maybe (Element (Const a b)) # safeMinimum :: Const a b -> Maybe (Element (Const a b)) # safeFoldr1 :: (Element (Const a b) -> Element (Const a b) -> Element (Const a b)) -> Const a b -> Maybe (Element (Const a b)) # safeFoldl1 :: (Element (Const a b) -> Element (Const a b) -> Element (Const a b)) -> Const a b -> Maybe (Element (Const a b)) # | |
| Unbox a => Unbox (Const a b) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 (Const a :: k -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| newtype MVector s (Const a b) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| type Element (Const a b) | |
Defined in Universum.Container.Class | |
| newtype Vector (Const a b) | |
Defined in Data.Vector.Unboxed.Base | |
foldrM :: (Foldable t, Monad m) => (a -> b -> m b) -> b -> t a -> m b #
Right-to-left monadic fold over the elements of a structure.
Given a structure t with elements (a, b, c, ..., x, y), the result of
a fold with an operator function f is equivalent to:
foldrM f z t = do
yy <- f y z
xx <- f x yy
...
bb <- f b cc
aa <- f a bb
return aa -- Just @return z@ when the structure is emptyFor a Monad m, given two functions f1 :: a -> m b and f2 :: b -> m c,
their Kleisli composition (f1 >=> f2) :: a -> m c is defined by:
(f1 >=> f2) a = f1 a >>= f2
Another way of thinking about foldrM is that it amounts to an application
to z of a Kleisli composition:
foldrM f z t = f y >=> f x >=> ... >=> f b >=> f a $ z
The monadic effects of foldrM are sequenced from right to left, and e.g.
folds of infinite lists will diverge.
If at some step the bind operator ( short-circuits (as with, e.g.,
>>=)mzero in a MonadPlus), the evaluated effects will be from a tail of the
element sequence. If you want to evaluate the monadic effects in
left-to-right order, or perhaps be able to short-circuit after an initial
sequence of elements, you'll need to use foldlM instead.
If the monadic effects don't short-circuit, the outermost application of
f is to the leftmost element a, so that, ignoring effects, the result
looks like a right fold:
a `f` (b `f` (c `f` (... (x `f` (y `f` z))))).
Examples
Basic usage:
>>>let f i acc = do { print i ; return $ i : acc }>>>foldrM f [] [0..3]3 2 1 0 [0,1,2,3]
foldlM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b #
Left-to-right monadic fold over the elements of a structure.
Given a structure t with elements (a, b, ..., w, x, y), the result of
a fold with an operator function f is equivalent to:
foldlM f z t = do
aa <- f z a
bb <- f aa b
...
xx <- f ww x
yy <- f xx y
return yy -- Just @return z@ when the structure is emptyFor a Monad m, given two functions f1 :: a -> m b and f2 :: b -> m c,
their Kleisli composition (f1 >=> f2) :: a -> m c is defined by:
(f1 >=> f2) a = f1 a >>= f2
Another way of thinking about foldlM is that it amounts to an application
to z of a Kleisli composition:
foldlM f z t =
flip f a >=> flip f b >=> ... >=> flip f x >=> flip f y $ zThe monadic effects of foldlM are sequenced from left to right.
If at some step the bind operator ( short-circuits (as with, e.g.,
>>=)mzero in a MonadPlus), the evaluated effects will be from an initial
segment of the element sequence. If you want to evaluate the monadic
effects in right-to-left order, or perhaps be able to short-circuit after
processing a tail of the sequence of elements, you'll need to use foldrM
instead.
If the monadic effects don't short-circuit, the outermost application of
f is to the rightmost element y, so that, ignoring effects, the result
looks like a left fold:
((((z `f` a) `f` b) ... `f` w) `f` x) `f` y
Examples
Basic usage:
>>>let f a e = do { print e ; return $ e : a }>>>foldlM f [] [0..3]0 1 2 3 [3,2,1,0]
concatMap :: Foldable t => (a -> [b]) -> t a -> [b] #
Map a function over all the elements of a container and concatenate the resulting lists.
Examples
Basic usage:
>>>concatMap (take 3) [[1..], [10..], [100..], [1000..]][1,2,3,10,11,12,100,101,102,1000,1001,1002]
>>>concatMap (take 3) (Just [1..])[1,2,3]
concat :: Foldable t => t [a] -> [a] #
The concatenation of all the elements of a container of lists.
Examples
Basic usage:
>>>concat (Just [1, 2, 3])[1,2,3]
>>>concat (Left 42)[]
>>>concat [[1, 2, 3], [4, 5], [6], []][1,2,3,4,5,6]
unfoldr :: (b -> Maybe (a, b)) -> b -> [a] #
The unfoldr function is a `dual' to foldr: while foldr
reduces a list to a summary value, unfoldr builds a list from
a seed value. The function takes the element and returns Nothing
if it is done producing the list or returns Just (a,b), in which
case, a is a prepended to the list and b is used as the next
element in a recursive call. For example,
iterate f == unfoldr (\x -> Just (x, f x))
In some cases, unfoldr can undo a foldr operation:
unfoldr f' (foldr f z xs) == xs
if the following holds:
f' (f x y) = Just (x,y) f' z = Nothing
A simple use of unfoldr:
>>>unfoldr (\b -> if b == 0 then Nothing else Just (b, b-1)) 10[10,9,8,7,6,5,4,3,2,1]
The transpose function transposes the rows and columns of its argument.
For example,
>>>transpose [[1,2,3],[4,5,6]][[1,4],[2,5],[3,6]]
If some of the rows are shorter than the following rows, their elements are skipped:
>>>transpose [[10,11],[20],[],[30,31,32]][[10,20,30],[11,31],[32]]
subsequences :: [a] -> [[a]] #
The subsequences function returns the list of all subsequences of the argument.
>>>subsequences "abc"["","a","b","ab","c","ac","bc","abc"]
sortOn :: Ord b => (a -> b) -> [a] -> [a] #
Sort a list by comparing the results of a key function applied to each
element. sortOn f is equivalent to sortBy (comparing f), but has the
performance advantage of only evaluating f once for each element in the
input list. This is called the decorate-sort-undecorate paradigm, or
Schwartzian transform.
Elements are arranged from lowest to highest, keeping duplicates in the order they appeared in the input.
>>>sortOn fst [(2, "world"), (4, "!"), (1, "Hello")][(1,"Hello"),(2,"world"),(4,"!")]
Since: base-4.8.0.0
permutations :: [a] -> [[a]] #
The permutations function returns the list of all permutations of the argument.
>>>permutations "abc"["abc","bac","cba","bca","cab","acb"]
isPrefixOf :: Eq a => [a] -> [a] -> Bool #
\(\mathcal{O}(\min(m,n))\). The isPrefixOf function takes two lists and
returns True iff the first list is a prefix of the second.
>>>"Hello" `isPrefixOf` "Hello World!"True
>>>"Hello" `isPrefixOf` "Wello Horld!"False
intersperse :: a -> [a] -> [a] #
\(\mathcal{O}(n)\). The intersperse function takes an element and a list
and `intersperses' that element between the elements of the list. For
example,
>>>intersperse ',' "abcde""a,b,c,d,e"
intercalate :: [a] -> [[a]] -> [a] #
intercalate xs xss is equivalent to (.
It inserts the list concat (intersperse xs xss))xs in between the lists in xss and concatenates the
result.
>>>intercalate ", " ["Lorem", "ipsum", "dolor"]"Lorem, ipsum, dolor"
group :: Eq a => [a] -> [[a]] #
The group function takes a list and returns a list of lists such
that the concatenation of the result is equal to the argument. Moreover,
each sublist in the result contains only equal elements. For example,
>>>group "Mississippi"["M","i","ss","i","ss","i","pp","i"]
It is a special case of groupBy, which allows the programmer to supply
their own equality test.
genericTake :: Integral i => i -> [a] -> [a] #
The genericTake function is an overloaded version of take, which
accepts any Integral value as the number of elements to take.
genericSplitAt :: Integral i => i -> [a] -> ([a], [a]) #
The genericSplitAt function is an overloaded version of splitAt, which
accepts any Integral value as the position at which to split.
genericReplicate :: Integral i => i -> a -> [a] #
The genericReplicate function is an overloaded version of replicate,
which accepts any Integral value as the number of repetitions to make.
genericLength :: Num i => [a] -> i #
\(\mathcal{O}(n)\). The genericLength function is an overloaded version
of length. In particular, instead of returning an Int, it returns any
type which is an instance of Num. It is, however, less efficient than
length.
>>>genericLength [1, 2, 3] :: Int3>>>genericLength [1, 2, 3] :: Float3.0
genericDrop :: Integral i => i -> [a] -> [a] #
The genericDrop function is an overloaded version of drop, which
accepts any Integral value as the number of elements to drop.
Maybe monoid returning the rightmost non-Nothing value.
Last aDual (First a)Dual (Alt Maybe a)
>>>getLast (Last (Just "hello") <> Last Nothing <> Last (Just "world"))Just "world"
Instances
| FromJSON1 Last | |
| ToJSON1 Last | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Last a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Last a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Last a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Last a] -> Encoding # | |
| Foldable Last | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Traversable Last | Since: base-4.8.0.0 |
| Applicative Last | Since: base-4.8.0.0 |
| Functor Last | Since: base-4.8.0.0 |
| Monad Last | Since: base-4.8.0.0 |
| NFData1 Last | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| FromJSON a => FromJSON (Last a) | |
| ToJSON a => ToJSON (Last a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Monoid (Last a) | Since: base-2.1 |
| Semigroup (Last a) | Since: base-4.9.0.0 |
| Generic (Last a) | |
| Read a => Read (Last a) | Since: base-2.1 |
| Show a => Show (Last a) | Since: base-2.1 |
| NFData a => NFData (Last a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Last a) | Since: base-2.1 |
| Ord a => Ord (Last a) | Since: base-2.1 |
| Container (Last a) | |
Defined in Universum.Container.Class Methods toList :: Last a -> [Element (Last a)] # foldr :: (Element (Last a) -> b -> b) -> b -> Last a -> b # foldl :: (b -> Element (Last a) -> b) -> b -> Last a -> b # foldl' :: (b -> Element (Last a) -> b) -> b -> Last a -> b # elem :: Element (Last a) -> Last a -> Bool # foldMap :: Monoid m => (Element (Last a) -> m) -> Last a -> m # fold :: Last a -> Element (Last a) # foldr' :: (Element (Last a) -> b -> b) -> b -> Last a -> b # notElem :: Element (Last a) -> Last a -> Bool # all :: (Element (Last a) -> Bool) -> Last a -> Bool # any :: (Element (Last a) -> Bool) -> Last a -> Bool # find :: (Element (Last a) -> Bool) -> Last a -> Maybe (Element (Last a)) # safeHead :: Last a -> Maybe (Element (Last a)) # safeMaximum :: Last a -> Maybe (Element (Last a)) # safeMinimum :: Last a -> Maybe (Element (Last a)) # safeFoldr1 :: (Element (Last a) -> Element (Last a) -> Element (Last a)) -> Last a -> Maybe (Element (Last a)) # safeFoldl1 :: (Element (Last a) -> Element (Last a) -> Element (Last a)) -> Last a -> Maybe (Element (Last a)) # | |
| Generic1 Last | |
| type Rep (Last a) | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
| type Element (Last a) | |
Defined in Universum.Container.Class | |
| type Rep1 Last | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
Maybe monoid returning the leftmost non-Nothing value.
First aAlt Maybe a
>>>getFirst (First (Just "hello") <> First Nothing <> First (Just "world"))Just "hello"
Instances
| FromJSON1 First | |
| ToJSON1 First | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> First a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [First a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> First a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [First a] -> Encoding # | |
| Foldable First | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Traversable First | Since: base-4.8.0.0 |
| Applicative First | Since: base-4.8.0.0 |
| Functor First | Since: base-4.8.0.0 |
| Monad First | Since: base-4.8.0.0 |
| NFData1 First | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| FromJSON a => FromJSON (First a) | |
| ToJSON a => ToJSON (First a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Monoid (First a) | Since: base-2.1 |
| Semigroup (First a) | Since: base-4.9.0.0 |
| Generic (First a) | |
| Read a => Read (First a) | Since: base-2.1 |
| Show a => Show (First a) | Since: base-2.1 |
| NFData a => NFData (First a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (First a) | Since: base-2.1 |
| Ord a => Ord (First a) | Since: base-2.1 |
| Container (First a) | |
Defined in Universum.Container.Class Methods toList :: First a -> [Element (First a)] # foldr :: (Element (First a) -> b -> b) -> b -> First a -> b # foldl :: (b -> Element (First a) -> b) -> b -> First a -> b # foldl' :: (b -> Element (First a) -> b) -> b -> First a -> b # elem :: Element (First a) -> First a -> Bool # foldMap :: Monoid m => (Element (First a) -> m) -> First a -> m # fold :: First a -> Element (First a) # foldr' :: (Element (First a) -> b -> b) -> b -> First a -> b # notElem :: Element (First a) -> First a -> Bool # all :: (Element (First a) -> Bool) -> First a -> Bool # any :: (Element (First a) -> Bool) -> First a -> Bool # find :: (Element (First a) -> Bool) -> First a -> Maybe (Element (First a)) # safeHead :: First a -> Maybe (Element (First a)) # safeMaximum :: First a -> Maybe (Element (First a)) # safeMinimum :: First a -> Maybe (Element (First a)) # safeFoldr1 :: (Element (First a) -> Element (First a) -> Element (First a)) -> First a -> Maybe (Element (First a)) # safeFoldl1 :: (Element (First a) -> Element (First a) -> Element (First a)) -> First a -> Maybe (Element (First a)) # | |
| Generic1 First | |
| type Rep (First a) | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
| type Element (First a) | |
Defined in Universum.Container.Class | |
| type Rep1 First | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
Monoid under addition.
>>>getSum (Sum 1 <> Sum 2 <> mempty)3
Instances
Monoid under multiplication.
>>>getProduct (Product 3 <> Product 4 <> mempty)12
Constructors
| Product | |
Fields
| |
Instances
The monoid of endomorphisms under composition.
>>>let computation = Endo ("Hello, " ++) <> Endo (++ "!")>>>appEndo computation "Haskell""Hello, Haskell!"
The dual of a Monoid, obtained by swapping the arguments of mappend.
>>>getDual (mappend (Dual "Hello") (Dual "World"))"WorldHello"
Instances
Boolean monoid under disjunction (||).
>>>getAny (Any True <> mempty <> Any False)True
>>>getAny (mconcat (map (\x -> Any (even x)) [2,4,6,7,8]))True
Instances
newtype Alt (f :: k -> Type) (a :: k) #
Monoid under <|>.
>>>getAlt (Alt (Just 12) <> Alt (Just 24))Just 12
>>>getAlt $ Alt Nothing <> Alt (Just 24)Just 24
Since: base-4.8.0.0
Instances
| Generic1 (Alt f :: k -> Type) | |
| Unbox (f a) => Vector Vector (Alt f a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: PrimMonad m => Mutable Vector (PrimState m) (Alt f a) -> m (Vector (Alt f a)) # basicUnsafeThaw :: PrimMonad m => Vector (Alt f a) -> m (Mutable Vector (PrimState m) (Alt f a)) # basicLength :: Vector (Alt f a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Alt f a) -> Vector (Alt f a) # basicUnsafeIndexM :: Monad m => Vector (Alt f a) -> Int -> m (Alt f a) # basicUnsafeCopy :: PrimMonad m => Mutable Vector (PrimState m) (Alt f a) -> Vector (Alt f a) -> m () # | |
| Unbox (f a) => MVector MVector (Alt f a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Alt f a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Alt f a) -> MVector s (Alt f a) # basicOverlaps :: MVector s (Alt f a) -> MVector s (Alt f a) -> Bool # basicUnsafeNew :: PrimMonad m => Int -> m (MVector (PrimState m) (Alt f a)) # basicInitialize :: PrimMonad m => MVector (PrimState m) (Alt f a) -> m () # basicUnsafeReplicate :: PrimMonad m => Int -> Alt f a -> m (MVector (PrimState m) (Alt f a)) # basicUnsafeRead :: PrimMonad m => MVector (PrimState m) (Alt f a) -> Int -> m (Alt f a) # basicUnsafeWrite :: PrimMonad m => MVector (PrimState m) (Alt f a) -> Int -> Alt f a -> m () # basicClear :: PrimMonad m => MVector (PrimState m) (Alt f a) -> m () # basicSet :: PrimMonad m => MVector (PrimState m) (Alt f a) -> Alt f a -> m () # basicUnsafeCopy :: PrimMonad m => MVector (PrimState m) (Alt f a) -> MVector (PrimState m) (Alt f a) -> m () # basicUnsafeMove :: PrimMonad m => MVector (PrimState m) (Alt f a) -> MVector (PrimState m) (Alt f a) -> m () # basicUnsafeGrow :: PrimMonad m => MVector (PrimState m) (Alt f a) -> Int -> m (MVector (PrimState m) (Alt f a)) # | |
| Foldable f => Foldable (Alt f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m # foldMap :: Monoid m => (a -> m) -> Alt f a -> m # foldMap' :: Monoid m => (a -> m) -> Alt f a -> m # foldr :: (a -> b -> b) -> b -> Alt f a -> b # foldr' :: (a -> b -> b) -> b -> Alt f a -> b # foldl :: (b -> a -> b) -> b -> Alt f a -> b # foldl' :: (b -> a -> b) -> b -> Alt f a -> b # foldr1 :: (a -> a -> a) -> Alt f a -> a # foldl1 :: (a -> a -> a) -> Alt f a -> a # elem :: Eq a => a -> Alt f a -> Bool # maximum :: Ord a => Alt f a -> a # minimum :: Ord a => Alt f a -> a # | |
| Traversable f => Traversable (Alt f) | Since: base-4.12.0.0 |
| Alternative f => Alternative (Alt f) | Since: base-4.8.0.0 |
| Applicative f => Applicative (Alt f) | Since: base-4.8.0.0 |
| Functor f => Functor (Alt f) | Since: base-4.8.0.0 |
| Monad f => Monad (Alt f) | Since: base-4.8.0.0 |
| MonadPlus f => MonadPlus (Alt f) | Since: base-4.8.0.0 |
| Alternative f => Monoid (Alt f a) | Since: base-4.8.0.0 |
| Alternative f => Semigroup (Alt f a) | Since: base-4.9.0.0 |
| Enum (f a) => Enum (Alt f a) | Since: base-4.8.0.0 |
| Generic (Alt f a) | |
| Num (f a) => Num (Alt f a) | Since: base-4.8.0.0 |
| Read (f a) => Read (Alt f a) | Since: base-4.8.0.0 |
| Show (f a) => Show (Alt f a) | Since: base-4.8.0.0 |
| Eq (f a) => Eq (Alt f a) | Since: base-4.8.0.0 |
| Ord (f a) => Ord (Alt f a) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
| Unbox (f a) => Unbox (Alt f a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 (Alt f :: k -> Type) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype MVector s (Alt f a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Alt f a) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype Vector (Alt f a) | |
Defined in Data.Vector.Unboxed.Base | |
Boolean monoid under conjunction (&&).
>>>getAll (All True <> mempty <> All False)False
>>>getAll (mconcat (map (\x -> All (even x)) [2,4,6,7,8]))False
Instances
stimesMonoid :: (Integral b, Monoid a) => b -> a -> a #
stimesIdempotent :: Integral b => b -> a -> a #
The Down type allows you to reverse sort order conveniently. A value of type
Down aa (represented as Down a
If a has an Ordthen sortWith by .Down x
>>>compare True FalseGT
>>>compare (Down True) (Down False)LT
If a has a BoundedminBoundmaxBound
>>>minBound :: Int-9223372036854775808
>>>minBound :: Down IntDown 9223372036854775807
All other instances of Down aa.
Since: base-4.6.0.0
Instances
| Foldable Down | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m # foldMap :: Monoid m => (a -> m) -> Down a -> m # foldMap' :: Monoid m => (a -> m) -> Down a -> m # foldr :: (a -> b -> b) -> b -> Down a -> b # foldr' :: (a -> b -> b) -> b -> Down a -> b # foldl :: (b -> a -> b) -> b -> Down a -> b # foldl' :: (b -> a -> b) -> b -> Down a -> b # foldr1 :: (a -> a -> a) -> Down a -> a # foldl1 :: (a -> a -> a) -> Down a -> a # elem :: Eq a => a -> Down a -> Bool # maximum :: Ord a => Down a -> a # | |
| Eq1 Down | Since: base-4.12.0.0 |
| Ord1 Down | Since: base-4.12.0.0 |
Defined in Data.Functor.Classes | |
| Read1 Down | Since: base-4.12.0.0 |
Defined in Data.Functor.Classes | |
| Show1 Down | Since: base-4.12.0.0 |
| Traversable Down | Since: base-4.12.0.0 |
| Applicative Down | Since: base-4.11.0.0 |
| Functor Down | Since: base-4.11.0.0 |
| Monad Down | Since: base-4.11.0.0 |
| NFData1 Down | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Unbox a => Vector Vector (Down a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: PrimMonad m => Mutable Vector (PrimState m) (Down a) -> m (Vector (Down a)) # basicUnsafeThaw :: PrimMonad m => Vector (Down a) -> m (Mutable Vector (PrimState m) (Down a)) # basicLength :: Vector (Down a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Down a) -> Vector (Down a) # basicUnsafeIndexM :: Monad m => Vector (Down a) -> Int -> m (Down a) # basicUnsafeCopy :: PrimMonad m => Mutable Vector (PrimState m) (Down a) -> Vector (Down a) -> m () # | |
| Unbox a => MVector MVector (Down a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Down a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Down a) -> MVector s (Down a) # basicOverlaps :: MVector s (Down a) -> MVector s (Down a) -> Bool # basicUnsafeNew :: PrimMonad m => Int -> m (MVector (PrimState m) (Down a)) # basicInitialize :: PrimMonad m => MVector (PrimState m) (Down a) -> m () # basicUnsafeReplicate :: PrimMonad m => Int -> Down a -> m (MVector (PrimState m) (Down a)) # basicUnsafeRead :: PrimMonad m => MVector (PrimState m) (Down a) -> Int -> m (Down a) # basicUnsafeWrite :: PrimMonad m => MVector (PrimState m) (Down a) -> Int -> Down a -> m () # basicClear :: PrimMonad m => MVector (PrimState m) (Down a) -> m () # basicSet :: PrimMonad m => MVector (PrimState m) (Down a) -> Down a -> m () # basicUnsafeCopy :: PrimMonad m => MVector (PrimState m) (Down a) -> MVector (PrimState m) (Down a) -> m () # basicUnsafeMove :: PrimMonad m => MVector (PrimState m) (Down a) -> MVector (PrimState m) (Down a) -> m () # basicUnsafeGrow :: PrimMonad m => MVector (PrimState m) (Down a) -> Int -> m (MVector (PrimState m) (Down a)) # | |
| Bits a => Bits (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods (.&.) :: Down a -> Down a -> Down a # (.|.) :: Down a -> Down a -> Down a # xor :: Down a -> Down a -> Down a # complement :: Down a -> Down a # shift :: Down a -> Int -> Down a # rotate :: Down a -> Int -> Down a # setBit :: Down a -> Int -> Down a # clearBit :: Down a -> Int -> Down a # complementBit :: Down a -> Int -> Down a # testBit :: Down a -> Int -> Bool # bitSizeMaybe :: Down a -> Maybe Int # shiftL :: Down a -> Int -> Down a # unsafeShiftL :: Down a -> Int -> Down a # shiftR :: Down a -> Int -> Down a # unsafeShiftR :: Down a -> Int -> Down a # rotateL :: Down a -> Int -> Down a # | |
| FiniteBits a => FiniteBits (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods finiteBitSize :: Down a -> Int # countLeadingZeros :: Down a -> Int # countTrailingZeros :: Down a -> Int # | |
| Storable a => Storable (Down a) | Since: base-4.14.0.0 |
| Monoid a => Monoid (Down a) | Since: base-4.11.0.0 |
| Semigroup a => Semigroup (Down a) | Since: base-4.11.0.0 |
| Bounded a => Bounded (Down a) | Swaps Since: base-4.14.0.0 |
| Floating a => Floating (Down a) | Since: base-4.14.0.0 |
| RealFloat a => RealFloat (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods floatRadix :: Down a -> Integer # floatDigits :: Down a -> Int # floatRange :: Down a -> (Int, Int) # decodeFloat :: Down a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Down a # significand :: Down a -> Down a # scaleFloat :: Int -> Down a -> Down a # isInfinite :: Down a -> Bool # isDenormalized :: Down a -> Bool # isNegativeZero :: Down a -> Bool # | |
| Generic (Down a) | |
| Ix a => Ix (Down a) | Since: base-4.14.0.0 |
| Num a => Num (Down a) | Since: base-4.11.0.0 |
| Read a => Read (Down a) | This instance would be equivalent to the derived instances of the
Since: base-4.7.0.0 |
| Fractional a => Fractional (Down a) | Since: base-4.14.0.0 |
| Real a => Real (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods toRational :: Down a -> Rational # | |
| RealFrac a => RealFrac (Down a) | Since: base-4.14.0.0 |
| Show a => Show (Down a) | This instance would be equivalent to the derived instances of the
Since: base-4.7.0.0 |
| NFData a => NFData (Down a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Down a) | Since: base-4.6.0.0 |
| Ord a => Ord (Down a) | Since: base-4.6.0.0 |
| Prim a => Prim (Down a) | Since: primitive-0.6.5.0 |
Defined in Data.Primitive.Types Methods alignment# :: Down a -> Int# # indexByteArray# :: ByteArray# -> Int# -> Down a # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Down a #) # writeByteArray# :: MutableByteArray# s -> Int# -> Down a -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Down a -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Down a # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Down a #) # writeOffAddr# :: Addr# -> Int# -> Down a -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Down a -> State# s -> State# s # | |
| Unbox a => Unbox (Down a) | |
Defined in Data.Vector.Unboxed.Base | |
| Generic1 Down | |
| newtype MVector s (Down a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Down a) | Since: base-4.12.0.0 |
Defined in GHC.Generics | |
| newtype Vector (Down a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 Down | Since: base-4.12.0.0 |
Defined in GHC.Generics | |
comparing :: Ord a => (b -> a) -> b -> b -> Ordering #
comparing p x y = compare (p x) (p y)
Useful combinator for use in conjunction with the xxxBy family
of functions from Data.List, for example:
... sortBy (comparing fst) ...
This type represents unknown type-level natural numbers.
Since: base-4.10.0.0
someNatVal :: Natural -> SomeNat #
Convert an integer into an unknown type-level natural.
Since: base-4.10.0.0
readMaybe :: Read a => String -> Maybe a #
Parse a string using the Read instance.
Succeeds if there is exactly one valid result.
>>>readMaybe "123" :: Maybe IntJust 123
>>>readMaybe "hello" :: Maybe IntNothing
Since: base-4.6.0.0
partitionEithers :: [Either a b] -> ([a], [b]) #
Partitions a list of Either into two lists.
All the Left elements are extracted, in order, to the first
component of the output. Similarly the Right elements are extracted
to the second component of the output.
Examples
Basic usage:
>>>let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]>>>partitionEithers list(["foo","bar","baz"],[3,7])
The pair returned by partitionEithers x(:lefts x, rights x)
>>>let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]>>>partitionEithers list == (lefts list, rights list)True
isRight :: Either a b -> Bool #
Return True if the given value is a Right-value, False otherwise.
Examples
Basic usage:
>>>isRight (Left "foo")False>>>isRight (Right 3)True
Assuming a Left value signifies some sort of error, we can use
isRight to write a very simple reporting function that only
outputs "SUCCESS" when a computation has succeeded.
This example shows how isRight might be used to avoid pattern
matching when one does not care about the value contained in the
constructor:
>>>import Control.Monad ( when )>>>let report e = when (isRight e) $ putStrLn "SUCCESS">>>report (Left "parse error")>>>report (Right 1)SUCCESS
Since: base-4.7.0.0
isLeft :: Either a b -> Bool #
Return True if the given value is a Left-value, False otherwise.
Examples
Basic usage:
>>>isLeft (Left "foo")True>>>isLeft (Right 3)False
Assuming a Left value signifies some sort of error, we can use
isLeft to write a very simple error-reporting function that does
absolutely nothing in the case of success, and outputs "ERROR" if
any error occurred.
This example shows how isLeft might be used to avoid pattern
matching when one does not care about the value contained in the
constructor:
>>>import Control.Monad ( when )>>>let report e = when (isLeft e) $ putStrLn "ERROR">>>report (Right 1)>>>report (Left "parse error")ERROR
Since: base-4.7.0.0
either :: (a -> c) -> (b -> c) -> Either a b -> c #
Case analysis for the Either type.
If the value is Left aa;
if it is Right bb.
Examples
We create two values of type Either String IntLeft constructor and another using the Right constructor. Then
we apply "either" the length function (if we have a String)
or the "times-two" function (if we have an Int):
>>>let s = Left "foo" :: Either String Int>>>let n = Right 3 :: Either String Int>>>either length (*2) s3>>>either length (*2) n6
Proxy is a type that holds no data, but has a phantom parameter of
arbitrary type (or even kind). Its use is to provide type information, even
though there is no value available of that type (or it may be too costly to
create one).
Historically, Proxy :: Proxy aundefined :: a
>>>Proxy :: Proxy (Void, Int -> Int)Proxy
Proxy can even hold types of higher kinds,
>>>Proxy :: Proxy EitherProxy
>>>Proxy :: Proxy FunctorProxy
>>>Proxy :: Proxy complicatedStructureProxy
Constructors
| Proxy |
Instances
| Generic1 (Proxy :: k -> Type) | |
| FromJSON1 (Proxy :: Type -> Type) | |
| ToJSON1 (Proxy :: Type -> Type) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Proxy a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Proxy a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Proxy a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Proxy a] -> Encoding # | |
| Foldable (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # | |
| Eq1 (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| Ord1 (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read1 (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Show1 (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Alternative (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| Applicative (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Functor (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Monad (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| MonadPlus (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| NFData1 (Proxy :: Type -> Type) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable1 (Proxy :: Type -> Type) | |
Defined in Data.Hashable.Class | |
| FromJSON (Proxy a) | |
| ToJSON (Proxy a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Monoid (Proxy s) | Since: base-4.7.0.0 |
| Semigroup (Proxy s) | Since: base-4.9.0.0 |
| Bounded (Proxy t) | Since: base-4.7.0.0 |
| Enum (Proxy s) | Since: base-4.7.0.0 |
| Generic (Proxy t) | |
| Ix (Proxy s) | Since: base-4.7.0.0 |
Defined in Data.Proxy | |
| Read (Proxy t) | Since: base-4.7.0.0 |
| Show (Proxy s) | Since: base-4.7.0.0 |
| NFData (Proxy a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq (Proxy s) | Since: base-4.7.0.0 |
| Ord (Proxy s) | Since: base-4.7.0.0 |
| Hashable (Proxy a) | |
Defined in Data.Hashable.Class | |
| type Rep1 (Proxy :: k -> Type) | Since: base-4.6.0.0 |
| type Rep (Proxy t) | Since: base-4.6.0.0 |
See openFile
Constructors
| ReadMode | |
| WriteMode | |
| AppendMode | |
| ReadWriteMode |
byteSwap64 :: Word64 -> Word64 #
Reverse order of bytes in Word64.
Since: base-4.7.0.0
byteSwap32 :: Word32 -> Word32 #
Reverse order of bytes in Word32.
Since: base-4.7.0.0
byteSwap16 :: Word16 -> Word16 #
Reverse order of bytes in Word16.
Since: base-4.7.0.0
underflowError :: a #
reduce :: Integral a => a -> a -> Ratio a #
reduce is a subsidiary function used only in this module.
It normalises a ratio by dividing both numerator and denominator by
their greatest common divisor.
ratioPrec1 :: Int #
overflowError :: a #
numericEnumFromTo :: (Ord a, Fractional a) => a -> a -> [a] #
numericEnumFromThenTo :: (Ord a, Fractional a) => a -> a -> a -> [a] #
numericEnumFromThen :: Fractional a => a -> a -> [a] #
numericEnumFrom :: Fractional a => a -> [a] #
Extract the numerator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive.
notANumber :: Rational #
naturalFromInt :: Int -> Natural #
Convert an Int into a Natural, throwing an underflow exception for negative values.
lcm :: Integral a => a -> a -> a #
lcm x yx and y divide.
integralEnumFromTo :: Integral a => a -> a -> [a] #
integralEnumFromThenTo :: Integral a => a -> a -> a -> [a] #
integralEnumFromThen :: (Integral a, Bounded a) => a -> a -> [a] #
integralEnumFrom :: (Integral a, Bounded a) => a -> [a] #
gcd :: Integral a => a -> a -> a #
gcd x yx and y of which
every common factor of x and y is also a factor; for example
gcd 4 2 = 2gcd (-4) 6 = 2gcd 0 44. gcd 0 00.
(That is, the common divisor that is "greatest" in the divisibility
preordering.)
Note: Since for signed fixed-width integer types, abs minBound < 0minBound0 or minBound
divZeroError :: a #
denominator :: Ratio a -> a #
Extract the denominator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive.
(^^) :: (Fractional a, Integral b) => a -> b -> a infixr 8 #
raise a number to an integral power
boundedEnumFromThen :: (Enum a, Bounded a) => a -> a -> [a] #
boundedEnumFrom :: (Enum a, Bounded a) => a -> [a] #
zipWith :: (a -> b -> c) -> [a] -> [b] -> [c] #
\(\mathcal{O}(\min(m,n))\). zipWith generalises zip by zipping with the
function given as the first argument, instead of a tupling function.
zipWith (,) xs ys == zip xs ys zipWith f [x1,x2,x3..] [y1,y2,y3..] == [f x1 y1, f x2 y2, f x3 y3..]
For example, zipWith (+)
>>>zipWith (+) [1, 2, 3] [4, 5, 6][5,7,9]
zipWith is right-lazy:
>>>zipWith f [] _|_[]
zipWith is capable of list fusion, but it is restricted to its
first list argument and its resulting list.
unzip :: [(a, b)] -> ([a], [b]) #
unzip transforms a list of pairs into a list of first components
and a list of second components.
>>>unzip []([],[])>>>unzip [(1, 'a'), (2, 'b')]([1,2],"ab")
takeWhile :: (a -> Bool) -> [a] -> [a] #
takeWhile, applied to a predicate p and a list xs, returns the
longest prefix (possibly empty) of xs of elements that satisfy p.
>>>takeWhile (< 3) [1,2,3,4,1,2,3,4][1,2]>>>takeWhile (< 9) [1,2,3][1,2,3]>>>takeWhile (< 0) [1,2,3][]
take n, applied to a list xs, returns the prefix of xs
of length n, or xs itself if n >= .length xs
>>>take 5 "Hello World!""Hello">>>take 3 [1,2,3,4,5][1,2,3]>>>take 3 [1,2][1,2]>>>take 3 [][]>>>take (-1) [1,2][]>>>take 0 [1,2][]
It is an instance of the more general genericTake,
in which n may be of any integral type.
splitAt :: Int -> [a] -> ([a], [a]) #
splitAt n xs returns a tuple where first element is xs prefix of
length n and second element is the remainder of the list:
>>>splitAt 6 "Hello World!"("Hello ","World!")>>>splitAt 3 [1,2,3,4,5]([1,2,3],[4,5])>>>splitAt 1 [1,2,3]([1],[2,3])>>>splitAt 3 [1,2,3]([1,2,3],[])>>>splitAt 4 [1,2,3]([1,2,3],[])>>>splitAt 0 [1,2,3]([],[1,2,3])>>>splitAt (-1) [1,2,3]([],[1,2,3])
It is equivalent to ( when take n xs, drop n xs)n is not _|_
(splitAt _|_ xs = _|_).
splitAt is an instance of the more general genericSplitAt,
in which n may be of any integral type.
scanr :: (a -> b -> b) -> b -> [a] -> [b] #
\(\mathcal{O}(n)\). scanr is the right-to-left dual of scanl. Note that the order of parameters on the accumulating function are reversed compared to scanl.
Also note that
head (scanr f z xs) == foldr f z xs.
>>>scanr (+) 0 [1..4][10,9,7,4,0]>>>scanr (+) 42 [][42]>>>scanr (-) 100 [1..4][98,-97,99,-96,100]>>>scanr (\nextChar reversedString -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']["abcdfoo","bcdfoo","cdfoo","dfoo","foo"]>>>force $ scanr (+) 0 [1..]*** Exception: stack overflow
scanl :: (b -> a -> b) -> b -> [a] -> [b] #
\(\mathcal{O}(n)\). scanl is similar to foldl, but returns a list of
successive reduced values from the left:
scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
Note that
last (scanl f z xs) == foldl f z xs
>>>scanl (+) 0 [1..4][0,1,3,6,10]>>>scanl (+) 42 [][42]>>>scanl (-) 100 [1..4][100,99,97,94,90]>>>scanl (\reversedString nextChar -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']["foo","afoo","bafoo","cbafoo","dcbafoo"]>>>scanl (+) 0 [1..]* Hangs forever *
reverse xs returns the elements of xs in reverse order.
xs must be finite.
>>>reverse [][]>>>reverse [42][42]>>>reverse [2,5,7][7,5,2]>>>reverse [1..]* Hangs forever *
replicate :: Int -> a -> [a] #
replicate n x is a list of length n with x the value of
every element.
It is an instance of the more general genericReplicate,
in which n may be of any integral type.
>>>replicate 0 True[]>>>replicate (-1) True[]>>>replicate 4 True[True,True,True,True]
repeat x is an infinite list, with x the value of every element.
>>>take 20 $ repeat 17[17,17,17,17,17,17,17,17,17...
iterate :: (a -> a) -> a -> [a] #
iterate f x returns an infinite list of repeated applications
of f to x:
iterate f x == [x, f x, f (f x), ...]
Note that iterate is lazy, potentially leading to thunk build-up if
the consumer doesn't force each iterate. See iterate' for a strict
variant of this function.
>>>take 10 $ iterate not True[True,False,True,False...>>>take 10 $ iterate (+3) 42[42,45,48,51,54,57,60,63...
drop n xs returns the suffix of xs
after the first n elements, or [] if n >= .length xs
>>>drop 6 "Hello World!""World!">>>drop 3 [1,2,3,4,5][4,5]>>>drop 3 [1,2][]>>>drop 3 [][]>>>drop (-1) [1,2][1,2]>>>drop 0 [1,2][1,2]
It is an instance of the more general genericDrop,
in which n may be of any integral type.
cycle ties a finite list into a circular one, or equivalently,
the infinite repetition of the original list. It is the identity
on infinite lists.
>>>cycle []*** Exception: Prelude.cycle: empty list>>>take 20 $ cycle [42][42,42,42,42,42,42,42,42,42,42...>>>take 20 $ cycle [2, 5, 7][2,5,7,2,5,7,2,5,7,2,5,7...
break :: (a -> Bool) -> [a] -> ([a], [a]) #
break, applied to a predicate p and a list xs, returns a tuple where
first element is longest prefix (possibly empty) of xs of elements that
do not satisfy p and second element is the remainder of the list:
>>>break (> 3) [1,2,3,4,1,2,3,4]([1,2,3],[4,1,2,3,4])>>>break (< 9) [1,2,3]([],[1,2,3])>>>break (> 9) [1,2,3]([1,2,3],[])
maybeToList :: Maybe a -> [a] #
The maybeToList function returns an empty list when given
Nothing or a singleton list when given Just.
Examples
Basic usage:
>>>maybeToList (Just 7)[7]
>>>maybeToList Nothing[]
One can use maybeToList to avoid pattern matching when combined
with a function that (safely) works on lists:
>>>import Text.Read ( readMaybe )>>>sum $ maybeToList (readMaybe "3")3>>>sum $ maybeToList (readMaybe "")0
maybe :: b -> (a -> b) -> Maybe a -> b #
The maybe function takes a default value, a function, and a Maybe
value. If the Maybe value is Nothing, the function returns the
default value. Otherwise, it applies the function to the value inside
the Just and returns the result.
Examples
Basic usage:
>>>maybe False odd (Just 3)True
>>>maybe False odd NothingFalse
Read an integer from a string using readMaybe. If we succeed,
return twice the integer; that is, apply (*2) to it. If instead
we fail to parse an integer, return 0 by default:
>>>import Text.Read ( readMaybe )>>>maybe 0 (*2) (readMaybe "5")10>>>maybe 0 (*2) (readMaybe "")0
Apply show to a Maybe Int. If we have Just n, we want to show
the underlying Int n. But if we have Nothing, we return the
empty string instead of (for example) "Nothing":
>>>maybe "" show (Just 5)"5">>>maybe "" show Nothing""
mapMaybe :: (a -> Maybe b) -> [a] -> [b] #
The mapMaybe function is a version of map which can throw
out elements. In particular, the functional argument returns
something of type Maybe bNothing, no element
is added on to the result list. If it is Just bb is
included in the result list.
Examples
Using mapMaybe f xcatMaybes $ map f x
>>>import Text.Read ( readMaybe )>>>let readMaybeInt = readMaybe :: String -> Maybe Int>>>mapMaybe readMaybeInt ["1", "Foo", "3"][1,3]>>>catMaybes $ map readMaybeInt ["1", "Foo", "3"][1,3]
If we map the Just constructor, the entire list should be returned:
>>>mapMaybe Just [1,2,3][1,2,3]
listToMaybe :: [a] -> Maybe a #
The listToMaybe function returns Nothing on an empty list
or Just aa is the first element of the list.
Examples
Basic usage:
>>>listToMaybe []Nothing
>>>listToMaybe [9]Just 9
>>>listToMaybe [1,2,3]Just 1
Composing maybeToList with listToMaybe should be the identity
on singleton/empty lists:
>>>maybeToList $ listToMaybe [5][5]>>>maybeToList $ listToMaybe [][]
But not on lists with more than one element:
>>>maybeToList $ listToMaybe [1,2,3][1]
fromMaybe :: a -> Maybe a -> a #
The fromMaybe function takes a default value and a Maybe
value. If the Maybe is Nothing, it returns the default value;
otherwise, it returns the value contained in the Maybe.
Examples
Basic usage:
>>>fromMaybe "" (Just "Hello, World!")"Hello, World!"
>>>fromMaybe "" Nothing""
Read an integer from a string using readMaybe. If we fail to
parse an integer, we want to return 0 by default:
>>>import Text.Read ( readMaybe )>>>fromMaybe 0 (readMaybe "5")5>>>fromMaybe 0 (readMaybe "")0
catMaybes :: [Maybe a] -> [a] #
The catMaybes function takes a list of Maybes and returns
a list of all the Just values.
Examples
Basic usage:
>>>catMaybes [Just 1, Nothing, Just 3][1,3]
When constructing a list of Maybe values, catMaybes can be used
to return all of the "success" results (if the list is the result
of a map, then mapMaybe would be more appropriate):
>>>import Text.Read ( readMaybe )>>>[readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ][Just 1,Nothing,Just 3]>>>catMaybes $ [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ][1,3]
Case analysis for the Bool type. bool x y px
when p is False, and evaluates to y when p is True.
This is equivalent to if p then y else x; that is, one can
think of it as an if-then-else construct with its arguments
reordered.
Examples
Basic usage:
>>>bool "foo" "bar" True"bar">>>bool "foo" "bar" False"foo"
Confirm that bool x y pif p then y else x are
equivalent:
>>>let p = True; x = "bar"; y = "foo">>>bool x y p == if p then y else xTrue>>>let p = False>>>bool x y p == if p then y else xTrue
Since: base-4.7.0.0
fix ff,
i.e. the least defined x such that f x = x.
For example, we can write the factorial function using direct recursion as
>>>let fac n = if n <= 1 then 1 else n * fac (n-1) in fac 5120
This uses the fact that Haskell’s let introduces recursive bindings. We can
rewrite this definition using fix,
>>>fix (\rec n -> if n <= 1 then 1 else n * rec (n-1)) 5120
Instead of making a recursive call, we introduce a dummy parameter rec;
when used within fix, this parameter then refers to fix’s argument, hence
the recursion is reintroduced.
void :: Functor f => f a -> f () #
void valueIO action.
Examples
Replace the contents of a Maybe Int
>>>void NothingNothing>>>void (Just 3)Just ()
Replace the contents of an Either Int IntEither Int ()
>>>void (Left 8675309)Left 8675309>>>void (Right 8675309)Right ()
Replace every element of a list with unit:
>>>void [1,2,3][(),(),()]
Replace the second element of a pair with unit:
>>>void (1,2)(1,())
Discard the result of an IO action:
>>>mapM print [1,2]1 2 [(),()]>>>void $ mapM print [1,2]1 2
($>) :: Functor f => f a -> b -> f b infixl 4 #
Flipped version of <$.
Examples
Replace the contents of a Maybe IntString:
>>>Nothing $> "foo"Nothing>>>Just 90210 $> "foo"Just "foo"
Replace the contents of an Either Int IntString, resulting in an Either
Int String
>>>Left 8675309 $> "foo"Left 8675309>>>Right 8675309 $> "foo"Right "foo"
Replace each element of a list with a constant String:
>>>[1,2,3] $> "foo"["foo","foo","foo"]
Replace the second element of a pair with a constant String:
>>>(1,2) $> "foo"(1,"foo")
Since: base-4.7.0.0
uncurry :: (a -> b -> c) -> (a, b) -> c #
uncurry converts a curried function to a function on pairs.
Examples
>>>uncurry (+) (1,2)3
>>>uncurry ($) (show, 1)"1"
>>>map (uncurry max) [(1,2), (3,4), (6,8)][2,4,8]
An MVar (pronounced "em-var") is a synchronising variable, used
for communication between concurrent threads. It can be thought of
as a box, which may be empty or full.
Instances
| NFData1 MVar | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| NFData (MVar a) | NOTE: Only strict in the reference and not the referenced value. Since: deepseq-1.4.2.0 |
Defined in Control.DeepSeq | |
| Eq (MVar a) | Since: base-4.1.0.0 |
currentCallStack :: IO [String] #
Returns a [String] representing the current call stack. This
can be useful for debugging.
The implementation uses the call-stack simulation maintained by the
profiler, so it only works if the program was compiled with -prof
and contains suitable SCC annotations (e.g. by using -fprof-auto).
Otherwise, the list returned is likely to be empty or
uninformative.
Since: base-4.5.0.0
Non-empty (and non-strict) list type.
Since: base-4.9.0.0
Constructors
| a :| [a] infixr 5 |
Instances
when :: Applicative f => Bool -> f () -> f () #
Conditional execution of Applicative expressions. For example,
when debug (putStrLn "Debugging")
will output the string Debugging if the Boolean value debug
is True, and otherwise do nothing.
liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r #
Promote a function to a monad, scanning the monadic arguments from
left to right (cf. liftM2).
liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r #
Promote a function to a monad, scanning the monadic arguments from
left to right (cf. liftM2).
liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r #
Promote a function to a monad, scanning the monadic arguments from
left to right (cf. liftM2).
liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r #
Promote a function to a monad, scanning the monadic arguments from left to right. For example,
liftM2 (+) [0,1] [0,2] = [0,2,1,3] liftM2 (+) (Just 1) Nothing = Nothing
liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d #
Lift a ternary function to actions.
flip :: (a -> b -> c) -> b -> a -> c #
flip ff.
>>>flip (++) "hello" "world""worldhello"
(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1 #
Same as >>=, but with the arguments interchanged.
type HasCallStack = ?callStack :: CallStack #
Request a CallStack.
NOTE: The implicit parameter ?callStack :: CallStack is an
implementation detail and should not be considered part of the
CallStack API, we may decide to change the implementation in the
future.
Since: base-4.9.0.0
getCallStack :: CallStack -> [([Char], SrcLoc)] #
Extract a list of call-sites from the CallStack.
The list is ordered by most recent call.
Since: base-4.8.1.0
stimesIdempotentMonoid :: (Integral b, Monoid a) => b -> a -> a #
data SomeException #
The SomeException type is the root of the exception type hierarchy.
When an exception of type e is thrown, behind the scenes it is
encapsulated in a SomeException.
Constructors
| Exception e => SomeException e |
Instances
| Exception SomeException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods toException :: SomeException -> SomeException # fromException :: SomeException -> Maybe SomeException # displayException :: SomeException -> String # | |
| Show SomeException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS # show :: SomeException -> String # showList :: [SomeException] -> ShowS # | |
decodeUtf8' :: ByteString -> Either UnicodeException Text #
Decode a ByteString containing UTF-8 encoded text.
If the input contains any invalid UTF-8 data, the relevant exception will be returned, otherwise the decoded text.
data IdentityT (f :: k -> Type) (a :: k) #
The trivial monad transformer, which maps a monad to an equivalent monad.
Instances
newtype StateT s (m :: Type -> Type) a #
A state transformer monad parameterized by:
s- The state.m- The inner monad.
The return function leaves the state unchanged, while >>= uses
the final state of the first computation as the initial state of
the second.
Instances
newtype ReaderT r (m :: Type -> Type) a #
The reader monad transformer, which adds a read-only environment to the given monad.
The return function ignores the environment, while >>= passes
the inherited environment to both subcomputations.
Constructors
| ReaderT | |
Fields
| |
Instances
newtype MaybeT (m :: Type -> Type) a #
The parameterizable maybe monad, obtained by composing an arbitrary
monad with the Maybe monad.
Computations are actions that may produce a value or exit.
The return function yields a computation that produces that
value, while >>= sequences two subcomputations, exiting if either
computation does.
Instances
newtype ExceptT e (m :: Type -> Type) a #
A monad transformer that adds exceptions to other monads.
ExceptT constructs a monad parameterized over two things:
- e - The exception type.
- m - The inner monad.
The return function yields a computation that produces the given
value, while >>= sequences two subcomputations, exiting on the
first exception.
Instances
class MonadIO m => MonadUnliftIO (m :: Type -> Type) where #
Monads which allow their actions to be run in IO.
While MonadIO allows an IO action to be lifted into another
monad, this class captures the opposite concept: allowing you to
capture the monadic context. Note that, in order to meet the laws
given below, the intuition is that a monad must have no monadic
state, but may have monadic context. This essentially limits
MonadUnliftIO to ReaderT and IdentityT transformers on top of
IO.
Laws. For any value u returned by askUnliftIO, it must meet the
monad transformer laws as reformulated for MonadUnliftIO:
unliftIO u . return = return
unliftIO u (m >>= f) = unliftIO u m >>= unliftIO u . f
Instances of MonadUnliftIO must also satisfy the idempotency law:
askUnliftIO >>= \u -> (liftIO . unliftIO u) m = m
This law showcases two properties. First, askUnliftIO doesn't change
the monadic context, and second, liftIO . unliftIO u is equivalent to
id IF called in the same monadic context as askUnliftIO.
Since: unliftio-core-0.1.0.0
Methods
withRunInIO :: ((forall a. m a -> IO a) -> IO b) -> m b #
Convenience function for capturing the monadic context and running an IO
action with a runner function. The runner function is used to run a monadic
action m in IO.
Since: unliftio-core-0.1.0.0
Instances
| MonadUnliftIO IO | |
Defined in Control.Monad.IO.Unlift | |
| MonadUnliftIO m => MonadUnliftIO (ResourceT m) | Since: resourcet-1.1.10 |
Defined in Control.Monad.Trans.Resource.Internal | |
| MonadUnliftIO m => MonadUnliftIO (IdentityT m) | |
Defined in Control.Monad.IO.Unlift | |
| MonadUnliftIO m => MonadUnliftIO (ReaderT r m) | |
Defined in Control.Monad.IO.Unlift | |
class MonadTrans (t :: (Type -> Type) -> Type -> Type) where #
The class of monad transformers. Instances should satisfy the
following laws, which state that lift is a monad transformation:
Methods
lift :: Monad m => m a -> t m a #
Lift a computation from the argument monad to the constructed monad.
Instances
| MonadTrans ResourceT | |
Defined in Control.Monad.Trans.Resource.Internal | |
| MonadTrans MaybeT | |
Defined in Control.Monad.Trans.Maybe | |
| MonadTrans (ErrorT e) | |
Defined in Control.Monad.Trans.Error | |
| MonadTrans (ExceptT e) | |
Defined in Control.Monad.Trans.Except | |
| MonadTrans (IdentityT :: (Type -> Type) -> Type -> Type) | |
Defined in Control.Monad.Trans.Identity | |
| MonadTrans (ReaderT r) | |
Defined in Control.Monad.Trans.Reader | |
| MonadTrans (StateT s) | |
Defined in Control.Monad.Trans.State.Lazy | |
| MonadTrans (StateT s) | |
Defined in Control.Monad.Trans.State.Strict | |
| MonadTrans (ConduitT i o) | |
Defined in Data.Conduit.Internal.Conduit | |
| MonadTrans (Pipe l i o u) | |
Defined in Data.Conduit.Internal.Pipe | |
class Monad m => MonadThrow (m :: Type -> Type) #
A class for monads in which exceptions may be thrown.
Instances should obey the following law:
throwM e >> x = throwM e
In other words, throwing an exception short-circuits the rest of the monadic computation.
Minimal complete definition
Instances
A map of integers to values a.
Instances
| FromJSON1 IntMap | |
| ToJSON1 IntMap | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> IntMap a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [IntMap a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> IntMap a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [IntMap a] -> Encoding # | |
| Foldable IntMap | Folds in order of increasing key. |
Defined in Data.IntMap.Internal Methods fold :: Monoid m => IntMap m -> m # foldMap :: Monoid m => (a -> m) -> IntMap a -> m # foldMap' :: Monoid m => (a -> m) -> IntMap a -> m # foldr :: (a -> b -> b) -> b -> IntMap a -> b # foldr' :: (a -> b -> b) -> b -> IntMap a -> b # foldl :: (b -> a -> b) -> b -> IntMap a -> b # foldl' :: (b -> a -> b) -> b -> IntMap a -> b # foldr1 :: (a -> a -> a) -> IntMap a -> a # foldl1 :: (a -> a -> a) -> IntMap a -> a # elem :: Eq a => a -> IntMap a -> Bool # maximum :: Ord a => IntMap a -> a # minimum :: Ord a => IntMap a -> a # | |
| Eq1 IntMap | Since: containers-0.5.9 |
| Ord1 IntMap | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal | |
| Read1 IntMap | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal | |
| Show1 IntMap | Since: containers-0.5.9 |
| Traversable IntMap | Traverses in order of increasing key. |
| Functor IntMap | |
| Hashable1 IntMap | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| FromJSON a => FromJSON (IntMap a) | |
| ToJSON a => ToJSON (IntMap a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (IntMap a) | |
Defined in Data.IntMap.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> IntMap a -> c (IntMap a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (IntMap a) # toConstr :: IntMap a -> Constr # dataTypeOf :: IntMap a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (IntMap a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (IntMap a)) # gmapT :: (forall b. Data b => b -> b) -> IntMap a -> IntMap a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> IntMap a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> IntMap a -> r # gmapQ :: (forall d. Data d => d -> u) -> IntMap a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> IntMap a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> IntMap a -> m (IntMap a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> IntMap a -> m (IntMap a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> IntMap a -> m (IntMap a) # | |
| Monoid (IntMap a) | |
| Semigroup (IntMap a) | Since: containers-0.5.7 |
| IsList (IntMap a) | Since: containers-0.5.6.2 |
| Read e => Read (IntMap e) | |
| Show a => Show (IntMap a) | |
| NFData a => NFData (IntMap a) | |
Defined in Data.IntMap.Internal | |
| Eq a => Eq (IntMap a) | |
| Ord a => Ord (IntMap a) | |
Defined in Data.IntMap.Internal | |
| Hashable v => Hashable (IntMap v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Container (IntMap v) | |
Defined in Universum.Container.Class Methods toList :: IntMap v -> [Element (IntMap v)] # foldr :: (Element (IntMap v) -> b -> b) -> b -> IntMap v -> b # foldl :: (b -> Element (IntMap v) -> b) -> b -> IntMap v -> b # foldl' :: (b -> Element (IntMap v) -> b) -> b -> IntMap v -> b # elem :: Element (IntMap v) -> IntMap v -> Bool # foldMap :: Monoid m => (Element (IntMap v) -> m) -> IntMap v -> m # fold :: IntMap v -> Element (IntMap v) # foldr' :: (Element (IntMap v) -> b -> b) -> b -> IntMap v -> b # notElem :: Element (IntMap v) -> IntMap v -> Bool # all :: (Element (IntMap v) -> Bool) -> IntMap v -> Bool # any :: (Element (IntMap v) -> Bool) -> IntMap v -> Bool # find :: (Element (IntMap v) -> Bool) -> IntMap v -> Maybe (Element (IntMap v)) # safeHead :: IntMap v -> Maybe (Element (IntMap v)) # safeMaximum :: IntMap v -> Maybe (Element (IntMap v)) # safeMinimum :: IntMap v -> Maybe (Element (IntMap v)) # safeFoldr1 :: (Element (IntMap v) -> Element (IntMap v) -> Element (IntMap v)) -> IntMap v -> Maybe (Element (IntMap v)) # safeFoldl1 :: (Element (IntMap v) -> Element (IntMap v) -> Element (IntMap v)) -> IntMap v -> Maybe (Element (IntMap v)) # | |
| FromList (IntMap v) | |
Defined in Universum.Container.Class Methods fromList :: [ListElement (IntMap v)] -> IntMap v # | |
| One (IntMap v) | |
| ToPairs (IntMap v) | |
| type Item (IntMap a) | |
Defined in Data.IntMap.Internal | |
| type Element (IntMap v) | |
Defined in Universum.Container.Class | |
| type FromListC (IntMap v) | |
Defined in Universum.Container.Class | |
| type Key (IntMap v) | |
Defined in Universum.Container.Class | |
| type ListElement (IntMap v) | |
Defined in Universum.Container.Class | |
| type OneItem (IntMap v) | |
Defined in Universum.Container.Class | |
| type Val (IntMap v) | |
Defined in Universum.Container.Class | |
A set of integers.
Instances
General-purpose finite sequences.
Instances
| FromJSON1 Seq | |
| ToJSON1 Seq | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Seq a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Seq a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Seq a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Seq a] -> Encoding # | |
| MonadFix Seq | Since: containers-0.5.11 |
Defined in Data.Sequence.Internal | |
| MonadZip Seq |
|
| Foldable Seq | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Seq m -> m # foldMap :: Monoid m => (a -> m) -> Seq a -> m # foldMap' :: Monoid m => (a -> m) -> Seq a -> m # foldr :: (a -> b -> b) -> b -> Seq a -> b # foldr' :: (a -> b -> b) -> b -> Seq a -> b # foldl :: (b -> a -> b) -> b -> Seq a -> b # foldl' :: (b -> a -> b) -> b -> Seq a -> b # foldr1 :: (a -> a -> a) -> Seq a -> a # foldl1 :: (a -> a -> a) -> Seq a -> a # elem :: Eq a => a -> Seq a -> Bool # maximum :: Ord a => Seq a -> a # | |
| Eq1 Seq | Since: containers-0.5.9 |
| Ord1 Seq | Since: containers-0.5.9 |
Defined in Data.Sequence.Internal | |
| Read1 Seq | Since: containers-0.5.9 |
Defined in Data.Sequence.Internal | |
| Show1 Seq | Since: containers-0.5.9 |
| Traversable Seq | |
| Alternative Seq | Since: containers-0.5.4 |
| Applicative Seq | Since: containers-0.5.4 |
| Functor Seq | |
| Monad Seq | |
| MonadPlus Seq | |
| UnzipWith Seq | |
Defined in Data.Sequence.Internal Methods unzipWith' :: (x -> (a, b)) -> Seq x -> (Seq a, Seq b) | |
| Hashable1 Seq | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| FromJSON a => FromJSON (Seq a) | |
| ToJSON a => ToJSON (Seq a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (Seq a) | |
Defined in Data.Sequence.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Seq a -> c (Seq a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Seq a) # dataTypeOf :: Seq a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Seq a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Seq a)) # gmapT :: (forall b. Data b => b -> b) -> Seq a -> Seq a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Seq a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Seq a -> r # gmapQ :: (forall d. Data d => d -> u) -> Seq a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Seq a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a) # | |
| a ~ Char => IsString (Seq a) | Since: containers-0.5.7 |
Defined in Data.Sequence.Internal Methods fromString :: String -> Seq a # | |
| Monoid (Seq a) | |
| Semigroup (Seq a) | Since: containers-0.5.7 |
| IsList (Seq a) | |
| Read a => Read (Seq a) | |
| Show a => Show (Seq a) | |
| NFData a => NFData (Seq a) | |
Defined in Data.Sequence.Internal | |
| Eq a => Eq (Seq a) | |
| Ord a => Ord (Seq a) | |
| Hashable v => Hashable (Seq v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Container (Seq a) | |
Defined in Universum.Container.Class Methods toList :: Seq a -> [Element (Seq a)] # foldr :: (Element (Seq a) -> b -> b) -> b -> Seq a -> b # foldl :: (b -> Element (Seq a) -> b) -> b -> Seq a -> b # foldl' :: (b -> Element (Seq a) -> b) -> b -> Seq a -> b # elem :: Element (Seq a) -> Seq a -> Bool # foldMap :: Monoid m => (Element (Seq a) -> m) -> Seq a -> m # fold :: Seq a -> Element (Seq a) # foldr' :: (Element (Seq a) -> b -> b) -> b -> Seq a -> b # notElem :: Element (Seq a) -> Seq a -> Bool # all :: (Element (Seq a) -> Bool) -> Seq a -> Bool # any :: (Element (Seq a) -> Bool) -> Seq a -> Bool # find :: (Element (Seq a) -> Bool) -> Seq a -> Maybe (Element (Seq a)) # safeHead :: Seq a -> Maybe (Element (Seq a)) # safeMaximum :: Seq a -> Maybe (Element (Seq a)) # safeMinimum :: Seq a -> Maybe (Element (Seq a)) # safeFoldr1 :: (Element (Seq a) -> Element (Seq a) -> Element (Seq a)) -> Seq a -> Maybe (Element (Seq a)) # safeFoldl1 :: (Element (Seq a) -> Element (Seq a) -> Element (Seq a)) -> Seq a -> Maybe (Element (Seq a)) # | |
| FromList (Seq a) | |
Defined in Universum.Container.Class Methods fromList :: [ListElement (Seq a)] -> Seq a # | |
| One (Seq a) | |
| type Item (Seq a) | |
Defined in Data.Sequence.Internal | |
| type Element (Seq a) | |
Defined in Universum.Container.Class | |
| type FromListC (Seq a) | |
Defined in Universum.Container.Class | |
| type ListElement (Seq a) | |
Defined in Universum.Container.Class | |
| type OneItem (Seq a) | |
Defined in Universum.Container.Class | |
A set of values a.
Instances
| ToJSON1 Set | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Set a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Set a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Set a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Set a] -> Encoding # | |
| Foldable Set | Folds in order of increasing key. |
Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # | |
| Eq1 Set | Since: containers-0.5.9 |
| Ord1 Set | Since: containers-0.5.9 |
Defined in Data.Set.Internal | |
| Show1 Set | Since: containers-0.5.9 |
| Hashable1 Set | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| (Ord a, FromJSON a) => FromJSON (Set a) | |
| ToJSON a => ToJSON (Set a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data a, Ord a) => Data (Set a) | |
Defined in Data.Set.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Set a -> c (Set a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Set a) # dataTypeOf :: Set a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Set a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Set a)) # gmapT :: (forall b. Data b => b -> b) -> Set a -> Set a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQ :: (forall d. Data d => d -> u) -> Set a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Set a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # | |
| Ord a => Monoid (Set a) | |
| Ord a => Semigroup (Set a) | Since: containers-0.5.7 |
| Ord a => IsList (Set a) | Since: containers-0.5.6.2 |
| (Read a, Ord a) => Read (Set a) | |
| Show a => Show (Set a) | |
| NFData a => NFData (Set a) | |
Defined in Data.Set.Internal | |
| Eq a => Eq (Set a) | |
| Ord a => Ord (Set a) | |
| Hashable v => Hashable (Set v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Ord v => Container (Set v) | |
Defined in Universum.Container.Class Methods toList :: Set v -> [Element (Set v)] # foldr :: (Element (Set v) -> b -> b) -> b -> Set v -> b # foldl :: (b -> Element (Set v) -> b) -> b -> Set v -> b # foldl' :: (b -> Element (Set v) -> b) -> b -> Set v -> b # elem :: Element (Set v) -> Set v -> Bool # foldMap :: Monoid m => (Element (Set v) -> m) -> Set v -> m # fold :: Set v -> Element (Set v) # foldr' :: (Element (Set v) -> b -> b) -> b -> Set v -> b # notElem :: Element (Set v) -> Set v -> Bool # all :: (Element (Set v) -> Bool) -> Set v -> Bool # any :: (Element (Set v) -> Bool) -> Set v -> Bool # find :: (Element (Set v) -> Bool) -> Set v -> Maybe (Element (Set v)) # safeHead :: Set v -> Maybe (Element (Set v)) # safeMaximum :: Set v -> Maybe (Element (Set v)) # safeMinimum :: Set v -> Maybe (Element (Set v)) # safeFoldr1 :: (Element (Set v) -> Element (Set v) -> Element (Set v)) -> Set v -> Maybe (Element (Set v)) # safeFoldl1 :: (Element (Set v) -> Element (Set v) -> Element (Set v)) -> Set v -> Maybe (Element (Set v)) # | |
| Ord a => FromList (Set a) | |
Defined in Universum.Container.Class Methods fromList :: [ListElement (Set a)] -> Set a # | |
| One (Set v) | |
| type Item (Set a) | |
Defined in Data.Set.Internal | |
| type Element (Set v) | |
Defined in Universum.Container.Class | |
| type FromListC (Set a) | |
Defined in Universum.Container.Class | |
| type ListElement (Set a) | |
Defined in Universum.Container.Class | |
| type OneItem (Set v) | |
Defined in Universum.Container.Class | |
A class of types that can be fully evaluated.
Since: deepseq-1.1.0.0
Minimal complete definition
Nothing
Methods
rnf should reduce its argument to normal form (that is, fully
evaluate all sub-components), and then return ().
Generic NFData deriving
Starting with GHC 7.2, you can automatically derive instances
for types possessing a Generic instance.
Note: Generic1 can be auto-derived starting with GHC 7.4
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics (Generic, Generic1)
import Control.DeepSeq
data Foo a = Foo a String
deriving (Eq, Generic, Generic1)
instance NFData a => NFData (Foo a)
instance NFData1 Foo
data Colour = Red | Green | Blue
deriving Generic
instance NFData ColourStarting with GHC 7.10, the example above can be written more
concisely by enabling the new DeriveAnyClass extension:
{-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}
import GHC.Generics (Generic)
import Control.DeepSeq
data Foo a = Foo a String
deriving (Eq, Generic, Generic1, NFData, NFData1)
data Colour = Red | Green | Blue
deriving (Generic, NFData)
Compatibility with previous deepseq versions
Prior to version 1.4.0.0, the default implementation of the rnf
method was defined as
rnfa =seqa ()
However, starting with deepseq-1.4.0.0, the default
implementation is based on DefaultSignatures allowing for
more accurate auto-derived NFData instances. If you need the
previously used exact default rnf method implementation
semantics, use
instance NFData Colour where rnf x = seq x ()
or alternatively
instance NFData Colour where rnf = rwhnf
or
{-# LANGUAGE BangPatterns #-}
instance NFData Colour where rnf !_ = ()Instances
a variant of deepseq that is useful in some circumstances:
force x = x `deepseq` x
force x fully evaluates x, and then returns it. Note that
force x only performs evaluation when the value of force x
itself is demanded, so essentially it turns shallow evaluation into
deep evaluation.
force can be conveniently used in combination with ViewPatterns:
{-# LANGUAGE BangPatterns, ViewPatterns #-}
import Control.DeepSeq
someFun :: ComplexData -> SomeResult
someFun (force -> !arg) = {- 'arg' will be fully evaluated -}Another useful application is to combine force with
evaluate in order to force deep evaluation
relative to other IO operations:
import Control.Exception (evaluate)
import Control.DeepSeq
main = do
result <- evaluate $ force $ pureComputation
{- 'result' will be fully evaluated at this point -}
return ()Finally, here's an exception safe variant of the readFile' example:
readFile' :: FilePath -> IO String
readFile' fn = bracket (openFile fn ReadMode) hClose $ \h ->
evaluate . force =<< hGetContents hSince: deepseq-1.2.0.0
deepseq :: NFData a => a -> b -> b #
deepseq: fully evaluates the first argument, before returning the
second.
The name deepseq is used to illustrate the relationship to seq:
where seq is shallow in the sense that it only evaluates the top
level of its argument, deepseq traverses the entire data structure
evaluating it completely.
deepseq can be useful for forcing pending exceptions,
eradicating space leaks, or forcing lazy I/O to happen. It is
also useful in conjunction with parallel Strategies (see the
parallel package).
There is no guarantee about the ordering of evaluation. The
implementation may evaluate the components of the structure in
any order or in parallel. To impose an actual order on
evaluation, use pseq from Control.Parallel in the
parallel package.
Since: deepseq-1.1.0.0
($!!) :: NFData a => (a -> b) -> a -> b infixr 0 #
the deep analogue of $!. In the expression f $!! x, x is
fully evaluated before the function f is applied to it.
Since: deepseq-1.2.0.0
class MonadThrow m => MonadCatch (m :: Type -> Type) #
A class for monads which allow exceptions to be caught, in particular
exceptions which were thrown by throwM.
Instances should obey the following law:
catch (throwM e) f = f e
Note that the ability to catch an exception does not guarantee that we can
deal with all possible exit points from a computation. Some monads, such as
continuation-based stacks, allow for more than just a success/failure
strategy, and therefore catch cannot be used by those monads to properly
implement a function such as finally. For more information, see
MonadMask.
Minimal complete definition
Instances
| MonadCatch STM | |
| MonadCatch IO | |
| e ~ SomeException => MonadCatch (Either e) | Since: exceptions-0.8.3 |
| MonadCatch m => MonadCatch (ResourceT m) | |
| MonadCatch m => MonadCatch (ListT m) | |
| MonadCatch m => MonadCatch (MaybeT m) | Catches exceptions from the base monad. |
| (Error e, MonadCatch m) => MonadCatch (ErrorT e m) | Catches exceptions from the base monad. |
| MonadCatch m => MonadCatch (ExceptT e m) | Catches exceptions from the base monad. |
| MonadCatch m => MonadCatch (IdentityT m) | |
| MonadCatch m => MonadCatch (ReaderT r m) | |
| MonadCatch m => MonadCatch (StateT s m) | |
| MonadCatch m => MonadCatch (StateT s m) | |
| (MonadCatch m, Monoid w) => MonadCatch (WriterT w m) | |
| (MonadCatch m, Monoid w) => MonadCatch (WriterT w m) | |
| (MonadCatch m, Monoid w) => MonadCatch (RWST r w s m) | |
| (MonadCatch m, Monoid w) => MonadCatch (RWST r w s m) | |
class MonadCatch m => MonadMask (m :: Type -> Type) where #
A class for monads which provide for the ability to account for all possible exit points from a computation, and to mask asynchronous exceptions. Continuation-based monads are invalid instances of this class.
Instances should ensure that, in the following code:
fg = f `finally` g
The action g is called regardless of what occurs within f, including
async exceptions. Some monads allow f to abort the computation via other
effects than throwing an exception. For simplicity, we will consider aborting
and throwing an exception to be two forms of "throwing an error".
If f and g both throw an error, the error thrown by fg depends on which
errors we're talking about. In a monad transformer stack, the deeper layers
override the effects of the inner layers; for example, ExceptT e1 (Except
e2) a represents a value of type Either e2 (Either e1 a), so throwing both
an e1 and an e2 will result in Left e2. If f and g both throw an
error from the same layer, instances should ensure that the error from g
wins.
Effects other than throwing an error are also overriden by the deeper layers.
For example, StateT s Maybe a represents a value of type s -> Maybe (a,
s), so if an error thrown from f causes this function to return Nothing,
any changes to the state which f also performed will be erased. As a
result, g will see the state as it was before f. Once g completes,
f's error will be rethrown, so g' state changes will be erased as well.
This is the normal interaction between effects in a monad transformer stack.
By contrast, lifted-base's
version of finally always discards all of g's non-IO effects, and g
never sees any of f's non-IO effects, regardless of the layer ordering and
regardless of whether f throws an error. This is not the result of
interacting effects, but a consequence of MonadBaseControl's approach.
Methods
mask :: ((forall a. m a -> m a) -> m b) -> m b #
Runs an action with asynchronous exceptions disabled. The action is
provided a method for restoring the async. environment to what it was
at the mask call. See Control.Exception's mask.
uninterruptibleMask :: ((forall a. m a -> m a) -> m b) -> m b #
Like mask, but the masked computation is not interruptible (see
Control.Exception's uninterruptibleMask. WARNING:
Only use if you need to mask exceptions around an interruptible operation
AND you can guarantee the interruptible operation will only block for a
short period of time. Otherwise you render the program/thread unresponsive
and/or unkillable.
Arguments
| :: m a | acquire some resource |
| -> (a -> ExitCase b -> m c) | release the resource, observing the outcome of the inner action |
| -> (a -> m b) | inner action to perform with the resource |
| -> m (b, c) |
A generalized version of bracket which uses ExitCase to distinguish
the different exit cases, and returns the values of both the use and
release actions. In practice, this extra information is rarely needed,
so it is often more convenient to use one of the simpler functions which
are defined in terms of this one, such as bracket, finally, onError,
and bracketOnError.
This function exists because in order to thread their effects through the
execution of bracket, monad transformers need values to be threaded from
use to release and from release to the output value.
NOTE This method was added in version 0.9.0 of this
library. Previously, implementation of functions like bracket
and finally in this module were based on the mask and
uninterruptibleMask functions only, disallowing some classes of
tranformers from having MonadMask instances (notably
multi-exit-point transformers like ExceptT). If you are a
library author, you'll now need to provide an implementation for
this method. The StateT implementation demonstrates most of the
subtleties:
generalBracket acquire release use = StateT $ s0 -> do
((b, _s2), (c, s3)) <- generalBracket
(runStateT acquire s0)
((resource, s1) exitCase -> case exitCase of
ExitCaseSuccess (b, s2) -> runStateT (release resource (ExitCaseSuccess b)) s2
-- In the two other cases, the base monad overrides use's state
-- changes and the state reverts to s1.
ExitCaseException e -> runStateT (release resource (ExitCaseException e)) s1
ExitCaseAbort -> runStateT (release resource ExitCaseAbort) s1
)
((resource, s1) -> runStateT (use resource) s1)
return ((b, c), s3)
The StateT s m implementation of generalBracket delegates to the m
implementation of generalBracket. The acquire, use, and release
arguments given to StateT's implementation produce actions of type
StateT s m a, StateT s m b, and StateT s m c. In order to run those
actions in the base monad, we need to call runStateT, from which we
obtain actions of type m (a, s), m (b, s), and m (c, s). Since each
action produces the next state, it is important to feed the state produced
by the previous action to the next action.
In the ExitCaseSuccess case, the state starts at s0, flows through
acquire to become s1, flows through use to become s2, and finally
flows through release to become s3. In the other two cases, release
does not receive the value s2, so its action cannot see the state changes
performed by use. This is fine, because in those two cases, an error was
thrown in the base monad, so as per the usual interaction between effects
in a monad transformer stack, those state changes get reverted. So we start
from s1 instead.
Finally, the m implementation of generalBracket returns the pairs
(b, s) and (c, s). For monad transformers other than StateT, this
will be some other type representing the effects and values performed and
returned by the use and release actions. The effect part of the use
result, in this case _s2, usually needs to be discarded, since those
effects have already been incorporated in the release action.
The only effect which is intentionally not incorporated in the release
action is the effect of throwing an error. In that case, the error must be
re-thrown. One subtlety which is easy to miss is that in the case in which
use and release both throw an error, the error from release should
take priority. Here is an implementation for ExceptT which demonstrates
how to do this.
generalBracket acquire release use = ExceptT $ do
(eb, ec) <- generalBracket
(runExceptT acquire)
(eresource exitCase -> case eresource of
Left e -> return (Left e) -- nothing to release, acquire didn't succeed
Right resource -> case exitCase of
ExitCaseSuccess (Right b) -> runExceptT (release resource (ExitCaseSuccess b))
ExitCaseException e -> runExceptT (release resource (ExitCaseException e))
_ -> runExceptT (release resource ExitCaseAbort))
(either (return . Left) (runExceptT . use))
return $ do
-- The order in which we perform those two Either effects determines
-- which error will win if they are both Lefts. We want the error from
-- release to win.
c <- ec
b <- eb
return (b, c)
Since: exceptions-0.9.0
Instances
| MonadMask IO | |
| e ~ SomeException => MonadMask (Either e) | Since: exceptions-0.8.3 |
Defined in Control.Monad.Catch | |
| MonadMask m => MonadMask (ResourceT m) | |
Defined in Control.Monad.Trans.Resource.Internal Methods mask :: ((forall a. ResourceT m a -> ResourceT m a) -> ResourceT m b) -> ResourceT m b # uninterruptibleMask :: ((forall a. ResourceT m a -> ResourceT m a) -> ResourceT m b) -> ResourceT m b # generalBracket :: ResourceT m a -> (a -> ExitCase b -> ResourceT m c) -> (a -> ResourceT m b) -> ResourceT m (b, c) # | |
| MonadMask m => MonadMask (MaybeT m) | Since: exceptions-0.10.0 |
Defined in Control.Monad.Catch | |
| (Error e, MonadMask m) => MonadMask (ErrorT e m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. ErrorT e m a -> ErrorT e m a) -> ErrorT e m b) -> ErrorT e m b # uninterruptibleMask :: ((forall a. ErrorT e m a -> ErrorT e m a) -> ErrorT e m b) -> ErrorT e m b # generalBracket :: ErrorT e m a -> (a -> ExitCase b -> ErrorT e m c) -> (a -> ErrorT e m b) -> ErrorT e m (b, c) # | |
| MonadMask m => MonadMask (ExceptT e m) | Since: exceptions-0.9.0 |
Defined in Control.Monad.Catch Methods mask :: ((forall a. ExceptT e m a -> ExceptT e m a) -> ExceptT e m b) -> ExceptT e m b # uninterruptibleMask :: ((forall a. ExceptT e m a -> ExceptT e m a) -> ExceptT e m b) -> ExceptT e m b # generalBracket :: ExceptT e m a -> (a -> ExitCase b -> ExceptT e m c) -> (a -> ExceptT e m b) -> ExceptT e m (b, c) # | |
| MonadMask m => MonadMask (IdentityT m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. IdentityT m a -> IdentityT m a) -> IdentityT m b) -> IdentityT m b # uninterruptibleMask :: ((forall a. IdentityT m a -> IdentityT m a) -> IdentityT m b) -> IdentityT m b # generalBracket :: IdentityT m a -> (a -> ExitCase b -> IdentityT m c) -> (a -> IdentityT m b) -> IdentityT m (b, c) # | |
| MonadMask m => MonadMask (ReaderT r m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. ReaderT r m a -> ReaderT r m a) -> ReaderT r m b) -> ReaderT r m b # uninterruptibleMask :: ((forall a. ReaderT r m a -> ReaderT r m a) -> ReaderT r m b) -> ReaderT r m b # generalBracket :: ReaderT r m a -> (a -> ExitCase b -> ReaderT r m c) -> (a -> ReaderT r m b) -> ReaderT r m (b, c) # | |
| MonadMask m => MonadMask (StateT s m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. StateT s m a -> StateT s m a) -> StateT s m b) -> StateT s m b # uninterruptibleMask :: ((forall a. StateT s m a -> StateT s m a) -> StateT s m b) -> StateT s m b # generalBracket :: StateT s m a -> (a -> ExitCase b -> StateT s m c) -> (a -> StateT s m b) -> StateT s m (b, c) # | |
| MonadMask m => MonadMask (StateT s m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. StateT s m a -> StateT s m a) -> StateT s m b) -> StateT s m b # uninterruptibleMask :: ((forall a. StateT s m a -> StateT s m a) -> StateT s m b) -> StateT s m b # generalBracket :: StateT s m a -> (a -> ExitCase b -> StateT s m c) -> (a -> StateT s m b) -> StateT s m (b, c) # | |
| (MonadMask m, Monoid w) => MonadMask (WriterT w m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. WriterT w m a -> WriterT w m a) -> WriterT w m b) -> WriterT w m b # uninterruptibleMask :: ((forall a. WriterT w m a -> WriterT w m a) -> WriterT w m b) -> WriterT w m b # generalBracket :: WriterT w m a -> (a -> ExitCase b -> WriterT w m c) -> (a -> WriterT w m b) -> WriterT w m (b, c) # | |
| (MonadMask m, Monoid w) => MonadMask (WriterT w m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. WriterT w m a -> WriterT w m a) -> WriterT w m b) -> WriterT w m b # uninterruptibleMask :: ((forall a. WriterT w m a -> WriterT w m a) -> WriterT w m b) -> WriterT w m b # generalBracket :: WriterT w m a -> (a -> ExitCase b -> WriterT w m c) -> (a -> WriterT w m b) -> WriterT w m (b, c) # | |
| (MonadMask m, Monoid w) => MonadMask (RWST r w s m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. RWST r w s m a -> RWST r w s m a) -> RWST r w s m b) -> RWST r w s m b # uninterruptibleMask :: ((forall a. RWST r w s m a -> RWST r w s m a) -> RWST r w s m b) -> RWST r w s m b # generalBracket :: RWST r w s m a -> (a -> ExitCase b -> RWST r w s m c) -> (a -> RWST r w s m b) -> RWST r w s m (b, c) # | |
| (MonadMask m, Monoid w) => MonadMask (RWST r w s m) | |
Defined in Control.Monad.Catch Methods mask :: ((forall a. RWST r w s m a -> RWST r w s m a) -> RWST r w s m b) -> RWST r w s m b # uninterruptibleMask :: ((forall a. RWST r w s m a -> RWST r w s m a) -> RWST r w s m b) -> RWST r w s m b # generalBracket :: RWST r w s m a -> (a -> ExitCase b -> RWST r w s m c) -> (a -> RWST r w s m b) -> RWST r w s m (b, c) # | |
class Monad m => MonadState s (m :: Type -> Type) | m -> s where #
Minimal definition is either both of get and put or just state
Methods
Return the state from the internals of the monad.
Replace the state inside the monad.
Instances
| MonadState s m => MonadState s (ResourceT m) | |
| MonadState s m => MonadState s (ListT m) | |
| MonadState s m => MonadState s (MaybeT m) | |
| (Error e, MonadState s m) => MonadState s (ErrorT e m) | |
| MonadState s m => MonadState s (ExceptT e m) | Since: mtl-2.2 |
| MonadState s m => MonadState s (IdentityT m) | |
| MonadState s m => MonadState s (ReaderT r m) | |
| Monad m => MonadState s (StateT s m) | |
| Monad m => MonadState s (StateT s m) | |
| (Monoid w, MonadState s m) => MonadState s (WriterT w m) | |
| (Monoid w, MonadState s m) => MonadState s (WriterT w m) | |
| MonadState s m => MonadState s (ConduitT i o m) | |
| MonadState s m => MonadState s (ContT r m) | |
| (Monad m, Monoid w) => MonadState s (RWST r w s m) | |
| (Monad m, Monoid w) => MonadState s (RWST r w s m) | |
| MonadState s m => MonadState s (Pipe l i o u m) | |
(^?) :: s -> Getting (First a) s a -> Maybe a infixl 8 #
s ^? t returns the 1st element t returns, or Nothing if t doesn't return anything. It's trivially implemented by passing the First monoid to the getter.
Safe head:
>>>[] ^? eachNothing
>>>[1..3] ^? eachJust 1
>>>Left 1 ^? _RightNothing
>>>Right 1 ^? _RightJust 1
A non-operator version of (^?) is called preview, and – like view – it's a bit more general than (^?) (it works in MonadReader). If you need the general version, you can get it from microlens-mtl; otherwise there's preview available in Lens.Micro.Extras.
(^..) :: s -> Getting (Endo [a]) s a -> [a] infixl 8 #
s ^.. t returns the list of all values that t gets from s.
A Maybe contains either 0 or 1 values:
>>>Just 3 ^.. _Just[3]
Gathering all values in a list of tuples:
>>>[(1,2),(3,4)] ^.. each.each[1,2,3,4]
(^.) :: s -> Getting a s a -> a infixl 8 #
(^.) applies a getter to a value; in other words, it gets a value out of a structure using a getter (which can be a lens, traversal, fold, etc.).
Getting 1st field of a tuple:
(^._1) :: (a, b) -> a (^._1) =fst
When (^.) is used with a traversal, it combines all results using the Monoid instance for the resulting type. For instance, for lists it would be simple concatenation:
>>>("str","ing") ^. each"string"
The reason for this is that traversals use Applicative, and the Applicative instance for Const uses monoid concatenation to combine “effects” of Const.
A non-operator version of (^.) is called view, and it's a bit more general than (^.) (it works in MonadReader). If you need the general version, you can get it from microlens-mtl; otherwise there's view available in Lens.Micro.Extras.
over :: ASetter s t a b -> (a -> b) -> s -> t #
Getting fmap in a roundabout way:
overmapped::Functorf => (a -> b) -> f a -> f bovermapped=fmap
Applying a function to both components of a pair:
overboth:: (a -> b) -> (a, a) -> (b, b)overboth= \f t -> (f (fst t), f (snd t))
Using over _2second:
>>>over _2 show (10,20)(10,"20")
(%~) :: ASetter s t a b -> (a -> b) -> s -> t infixr 4 #
(%~) applies a function to the target; an alternative explanation is that it is an inverse of sets, which turns a setter into an ordinary function. mapped %~ reversefmap reverse
See over if you want a non-operator synonym.
Negating the 1st element of a pair:
>>>(1,2) & _1 %~ negate(-1,2)
Turning all Lefts in a list to upper case:
>>>(mapped._Left.mapped %~ toUpper) [Left "foo", Right "bar"][Left "FOO",Right "bar"]
_1 :: Field1 s t a b => Lens s t a b #
Gives access to the 1st field of a tuple (up to 5-tuples).
Getting the 1st component:
>>>(1,2,3,4,5) ^. _11
Setting the 1st component:
>>>(1,2,3) & _1 .~ 10(10,2,3)
Note that this lens is lazy, and can set fields even of undefined:
>>>set _1 10 undefined :: (Int, Int)(10,*** Exception: Prelude.undefined
This is done to avoid violating a lens law stating that you can get back what you put:
>>>view _1 . set _1 10 $ (undefined :: (Int, Int))10
The implementation (for 2-tuples) is:
_1f t = (,)<$>f (fstt)<*>pure(sndt)
or, alternatively,
_1f ~(a,b) = (\a' -> (a',b))<$>f a
(where ~ means a lazy pattern).
type Lens s t a b = forall (f :: Type -> Type). Functor f => (a -> f b) -> s -> f t #
Lens s t a b is the lowest common denominator of a setter and a getter, something that has the power of both; it has a Functor constraint, and since both Const and Identity are functors, it can be used whenever a getter or a setter is needed.
ais the type of the value inside of structurebis the type of the replaced valuesis the type of the whole structuretis the type of the structure after replacingain it withb
type Lens' s a = Lens s s a a #
This is a type alias for monomorphic lenses which don't change the type of the container (or of the value inside).
type Traversal s t a b = forall (f :: Type -> Type). Applicative f => (a -> f b) -> s -> f t #
Traversal s t a b is a generalisation of Lens which allows many targets (possibly 0). It's achieved by changing the constraint to Applicative instead of Functor – indeed, the point of Applicative is that you can combine effects, which is just what we need to have many targets.
Ultimately, traversals should follow 2 laws:
t pure ≡ pure fmap (t f) . t g ≡ getCompose . t (Compose . fmap f . g)
The 1st law states that you can't change the shape of the structure or do anything funny with elements (traverse elements which aren't in the structure, create new elements out of thin air, etc.). The 2nd law states that you should be able to fuse 2 identical traversals into one. For a more detailed explanation of the laws, see this blog post (if you prefer rambling blog posts), or The Essence Of The Iterator Pattern (if you prefer papers).
Traversing any value twice is a violation of traversal laws. You can, however, traverse values in any order.
type Traversal' s a = Traversal s s a a #
This is a type alias for monomorphic traversals which don't change the type of the container (or of the values inside).
modify :: MonadState s m => (s -> s) -> m () #
Monadic state transformer.
Maps an old state to a new state inside a state monad. The old state is thrown away.
Main> :t modify ((+1) :: Int -> Int)
modify (...) :: (MonadState Int a) => a ()This says that modify (+1) acts over any
Monad that is a member of the MonadState class,
with an Int state.
gets :: MonadState s m => (s -> a) -> m a #
Gets specific component of the state, using a projection function supplied.
Arguments
| :: MonadReader r m | |
| => (r -> a) | The selector function to apply to the environment. |
| -> m a |
Retrieves a function of the current environment.
class Monad m => MonadReader r (m :: Type -> Type) | m -> r where #
See examples in Control.Monad.Reader.
Note, the partially applied function type (->) r is a simple reader monad.
See the instance declaration below.
Methods
Retrieves the monad environment.
Arguments
| :: (r -> r) | The function to modify the environment. |
| -> m a |
|
| -> m a |
Executes a computation in a modified environment.
Arguments
| :: (r -> a) | The selector function to apply to the environment. |
| -> m a |
Retrieves a function of the current environment.
Instances
| MonadReader r m => MonadReader r (ResourceT m) | |
| MonadReader r m => MonadReader r (ListT m) | |
| MonadReader r m => MonadReader r (MaybeT m) | |
| (Error e, MonadReader r m) => MonadReader r (ErrorT e m) | |
| MonadReader r m => MonadReader r (ExceptT e m) | Since: mtl-2.2 |
| MonadReader r m => MonadReader r (IdentityT m) | |
| Monad m => MonadReader r (ReaderT r m) | |
| MonadReader r m => MonadReader r (StateT s m) | |
| MonadReader r m => MonadReader r (StateT s m) | |
| (Monoid w, MonadReader r m) => MonadReader r (WriterT w m) | |
| (Monoid w, MonadReader r m) => MonadReader r (WriterT w m) | |
| MonadReader r m => MonadReader r (ConduitT i o m) | |
| MonadReader r ((->) r) | |
| MonadReader r' m => MonadReader r' (ContT r m) | |
| (Monad m, Monoid w) => MonadReader r (RWST r w s m) | |
| (Monad m, Monoid w) => MonadReader r (RWST r w s m) | |
| MonadReader r m => MonadReader r (Pipe l i o u m) | |
type Reader r = ReaderT r Identity #
The parameterizable reader monad.
Computations are functions of a shared environment.
The return function ignores the environment, while >>= passes
the inherited environment to both subcomputations.
use :: MonadState s m => Getting a s a -> m a #
use is (^.) (or view) which implicitly operates on the state; for instance, if your state is a record containing a field foo, you can write
x <- use foo
to extract foo from the state. In other words, use is the same as gets, but for getters instead of functions.
The implementation of use is straightforward:
usel =gets(viewl)
If you need to extract something with a fold or traversal, you need preuse.
preview :: MonadReader s m => Getting (First a) s a -> m (Maybe a) #
preview is a synonym for (^?), generalised for MonadReader (just like view, which is a synonym for (^.)).
>>>preview each [1..5]Just 1
view :: MonadReader s m => Getting a s a -> m a #
view is a synonym for (^.), generalised for MonadReader (we are able to use it instead of (^.) since functions are instances of the MonadReader class):
>>>view _1 (1, 2)1
When you're using Reader for config and your config type has lenses generated for it, most of the time you'll be using view instead of asks:
doSomething :: (MonadReaderConfig m) => m Int doSomething = do thingy <-viewsetting1 -- same as “asks(^.setting1)” anotherThingy <-viewsetting2 ...
modify' :: MonadState s m => (s -> s) -> m () #
A variant of modify in which the computation is strict in the
new state.
Since: mtl-2.2
runExceptT :: ExceptT e m a -> m (Either e a) #
The inverse of ExceptT.
withExceptT :: forall (m :: Type -> Type) e e' a. Functor m => (e -> e') -> ExceptT e m a -> ExceptT e' m a #
Transform any exceptions thrown by the computation using the given function.
Arguments
| :: Reader r a | A |
| -> r | An initial environment. |
| -> a |
Runs a Reader and extracts the final value from it.
(The inverse of reader.)
type State s = StateT s Identity #
A state monad parameterized by the type s of the state to carry.
The return function leaves the state unchanged, while >>= uses
the final state of the first computation as the initial state of
the second.
Arguments
| :: State s a | state-passing computation to execute |
| -> s | initial state |
| -> (a, s) | return value and final state |
Unwrap a state monad computation as a function.
(The inverse of state.)
Arguments
| :: State s a | state-passing computation to execute |
| -> s | initial value |
| -> a | return value of the state computation |
Arguments
| :: State s a | state-passing computation to execute |
| -> s | initial value |
| -> s | final state |
evalStateT :: Monad m => StateT s m a -> s -> m a #
Evaluate a state computation with the given initial state and return the final value, discarding the final state.
evalStateTm s =liftMfst(runStateTm s)
execStateT :: Monad m => StateT s m a -> s -> m s #
Evaluate a state computation with the given initial state and return the final state, discarding the final value.
execStateTm s =liftMsnd(runStateTm s)
bracketOnError :: MonadMask m => m a -> (a -> m b) -> (a -> m c) -> m c #
Async safe version of bracketOnError
Since: safe-exceptions-0.1.0.0
bracket_ :: MonadMask m => m a -> m b -> m c -> m c #
Async safe version of bracket_
Since: safe-exceptions-0.1.0.0
onException :: MonadMask m => m a -> m b -> m a #
Async safe version of onException
Since: safe-exceptions-0.1.0.0
tryAny :: MonadCatch m => m a -> m (Either SomeException a) #
try specialized to catch all synchronous exceptions
Since: safe-exceptions-0.1.0.0
try :: (MonadCatch m, Exception e) => m a -> m (Either e a) #
Same as upstream try, but will not catch asynchronous
exceptions
Since: safe-exceptions-0.1.0.0
handleAny :: MonadCatch m => (SomeException -> m a) -> m a -> m a #
Flipped version of catchAny
Since: safe-exceptions-0.1.0.0
catchAny :: MonadCatch m => m a -> (SomeException -> m a) -> m a #
catch specialized to catch all synchronous exception
Since: safe-exceptions-0.1.0.0
catch :: (MonadCatch m, Exception e) => m a -> (e -> m a) -> m a #
Same as upstream catch, but will not catch asynchronous
exceptions
Since: safe-exceptions-0.1.0.0
throwM :: (MonadThrow m, Exception e) => e -> m a #
Synonym for throw
Since: safe-exceptions-0.1.0.0
modifyTVar' :: TVar a -> (a -> a) -> STM () #
Strict version of modifyTVar.
Since: stm-2.3
decodeUtf8With :: OnDecodeError -> ByteString -> Text #
Decode a ByteString containing UTF-8 encoded text.
NOTE: The replacement character returned by OnDecodeError
MUST be within the BMP plane; surrogate code points will
automatically be remapped to the replacement char U+FFFD
(since 0.11.3.0), whereas code points beyond the BMP will throw an
error (since 1.2.3.1); For earlier versions of text using
those unsupported code points would result in undefined behavior.
lenientDecode :: OnDecodeError #
Replace an invalid input byte with the Unicode replacement character U+FFFD.
strictDecode :: OnDecodeError #
Throw a UnicodeException if decoding fails.
type OnError a b = String -> Maybe a -> Maybe b #
Function type for handling a coding error. It is supplied with two inputs:
- A
Stringthat describes the error. - The input value that caused the error. If the error arose
because the end of input was reached or could not be identified
precisely, this value will be
Nothing.
If the handler returns a value wrapped with Just, that value will
be used in the output as the replacement for the invalid input. If
it returns Nothing, no value will be used in the output.
Should the handler need to abort processing, it should use error
or throw an exception (preferably a UnicodeException). It may
use the description provided to construct a more helpful error
report.
type OnDecodeError = OnError Word8 Char #
A handler for a decoding error.
data UnicodeException #
An exception type for representing Unicode encoding errors.
Instances
| Exception UnicodeException | |
Defined in Data.Text.Encoding.Error Methods toException :: UnicodeException -> SomeException # | |
| Show UnicodeException | |
Defined in Data.Text.Encoding.Error Methods showsPrec :: Int -> UnicodeException -> ShowS # show :: UnicodeException -> String # showList :: [UnicodeException] -> ShowS # | |
| NFData UnicodeException | |
Defined in Data.Text.Encoding.Error Methods rnf :: UnicodeException -> () # | |
| Eq UnicodeException | |
Defined in Data.Text.Encoding.Error Methods (==) :: UnicodeException -> UnicodeException -> Bool # (/=) :: UnicodeException -> UnicodeException -> Bool # | |
except :: forall (m :: Type -> Type) e a. Monad m => Either e a -> ExceptT e m a #
Constructor for computations in the exception monad.
(The inverse of runExcept).
class SuperComposition a b c | a b -> c where #
This type class allows to implement variadic composition operator.
Methods
(...) :: a -> b -> c infixl 8 #
Allows to apply function to result of another function with multiple arguments.
>>>(show ... (+)) 1 2"3">>>show ... 5"5">>>(null ... zip5) [1] [2] [3] [] [5]True
Inspired by http://stackoverflow.com/questions/9656797/variadic-compose-function.
Performance
To check the performance there was done a bunch of benchmarks. Benchmarks were made on
examples given above and also on the functions of many arguments.
The results are showing that the operator (...) performs as fast as
plain applications of the operator (.) on almost all the tests, but (...)
leads to the performance draw-down if ghc fails to inline it.
Slow behavior was noticed on functions without type specifications.
That's why keep in mind that providing explicit type declarations for functions is very
important when using (...).
Relying on type inference will lead to the situation when all optimizations
disappear due to very general inferred type. However, functions without type
specification but with applied INLINE pragma are fast again.
Instances
| (a ~ c, r ~ b) => SuperComposition (a -> b) c r | |
Defined in Universum.VarArg | |
| (SuperComposition (a -> b) d r1, r ~ (c -> r1)) => SuperComposition (a -> b) (c -> d) r | |
Defined in Universum.VarArg | |
type ($) (f :: k1 -> k) (a :: k1) = f a infixr 2 #
Infix application.
f :: Either String $ Maybe Int = f :: Either String (Maybe Int)
type family Each (c :: [k -> Constraint]) (as :: [k]) where ... #
Map several constraints over several variables.
f :: Each [Show, Read] [a, b] => a -> b -> String = f :: (Show a, Show b, Read a, Read b) => a -> b -> String
To specify list with single constraint / variable, don't forget to prefix
it with ':
f :: Each '[Show] [a, b] => a -> b -> String
Equations
| Each (_1 :: [k -> Constraint]) ('[] :: [k]) = () | |
| Each (c :: [k -> Constraint]) (h ': t :: [k]) = (c <+> h, Each c t) |
type With (a :: [k -> Constraint]) (b :: k) = a <+> b #
Map several constraints over a single variable.
Note, that With a b ≡ Each a '[b]
a :: With [Show, Read] a => a -> a = a :: (Show a, Read a) => a -> a
readEither :: (ToString a, Read b) => a -> Either Text b #
Polymorhpic version of readEither.
>>>readEither @Text @Int "123"Right 123>>>readEither @Text @Int "aa"Left "Prelude.read: no parse"
type LByteString = ByteString #
Type synonym for ByteString.
class ConvertUtf8 a b where #
Type class for conversion to utf8 representation of text.
Methods
encodeUtf8 :: a -> b #
Encode as utf8 string (usually ByteString).
>>>encodeUtf8 @Text @ByteString "патак""\208\191\208\176\209\130\208\176\208\186"
decodeUtf8 :: b -> a #
Decode from utf8 string.
>>>decodeUtf8 @Text @ByteString "\208\191\208\176\209\130\208\176\208\186""\1087\1072\1090\1072\1082">>>putStrLn $ decodeUtf8 @Text @ByteString "\208\191\208\176\209\130\208\176\208\186"патак
decodeUtf8Strict :: b -> Either UnicodeException a #
Decode as utf8 string but returning execption if byte sequence is malformed.
>>>decodeUtf8 @Text @ByteString "\208\208\176\209\130\208\176\208\186""\65533\1072\1090\1072\1082"
>>>decodeUtf8Strict @Text @ByteString "\208\208\176\209\130\208\176\208\186"Left Cannot decode byte '\xd0': Data.Text.Internal.Encoding.decodeUtf8: Invalid UTF-8 stream
Instances
Type class for converting other strings to Text.
Type class for converting other strings to Text.
Type class for converting other strings to String.
undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a #
undefined that leaves a warning in code on every usage.
traceShowM :: (Show a, Monad m) => a -> m () #
Version of traceShowM that leaves a warning.
traceShowIdWith :: Show s => (a -> s) -> a -> a #
Version of traceShowId that leaves a warning.
Useful to tag printed data, for instance:
traceShowIdWith ("My data: ", ) (veryLargeExpression)
traceIdWith :: (a -> Text) -> a -> a #
Version of traceId that leaves a warning.
Useful to tag printed data, for instance:
traceIdWith (x -> "My data: " <> show x) (veryLargeExpression)
This is especially useful with custom formatters:
traceIdWith (x -> "My data: " <> pretty x) (veryLargeExpression)
traceShowId :: Show a => a -> a #
Version of traceShowId that leaves a warning.
error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => Text -> a #
Similar to undefined but data type.
Constructors
| Undefined |
Instances
| Data Undefined | |
Defined in Universum.Debug Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Undefined -> c Undefined # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Undefined # toConstr :: Undefined -> Constr # dataTypeOf :: Undefined -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Undefined) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Undefined) # gmapT :: (forall b. Data b => b -> b) -> Undefined -> Undefined # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Undefined -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Undefined -> r # gmapQ :: (forall d. Data d => d -> u) -> Undefined -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Undefined -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Undefined -> m Undefined # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Undefined -> m Undefined # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Undefined -> m Undefined # | |
| Bounded Undefined | |
| Enum Undefined | |
Defined in Universum.Debug Methods succ :: Undefined -> Undefined # pred :: Undefined -> Undefined # fromEnum :: Undefined -> Int # enumFrom :: Undefined -> [Undefined] # enumFromThen :: Undefined -> Undefined -> [Undefined] # enumFromTo :: Undefined -> Undefined -> [Undefined] # enumFromThenTo :: Undefined -> Undefined -> Undefined -> [Undefined] # | |
| Generic Undefined | |
| Read Undefined | |
| Show Undefined | |
| Eq Undefined | |
| Ord Undefined | |
| type Rep Undefined | |
putLTextLn :: MonadIO m => Text -> m () #
putStrLn :: (Print a, MonadIO m) => a -> m () #
Write a string like value to stdout appending a newline character.
hPutStrLn :: (Print a, MonadIO m) => Handle -> a -> m () #
Write a string like value a to a supplied Handle, appending a
newline character.
hPutStr :: (Print a, MonadIO m) => Handle -> a -> m () #
Write a string like value a to a supplied Handle.
Support class to overload writing of string like values.
Instances
| Print ByteString | |
Defined in Universum.Print.Internal | |
| Print ByteString | |
Defined in Universum.Print.Internal | |
| Print Text | |
| Print Text | |
| Print [Char] | |
unstableNub :: (Eq a, Hashable a) => [a] -> [a] #
Like hashNub but has better performance and also doesn't save the order.
>>>unstableNub [3, 3, 3, 2, 2, -1, 1][1,2,3,-1]
sortNub :: Ord a => [a] -> [a] #
Like ordNub but also sorts a list.
>>>sortNub [3, 3, 3, 2, 2, -1, 1][-1,1,2,3]
guardM :: MonadPlus m => m Bool -> m () #
Monadic version of guard. Occasionally useful.
Here some complex but real-life example:
findSomePath :: IO (Maybe FilePath)
somePath :: MaybeT IO FilePath
somePath = do
path <- MaybeT findSomePath
guardM $ liftIO $ doesDirectoryExist path
return path
ifM :: Monad m => m Bool -> m a -> m a -> m a #
Monadic version of if-then-else.
>>>ifM (pure True) (putTextLn "True text") (putTextLn "False text")True text
unlessM :: Monad m => m Bool -> m () -> m () #
Monadic version of unless.
>>>unlessM (pure False) $ putTextLn "No text :("No text :(>>>unlessM (pure True) $ putTextLn "Yes text :)"
whenM :: Monad m => m Bool -> m () -> m () #
Monadic version of when.
>>>whenM (pure False) $ putTextLn "No text :(">>>whenM (pure True) $ putTextLn "Yes text :)"Yes text :)>>>whenM (Just True) (pure ())Just ()>>>whenM (Just False) (pure ())Just ()>>>whenM Nothing (pure ())Nothing
evaluateNF_ :: (NFData a, MonadIO m) => a -> m () #
Alias for evaluateWHNF . rnf. Similar to evaluateNF
but discards resulting value.
evaluateNF :: (NFData a, MonadIO m) => a -> m a #
Alias for evaluateWHNF . force with clearer name.
evaluateWHNF_ :: MonadIO m => a -> m () #
Like evaluateWNHF but discards value.
evaluateWHNF :: MonadIO m => a -> m a #
Lifted alias for evaluate with clearer name.
note :: MonadError e m => e -> Maybe a -> m a #
Throws error for Maybe if Nothing is given.
Operates over MonadError.
bug :: (HasCallStack, Exception e) => e -> a #
Generate a pure value which, when forced, will synchronously
throw the exception wrapped into Bug data type.
pattern Exc :: Exception e => e -> SomeException #
Pattern synonym to easy pattern matching on exceptions. So intead of writing something like this:
isNonCriticalExc e
| Just (_ :: NodeAttackedError) <- fromException e = True
| Just DialogUnexpected{} <- fromException e = True
| otherwise = False
you can use Exc pattern synonym:
isNonCriticalExc = case
Exc (_ :: NodeAttackedError) -> True -- matching all exceptions of type NodeAttackedError
Exc DialogUnexpected{} -> True
_ -> False
This pattern is bidirectional. You can use Exc e instead of toException e.
Type that represents exceptions used in cases when a particular codepath is not meant to be ever executed, but happens to be executed anyway.
Constructors
| Bug SomeException CallStack |
Instances
| Exception Bug | |
Defined in Universum.Exception Methods toException :: Bug -> SomeException # fromException :: SomeException -> Maybe Bug # displayException :: Bug -> String # | |
| Show Bug | |
maximum :: Ord a => NonEmpty a -> a #
The largest element of a NonEmpty.
>>>maximum (1 :| [2,3,4,5])5
maximumBy :: (a -> a -> Ordering) -> NonEmpty a -> a #
The largest element of a NonEmpty with respect to the given
comparison function.
minimumBy :: (a -> a -> Ordering) -> NonEmpty a -> a #
The least element of a NonEmpty with respect to the given
comparison function.
foldr1 :: (a -> a -> a) -> NonEmpty a -> a #
A variant of foldr that has no base case, and thus may only be
applied to NonEmpty.
>>>foldr1 (+) (1 :| [2,3,4,5])15
foldl1 :: (a -> a -> a) -> NonEmpty a -> a #
A variant of foldl that has no base case, and thus may only be
applied to NonEmpty.
>>>foldl1 (+) (1 :| [2,3,4,5])15
whenNotNullM :: Monad m => m [a] -> (NonEmpty a -> m ()) -> m () #
Monadic version of whenNotNull.
whenNotNull :: Applicative f => [a] -> (NonEmpty a -> f ()) -> f () #
Performs given action over NonEmpty list if given list is non empty.
>>>whenNotNull [] $ \(b :| _) -> print (not b)>>>whenNotNull [False,True] $ \(b :| _) -> print (not b)True
uncons :: [a] -> Maybe (a, [a]) #
Destructuring list into its head and tail if possible. This function is total.
>>>uncons []Nothing>>>uncons [1..5]Just (1,[2,3,4,5])>>>uncons (5 : [1..5]) >>= \(f, l) -> pure $ f == length lJust True
andM :: (Container f, Element f ~ m Bool, Monad m) => f -> m Bool #
Monadic and constrained to Container version of and.
>>>andM [Just True, Just False]Just False>>>andM [Just True]Just True>>>andM [Just True, Just False, Nothing]Just False>>>andM [Just True, Nothing]Nothing>>>andM [putTextLn "1" >> pure True, putTextLn "2" >> pure False, putTextLn "3" >> pure True]1 2 False
concatForM :: (Applicative f, Monoid m, Container (l m), Element (l m) ~ m, Traversable l) => l a -> (a -> f m) -> f m #
Like concatMapM, but has its arguments flipped, so can be used
instead of the common fmap concat $ forM pattern.
concatMapM :: (Applicative f, Monoid m, Container (l m), Element (l m) ~ m, Traversable l) => (a -> f m) -> l a -> f m #
Lifting bind into a monad. Generalized version of concatMap
that works with a monadic predicate. Old and simpler specialized to list
version had next type:
concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b]
Side note: previously it had type
concatMapM :: (Applicative q, Monad m, Traversable m)
=> (a -> q (m b)) -> m a -> q (m b)
Such signature didn't allow to use this function when traversed container type and type of returned by function-argument differed. Now you can use it like e.g.
concatMapM readFile files >>= putTextLn
asum :: (Container t, Alternative f, Element t ~ f a) => t -> f a #
sequenceA_ :: (Container t, Applicative f, Element t ~ f a) => t -> f () #
Constrained to Container version of sequenceA_.
>>>sequenceA_ [putTextLn "foo", print True]foo True
for_ :: (Container t, Applicative f) => t -> (Element t -> f b) -> f () #
traverse_ :: (Container t, Applicative f) => (Element t -> f b) -> t -> f () #
product :: (Container t, Num (Element t)) => t -> Element t #
Stricter version of product.
>>>product [1..10]3628800>>>product (Right 3)... • Do not use 'Foldable' methods on Either Suggestions: Instead of for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f () use whenJust :: Applicative f => Maybe a -> (a -> f ()) -> f () whenRight :: Applicative f => Either l r -> (r -> f ()) -> f () ... Instead of fold :: (Foldable t, Monoid m) => t m -> m use maybeToMonoid :: Monoid m => Maybe m -> m ...
sum :: (Container t, Num (Element t)) => t -> Element t #
Stricter version of sum.
>>>sum [1..10]55>>>sum (Just 3)... • Do not use 'Foldable' methods on Maybe Suggestions: Instead of for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f () use whenJust :: Applicative f => Maybe a -> (a -> f ()) -> f () whenRight :: Applicative f => Either l r -> (r -> f ()) -> f () ... Instead of fold :: (Foldable t, Monoid m) => t m -> m use maybeToMonoid :: Monoid m => Maybe m -> m ...
flipfoldl' :: (Container t, Element t ~ a) => (a -> b -> b) -> b -> t -> b #
Similar to foldl' but takes a function with its arguments flipped.
>>>flipfoldl' (/) 5 [2,3] :: Rational15 % 2
Type of value of the mapping.
Instances
| type Val (NonEmpty (k, v)) | |
Defined in Universum.Container.Class | |
| type Val (IntMap v) | |
Defined in Universum.Container.Class | |
| type Val [(k, v)] | |
Defined in Universum.Container.Class type Val [(k, v)] = v | |
| type Val (Map k v) | |
Defined in Universum.Container.Class | |
| type Val (HashMap k v) | |
Defined in Universum.Container.Class | |
Type of keys of the mapping.
Instances
| type Key (NonEmpty (k, v)) | |
Defined in Universum.Container.Class | |
| type Key (IntMap v) | |
Defined in Universum.Container.Class | |
| type Key [(k, v)] | |
Defined in Universum.Container.Class type Key [(k, v)] = k | |
| type Key (Map k v) | |
Defined in Universum.Container.Class | |
| type Key (HashMap k v) | |
Defined in Universum.Container.Class | |
Type class for data types that can be converted to List of Pairs.
You can define ToPairs by just defining toPairs function.
But the following laws should be met:
toPairsm ≡zip(keysm) (elemsm)keys≡mapfst.toPairselems≡mapsnd.toPairs
Minimal complete definition
Methods
toPairs :: t -> [(Key t, Val t)] #
Converts the structure to the list of the key-value pairs.
>>> toPairs (HashMap.fromList [(a, "xxx"), (b, "yyy")])
[(a,"xxx"),(b,"yyy")]
Converts the structure to the list of the keys.
>>>keys (HashMap.fromList [('a', "xxx"), ('b', "yyy")])"ab"
Converts the structure to the list of the values.
>>>elems (HashMap.fromList [('a', "xxx"), ('b', "yyy")])["xxx","yyy"]
Instances
| type FromListC ByteString | |
Defined in Universum.Container.Class | |
| type FromListC ByteString | |
Defined in Universum.Container.Class | |
| type FromListC IntSet | |
Defined in Universum.Container.Class | |
| type FromListC Text | |
Defined in Universum.Container.Class | |
| type FromListC Text | |
Defined in Universum.Container.Class | |
| type FromListC (ZipList a) | |
Defined in Universum.Container.Class | |
| type FromListC (NonEmpty a) | |
Defined in Universum.Container.Class | |
| type FromListC (IntMap v) | |
Defined in Universum.Container.Class | |
| type FromListC (Seq a) | |
Defined in Universum.Container.Class | |
| type FromListC (Set a) | |
Defined in Universum.Container.Class | |
| type FromListC (Vector a) | |
Defined in Universum.Container.Class | |
| type FromListC [a] | |
Defined in Universum.Container.Class type FromListC [a] = () | |
| type FromListC (Map k v) | |
Defined in Universum.Container.Class | |
| type FromListC (HashMap k v) | |
Defined in Universum.Container.Class | |
type family ListElement l #
Instances
| type ListElement ByteString | |
Defined in Universum.Container.Class | |
| type ListElement ByteString | |
Defined in Universum.Container.Class | |
| type ListElement IntSet | |
Defined in Universum.Container.Class | |
| type ListElement Text | |
Defined in Universum.Container.Class | |
| type ListElement Text | |
Defined in Universum.Container.Class | |
| type ListElement (ZipList a) | |
Defined in Universum.Container.Class | |
| type ListElement (NonEmpty a) | |
Defined in Universum.Container.Class | |
| type ListElement (IntMap v) | |
Defined in Universum.Container.Class | |
| type ListElement (Seq a) | |
Defined in Universum.Container.Class | |
| type ListElement (Set a) | |
Defined in Universum.Container.Class | |
| type ListElement (Vector a) | |
Defined in Universum.Container.Class | |
| type ListElement [a] | |
Defined in Universum.Container.Class | |
| type ListElement (Map k v) | |
Defined in Universum.Container.Class | |
| type ListElement (HashMap k v) | |
Defined in Universum.Container.Class | |
Type class for data types that can be constructed from a list.
Minimal complete definition
Nothing
Methods
fromList :: [ListElement l] -> l #
Instances
Type of element for some container. Implemented as an asscociated type family because
some containers are monomorphic over element type (like Text, IntSet, etc.)
so we can't implement nice interface using old higher-kinded types
approach. Implementing this as an associated type family instead of
top-level family gives you more control over element types.
Instances
Very similar to Foldable but also allows instances for monomorphic types
like Text but forbids instances for Maybe and similar. This class is used as
a replacement for Foldable type class. It solves the following problems:
length,foldrand other functions work on more types for which it makes sense.- You can't accidentally use
lengthon polymorphicFoldable(like list), replace list withMaybeand then debug error for two days. - More efficient implementaions of functions for polymorphic types (like
elemforSet).
The drawbacks:
- Type signatures of polymorphic functions look more scary.
- Orphan instances are involved if you want to use
foldr(and similar) on types from libraries.
Minimal complete definition
Nothing
Associated Types
Type of element for some container. Implemented as an asscociated type family because
some containers are monomorphic over element type (like Text, IntSet, etc.)
so we can't implement nice interface using old higher-kinded types
approach. Implementing this as an associated type family instead of
top-level family gives you more control over element types.
type Element t = ElementDefault t
Methods
Convert container to list of elements.
>>>toList @Text "aba""aba">>>:t toList @Text "aba"toList @Text "aba" :: [Char]
Checks whether container is empty.
>>>null @Text ""True>>>null @Text "aba"False
foldr :: (Element t -> b -> b) -> b -> t -> b #
foldl :: (b -> Element t -> b) -> b -> t -> b #
foldl' :: (b -> Element t -> b) -> b -> t -> b #
elem :: Element t -> t -> Bool #
foldMap :: Monoid m => (Element t -> m) -> t -> m #
foldr' :: (Element t -> b -> b) -> b -> t -> b #
notElem :: Element t -> t -> Bool #
all :: (Element t -> Bool) -> t -> Bool #
any :: (Element t -> Bool) -> t -> Bool #
find :: (Element t -> Bool) -> t -> Maybe (Element t) #
safeHead :: t -> Maybe (Element t) #
safeMaximum :: t -> Maybe (Element t) #
safeMinimum :: t -> Maybe (Element t) #
safeFoldr1 :: (Element t -> Element t -> Element t) -> t -> Maybe (Element t) #
safeFoldl1 :: (Element t -> Element t -> Element t) -> t -> Maybe (Element t) #
Instances
Instances
Type class for types that can be created from one element. singleton
is lone name for this function. Also constructions of different type differ:
:[] for lists, two arguments for Maps. Also some data types are monomorphic.
>>>one True :: [Bool][True]>>>one 'a' :: Text"a">>>one (3, "hello") :: HashMap Int StringfromList [(3,"hello")]
Instances
| One ByteString | |
Defined in Universum.Container.Class Associated Types type OneItem ByteString # Methods one :: OneItem ByteString -> ByteString # | |
| One ByteString | |
Defined in Universum.Container.Class Associated Types type OneItem ByteString # Methods one :: OneItem ByteString -> ByteString # | |
| One IntSet | |
| One Text | |
| One Text | |
| One (NonEmpty a) | |
| One (IntMap v) | |
| One (Seq a) | |
| One (Set v) | |
| Hashable v => One (HashSet v) | |
| One (Vector a) | |
| Prim a => One (Vector a) | |
| Storable a => One (Vector a) | |
| Unbox a => One (Vector a) | |
| One [a] | |
| One (Map k v) | |
| Hashable k => One (HashMap k v) | |
maybeToMonoid :: Monoid m => Maybe m -> m #
hoistEither :: forall (m :: Type -> Type) e a. Applicative m => Either e a -> ExceptT e m a #
hoistMaybe :: forall (m :: Type -> Type) a. Applicative m => Maybe a -> MaybeT m a #
executingState :: s -> State s a -> s #
Alias for flip execState. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
executingStateT :: Functor f => s -> StateT s f a -> f s #
Alias for flip execStateT. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
evaluatingState :: s -> State s a -> a #
Alias for flip evalState. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
evaluatingStateT :: Functor f => s -> StateT s f a -> f a #
Alias for flip evalStateT. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
usingState :: s -> State s a -> (a, s) #
Shorter and more readable alias for flip runState.
usingStateT :: s -> StateT s m a -> m (a, s) #
Shorter and more readable alias for flip runStateT.
usingReader :: r -> Reader r a -> a #
Shorter and more readable alias for flip runReader.
usingReaderT :: r -> ReaderT r m a -> m a #
Shorter and more readable alias for flip runReaderT.
whenRightM :: Monad m => m (Either l r) -> (r -> m ()) -> m () #
Monadic version of whenRight.
whenRight :: Applicative f => Either l r -> (r -> f ()) -> f () #
whenLeft :: Applicative f => Either l r -> (l -> f ()) -> f () #
maybeToLeft :: r -> Maybe l -> Either l r #
maybeToRight :: l -> Maybe r -> Either l r #
rightToMaybe :: Either l r -> Maybe r #
leftToMaybe :: Either l r -> Maybe l #
fromRight :: b -> Either a b -> b #
Extracts value from Right or return given default value.
>>>fromRight 0 (Left 3)0>>>fromRight 0 (Right 5)5
fromLeft :: a -> Either a b -> a #
Extracts value from Left or return given default value.
>>>fromLeft 0 (Left 3)3>>>fromLeft 0 (Right 5)0
whenNothingM_ :: Monad m => m (Maybe a) -> m () -> m () #
Monadic version of whenNothingM_.
whenNothingM :: Monad m => m (Maybe a) -> m a -> m a #
Monadic version of whenNothing.
whenNothing_ :: Applicative f => Maybe a -> f () -> f () #
Performs default Applicative action if Nothing is given.
Do nothing for Just. Convenient for discarding Just content.
>>>whenNothing_ Nothing $ putTextLn "Nothing!"Nothing!>>>whenNothing_ (Just True) $ putTextLn "Nothing!"
whenNothing :: Applicative f => Maybe a -> f a -> f a #
Performs default Applicative action if Nothing is given.
Otherwise returns content of Just pured to Applicative.
>>>whenNothing Nothing [True, False][True,False]>>>whenNothing (Just True) [True, False][True]
whenJust :: Applicative f => Maybe a -> (a -> f ()) -> f () #
Specialized version of for_ for Maybe. It's used for code readability.
Also helps to avoid space leaks:
Foldable.mapM_ space leak.
>>>whenJust Nothing $ \b -> print (not b)>>>whenJust (Just True) $ \b -> print (not b)False
(?:) :: Maybe a -> a -> a infixr 0 #
Similar to fromMaybe but with flipped arguments.
>>>readMaybe "True" ?: FalseTrue
>>>readMaybe "Tru" ?: FalseFalse
atomicWriteIORef :: MonadIO m => IORef a -> a -> m () #
Lifted version of atomicWriteIORef.
atomicModifyIORef' :: MonadIO m => IORef a -> (a -> (a, b)) -> m b #
Lifted version of atomicModifyIORef'.
atomicModifyIORef :: MonadIO m => IORef a -> (a -> (a, b)) -> m b #
Lifted version of atomicModifyIORef.
modifyIORef' :: MonadIO m => IORef a -> (a -> a) -> m () #
Lifted version of modifyIORef'.
modifyIORef :: MonadIO m => IORef a -> (a -> a) -> m () #
Lifted version of modifyIORef.
writeIORef :: MonadIO m => IORef a -> a -> m () #
Lifted version of writeIORef.
withFile :: (MonadIO m, MonadMask m) => FilePath -> IOMode -> (Handle -> m a) -> m a #
Opens a file, manipulates it with the provided function and closes the
handle before returning. The Handle can be written to using the
hPutStr and hPutStrLn functions.
withFile is essentially the bracket pattern, specialized to files. This
should be preferred over openFile + hClose as it properly deals with
(asynchronous) exceptions. In cases where withFile is insufficient, for
instance because the it is not statically known when manipulating the
Handle has finished, one should consider other safe paradigms for resource
usage, such as the ResourceT transformer from the resourcet package,
before resorting to openFile and hClose.
appendFile :: MonadIO m => FilePath -> Text -> m () #
Lifted version of appendFile.
exitSuccess :: MonadIO m => m a #
Lifted version of exitSuccess.
exitFailure :: MonadIO m => m a #
Lifted version of exitFailure.
updateTVar' :: TVar s -> StateT s STM a -> STM a #
Like 'modifyTVar'', but modification is specified as a State monad.
updateMVar' :: MonadIO m => MVar s -> StateT s IO a -> m a #
Like modifyMVar, but modification is specified as a State computation.
This method is strict in produced s value.
readTVarIO :: MonadIO m => TVar a -> m a #
Lifted to MonadIO version of readTVarIO.
tryTakeMVar :: MonadIO m => MVar a -> m (Maybe a) #
Lifted to MonadIO version of tryTakeMVar.
tryReadMVar :: MonadIO m => MVar a -> m (Maybe a) #
Lifted to MonadIO version of tryReadMVar.
tryPutMVar :: MonadIO m => MVar a -> a -> m Bool #
Lifted to MonadIO version of tryPutMVar.
newEmptyMVar :: MonadIO m => m (MVar a) #
Lifted to MonadIO version of newEmptyMVar.
(<<$>>) :: (Functor f, Functor g) => (a -> b) -> f (g a) -> f (g b) infixl 4 #
Alias for fmap . fmap. Convenient to work with two nested Functors.
>>>negate <<$>> Just [1,2,3]Just [-1,-2,-3]
($!) :: (a -> b) -> a -> b infixr 0 #
Stricter version of $ operator.
Default Prelude defines this at the toplevel module, so we do as well.
>>>const 3 $ Prelude.undefined3>>>const 3 $! Prelude.undefined*** Exception: Prelude.undefined ...
someNE :: Alternative f => f a -> f (NonEmpty a) #
Similar to some, but reflects in types that a non-empty list
is returned.
pass :: Applicative f => f () #
Shorter alias for pure ().
>>>pass :: Maybe ()Just ()
Boxed vectors, supporting efficient slicing.
Instances
| FromJSON1 Vector | |
| ToJSON1 Vector | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Vector a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Vector a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Vector a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Vector a] -> Encoding # | |
| MonadFail Vector | Since: vector-0.12.1.0 |
Defined in Data.Vector | |
| MonadFix Vector | Instance has same semantics as one for lists Since: vector-0.12.2.0 |
Defined in Data.Vector | |
| MonadZip Vector | |
| Foldable Vector | |
Defined in Data.Vector Methods fold :: Monoid m => Vector m -> m # foldMap :: Monoid m => (a -> m) -> Vector a -> m # foldMap' :: Monoid m => (a -> m) -> Vector a -> m # foldr :: (a -> b -> b) -> b -> Vector a -> b # foldr' :: (a -> b -> b) -> b -> Vector a -> b # foldl :: (b -> a -> b) -> b -> Vector a -> b # foldl' :: (b -> a -> b) -> b -> Vector a -> b # foldr1 :: (a -> a -> a) -> Vector a -> a # foldl1 :: (a -> a -> a) -> Vector a -> a # elem :: Eq a => a -> Vector a -> Bool # maximum :: Ord a => Vector a -> a # minimum :: Ord a => Vector a -> a # | |
| Eq1 Vector | |
| Ord1 Vector | |
Defined in Data.Vector | |
| Read1 Vector | |
Defined in Data.Vector | |
| Show1 Vector | |
| Traversable Vector | |
| Alternative Vector | |
| Applicative Vector | |
| Functor Vector | |
| Monad Vector | |
| MonadPlus Vector | |
| NFData1 Vector | Since: vector-0.12.1.0 |
Defined in Data.Vector | |
| Vector Vector a | |
Defined in Data.Vector Methods basicUnsafeFreeze :: PrimMonad m => Mutable Vector (PrimState m) a -> m (Vector a) # basicUnsafeThaw :: PrimMonad m => Vector a -> m (Mutable Vector (PrimState m) a) # basicLength :: Vector a -> Int # basicUnsafeSlice :: Int -> Int -> Vector a -> Vector a # basicUnsafeIndexM :: Monad m => Vector a -> Int -> m a # basicUnsafeCopy :: PrimMonad m => Mutable Vector (PrimState m) a -> Vector a -> m () # | |
| FromJSON a => FromJSON (Vector a) | |
| ToJSON a => ToJSON (Vector a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (Vector a) | |
Defined in Data.Vector Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Vector a -> c (Vector a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Vector a) # toConstr :: Vector a -> Constr # dataTypeOf :: Vector a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Vector a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Vector a)) # gmapT :: (forall b. Data b => b -> b) -> Vector a -> Vector a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Vector a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Vector a -> r # gmapQ :: (forall d. Data d => d -> u) -> Vector a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Vector a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Vector a -> m (Vector a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Vector a -> m (Vector a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Vector a -> m (Vector a) # | |
| Monoid (Vector a) | |
| Semigroup (Vector a) | |
| IsList (Vector a) | |
| Read a => Read (Vector a) | |
| Show a => Show (Vector a) | |
| NFData a => NFData (Vector a) | |
Defined in Data.Vector | |
| Eq a => Eq (Vector a) | |
| Ord a => Ord (Vector a) | |
Defined in Data.Vector | |
| Container (Vector a) | |
Defined in Universum.Container.Class Methods toList :: Vector a -> [Element (Vector a)] # foldr :: (Element (Vector a) -> b -> b) -> b -> Vector a -> b # foldl :: (b -> Element (Vector a) -> b) -> b -> Vector a -> b # foldl' :: (b -> Element (Vector a) -> b) -> b -> Vector a -> b # elem :: Element (Vector a) -> Vector a -> Bool # foldMap :: Monoid m => (Element (Vector a) -> m) -> Vector a -> m # fold :: Vector a -> Element (Vector a) # foldr' :: (Element (Vector a) -> b -> b) -> b -> Vector a -> b # notElem :: Element (Vector a) -> Vector a -> Bool # all :: (Element (Vector a) -> Bool) -> Vector a -> Bool # any :: (Element (Vector a) -> Bool) -> Vector a -> Bool # find :: (Element (Vector a) -> Bool) -> Vector a -> Maybe (Element (Vector a)) # safeHead :: Vector a -> Maybe (Element (Vector a)) # safeMaximum :: Vector a -> Maybe (Element (Vector a)) # safeMinimum :: Vector a -> Maybe (Element (Vector a)) # safeFoldr1 :: (Element (Vector a) -> Element (Vector a) -> Element (Vector a)) -> Vector a -> Maybe (Element (Vector a)) # safeFoldl1 :: (Element (Vector a) -> Element (Vector a) -> Element (Vector a)) -> Vector a -> Maybe (Element (Vector a)) # | |
| FromList (Vector a) | |
Defined in Universum.Container.Class Methods fromList :: [ListElement (Vector a)] -> Vector a # | |
| One (Vector a) | |
| type Mutable Vector | |
Defined in Data.Vector | |
| type Item (Vector a) | |
Defined in Data.Vector | |
| type Element (Vector a) | |
Defined in Universum.Container.Class | |
| type FromListC (Vector a) | |
Defined in Universum.Container.Class | |
| type ListElement (Vector a) | |
Defined in Universum.Container.Class | |
| type OneItem (Vector a) | |
Defined in Universum.Container.Class | |
A set of values. A set cannot contain duplicate values.
Instances
| ToJSON1 HashSet | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> HashSet a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [HashSet a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> HashSet a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [HashSet a] -> Encoding # | |
| Foldable HashSet | |
Defined in Data.HashSet.Internal Methods fold :: Monoid m => HashSet m -> m # foldMap :: Monoid m => (a -> m) -> HashSet a -> m # foldMap' :: Monoid m => (a -> m) -> HashSet a -> m # foldr :: (a -> b -> b) -> b -> HashSet a -> b # foldr' :: (a -> b -> b) -> b -> HashSet a -> b # foldl :: (b -> a -> b) -> b -> HashSet a -> b # foldl' :: (b -> a -> b) -> b -> HashSet a -> b # foldr1 :: (a -> a -> a) -> HashSet a -> a # foldl1 :: (a -> a -> a) -> HashSet a -> a # elem :: Eq a => a -> HashSet a -> Bool # maximum :: Ord a => HashSet a -> a # minimum :: Ord a => HashSet a -> a # | |
| Eq1 HashSet | |
| Ord1 HashSet | |
Defined in Data.HashSet.Internal | |
| Show1 HashSet | |
| NFData1 HashSet | Since: unordered-containers-0.2.14.0 |
Defined in Data.HashSet.Internal | |
| Hashable1 HashSet | |
Defined in Data.HashSet.Internal | |
| Lift a => Lift (HashSet a :: Type) | Since: unordered-containers-0.2.17.0 |
| (Eq a, Hashable a, FromJSON a) => FromJSON (HashSet a) | |
| ToJSON a => ToJSON (HashSet a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data a, Eq a, Hashable a) => Data (HashSet a) | |
Defined in Data.HashSet.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> HashSet a -> c (HashSet a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (HashSet a) # toConstr :: HashSet a -> Constr # dataTypeOf :: HashSet a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (HashSet a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (HashSet a)) # gmapT :: (forall b. Data b => b -> b) -> HashSet a -> HashSet a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> HashSet a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> HashSet a -> r # gmapQ :: (forall d. Data d => d -> u) -> HashSet a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> HashSet a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # | |
| (Hashable a, Eq a) => Monoid (HashSet a) | O(n+m) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| (Hashable a, Eq a) => Semigroup (HashSet a) | O(n+m) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| (Eq a, Hashable a) => IsList (HashSet a) | |
| (Eq a, Hashable a, Read a) => Read (HashSet a) | |
| Show a => Show (HashSet a) | |
| NFData a => NFData (HashSet a) | |
Defined in Data.HashSet.Internal | |
| Eq a => Eq (HashSet a) | Note that, in the presence of hash collisions, equal
In general, the lack of substitutivity can be observed with any function that depends on the key ordering, such as folds and traversals. |
| Ord a => Ord (HashSet a) | |
| Hashable a => Hashable (HashSet a) | |
Defined in Data.HashSet.Internal | |
| (Eq v, Hashable v) => Container (HashSet v) | |
Defined in Universum.Container.Class Methods toList :: HashSet v -> [Element (HashSet v)] # foldr :: (Element (HashSet v) -> b -> b) -> b -> HashSet v -> b # foldl :: (b -> Element (HashSet v) -> b) -> b -> HashSet v -> b # foldl' :: (b -> Element (HashSet v) -> b) -> b -> HashSet v -> b # elem :: Element (HashSet v) -> HashSet v -> Bool # foldMap :: Monoid m => (Element (HashSet v) -> m) -> HashSet v -> m # fold :: HashSet v -> Element (HashSet v) # foldr' :: (Element (HashSet v) -> b -> b) -> b -> HashSet v -> b # notElem :: Element (HashSet v) -> HashSet v -> Bool # all :: (Element (HashSet v) -> Bool) -> HashSet v -> Bool # any :: (Element (HashSet v) -> Bool) -> HashSet v -> Bool # find :: (Element (HashSet v) -> Bool) -> HashSet v -> Maybe (Element (HashSet v)) # safeHead :: HashSet v -> Maybe (Element (HashSet v)) # safeMaximum :: HashSet v -> Maybe (Element (HashSet v)) # safeMinimum :: HashSet v -> Maybe (Element (HashSet v)) # safeFoldr1 :: (Element (HashSet v) -> Element (HashSet v) -> Element (HashSet v)) -> HashSet v -> Maybe (Element (HashSet v)) # safeFoldl1 :: (Element (HashSet v) -> Element (HashSet v) -> Element (HashSet v)) -> HashSet v -> Maybe (Element (HashSet v)) # | |
| Hashable v => One (HashSet v) | |
| type Item (HashSet a) | |
Defined in Data.HashSet.Internal | |
| type Element (HashSet v) | |
Defined in Universum.Container.Class | |
| type OneItem (HashSet v) | |
Defined in Universum.Container.Class | |
newtype UnliftIO (m :: Type -> Type) #
The ability to run any monadic action m a as IO a.
This is more precisely a natural transformation. We need to new
datatype (instead of simply using a forall) due to lack of
support in GHC for impredicative types.
Since: unliftio-core-0.1.0.0
askRunInIO :: MonadUnliftIO m => m (m a -> IO a) #
Same as askUnliftIO, but returns a monomorphic function
instead of a polymorphic newtype wrapper. If you only need to apply
the transformation on one concrete type, this function can be more
convenient.
Since: unliftio-core-0.1.0.0
withUnliftIO :: MonadUnliftIO m => (UnliftIO m -> IO a) -> m a #
Convenience function for capturing the monadic context and running
an IO action. The UnliftIO newtype wrapper is rarely needed, so
prefer withRunInIO to this function.
Since: unliftio-core-0.1.0.0
race :: MonadUnliftIO m => m a -> m b -> m (Either a b) #
Unlifted race.
Since: unliftio-0.1.0.0
Arguments
| :: MonadUnliftIO m | |
| => m a | thing |
| -> m b | after |
| -> m a |
bracket :: MonadUnliftIO m => m a -> (a -> m b) -> (a -> m c) -> m c #
Allocate and clean up a resource safely.
For more information on motivation and usage of this function, see base's
bracket. This function has two differences from the one in base.
The first, and more obvious, is that it works on any MonadUnliftIO
instance, not just IO.
The more subtle difference is that this function will use uninterruptible masking for its cleanup handler. This is a subtle distinction, but at a high level, means that resource cleanup has more guarantees to complete. This comes at the cost that an incorrectly written cleanup function cannot be interrupted.
For more information, please see https://github.com/fpco/safe-exceptions/issues/3.
Since: unliftio-0.1.0.0