| Safe Haskell | None |
|---|---|
| Language | GHC2021 |
Freckle.App.Prelude
Description
Those functions and types we can't do without!
Synopsis
- class Monad m => MonadFail (m :: Type -> Type) where
- data Bool
- data Char
- data Double
- data Float
- data Int
- data Word
- data Ordering
- data Maybe a
- class a ~# b => (a :: k) ~ (b :: k)
- data Integer
- class Show a where
- 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 (Real a, Fractional a) => RealFrac a where
- class (Real a, Enum a) => Integral a where
- class Read a where
- data IO a
- class Eq a where
- class Eq a => Ord a where
- type String = [Char]
- realToFrac :: (Real a, Fractional b) => a -> b
- fromIntegral :: (Integral a, Num b) => a -> b
- class (Num a, Ord a) => Real a where
- toRational :: a -> Rational
- class Num a => Fractional a where
- (/) :: a -> a -> a
- recip :: a -> a
- fromRational :: Rational -> a
- type Rational = Ratio Integer
- ($) :: (a -> b) -> a -> b
- otherwise :: Bool
- (++) :: [a] -> [a] -> [a]
- class Foldable (t :: Type -> Type) where
- map :: (a -> b) -> [a] -> [b]
- class Applicative m => Monad (m :: Type -> Type) where
- class Functor (f :: Type -> Type) where
- class Functor f => Applicative (f :: Type -> Type) where
- class Semigroup a => Monoid a where
- class Semigroup a where
- (<>) :: a -> a -> a
- lookup :: Eq a => a -> [(a, b)] -> Maybe b
- class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where
- traverse :: Applicative f => (a -> f b) -> t a -> f (t b)
- sequenceA :: Applicative f => t (f a) -> f (t a)
- mapM :: Monad m => (a -> m b) -> t a -> m (t b)
- sequence :: Monad m => t (m a) -> m (t a)
- filter :: (a -> Bool) -> [a] -> [a]
- data Either a b
- id :: a -> a
- (<$>) :: Functor f => (a -> b) -> f a -> f b
- seq :: a -> b -> b
- mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
- takeWhile :: (a -> Bool) -> [a] -> [a]
- take :: Int -> [a] -> [a]
- const :: a -> b -> a
- concat :: Foldable t => t [a] -> [a]
- zip :: [a] -> [b] -> [(a, b)]
- print :: Show a => a -> IO ()
- class Num a where
- class Fractional a => Floating a where
- class (RealFrac a, Floating a) => RealFloat a where
- floatRadix :: a -> Integer
- floatDigits :: a -> Int
- floatRange :: a -> (Int, Int)
- decodeFloat :: a -> (Integer, Int)
- encodeFloat :: Integer -> Int -> a
- exponent :: a -> Int
- significand :: a -> a
- scaleFloat :: Int -> a -> a
- isNaN :: a -> Bool
- isInfinite :: a -> Bool
- isDenormalized :: a -> Bool
- isNegativeZero :: a -> Bool
- isIEEE :: a -> Bool
- atan2 :: a -> a -> a
- (^) :: (Num a, Integral b) => a -> b -> a
- (&&) :: Bool -> Bool -> Bool
- (||) :: Bool -> Bool -> Bool
- not :: Bool -> Bool
- fst :: (a, b) -> a
- snd :: (a, b) -> b
- curry :: ((a, b) -> c) -> a -> b -> c
- uncurry :: (a -> b -> c) -> (a, b) -> c
- error :: HasCallStack => [Char] -> a
- errorWithoutStackTrace :: [Char] -> a
- undefined :: HasCallStack => a
- (=<<) :: Monad m => (a -> m b) -> m a -> m b
- (.) :: (b -> c) -> (a -> b) -> a -> c
- flip :: (a -> b -> c) -> b -> a -> c
- ($!) :: (a -> b) -> a -> b
- until :: (a -> Bool) -> (a -> a) -> a -> a
- asTypeOf :: a -> a -> a
- subtract :: Num a => a -> a -> a
- maybe :: b -> (a -> b) -> Maybe a -> b
- scanl :: (b -> a -> b) -> b -> [a] -> [b]
- scanl1 :: (a -> a -> a) -> [a] -> [a]
- scanr :: (a -> b -> b) -> b -> [a] -> [b]
- scanr1 :: (a -> a -> a) -> [a] -> [a]
- iterate :: (a -> a) -> a -> [a]
- repeat :: a -> [a]
- replicate :: Int -> a -> [a]
- dropWhile :: (a -> Bool) -> [a] -> [a]
- drop :: Int -> [a] -> [a]
- splitAt :: Int -> [a] -> ([a], [a])
- span :: (a -> Bool) -> [a] -> ([a], [a])
- break :: (a -> Bool) -> [a] -> ([a], [a])
- reverse :: [a] -> [a]
- and :: Foldable t => t Bool -> Bool
- or :: Foldable t => t Bool -> Bool
- any :: Foldable t => (a -> Bool) -> t a -> Bool
- all :: Foldable t => (a -> Bool) -> t a -> Bool
- notElem :: (Foldable t, Eq a) => a -> t a -> Bool
- concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
- zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
- zipWith3 :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d]
- unzip :: [(a, b)] -> ([a], [b])
- unzip3 :: [(a, b, c)] -> ([a], [b], [c])
- type ShowS = String -> String
- shows :: Show a => a -> ShowS
- showChar :: Char -> ShowS
- showString :: String -> ShowS
- showParen :: Bool -> ShowS -> ShowS
- even :: Integral a => a -> Bool
- odd :: Integral a => a -> Bool
- (^^) :: (Fractional a, Integral b) => a -> b -> a
- gcd :: Integral a => a -> a -> a
- lcm :: Integral a => a -> a -> a
- type ReadS a = String -> [(a, String)]
- lex :: ReadS String
- readParen :: Bool -> ReadS a -> ReadS a
- either :: (a -> c) -> (b -> c) -> Either a b -> c
- reads :: Read a => ReadS a
- sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
- lines :: String -> [String]
- unlines :: [String] -> String
- words :: String -> [String]
- unwords :: [String] -> String
- type IOError = IOException
- userError :: String -> IOError
- type FilePath = String
- ioError :: IOError -> IO a
- putChar :: Char -> IO ()
- putStr :: String -> IO ()
- putStrLn :: String -> IO ()
- getChar :: IO Char
- getLine :: IO String
- getContents :: IO String
- interact :: (String -> String) -> IO ()
- readFile :: FilePath -> IO String
- writeFile :: FilePath -> String -> IO ()
- appendFile :: FilePath -> String -> IO ()
- readLn :: Read a => IO a
- readIO :: Read a => String -> IO a
- class Applicative f => Alternative (f :: Type -> Type)
- class Generic a
- type HasCallStack = ?callStack :: CallStack
- class Eq a => Hashable a
- data HashMap k v
- data HashSet a
- data Int64
- data Map k a
- class Monad m => MonadIO (m :: Type -> Type)
- class Monad m => MonadReader r (m :: Type -> Type) | m -> r
- class MonadIO m => MonadUnliftIO (m :: Type -> Type)
- data NominalDiffTime
- data NonEmpty a
- class Monad m => PrimMonad (m :: Type -> Type)
- data ReaderT r (m :: Type -> Type) a
- data Set a
- data Text
- data UTCTime
- data Vector a
- lift :: (MonadTrans t, Monad m) => m a -> t m a
- liftIO :: MonadIO m => IO a -> m a
- tshow :: Show a => a -> Text
- pack :: String -> Text
- unpack :: Text -> String
- encodeUtf8 :: Text -> ByteString
- decodeUtf8 :: ByteString -> Text
- catMaybes :: [Maybe a] -> [a]
- fromMaybe :: a -> Maybe a -> a
- isJust :: Maybe a -> Bool
- isNothing :: Maybe a -> Bool
- listToMaybe :: [a] -> Maybe a
- mapMaybe :: (a -> Maybe b) -> [a] -> [b]
- maybeToList :: Maybe a -> [a]
- fold1 :: (Foldable1 t, Semigroup m) => t m -> m
- foldMap1 :: (Foldable1 t, Semigroup m) => (a -> m) -> t a -> m
- headMay :: [a] -> Maybe a
- lastMay :: [a] -> Maybe a
- maximumMay :: Ord a => [a] -> Maybe a
- minimumMay :: Ord a => [a] -> Maybe a
- tailMay :: [a] -> Maybe [a]
- initMay :: [a] -> Maybe [a]
- cycleMay :: [a] -> Maybe [a]
- atMay :: [a] -> Int -> Maybe a
- readMay :: Read a => String -> Maybe a
- partitionEithers :: [Either a b] -> ([a], [b])
- class Foldable (t :: Type -> Type) where
- fold :: Monoid m => t m -> m
- foldMap :: Monoid m => (a -> m) -> t a -> m
- foldMap' :: Monoid m => (a -> m) -> t a -> m
- foldr :: (a -> b -> b) -> b -> t a -> b
- foldr' :: (a -> b -> b) -> b -> t a -> b
- foldl :: (b -> a -> b) -> b -> t a -> b
- foldl' :: (b -> a -> b) -> b -> t a -> b
- toList :: t a -> [a]
- null :: t a -> Bool
- length :: t a -> Int
- elem :: Eq a => a -> t a -> Bool
- maximum :: Ord a => t a -> a
- minimum :: Ord a => t a -> a
- sum :: Num a => t a -> a
- product :: Num a => t a -> a
- mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
- forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m ()
- concat :: Foldable t => t [a] -> [a]
- and :: Foldable t => t Bool -> Bool
- or :: Foldable t => t Bool -> Bool
- any :: Foldable t => (a -> Bool) -> t a -> Bool
- all :: Foldable t => (a -> Bool) -> t a -> Bool
- notElem :: (Foldable t, Eq a) => a -> t a -> Bool
- concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
- 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
- traverse_ :: (Foldable t, Applicative f) => (a -> f b) -> t a -> f ()
- for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f ()
- sequenceA_ :: (Foldable t, Applicative f) => t (f a) -> f ()
- sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
- asum :: (Foldable t, Alternative f) => t (f a) -> f a
- msum :: (Foldable t, MonadPlus m) => t (m a) -> m a
- maximumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a
- minimumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a
- find :: Foldable t => (a -> Bool) -> t a -> Maybe a
- module Data.Traversable
- (<$$>) :: (Functor c, Functor d) => (a -> b) -> c (d a) -> c (d b)
- bimap :: Bifunctor p => (a -> b) -> (c -> d) -> p a c -> p b d
- first :: Bifunctor p => (a -> b) -> p a c -> p b c
- second :: Bifunctor p => (b -> c) -> p a b -> p a c
- (<|>) :: Alternative f => f a -> f a -> f a
- liftA2 :: Applicative f => (a -> b -> c) -> f a -> f b -> f c
- optional :: Alternative f => f a -> f (Maybe a)
- (<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c
- (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
- guard :: Alternative f => Bool -> f ()
- join :: Monad m => m (m a) -> m a
- unless :: Applicative f => Bool -> f () -> f ()
- void :: Functor f => f a -> f ()
- when :: Applicative f => Bool -> f () -> f ()
- (&&&) :: Arrow a => a b c -> a b c' -> a b (c, c')
- (***) :: Arrow a => a b c -> a b' c' -> a (b, b') (c, c')
- getCurrentTime :: IO UTCTime
- throwM :: (Exception e, MonadIO m, HasCallStack) => e -> m a
- throwString :: (MonadIO m, HasCallStack) => String -> m a
- fromJustNoteM :: (MonadIO m, HasCallStack) => String -> Maybe a -> m a
- catch :: (Exception e, MonadUnliftIO m, HasCallStack) => m a -> (e -> m a) -> m a
- catchJust :: forall e b m a. (Exception e, MonadUnliftIO m, HasCallStack) => (e -> Maybe b) -> m a -> (b -> m a) -> m a
- catches :: (MonadUnliftIO m, HasCallStack) => m a -> [ExceptionHandler m a] -> m a
- try :: (Exception e, MonadUnliftIO m, HasCallStack) => m a -> m (Either e a)
- tryJust :: forall e b m a. (Exception e, MonadUnliftIO m, HasCallStack) => (e -> Maybe b) -> m a -> m (Either b a)
- impossible :: (MonadIO m, HasCallStack) => m a
- data ExceptionHandler (m :: k -> Type) (a :: k) = Exception e => ExceptionHandler (e -> m a)
- class (Typeable e, Show e) => Exception e where
- displayException :: e -> String
- data SomeException = (Exception e, HasExceptionContext) => SomeException e
Documentation
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
fail s should be an action that runs in the monad itself, not an
exception (except in instances of MonadIO). In particular,
fail should not be implemented in terms of error.
Since: base-4.9.0.0
Instances
Instances
The character type Char represents Unicode codespace
and its elements are code points as in definitions
D9 and D10 of the Unicode Standard.
Character literals in Haskell are single-quoted: 'Q', 'Я' or 'Ω'.
To represent a single quote itself use '\'', and to represent a backslash
use '\\'. The full grammar can be found in the section 2.6 of the
Haskell 2010 Language Report.
To specify a character by its code point one can use decimal, hexadecimal
or octal notation: '\65', '\x41' and '\o101' are all alternative forms
of 'A'. The largest code point is '\x10ffff'.
There is a special escape syntax for ASCII control characters:
| Escape | Alternatives | Meaning |
|---|---|---|
'\NUL' | '\0' | null character |
'\SOH' | '\1' | start of heading |
'\STX' | '\2' | start of text |
'\ETX' | '\3' | end of text |
'\EOT' | '\4' | end of transmission |
'\ENQ' | '\5' | enquiry |
'\ACK' | '\6' | acknowledge |
'\BEL' | '\7', '\a' | bell (alert) |
'\BS' | '\8', '\b' | backspace |
'\HT' | '\9', '\t' | horizontal tab |
'\LF' | '\10', '\n' | line feed (new line) |
'\VT' | '\11', '\v' | vertical tab |
'\FF' | '\12', '\f' | form feed |
'\CR' | '\13', '\r' | carriage return |
'\SO' | '\14' | shift out |
'\SI' | '\15' | shift in |
'\DLE' | '\16' | data link escape |
'\DC1' | '\17' | device control 1 |
'\DC2' | '\18' | device control 2 |
'\DC3' | '\19' | device control 3 |
'\DC4' | '\20' | device control 4 |
'\NAK' | '\21' | negative acknowledge |
'\SYN' | '\22' | synchronous idle |
'\ETB' | '\23' | end of transmission block |
'\CAN' | '\24' | cancel |
'\EM' | '\25' | end of medium |
'\SUB' | '\26' | substitute |
'\ESC' | '\27' | escape |
'\FS' | '\28' | file separator |
'\GS' | '\29' | group separator |
'\RS' | '\30' | record separator |
'\US' | '\31' | unit separator |
'\SP' | '\32', ' ' | space |
'\DEL' | '\127' | delete |
Instances
| IsChar Char | Since: base-2.1 | ||||
| PrintfArg Char | Since: base-2.1 | ||||
Defined in Text.Printf | |||||
| Bounded Char | Since: base-2.1 | ||||
| Enum Char | Since: base-2.1 | ||||
| Read Char | Since: base-2.1 | ||||
| Show Char | Since: base-2.1 | ||||
| Eq Char | |||||
| Ord Char | |||||
| Hashable Char | |||||
Defined in Data.Hashable.Class | |||||
| Prim Char | |||||
Defined in Data.Primitive.Types Methods sizeOfType# :: Proxy Char -> Int# # alignmentOfType# :: Proxy Char -> Int# # alignment# :: Char -> Int# # indexByteArray# :: ByteArray# -> Int# -> Char # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Char #) # writeByteArray# :: MutableByteArray# s -> Int# -> Char -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Char -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Char # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Char #) # writeOffAddr# :: Addr# -> Int# -> Char -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Char -> State# s -> State# s # | |||||
| Uniform Char | |||||
Defined in System.Random.Internal Methods uniformM :: StatefulGen g m => g -> m Char # | |||||
| UniformRange Char | |||||
Defined in System.Random.Internal | |||||
| Unbox Char | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| Lift Char | |||||
| Vector Vector Char | |||||
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Char -> ST s (Vector Char) basicUnsafeThaw :: Vector Char -> ST s (Mutable Vector s Char) basicLength :: Vector Char -> Int basicUnsafeSlice :: Int -> Int -> Vector Char -> Vector Char basicUnsafeIndexM :: Vector Char -> Int -> Box Char basicUnsafeCopy :: Mutable Vector s Char -> Vector Char -> ST s () | |||||
| MVector MVector Char | |||||
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Char -> Int basicUnsafeSlice :: Int -> Int -> MVector s Char -> MVector s Char basicOverlaps :: MVector s Char -> MVector s Char -> Bool basicUnsafeNew :: Int -> ST s (MVector s Char) basicInitialize :: MVector s Char -> ST s () basicUnsafeReplicate :: Int -> Char -> ST s (MVector s Char) basicUnsafeRead :: MVector s Char -> Int -> ST s Char basicUnsafeWrite :: MVector s Char -> Int -> Char -> ST s () basicClear :: MVector s Char -> ST s () basicSet :: MVector s Char -> Char -> ST s () basicUnsafeCopy :: MVector s Char -> MVector s Char -> ST s () basicUnsafeMove :: MVector s Char -> MVector s Char -> ST s () basicUnsafeGrow :: MVector s Char -> Int -> ST s (MVector s Char) | |||||
| Generic1 (URec Char :: k -> Type) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Foldable (UChar :: Type -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.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 # | |||||
| Traversable (UChar :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Functor (URec Char :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Generic (URec Char p) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Show (URec Char p) | Since: base-4.9.0.0 | ||||
| Eq (URec Char p) | Since: base-4.9.0.0 | ||||
| Ord (URec Char p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| newtype Vector Char | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| data URec Char (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 | ||||
| newtype MVector s Char | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| type Rep1 (URec Char :: k -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| type Rep (URec Char p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
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
| PrintfArg Double | Since: base-2.1 | ||||
Defined in Text.Printf | |||||
| Floating Double | Since: base-2.1 | ||||
| RealFloat Double | Since: base-2.1 | ||||
Defined in GHC.Internal.Float Methods floatRadix :: Double -> Integer # floatDigits :: Double -> Int # floatRange :: Double -> (Int, Int) # decodeFloat :: Double -> (Integer, Int) # encodeFloat :: Integer -> Int -> Double # significand :: Double -> Double # scaleFloat :: Int -> Double -> Double # isInfinite :: Double -> Bool # isDenormalized :: Double -> Bool # isNegativeZero :: Double -> Bool # | |||||
| Read Double | Since: base-2.1 | ||||
| Eq Double | Note that due to the presence of
Also note that
| ||||
| Ord Double | IEEE 754 IEEE 754-2008, section 5.11 requires that if at least one of arguments of
IEEE 754-2008, section 5.10 defines Thus, users must be extremely cautious when using Moving further, the behaviour of IEEE 754-2008 compliant | ||||
| Hashable Double | Note: prior to The Since: hashable-1.3.0.0 | ||||
Defined in Data.Hashable.Class | |||||
| Prim Double | |||||
Defined in Data.Primitive.Types Methods sizeOfType# :: Proxy Double -> Int# # alignmentOfType# :: Proxy Double -> Int# # alignment# :: Double -> Int# # indexByteArray# :: ByteArray# -> Int# -> Double # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Double #) # writeByteArray# :: MutableByteArray# s -> Int# -> Double -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Double -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Double # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Double #) # writeOffAddr# :: Addr# -> Int# -> Double -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Double -> State# s -> State# s # | |||||
| UniformRange Double | |||||
Defined in System.Random.Internal | |||||
| Unbox Double | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| Lift Double | |||||
| Vector Vector Double | |||||
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Double -> ST s (Vector Double) basicUnsafeThaw :: Vector Double -> ST s (Mutable Vector s Double) basicLength :: Vector Double -> Int basicUnsafeSlice :: Int -> Int -> Vector Double -> Vector Double basicUnsafeIndexM :: Vector Double -> Int -> Box Double basicUnsafeCopy :: Mutable Vector s Double -> Vector Double -> ST s () | |||||
| MVector MVector Double | |||||
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Double -> Int basicUnsafeSlice :: Int -> Int -> MVector s Double -> MVector s Double basicOverlaps :: MVector s Double -> MVector s Double -> Bool basicUnsafeNew :: Int -> ST s (MVector s Double) basicInitialize :: MVector s Double -> ST s () basicUnsafeReplicate :: Int -> Double -> ST s (MVector s Double) basicUnsafeRead :: MVector s Double -> Int -> ST s Double basicUnsafeWrite :: MVector s Double -> Int -> Double -> ST s () basicClear :: MVector s Double -> ST s () basicSet :: MVector s Double -> Double -> ST s () basicUnsafeCopy :: MVector s Double -> MVector s Double -> ST s () basicUnsafeMove :: MVector s Double -> MVector s Double -> ST s () basicUnsafeGrow :: MVector s Double -> Int -> ST s (MVector s Double) | |||||
| Generic1 (URec Double :: k -> Type) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Foldable (UDouble :: Type -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.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 # | |||||
| Traversable (UDouble :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Functor (URec Double :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Generic (URec Double p) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Show (URec Double p) | Since: base-4.9.0.0 | ||||
| Eq (URec Double p) | Since: base-4.9.0.0 | ||||
| Ord (URec Double p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.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 # | |||||
| newtype Vector Double | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| data URec Double (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 | ||||
| newtype MVector s Double | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| type Rep1 (URec Double :: k -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| type Rep (URec Double p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
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
| PrintfArg Float | Since: base-2.1 | ||||
Defined in Text.Printf | |||||
| Floating Float | Since: base-2.1 | ||||
| RealFloat Float | Since: base-2.1 | ||||
Defined in GHC.Internal.Float Methods floatRadix :: Float -> Integer # floatDigits :: Float -> Int # floatRange :: Float -> (Int, Int) # decodeFloat :: Float -> (Integer, Int) # encodeFloat :: Integer -> Int -> Float # significand :: Float -> Float # scaleFloat :: Int -> Float -> Float # isInfinite :: Float -> Bool # isDenormalized :: Float -> Bool # isNegativeZero :: Float -> Bool # | |||||
| Read Float | Since: base-2.1 | ||||
| Eq Float | Note that due to the presence of
Also note that
| ||||
| Ord Float | See | ||||
| Hashable Float | Note: prior to The Since: hashable-1.3.0.0 | ||||
Defined in Data.Hashable.Class | |||||
| Prim Float | |||||
Defined in Data.Primitive.Types Methods sizeOfType# :: Proxy Float -> Int# # alignmentOfType# :: Proxy Float -> Int# # alignment# :: Float -> Int# # indexByteArray# :: ByteArray# -> Int# -> Float # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Float #) # writeByteArray# :: MutableByteArray# s -> Int# -> Float -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Float -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Float # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Float #) # writeOffAddr# :: Addr# -> Int# -> Float -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Float -> State# s -> State# s # | |||||
| UniformRange Float | |||||
Defined in System.Random.Internal | |||||
| Unbox Float | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| Lift Float | |||||
| Vector Vector Float | |||||
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Float -> ST s (Vector Float) basicUnsafeThaw :: Vector Float -> ST s (Mutable Vector s Float) basicLength :: Vector Float -> Int basicUnsafeSlice :: Int -> Int -> Vector Float -> Vector Float basicUnsafeIndexM :: Vector Float -> Int -> Box Float basicUnsafeCopy :: Mutable Vector s Float -> Vector Float -> ST s () | |||||
| MVector MVector Float | |||||
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Float -> Int basicUnsafeSlice :: Int -> Int -> MVector s Float -> MVector s Float basicOverlaps :: MVector s Float -> MVector s Float -> Bool basicUnsafeNew :: Int -> ST s (MVector s Float) basicInitialize :: MVector s Float -> ST s () basicUnsafeReplicate :: Int -> Float -> ST s (MVector s Float) basicUnsafeRead :: MVector s Float -> Int -> ST s Float basicUnsafeWrite :: MVector s Float -> Int -> Float -> ST s () basicClear :: MVector s Float -> ST s () basicSet :: MVector s Float -> Float -> ST s () basicUnsafeCopy :: MVector s Float -> MVector s Float -> ST s () basicUnsafeMove :: MVector s Float -> MVector s Float -> ST s () basicUnsafeGrow :: MVector s Float -> Int -> ST s (MVector s Float) | |||||
| Generic1 (URec Float :: k -> Type) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Foldable (UFloat :: Type -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.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 # | |||||
| Traversable (UFloat :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Functor (URec Float :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Generic (URec Float p) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Show (URec Float p) | |||||
| Eq (URec Float p) | |||||
| Ord (URec Float p) | |||||
Defined in GHC.Internal.Generics | |||||
| newtype Vector Float | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| data URec Float (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 | ||||
| newtype MVector s Float | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| type Rep1 (URec Float :: k -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| type Rep (URec Float p) | |||||
Defined in GHC.Internal.Generics | |||||
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
| PrintfArg Int | Since: base-2.1 | ||||
Defined in Text.Printf | |||||
| Bounded Int | Since: base-2.1 | ||||
| Enum Int | Since: base-2.1 | ||||
| Num Int | Since: base-2.1 | ||||
| Read Int | Since: base-2.1 | ||||
| Integral Int | Since: base-2.0.1 | ||||
| Real Int | Since: base-2.0.1 | ||||
Defined in GHC.Internal.Real Methods toRational :: Int -> Rational # | |||||
| Show Int | Since: base-2.1 | ||||
| Eq Int | |||||
| Ord Int | |||||
| Hashable Int | |||||
Defined in Data.Hashable.Class | |||||
| Prim Int | |||||
Defined in Data.Primitive.Types Methods sizeOfType# :: Proxy Int -> Int# # alignmentOfType# :: Proxy Int -> Int# # alignment# :: Int -> Int# # indexByteArray# :: ByteArray# -> Int# -> Int # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Int #) # writeByteArray# :: MutableByteArray# s -> Int# -> Int -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Int -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Int # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Int #) # writeOffAddr# :: Addr# -> Int# -> Int -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Int -> State# s -> State# s # | |||||
| Uniform Int | |||||
Defined in System.Random.Internal Methods uniformM :: StatefulGen g m => g -> m Int # | |||||
| UniformRange Int | |||||
Defined in System.Random.Internal | |||||
| ByteSource Int | |||||
Defined in Data.UUID.Types.Internal.Builder | |||||
| Unbox Int | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| Lift Int | |||||
| Vector Vector Int | |||||
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Int -> ST s (Vector Int) basicUnsafeThaw :: Vector Int -> ST s (Mutable Vector s Int) basicLength :: Vector Int -> Int basicUnsafeSlice :: Int -> Int -> Vector Int -> Vector Int basicUnsafeIndexM :: Vector Int -> Int -> Box Int basicUnsafeCopy :: Mutable Vector s Int -> Vector Int -> ST s () | |||||
| MVector MVector Int | |||||
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Int -> Int basicUnsafeSlice :: Int -> Int -> MVector s Int -> MVector s Int basicOverlaps :: MVector s Int -> MVector s Int -> Bool basicUnsafeNew :: Int -> ST s (MVector s Int) basicInitialize :: MVector s Int -> ST s () basicUnsafeReplicate :: Int -> Int -> ST s (MVector s Int) basicUnsafeRead :: MVector s Int -> Int -> ST s Int basicUnsafeWrite :: MVector s Int -> Int -> Int -> ST s () basicClear :: MVector s Int -> ST s () basicSet :: MVector s Int -> Int -> ST s () basicUnsafeCopy :: MVector s Int -> MVector s Int -> ST s () basicUnsafeMove :: MVector s Int -> MVector s Int -> ST s () basicUnsafeGrow :: MVector s Int -> Int -> ST s (MVector s Int) | |||||
| Generic1 (URec Int :: k -> Type) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Foldable (UInt :: Type -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.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 # | |||||
| Traversable (UInt :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Functor (URec Int :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Generic (URec Int p) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Show (URec Int p) | Since: base-4.9.0.0 | ||||
| Eq (URec Int p) | Since: base-4.9.0.0 | ||||
| Ord (URec Int p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| newtype Vector Int | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| data URec Int (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 | ||||
| type ByteSink Int g | |||||
Defined in Data.UUID.Types.Internal.Builder type ByteSink Int g = Takes4Bytes g | |||||
| newtype MVector s Int | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| type Rep1 (URec Int :: k -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| type Rep (URec Int p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
Instances
| PrintfArg Word | Since: base-2.1 | ||||
Defined in Text.Printf | |||||
| Bounded Word | Since: base-2.1 | ||||
| Enum Word | Since: base-2.1 | ||||
| Num Word | Since: base-2.1 | ||||
| Read Word | Since: base-4.5.0.0 | ||||
| Integral Word | Since: base-2.1 | ||||
| Real Word | Since: base-2.1 | ||||
Defined in GHC.Internal.Real Methods toRational :: Word -> Rational # | |||||
| Show Word | Since: base-2.1 | ||||
| Eq Word | |||||
| Ord Word | |||||
| Hashable Word | |||||
Defined in Data.Hashable.Class | |||||
| Prim Word | |||||
Defined in Data.Primitive.Types Methods sizeOfType# :: Proxy Word -> Int# # alignmentOfType# :: Proxy Word -> Int# # alignment# :: Word -> Int# # indexByteArray# :: ByteArray# -> Int# -> Word # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Word #) # writeByteArray# :: MutableByteArray# s -> Int# -> Word -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Word -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Word # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Word #) # writeOffAddr# :: Addr# -> Int# -> Word -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Word -> State# s -> State# s # | |||||
| Uniform Word | |||||
Defined in System.Random.Internal Methods uniformM :: StatefulGen g m => g -> m Word # | |||||
| UniformRange Word | |||||
Defined in System.Random.Internal | |||||
| Unbox Word | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| Lift Word | |||||
| Vector Vector Word | |||||
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Word -> ST s (Vector Word) basicUnsafeThaw :: Vector Word -> ST s (Mutable Vector s Word) basicLength :: Vector Word -> Int basicUnsafeSlice :: Int -> Int -> Vector Word -> Vector Word basicUnsafeIndexM :: Vector Word -> Int -> Box Word basicUnsafeCopy :: Mutable Vector s Word -> Vector Word -> ST s () | |||||
| MVector MVector Word | |||||
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Word -> Int basicUnsafeSlice :: Int -> Int -> MVector s Word -> MVector s Word basicOverlaps :: MVector s Word -> MVector s Word -> Bool basicUnsafeNew :: Int -> ST s (MVector s Word) basicInitialize :: MVector s Word -> ST s () basicUnsafeReplicate :: Int -> Word -> ST s (MVector s Word) basicUnsafeRead :: MVector s Word -> Int -> ST s Word basicUnsafeWrite :: MVector s Word -> Int -> Word -> ST s () basicClear :: MVector s Word -> ST s () basicSet :: MVector s Word -> Word -> ST s () basicUnsafeCopy :: MVector s Word -> MVector s Word -> ST s () basicUnsafeMove :: MVector s Word -> MVector s Word -> ST s () basicUnsafeGrow :: MVector s Word -> Int -> ST s (MVector s Word) | |||||
| Generic1 (URec Word :: k -> Type) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Foldable (UWord :: Type -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.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 # | |||||
| Traversable (UWord :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Functor (URec Word :: Type -> Type) | Since: base-4.9.0.0 | ||||
| Generic (URec Word p) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Show (URec Word p) | Since: base-4.9.0.0 | ||||
| Eq (URec Word p) | Since: base-4.9.0.0 | ||||
| Ord (URec Word p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| newtype Vector Word | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| data URec Word (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 | ||||
| newtype MVector s Word | |||||
Defined in Data.Vector.Unboxed.Base | |||||
| type Rep1 (URec Word :: k -> Type) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| type Rep (URec Word p) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
Instances
| 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 |
Defined in GHC.Internal.Enum | |
| Generic Ordering | |
Defined in GHC.Internal.Generics | |
| Read Ordering | Since: base-2.1 |
| Show Ordering | Since: base-2.1 |
| Eq Ordering | |
| Ord Ordering | |
Defined in GHC.Classes | |
| Hashable Ordering | |
Defined in Data.Hashable.Class | |
| type Rep Ordering | Since: base-4.6.0.0 |
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
| MonadZip Maybe | Since: base-4.8.0.0 | ||||
| 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 | ||||
| Alternative Maybe | Picks the leftmost Since: base-2.1 | ||||
| Applicative Maybe | Since: base-2.1 | ||||
| Functor Maybe | Since: base-2.1 | ||||
| Monad Maybe | Since: base-2.1 | ||||
| MonadPlus Maybe | Picks the leftmost Since: base-2.1 | ||||
| MonadFail Maybe | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Control.Monad.Fail | |||||
| Foldable Maybe | Since: base-2.1 | ||||
Defined in GHC.Internal.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 # | |||||
| Traversable Maybe | Since: base-2.1 | ||||
| Hashable1 Maybe | |||||
Defined in Data.Hashable.Class | |||||
| Alt Maybe | |||||
| Apply Maybe | |||||
| Bind Maybe | |||||
| Extend Maybe | |||||
| Plus Maybe | |||||
Defined in Data.Functor.Plus | |||||
| Generic1 Maybe | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| MonadBaseControl Maybe Maybe | |||||
| MonadError () Maybe | Since: mtl-2.2.2 | ||||
Defined in Control.Monad.Error.Class | |||||
| Lift a => Lift (Maybe a :: Type) | |||||
| 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) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| SingKind a => SingKind (Maybe a) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| Read a => Read (Maybe a) | Since: base-2.1 | ||||
| Show a => Show (Maybe a) | Since: base-2.1 | ||||
| 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 | |||||
| SingI ('Nothing :: Maybe a) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| SingI a2 => SingI ('Just a2 :: Maybe a1) | Since: base-4.9.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| type Rep1 Maybe | Since: base-4.6.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| type StM Maybe a | |||||
Defined in Control.Monad.Trans.Control | |||||
| type DemoteRep (Maybe a) | |||||
Defined in GHC.Internal.Generics | |||||
| type Rep (Maybe a) | Since: base-4.6.0.0 | ||||
Defined in GHC.Internal.Generics | |||||
| data Sing (b :: Maybe a) | |||||
class a ~# b => (a :: k) ~ (b :: k) infix 4 #
Lifted, homogeneous equality. By lifted, we mean that it
can be bogus (deferred type error). By homogeneous, the two
types a and b must have the same kinds.
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 (i.e., fits into an Int), the IS constructor is
used. Otherwise IP and IN constructors are used to store a BigNat
representing the positive or the negative value magnitude, respectively.
Invariant: IP and IN are used iff the value does not fit in IS.
Instances
| PrintfArg Integer | Since: base-2.1 |
Defined in Text.Printf | |
| Enum Integer | Since: base-2.1 |
| Num Integer | Since: base-2.1 |
| Read Integer | Since: base-2.1 |
| Integral Integer | Since: base-2.0.1 |
Defined in GHC.Internal.Real | |
| Real Integer | Since: base-2.0.1 |
Defined in GHC.Internal.Real Methods toRational :: Integer -> Rational # | |
| Show Integer | Since: base-2.1 |
| Eq Integer | |
| Ord Integer | |
| Hashable Integer | |
Defined in Data.Hashable.Class | |
| UniformRange Integer | |
Defined in System.Random.Internal | |
| Lift Integer | |
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)".
Methods
Arguments
| :: Int | the operator precedence of the enclosing
context (a number from |
| -> a | the value to be converted to a |
| -> ShowS |
Convert a value to a readable String.
showsPrec should satisfy the law
showsPrec d x r ++ s == showsPrec d x (r ++ s)
Derived instances of Read and Show satisfy the following:
That is, readsPrec parses the string produced by
showsPrec, and delivers the value that showsPrec started with.
Instances
| Show AesonException | |
Defined in Data.Aeson.Types.Internal Methods showsPrec :: Int -> AesonException -> ShowS # show :: AesonException -> String # showList :: [AesonException] -> ShowS # | |
| Show DotNetTime | |
Defined in Data.Aeson.Types.Internal Methods showsPrec :: Int -> DotNetTime -> ShowS # show :: DotNetTime -> String # showList :: [DotNetTime] -> ShowS # | |
| Show JSONPathElement | |
Defined in Data.Aeson.Types.Internal Methods showsPrec :: Int -> JSONPathElement -> ShowS # show :: JSONPathElement -> String # showList :: [JSONPathElement] -> ShowS # | |
| Show Options | |
| Show SumEncoding | |
Defined in Data.Aeson.Types.Internal Methods showsPrec :: Int -> SumEncoding -> ShowS # show :: SumEncoding -> String # showList :: [SumEncoding] -> ShowS # | |
| Show Value | Since version 1.5.6.0 version object values are printed in lexicographic key order
|
| Show ByteArray | Since: base-4.17.0.0 |
| Show Timeout | Since: base-4.0 |
| Show ByteString | |
Defined in Data.ByteString.Internal.Type Methods showsPrec :: Int -> ByteString -> ShowS # show :: ByteString -> String # showList :: [ByteString] -> ShowS # | |
| Show SizeOverflowException | |
Defined in Data.ByteString.Internal.Type Methods showsPrec :: Int -> SizeOverflowException -> ShowS # show :: SizeOverflowException -> String # showList :: [SizeOverflowException] -> ShowS # | |
| Show IntSet | |
| Show BitQueue | |
| Show BitQueueB | |
| Show NotFoundException | |
Defined in Context.Internal Methods showsPrec :: Int -> NotFoundException -> ShowS # show :: NotFoundException -> String # showList :: [NotFoundException] -> ShowS # | |
| Show Void | Since: base-4.8.0.0 |
| Show BlockReason | Since: base-4.3.0.0 |
Defined in GHC.Internal.Conc.Sync Methods showsPrec :: Int -> BlockReason -> ShowS # show :: BlockReason -> String # showList :: [BlockReason] -> ShowS # | |
| Show ThreadId | Since: base-4.2.0.0 |
| Show ThreadStatus | Since: base-4.3.0.0 |
Defined in GHC.Internal.Conc.Sync Methods showsPrec :: Int -> ThreadStatus -> ShowS # show :: ThreadStatus -> String # showList :: [ThreadStatus] -> ShowS # | |
| Show Version | Since: base-2.1 |
| Show ArithException | Since: base-4.0.0.0 |
Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> ArithException -> ShowS # show :: ArithException -> String # showList :: [ArithException] -> ShowS # | |
| Show SomeException | Since: ghc-internal-3.0 |
Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS # show :: SomeException -> String # showList :: [SomeException] -> ShowS # | |
| Show CBool | |
| Show CChar | |
| Show CClock | |
| Show CDouble | |
| Show CFloat | |
| Show CInt | |
| Show CIntMax | |
| Show CIntPtr | |
| Show CLLong | |
| Show CLong | |
| Show CPtrdiff | |
| Show CSChar | |
| Show CSUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods showsPrec :: Int -> CSUSeconds -> ShowS # show :: CSUSeconds -> String # showList :: [CSUSeconds] -> ShowS # | |
| Show CShort | |
| Show CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types Methods showsPrec :: Int -> CSigAtomic -> ShowS # show :: CSigAtomic -> String # showList :: [CSigAtomic] -> ShowS # | |
| Show CSize | |
| Show CTime | |
| Show CUChar | |
| Show CUInt | |
| Show CUIntMax | |
| Show CUIntPtr | |
| Show CULLong | |
| Show CULong | |
| Show CUSeconds | |
| Show CUShort | |
| Show CWchar | |
| Show Associativity | Since: base-4.6.0.0 |
Defined in GHC.Internal.Generics Methods showsPrec :: Int -> Associativity -> ShowS # show :: Associativity -> String # showList :: [Associativity] -> ShowS # | |
| Show DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods showsPrec :: Int -> DecidedStrictness -> ShowS # show :: DecidedStrictness -> String # showList :: [DecidedStrictness] -> ShowS # | |
| Show Fixity | Since: base-4.6.0.0 |
| Show SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods showsPrec :: Int -> SourceStrictness -> ShowS # show :: SourceStrictness -> String # showList :: [SourceStrictness] -> ShowS # | |
| Show SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods showsPrec :: Int -> SourceUnpackedness -> ShowS # show :: SourceUnpackedness -> String # showList :: [SourceUnpackedness] -> ShowS # | |
| Show MaskingState | Since: base-4.3.0.0 |
Defined in GHC.Internal.IO Methods showsPrec :: Int -> MaskingState -> ShowS # show :: MaskingState -> String # showList :: [MaskingState] -> ShowS # | |
| Show AllocationLimitExceeded | Since: base-4.7.1.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> AllocationLimitExceeded -> ShowS # show :: AllocationLimitExceeded -> String # showList :: [AllocationLimitExceeded] -> ShowS # | |
| Show ArrayException | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> ArrayException -> ShowS # show :: ArrayException -> String # showList :: [ArrayException] -> ShowS # | |
| Show AssertionFailed | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> AssertionFailed -> ShowS # show :: AssertionFailed -> String # showList :: [AssertionFailed] -> ShowS # | |
| Show AsyncException | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> AsyncException -> ShowS # show :: AsyncException -> String # showList :: [AsyncException] -> ShowS # | |
| Show BlockedIndefinitelyOnMVar | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS # show :: BlockedIndefinitelyOnMVar -> String # showList :: [BlockedIndefinitelyOnMVar] -> ShowS # | |
| Show BlockedIndefinitelyOnSTM | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS # show :: BlockedIndefinitelyOnSTM -> String # showList :: [BlockedIndefinitelyOnSTM] -> ShowS # | |
| Show CompactionFailed | Since: base-4.10.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> CompactionFailed -> ShowS # show :: CompactionFailed -> String # showList :: [CompactionFailed] -> ShowS # | |
| Show Deadlock | Since: base-4.1.0.0 |
| Show ExitCode | |
| Show FixIOException | Since: base-4.11.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> FixIOException -> ShowS # show :: FixIOException -> String # showList :: [FixIOException] -> ShowS # | |
| Show IOErrorType | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> IOErrorType -> ShowS # show :: IOErrorType -> String # showList :: [IOErrorType] -> ShowS # | |
| Show IOException | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> IOException -> ShowS # show :: IOException -> String # showList :: [IOException] -> ShowS # | |
| Show SomeAsyncException | Since: base-4.7.0.0 |
Defined in GHC.Internal.IO.Exception Methods showsPrec :: Int -> SomeAsyncException -> ShowS # show :: SomeAsyncException -> String # showList :: [SomeAsyncException] -> ShowS # | |
| Show Int16 | Since: base-2.1 |
| Show Int32 | Since: base-2.1 |
| Show Int64 | Since: base-2.1 |
| Show Int8 | Since: base-2.1 |
| Show FractionalExponentBase | |
Defined in GHC.Internal.Real Methods showsPrec :: Int -> FractionalExponentBase -> ShowS # show :: FractionalExponentBase -> String # showList :: [FractionalExponentBase] -> ShowS # | |
| Show CallStack | Since: base-4.9.0.0 |
| Show SrcLoc | Since: base-4.9.0.0 |
| Show KindRep | |
| Show Module | Since: base-4.9.0.0 |
| Show Ordering | Since: base-2.1 |
| Show TrName | Since: base-4.9.0.0 |
| Show TyCon | Since: base-2.1 |
| Show TypeLitSort | Since: base-4.11.0.0 |
Defined in GHC.Internal.Show Methods showsPrec :: Int -> TypeLitSort -> ShowS # show :: TypeLitSort -> String # showList :: [TypeLitSort] -> ShowS # | |
| Show LogLevel | |
| Show LoggedMessage | |
Defined in Control.Monad.Logger.Aeson.Internal Methods showsPrec :: Int -> LoggedMessage -> ShowS # show :: LoggedMessage -> String # showList :: [LoggedMessage] -> ShowS # | |
| Show URI | |
| Show URIAuth | |
| Show StdGen | |
| Show InvalidAccess | |
Defined in Control.Monad.Trans.Resource.Internal Methods showsPrec :: Int -> InvalidAccess -> ShowS # show :: InvalidAccess -> String # showList :: [InvalidAccess] -> ShowS # | |
| Show ResourceCleanupException | |
Defined in Control.Monad.Trans.Resource.Internal Methods showsPrec :: Int -> ResourceCleanupException -> ShowS # show :: ResourceCleanupException -> String # showList :: [ResourceCleanupException] -> ShowS # | |
| Show Scientific | See |
Defined in Data.Scientific Methods showsPrec :: Int -> Scientific -> ShowS # show :: Scientific -> String # showList :: [Scientific] -> ShowS # | |
| Show AnnLookup | |
| Show AnnTarget | |
| Show Bang | |
| Show BndrVis | |
| Show Body | |
| Show Bytes | |
| Show Callconv | |
| Show Clause | |
| Show Con | |
| Show Dec | |
| Show DecidedStrictness | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> DecidedStrictness -> ShowS # show :: DecidedStrictness -> String # showList :: [DecidedStrictness] -> ShowS # | |
| Show DerivClause | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> DerivClause -> ShowS # show :: DerivClause -> String # showList :: [DerivClause] -> ShowS # | |
| Show DerivStrategy | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> DerivStrategy -> ShowS # show :: DerivStrategy -> String # showList :: [DerivStrategy] -> ShowS # | |
| Show DocLoc | |
| Show Exp | |
| Show FamilyResultSig | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> FamilyResultSig -> ShowS # show :: FamilyResultSig -> String # showList :: [FamilyResultSig] -> ShowS # | |
| Show Fixity | |
| Show FixityDirection | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> FixityDirection -> ShowS # show :: FixityDirection -> String # showList :: [FixityDirection] -> ShowS # | |
| Show Foreign | |
| Show FunDep | |
| Show Guard | |
| Show Info | |
| Show InjectivityAnn | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> InjectivityAnn -> ShowS # show :: InjectivityAnn -> String # showList :: [InjectivityAnn] -> ShowS # | |
| Show Inline | |
| Show Lit | |
| Show Loc | |
| Show Match | |
| Show ModName | |
| Show Module | |
| Show ModuleInfo | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> ModuleInfo -> ShowS # show :: ModuleInfo -> String # showList :: [ModuleInfo] -> ShowS # | |
| Show Name | |
| Show NameFlavour | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> NameFlavour -> ShowS # show :: NameFlavour -> String # showList :: [NameFlavour] -> ShowS # | |
| Show NameSpace | |
| Show NamespaceSpecifier | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> NamespaceSpecifier -> ShowS # show :: NamespaceSpecifier -> String # showList :: [NamespaceSpecifier] -> ShowS # | |
| Show OccName | |
| Show Overlap | |
| Show Pat | |
| Show PatSynArgs | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> PatSynArgs -> ShowS # show :: PatSynArgs -> String # showList :: [PatSynArgs] -> ShowS # | |
| Show PatSynDir | |
| Show Phases | |
| Show PkgName | |
| Show Pragma | |
| Show Range | |
| Show Role | |
| Show RuleBndr | |
| Show RuleMatch | |
| Show Safety | |
| Show SourceStrictness | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> SourceStrictness -> ShowS # show :: SourceStrictness -> String # showList :: [SourceStrictness] -> ShowS # | |
| Show SourceUnpackedness | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> SourceUnpackedness -> ShowS # show :: SourceUnpackedness -> String # showList :: [SourceUnpackedness] -> ShowS # | |
| Show Specificity | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> Specificity -> ShowS # show :: Specificity -> String # showList :: [Specificity] -> ShowS # | |
| Show Stmt | |
| Show TyLit | |
| Show TySynEqn | |
| Show Type | |
| Show TypeFamilyHead | |
Defined in Language.Haskell.TH.Syntax Methods showsPrec :: Int -> TypeFamilyHead -> ShowS # show :: TypeFamilyHead -> String # showList :: [TypeFamilyHead] -> ShowS # | |
| Show Decoding | |
| Show UnicodeException | |
Defined in Data.Text.Encoding.Error Methods showsPrec :: Int -> UnicodeException -> ShowS # show :: UnicodeException -> String # showList :: [UnicodeException] -> ShowS # | |
| Show I8 | |
| Show Builder | |
| Show PartialUtf8CodePoint | |
| Show Utf8State | |
| Show DecoderState | |
Defined in Data.Text.Internal.Encoding.Utf8 Methods showsPrec :: Int -> DecoderState -> ShowS # show :: DecoderState -> String # showList :: [DecoderState] -> ShowS # | |
| Show Size | |
| Show FPFormat | |
| Show Iter | |
| Show ShortText | |
| Show Month | Show as |
| Show Quarter | Show as |
| Show QuarterOfYear | |
Defined in Data.Time.Calendar.Quarter Methods showsPrec :: Int -> QuarterOfYear -> ShowS # show :: QuarterOfYear -> String # showList :: [QuarterOfYear] -> ShowS # | |
| Show DiffTime | |
| Show NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods showsPrec :: Int -> NominalDiffTime -> ShowS # show :: NominalDiffTime -> String # showList :: [NominalDiffTime] -> ShowS # | |
| Show LocalTime | |
| Show ZonedTime | For the time zone, this only shows the name, or offset if the name is empty. |
| Show UnixDiffTime | |
Defined in Data.UnixTime.Types Methods showsPrec :: Int -> UnixDiffTime -> ShowS # show :: UnixDiffTime -> String # showList :: [UnixDiffTime] -> ShowS # | |
| Show UnixTime | |
| Show ConcException | |
Defined in UnliftIO.Internals.Async Methods showsPrec :: Int -> ConcException -> ShowS # show :: ConcException -> String # showList :: [ConcException] -> ShowS # | |
| Show SubHashPath | |
Defined in Data.HashMap.Internal.Debug Methods showsPrec :: Int -> SubHashPath -> ShowS # show :: SubHashPath -> String # showList :: [SubHashPath] -> ShowS # | |
| Show UUID | Pretty prints a
|
| Show UnpackedUUID | |
| Show Size | |
| Show Integer | Since: base-2.1 |
| Show Natural | Since: base-4.8.0.0 |
| Show () | Since: base-2.1 |
| Show Bool | Since: base-2.1 |
| Show Char | Since: base-2.1 |
| Show Int | Since: base-2.1 |
| Show Levity | Since: base-4.15.0.0 |
| Show RuntimeRep | Since: base-4.11.0.0 |
Defined in GHC.Internal.Show Methods showsPrec :: Int -> RuntimeRep -> ShowS # show :: RuntimeRep -> String # showList :: [RuntimeRep] -> ShowS # | |
| Show VecCount | Since: base-4.11.0.0 |
| Show VecElem | Since: base-4.11.0.0 |
| Show Word | Since: base-2.1 |
| Show v => Show (KeyMap v) | |
| Show a => Show (IResult a) | |
| Show a => Show (Result a) | |
| Show a => Show (Complex a) | Since: base-2.1 |
| Show a => Show (First a) | Since: base-4.9.0.0 |
| Show a => Show (Last a) | Since: base-4.9.0.0 |
| Show a => Show (Max a) | Since: base-4.9.0.0 |
| Show a => Show (Min a) | Since: base-4.9.0.0 |
| Show m => Show (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods showsPrec :: Int -> WrappedMonoid m -> ShowS # show :: WrappedMonoid m -> String # showList :: [WrappedMonoid m] -> ShowS # | |
| Show a => Show (Flush a) | |
| Show vertex => Show (SCC vertex) | Since: containers-0.5.9 |
| Show a => Show (IntMap a) | |
| Show a => Show (Seq a) | |
| Show a => Show (ViewL a) | |
| Show a => Show (ViewR a) | |
| Show a => Show (Intersection a) | |
Defined in Data.Set.Internal Methods showsPrec :: Int -> Intersection a -> ShowS # show :: Intersection a -> String # showList :: [Intersection a] -> ShowS # | |
| Show a => Show (Set a) | |
| Show a => Show (Tree a) | |
| Show1 f => Show (Fix f) | |
| (Functor f, Show1 f) => Show (Mu f) | |
| (Functor f, Show1 f) => Show (Nu f) | |
| Show a => Show (DNonEmpty a) | |
| Show a => Show (DList a) | |
| Show a => Show (NonEmpty a) | Since: base-4.11.0.0 |
| Show a => Show (ExceptionWithContext a) | |
Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> ExceptionWithContext a -> ShowS # show :: ExceptionWithContext a -> String # showList :: [ExceptionWithContext a] -> ShowS # | |
| Show e => Show (NoBacktrace e) | |
Defined in GHC.Internal.Exception.Type Methods showsPrec :: Int -> NoBacktrace e -> ShowS # show :: NoBacktrace e -> String # showList :: [NoBacktrace e] -> ShowS # | |
| Show p => Show (Par1 p) | Since: base-4.7.0.0 |
| Show a => Show (Ratio a) | Since: base-2.0.1 |
| Show a => Show (Hashed a) | |
| Show a => Show (Array a) | |
| (Show a, Prim a) => Show (PrimArray a) | Since: primitive-0.6.4.0 |
| Show a => Show (SmallArray a) | |
Defined in Data.Primitive.SmallArray Methods showsPrec :: Int -> SmallArray a -> ShowS # show :: SmallArray a -> String # showList :: [SmallArray a] -> ShowS # | |
| Show g => Show (StateGen g) | |
| Show g => Show (AtomicGen g) | |
| Show g => Show (IOGen g) | |
| Show g => Show (STGen g) | |
| Show g => Show (TGen g) | |
| Show a => Show (Maybe a) | |
| Show flag => Show (TyVarBndr flag) | |
| Show a => Show (Array a) | |
| Show k => Show (Error k) | |
| Show k => Show (Validity k) | |
| Show a => Show (HashSet a) | |
| Show a => Show (Vector a) | |
| (Show a, Prim a) => Show (Vector a) | |
| (Show a, Storable a) => Show (Vector a) | |
| Show a => Show (Vector a) | |
| Show a => Show (Maybe a) | Since: base-2.1 |
| Show a => Show (Solo a) | Since: base-4.15 |
| Show a => Show [a] | Since: base-2.1 |
| HasResolution a => Show (Fixed a) | Since: base-2.1 |
| (Show a, Show b) => Show (Arg a b) | Since: base-4.9.0.0 |
| (Show k, Show a) => Show (Map k a) | |
| (Show a, Show b) => Show (Either a b) | Since: base-3.0 |
| Show (U1 p) | Since: base-4.9.0.0 |
| Show (V1 p) | Since: base-4.9.0.0 |
| (Show a, Show b) => Show (Either a b) | |
| (Show a, Show b) => Show (These a b) | |
| (Show a, Show b) => Show (Pair a b) | |
| (Show a, Show b) => Show (These a b) | |
| (Show1 f, Show a) => Show (Lift f a) | |
| (Show k, Show v) => Show (HashMap k v) | |
| (Show a, Show b) => Show (a, b) | Since: base-2.1 |
| Show (p a a) => Show (Join p a) | |
| Show (f p) => Show (Rec1 f p) | Since: base-4.7.0.0 |
| Show (URec Char p) | Since: base-4.9.0.0 |
| Show (URec Double p) | Since: base-4.9.0.0 |
| Show (URec Float p) | |
| Show (URec Int p) | Since: base-4.9.0.0 |
| Show (URec Word p) | Since: base-4.9.0.0 |
| (Show (f a), Show (g a), Show a) => Show (These1 f g a) | |
| (Show a, Show b, Show c) => Show (a, b, c) | Since: base-2.1 |
| (Show (f a), Show (g a)) => Show (Product f g a) | Since: base-4.18.0.0 |
| (Show (f a), Show (g a)) => Show (Sum f g a) | Since: base-4.18.0.0 |
| (Show (f p), Show (g p)) => Show ((f :*: g) p) | Since: base-4.7.0.0 |
| (Show (f p), Show (g p)) => Show ((f :+: g) p) | Since: base-4.7.0.0 |
| Show c => Show (K1 i c p) | Since: base-4.7.0.0 |
| (Show a, Show b, Show c, Show d) => Show (a, b, c, d) | Since: base-2.1 |
| Show (f (g a)) => Show (Compose f g a) | Since: base-4.18.0.0 |
| Show (f a) => Show (Clown f a b) | |
| Show (p b a) => Show (Flip p a b) | |
| Show (g b) => Show (Joker g a b) | |
| Show (p a b) => Show (WrappedBifunctor p a b) | |
Defined in Data.Bifunctor.Wrapped Methods showsPrec :: Int -> WrappedBifunctor p a b -> ShowS # show :: WrappedBifunctor p a b -> String # showList :: [WrappedBifunctor p a b] -> ShowS # | |
| Show (f (g p)) => Show ((f :.: g) p) | Since: base-4.7.0.0 |
| Show (f p) => Show (M1 i c f p) | Since: base-4.7.0.0 |
| (Show a, Show b, Show c, Show d, Show e) => Show (a, b, c, d, e) | Since: base-2.1 |
| (Show (f a b), Show (g a b)) => Show (Product f g a b) | |
| (Show a, Show b, Show c, Show d, Show e, Show f) => Show (a, b, c, d, e, f) | Since: base-2.1 |
| Show (f (p a b)) => Show (Tannen f p a b) | |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g) => Show (a, b, c, d, e, f, g) | Since: base-2.1 |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h) => Show (a, b, c, d, e, f, g, h) | Since: base-2.1 |
| Show (p (f a) (g b)) => Show (Biff p f g a b) | |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i) => Show (a, b, c, d, e, f, g, h, i) | Since: base-2.1 |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j) => Show (a, b, c, d, e, f, g, h, i, j) | Since: base-2.1 |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k) => Show (a, b, c, d, e, f, g, h, i, j, k) | Since: base-2.1 |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l) => Show (a, b, c, d, e, f, g, h, i, j, k, l) | Since: base-2.1 |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m) | Since: base-2.1 |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | Since: base-2.1 |
| (Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n, Show o) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | Since: base-2.1 |
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 CBool | |
| Bounded CChar | |
| Bounded CInt | |
| Bounded CIntMax | |
| Bounded CIntPtr | |
| Bounded CLLong | |
| Bounded CLong | |
| Bounded CPtrdiff | |
| Bounded CSChar | |
| Bounded CShort | |
| Bounded CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types | |
| Bounded CSize | |
| Bounded CUChar | |
| Bounded CUInt | |
| Bounded CUIntMax | |
| Bounded CUIntPtr | |
| Bounded CULLong | |
| Bounded CULong | |
| Bounded CUShort | |
| Bounded CWchar | |
| Bounded Associativity | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics | |
| Bounded DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics | |
| Bounded SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics | |
| Bounded SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Internal.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 Ordering | Since: base-2.1 |
| Bounded I8 | |
| Bounded FPFormat | |
| Bounded QuarterOfYear | |
Defined in Data.Time.Calendar.Quarter | |
| Bounded () | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| Bounded Bool | Since: base-2.1 |
| Bounded Char | Since: base-2.1 |
| Bounded Int | Since: base-2.1 |
| Bounded Levity | Since: base-4.16.0.0 |
| 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 (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 (Solo a) | |
| (Bounded a, Bounded b) => Bounded (Pair a b) | |
| (Bounded a, Bounded b) => Bounded (a, b) | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| (Bounded a, Bounded b, Bounded c) => Bounded (a, b, c) | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| (Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d) | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| Bounded (f (g a)) => Bounded (Compose f g a) | Since: base-4.19.0.0 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e) | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f) | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
| (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 |
Defined in GHC.Internal.Enum | |
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
Successor of a value. For numeric types, succ adds 1.
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).
Examples
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
Examples
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 = []
Examples
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 = []
Examples
enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]
enumFromThenTo 6 8 2 :: [Int] = []
Instances
| Enum CBool | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CChar | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CClock | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CDouble | |
| Enum CFloat | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CInt | |
| Enum CIntMax | |
| Enum CIntPtr | |
| Enum CLLong | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CLong | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CPtrdiff | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CSChar | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CSUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods succ :: CSUSeconds -> CSUSeconds # pred :: CSUSeconds -> CSUSeconds # toEnum :: Int -> CSUSeconds # fromEnum :: CSUSeconds -> Int # enumFrom :: CSUSeconds -> [CSUSeconds] # enumFromThen :: CSUSeconds -> CSUSeconds -> [CSUSeconds] # enumFromTo :: CSUSeconds -> CSUSeconds -> [CSUSeconds] # enumFromThenTo :: CSUSeconds -> CSUSeconds -> CSUSeconds -> [CSUSeconds] # | |
| Enum CShort | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types Methods succ :: CSigAtomic -> CSigAtomic # pred :: CSigAtomic -> CSigAtomic # toEnum :: Int -> CSigAtomic # fromEnum :: CSigAtomic -> Int # enumFrom :: CSigAtomic -> [CSigAtomic] # enumFromThen :: CSigAtomic -> CSigAtomic -> [CSigAtomic] # enumFromTo :: CSigAtomic -> CSigAtomic -> [CSigAtomic] # enumFromThenTo :: CSigAtomic -> CSigAtomic -> CSigAtomic -> [CSigAtomic] # | |
| Enum CSize | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CTime | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CUChar | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CUInt | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CUIntMax | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CUIntPtr | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CULLong | |
| Enum CULong | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum CUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods succ :: CUSeconds -> CUSeconds # pred :: CUSeconds -> CUSeconds # fromEnum :: CUSeconds -> Int # enumFrom :: CUSeconds -> [CUSeconds] # enumFromThen :: CUSeconds -> CUSeconds -> [CUSeconds] # enumFromTo :: CUSeconds -> CUSeconds -> [CUSeconds] # enumFromThenTo :: CUSeconds -> CUSeconds -> CUSeconds -> [CUSeconds] # | |
| Enum CUShort | |
| Enum CWchar | |
Defined in GHC.Internal.Foreign.C.Types | |
| Enum Associativity | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods succ :: Associativity -> Associativity # pred :: Associativity -> Associativity # toEnum :: Int -> Associativity # fromEnum :: Associativity -> Int # enumFrom :: Associativity -> [Associativity] # enumFromThen :: Associativity -> Associativity -> [Associativity] # enumFromTo :: Associativity -> Associativity -> [Associativity] # enumFromThenTo :: Associativity -> Associativity -> Associativity -> [Associativity] # | |
| Enum DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods succ :: DecidedStrictness -> DecidedStrictness # pred :: DecidedStrictness -> DecidedStrictness # toEnum :: Int -> DecidedStrictness # fromEnum :: DecidedStrictness -> Int # enumFrom :: DecidedStrictness -> [DecidedStrictness] # enumFromThen :: DecidedStrictness -> DecidedStrictness -> [DecidedStrictness] # enumFromTo :: DecidedStrictness -> DecidedStrictness -> [DecidedStrictness] # enumFromThenTo :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness -> [DecidedStrictness] # | |
| Enum SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods succ :: SourceStrictness -> SourceStrictness # pred :: SourceStrictness -> SourceStrictness # toEnum :: Int -> SourceStrictness # fromEnum :: SourceStrictness -> Int # enumFrom :: SourceStrictness -> [SourceStrictness] # enumFromThen :: SourceStrictness -> SourceStrictness -> [SourceStrictness] # enumFromTo :: SourceStrictness -> SourceStrictness -> [SourceStrictness] # enumFromThenTo :: SourceStrictness -> SourceStrictness -> SourceStrictness -> [SourceStrictness] # | |
| Enum SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods succ :: SourceUnpackedness -> SourceUnpackedness # pred :: SourceUnpackedness -> SourceUnpackedness # toEnum :: Int -> SourceUnpackedness # fromEnum :: SourceUnpackedness -> Int # enumFrom :: SourceUnpackedness -> [SourceUnpackedness] # enumFromThen :: SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness] # enumFromTo :: SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness] # enumFromThenTo :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness] # | |
| Enum Int16 | Since: base-2.1 |
Defined in GHC.Internal.Int | |
| Enum Int32 | Since: base-2.1 |
Defined in GHC.Internal.Int | |
| Enum Int64 | Since: base-2.1 |
Defined in GHC.Internal.Int | |
| Enum Int8 | Since: base-2.1 |
| Enum Ordering | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| Enum I8 | |
| Enum FPFormat | |
Defined in Data.Text.Lazy.Builder.RealFloat | |
| Enum Day | |
| Enum Month | |
Defined in Data.Time.Calendar.Month | |
| Enum Quarter | |
| Enum QuarterOfYear | maps Q1..Q4 to 1..4 |
Defined in Data.Time.Calendar.Quarter Methods succ :: QuarterOfYear -> QuarterOfYear # pred :: QuarterOfYear -> QuarterOfYear # toEnum :: Int -> QuarterOfYear # fromEnum :: QuarterOfYear -> Int # enumFrom :: QuarterOfYear -> [QuarterOfYear] # enumFromThen :: QuarterOfYear -> QuarterOfYear -> [QuarterOfYear] # enumFromTo :: QuarterOfYear -> QuarterOfYear -> [QuarterOfYear] # enumFromThenTo :: QuarterOfYear -> QuarterOfYear -> QuarterOfYear -> [QuarterOfYear] # | |
| Enum DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Enum NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods succ :: NominalDiffTime -> NominalDiffTime # pred :: NominalDiffTime -> NominalDiffTime # toEnum :: Int -> NominalDiffTime # fromEnum :: NominalDiffTime -> Int # enumFrom :: NominalDiffTime -> [NominalDiffTime] # enumFromThen :: NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] # enumFromTo :: NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] # enumFromThenTo :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] # | |
| Enum Integer | Since: base-2.1 |
| Enum Natural | Since: base-4.8.0.0 |
| Enum () | Since: base-2.1 |
Defined in GHC.Internal.Enum | |
| Enum Bool | Since: base-2.1 |
| Enum Char | Since: base-2.1 |
| Enum Int | Since: base-2.1 |
| Enum Levity | Since: base-4.16.0.0 |
Defined in GHC.Internal.Enum | |
| Enum VecCount | Since: base-4.10.0.0 |
Defined in GHC.Internal.Enum | |
| Enum VecElem | Since: base-4.10.0.0 |
| Enum Word | Since: base-2.1 |
| Enum a => Enum (First a) | Since: base-4.9.0.0 |
| Enum a => Enum (Last a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| Enum a => Enum (Max a) | Since: base-4.9.0.0 |
| Enum a => Enum (Min a) | Since: base-4.9.0.0 |
| Enum a => Enum (WrappedMonoid a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods succ :: WrappedMonoid a -> WrappedMonoid a # pred :: WrappedMonoid a -> WrappedMonoid a # toEnum :: Int -> WrappedMonoid a # fromEnum :: WrappedMonoid a -> Int # enumFrom :: WrappedMonoid a -> [WrappedMonoid a] # enumFromThen :: WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a] # enumFromTo :: WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a] # enumFromThenTo :: WrappedMonoid a -> WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a] # | |
| Integral a => Enum (Ratio a) | Since: base-2.0.1 |
| Enum a => Enum (Solo a) | |
Defined in GHC.Internal.Enum | |
| Enum (Fixed a) | Recall that, for numeric types,
and likewise
In other words,
and similarly
This is worth bearing in mind when defining [1..10] :: [Pico] evaluates to However, this is not true. On the contrary, similarly to the above
implementations of [1.000000000000, 1.00000000001, 1.00000000002, ..., 10.000000000000] and contains Since: base-2.1 |
| Enum (f (g a)) => Enum (Compose f g a) | Since: base-4.19.0.0 |
Defined in Data.Functor.Compose Methods succ :: Compose f g a -> Compose f g a # pred :: Compose f g a -> Compose f g a # toEnum :: Int -> Compose f g a # fromEnum :: Compose f g a -> Int # enumFrom :: Compose f g a -> [Compose f g a] # enumFromThen :: Compose f g a -> Compose f g a -> [Compose f g a] # enumFromTo :: Compose f g a -> Compose f g a -> [Compose f g a] # enumFromThenTo :: Compose f g a -> Compose f g a -> Compose f g a -> [Compose f g a] # | |
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 CDouble | |
| RealFrac CFloat | |
| 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 DiffTime | |
| RealFrac NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods properFraction :: Integral b => NominalDiffTime -> (b, NominalDiffTime) # truncate :: Integral b => NominalDiffTime -> b # round :: Integral b => NominalDiffTime -> b # ceiling :: Integral b => NominalDiffTime -> b # floor :: Integral b => NominalDiffTime -> b # | |
| Integral a => RealFrac (Ratio a) | Since: base-2.0.1 |
| HasResolution a => RealFrac (Fixed a) | Since: base-2.1 |
| RealFrac (f (g a)) => RealFrac (Compose f g a) | Since: base-4.20.0.0 |
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.
In addition, toInteger should be total, and fromInteger should be a left
inverse for it, i.e. fromInteger (toInteger i) = i.
Methods
quot :: a -> a -> a infixl 7 #
Integer division truncated toward zero.
WARNING: This function is partial (because it throws when 0 is passed as
the divisor) for all the integer types in base.
Integer remainder, satisfying
(x `quot` y)*y + (x `rem` y) == x
WARNING: This function is partial (because it throws when 0 is passed as
the divisor) for all the integer types in base.
Integer division truncated toward negative infinity.
WARNING: This function is partial (because it throws when 0 is passed as
the divisor) for all the integer types in base.
Integer modulus, satisfying
(x `div` y)*y + (x `mod` y) == x
WARNING: This function is partial (because it throws when 0 is passed as
the divisor) for all the integer types in base.
WARNING: This function is partial (because it throws when 0 is passed as
the divisor) for all the integer types in base.
WARNING: This function is partial (because it throws when 0 is passed as
the divisor) for all the integer types in base.
Conversion to Integer.
Instances
| Integral CBool | |
| Integral CChar | |
| Integral CInt | |
| Integral CIntMax | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CIntPtr | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CLLong | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CLong | |
| Integral CPtrdiff | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CSChar | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CShort | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types Methods quot :: CSigAtomic -> CSigAtomic -> CSigAtomic # rem :: CSigAtomic -> CSigAtomic -> CSigAtomic # div :: CSigAtomic -> CSigAtomic -> CSigAtomic # mod :: CSigAtomic -> CSigAtomic -> CSigAtomic # quotRem :: CSigAtomic -> CSigAtomic -> (CSigAtomic, CSigAtomic) # divMod :: CSigAtomic -> CSigAtomic -> (CSigAtomic, CSigAtomic) # toInteger :: CSigAtomic -> Integer # | |
| Integral CSize | |
| Integral CUChar | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CUInt | |
| Integral CUIntMax | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CUIntPtr | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CULLong | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CULong | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CUShort | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral CWchar | |
Defined in GHC.Internal.Foreign.C.Types | |
| Integral Int16 | Since: base-2.1 |
| Integral Int32 | Since: base-2.1 |
| Integral Int64 | Since: base-2.1 |
| Integral Int8 | Since: base-2.1 |
| Integral I8 | |
| Integral Integer | Since: base-2.0.1 |
Defined in GHC.Internal.Real | |
| Integral Natural | Since: base-4.8.0.0 |
Defined in GHC.Internal.Real | |
| Integral Int | Since: base-2.0.1 |
| Integral Word | Since: base-2.1 |
| Integral (f (g a)) => Integral (Compose f g a) | Since: base-4.19.0.0 |
Defined in Data.Functor.Compose Methods quot :: Compose f g a -> Compose f g a -> Compose f g a # rem :: Compose f g a -> Compose f g a -> Compose f g a # div :: Compose f g a -> Compose f g a -> Compose f g a # mod :: Compose f g a -> Compose f g a -> Compose f g a # quotRem :: Compose f g a -> Compose f g a -> (Compose f g a, Compose f g a) # divMod :: Compose f g a -> Compose f g a -> (Compose f g a, Compose f g a) # | |
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
Methods
Arguments
| :: Int | the operator precedence of the enclosing
context (a number from |
| -> ReadS a |
attempts to parse a value from the front of the string, returning a list of (parsed value, remaining string) pairs. If there is no successful parse, the returned list is empty.
Derived instances of Read and Show satisfy the following:
That is, readsPrec parses the string produced by
showsPrec, and delivers the value that
showsPrec started with.
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 ByteString | |
Defined in Data.ByteString.Internal.Type Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] # | |
| Read IntSet | |
| Read Void | Reading a Since: base-4.8.0.0 |
| Read Version | Since: base-2.1 |
| Read CBool | |
| Read CChar | |
| Read CClock | |
| Read CDouble | |
| Read CFloat | |
| Read CInt | |
| Read CIntMax | |
| Read CIntPtr | |
| Read CLLong | |
| Read CLong | |
| Read CPtrdiff | |
| Read CSChar | |
| Read CSUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods readsPrec :: Int -> ReadS CSUSeconds # readList :: ReadS [CSUSeconds] # readPrec :: ReadPrec CSUSeconds # readListPrec :: ReadPrec [CSUSeconds] # | |
| Read CShort | |
| Read CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types Methods readsPrec :: Int -> ReadS CSigAtomic # readList :: ReadS [CSigAtomic] # readPrec :: ReadPrec CSigAtomic # readListPrec :: ReadPrec [CSigAtomic] # | |
| Read CSize | |
| Read CTime | |
| Read CUChar | |
| Read CUInt | |
| Read CUIntMax | |
| Read CUIntPtr | |
| Read CULLong | |
| Read CULong | |
| Read CUSeconds | |
| Read CUShort | |
| Read CWchar | |
| Read Associativity | Since: base-4.6.0.0 |
Defined in GHC.Internal.Generics Methods readsPrec :: Int -> ReadS Associativity # readList :: ReadS [Associativity] # | |
| Read DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.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.Internal.Generics Methods readsPrec :: Int -> ReadS SourceStrictness # readList :: ReadS [SourceStrictness] # | |
| Read SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods readsPrec :: Int -> ReadS SourceUnpackedness # readList :: ReadS [SourceUnpackedness] # | |
| Read ExitCode | |
| 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 Lexeme | Since: base-2.1 |
| Read GeneralCategory | Since: base-2.1 |
Defined in GHC.Internal.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 Word8 | Since: base-2.1 |
| Read Ordering | Since: base-2.1 |
| Read LogLevel | |
| 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 I8 | |
| Read FPFormat | |
| Read ShortText | |
| Read Month | Read as |
| Read Quarter | Read as |
| Read QuarterOfYear | |
Defined in Data.Time.Calendar.Quarter Methods readsPrec :: Int -> ReadS QuarterOfYear # readList :: ReadS [QuarterOfYear] # | |
| Read DiffTime | |
| Read NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods readsPrec :: Int -> ReadS NominalDiffTime # readList :: ReadS [NominalDiffTime] # | |
| Read UUID | |
| Read UnpackedUUID | |
| 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 v => Read (KeyMap v) | |
| Read a => Read (Complex a) | Since: base-2.1 |
| 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 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 vertex => Read (SCC vertex) | Since: containers-0.5.9 |
| 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 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 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 (Vector a) | |
| Read a => Read (Maybe a) | Since: base-2.1 |
| Read a => Read (Solo a) | Since: base-4.15 |
| Read a => Read [a] | Since: base-2.1 |
| HasResolution a => Read (Fixed a) | Since: base-4.3.0.0 |
| (Read a, Read b) => Read (Arg a b) | Since: base-4.9.0.0 |
| (Ord k, Read k, Read e) => Read (Map k e) | |
| (Ix a, Read a, Read b) => Read (Array a b) | Since: base-2.1 |
| (Read a, Read b) => Read (Either a b) | Since: base-3.0 |
| Read (U1 p) | Since: base-4.9.0.0 |
| Read (V1 p) | Since: base-4.9.0.0 |
| (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 f, Read a) => Read (Lift f 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 (p a a) => Read (Join p a) | |
| Read (f p) => Read (Rec1 f p) | Since: base-4.7.0.0 |
| (Read (f a), Read (g a), Read a) => Read (These1 f g a) | |
| (Read a, Read b, Read c) => Read (a, b, c) | Since: base-2.1 |
| (Read (f a), Read (g a)) => Read (Product f g a) | Since: base-4.18.0.0 |
| (Read (f a), Read (g a)) => Read (Sum f g a) | Since: base-4.18.0.0 |
| (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 |
| Read (f (g a)) => Read (Compose f g a) | Since: base-4.18.0.0 |
| Read (f a) => Read (Clown f a b) | |
| Read (p b a) => Read (Flip p a b) | |
| Read (g b) => Read (Joker g a b) | |
| Read (p a b) => Read (WrappedBifunctor p a b) | |
Defined in Data.Bifunctor.Wrapped Methods readsPrec :: Int -> ReadS (WrappedBifunctor p a b) # readList :: ReadS [WrappedBifunctor p a b] # readPrec :: ReadPrec (WrappedBifunctor p a b) # readListPrec :: ReadPrec [WrappedBifunctor p a b] # | |
| 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 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 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 |
Defined in GHC.Internal.Read | |
| (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.Internal.Read | |
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
| MonadIO IO | Since: base-4.9.0.0 |
Defined in Control.Monad.IO.Class | |
| Alternative IO | Takes the first non-throwing Since: base-4.9.0.0 |
| Applicative IO | Since: base-2.1 |
| Functor IO | Since: base-2.1 |
| Monad IO | Since: base-2.1 |
| MonadPlus IO | Takes the first non-throwing Since: base-4.9.0.0 |
| MonadFail IO | Since: base-4.9.0.0 |
Defined in GHC.Internal.Control.Monad.Fail | |
| PrimBase IO | |
| PrimMonad IO | |
| Alt IO | This instance does not actually satisfy the ( |
| Apply IO | |
| Bind IO | |
| Plus IO | |
Defined in Data.Functor.Plus | |
| Quasi IO | |
Defined in Language.Haskell.TH.Syntax Methods qNewName :: String -> IO Name # qReport :: Bool -> String -> IO () # qRecover :: IO a -> IO a -> IO a # qLookupName :: Bool -> String -> IO (Maybe Name) # qReifyFixity :: Name -> IO (Maybe Fixity) # qReifyType :: Name -> IO Type # qReifyInstances :: Name -> [Type] -> IO [Dec] # qReifyRoles :: Name -> IO [Role] # qReifyAnnotations :: Data a => AnnLookup -> IO [a] # qReifyModule :: Module -> IO ModuleInfo # qReifyConStrictness :: Name -> IO [DecidedStrictness] # qGetPackageRoot :: IO FilePath # qAddDependentFile :: FilePath -> IO () # qAddTempFile :: String -> IO FilePath # qAddTopDecls :: [Dec] -> IO () # qAddForeignFilePath :: ForeignSrcLang -> String -> IO () # qAddModFinalizer :: Q () -> IO () # qAddCorePlugin :: String -> IO () # qGetQ :: Typeable a => IO (Maybe a) # qPutQ :: Typeable a => a -> IO () # qIsExtEnabled :: Extension -> IO Bool # qExtsEnabled :: IO [Extension] # | |
| Quote IO | |
| MonadUnliftIO IO | |
Defined in Control.Monad.IO.Unlift | |
| MonadBaseControl IO IO | |
| MonadError IOException IO | |
Defined in Control.Monad.Error.Class | |
| a ~ () => HPrintfType (IO a) | Since: base-4.7.0.0 |
Defined in Text.Printf | |
| a ~ () => PrintfType (IO a) | Since: base-4.7.0.0 |
Defined in Text.Printf | |
| Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (IO a) | Since: base-4.10.0.0 |
| type PrimState IO | |
Defined in Control.Monad.Primitive | |
| type StM IO a | |
Defined in Control.Monad.Trans.Control | |
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, instances are
encouraged to follow these 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 ByteArray | Since: base-4.17.0.0 |
| Eq Timeout | |
| Eq ByteString | |
Defined in Data.ByteString.Internal.Type | |
| Eq IntSet | |
| Eq NotFoundException | |
Defined in Context.Internal Methods (==) :: NotFoundException -> NotFoundException -> Bool # (/=) :: NotFoundException -> NotFoundException -> Bool # | |
| Eq BigNat | |
| Eq Void | Since: base-4.8.0.0 |
| Eq BlockReason | Since: base-4.3.0.0 |
Defined in GHC.Internal.Conc.Sync | |
| Eq ThreadId | Since: base-4.2.0.0 |
| Eq ThreadStatus | Since: base-4.3.0.0 |
Defined in GHC.Internal.Conc.Sync | |
| Eq Version | Since: base-2.1 |
| Eq ArithException | Since: base-3.0 |
Defined in GHC.Internal.Exception.Type Methods (==) :: ArithException -> ArithException -> Bool # (/=) :: ArithException -> ArithException -> Bool # | |
| Eq CBool | |
| Eq CChar | |
| Eq CClock | |
| Eq CDouble | |
| Eq CFloat | |
| Eq CInt | |
| Eq CIntMax | |
| Eq CIntPtr | |
| Eq CLLong | |
| Eq CLong | |
| Eq CPtrdiff | |
| Eq CSChar | |
| Eq CSUSeconds | |
Defined in GHC.Internal.Foreign.C.Types | |
| Eq CShort | |
| Eq CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types | |
| Eq CSize | |
| Eq CTime | |
| Eq CUChar | |
| Eq CUInt | |
| Eq CUIntMax | |
| Eq CUIntPtr | |
| Eq CULLong | |
| Eq CULong | |
| Eq CUSeconds | |
| Eq CUShort | |
| Eq CWchar | |
| Eq Associativity | Since: base-4.6.0.0 |
Defined in GHC.Internal.Generics Methods (==) :: Associativity -> Associativity -> Bool # (/=) :: Associativity -> Associativity -> Bool # | |
| Eq DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Internal.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.Internal.Generics Methods (==) :: SourceStrictness -> SourceStrictness -> Bool # (/=) :: SourceStrictness -> SourceStrictness -> Bool # | |
| Eq SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics Methods (==) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # | |
| Eq MaskingState | Since: base-4.3.0.0 |
Defined in GHC.Internal.IO | |
| Eq ArrayException | Since: base-4.2.0.0 |
Defined in GHC.Internal.IO.Exception Methods (==) :: ArrayException -> ArrayException -> Bool # (/=) :: ArrayException -> ArrayException -> Bool # | |
| Eq AsyncException | Since: base-4.2.0.0 |
Defined in GHC.Internal.IO.Exception Methods (==) :: AsyncException -> AsyncException -> Bool # (/=) :: AsyncException -> AsyncException -> Bool # | |
| Eq ExitCode | |
| Eq IOErrorType | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception | |
| Eq IOException | Since: base-4.1.0.0 |
Defined in GHC.Internal.IO.Exception | |
| 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 SrcLoc | Since: base-4.9.0.0 |
| Eq Module | |
| Eq Ordering | |
| Eq TrName | |
| Eq TyCon | |
| Eq LogLevel | |
| Eq LoggedMessage | |
Defined in Control.Monad.Logger.Aeson.Internal Methods (==) :: LoggedMessage -> LoggedMessage -> Bool # (/=) :: LoggedMessage -> LoggedMessage -> Bool # | |
| Eq URI | |
| Eq URIAuth | |
| Eq StdGen | |
| Eq Scientific | Scientific numbers can be safely compared for equality. No magnitude |
Defined in Data.Scientific | |
| Eq AnnLookup | |
| Eq AnnTarget | |
| Eq Bang | |
| Eq BndrVis | |
| 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 DocLoc | |
| 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 NamespaceSpecifier | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: NamespaceSpecifier -> NamespaceSpecifier -> Bool # (/=) :: NamespaceSpecifier -> NamespaceSpecifier -> Bool # | |
| 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 UnicodeException | |
Defined in Data.Text.Encoding.Error Methods (==) :: UnicodeException -> UnicodeException -> Bool # (/=) :: UnicodeException -> UnicodeException -> Bool # | |
| Eq I8 | |
| Eq Builder | |
| Eq PartialUtf8CodePoint | |
| Eq Utf8State | |
| Eq DecoderState | |
Defined in Data.Text.Internal.Encoding.Utf8 | |
| Eq Size | |
| Eq B | |
| Eq ShortText | |
| Eq Day | |
| Eq Month | |
| Eq Quarter | |
| Eq QuarterOfYear | |
Defined in Data.Time.Calendar.Quarter Methods (==) :: QuarterOfYear -> QuarterOfYear -> Bool # (/=) :: QuarterOfYear -> QuarterOfYear -> Bool # | |
| Eq FirstWeekType | |
Defined in Data.Time.Calendar.WeekDate Methods (==) :: FirstWeekType -> FirstWeekType -> Bool # (/=) :: FirstWeekType -> FirstWeekType -> Bool # | |
| Eq DiffTime | |
| Eq NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (==) :: NominalDiffTime -> NominalDiffTime -> Bool # (/=) :: NominalDiffTime -> NominalDiffTime -> Bool # | |
| Eq UTCTime | |
| Eq LocalTime | |
| Eq UnixDiffTime | |
Defined in Data.UnixTime.Types | |
| Eq UnixTime | |
| Eq ConcException | |
Defined in UnliftIO.Internals.Async Methods (==) :: ConcException -> ConcException -> Bool # (/=) :: ConcException -> ConcException -> Bool # | |
| Eq SubHashPath | |
Defined in Data.HashMap.Internal.Debug | |
| Eq UUID | |
| Eq UnpackedUUID | |
| Eq Size | |
| Eq Checks | |
| 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 v => Eq (KeyMap v) | |
| Eq a => Eq (IResult a) | |
| Eq a => Eq (Result a) | |
| Eq (Chan a) | Since: base-4.4.0.0 |
| Eq (MutableByteArray s) | Since: base-4.17.0.0 |
Defined in Data.Array.Byte Methods (==) :: MutableByteArray s -> MutableByteArray s -> Bool # (/=) :: MutableByteArray s -> MutableByteArray s -> Bool # | |
| Eq a => Eq (Complex a) | Since: base-2.1 |
| 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 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 (Flush a) | |
| Eq vertex => Eq (SCC vertex) | Since: containers-0.5.9 |
| Eq a => Eq (IntMap a) | |
| Eq a => Eq (Seq a) | |
| Eq a => Eq (ViewL a) | |
| Eq a => Eq (ViewR a) | |
| Eq a => Eq (Intersection a) | |
Defined in Data.Set.Internal Methods (==) :: Intersection a -> Intersection a -> Bool # (/=) :: Intersection a -> Intersection a -> Bool # | |
| 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 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 a => Eq (Ratio a) | Since: base-2.1 |
| Eq a => Eq (Hashed a) | Uses precomputed hash to detect inequality faster |
| Eq a => Eq (Array a) | |
| (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 (Stream a) | |
| Eq k => Eq (Error k) | |
| Eq k => Eq (Validity k) | |
| Eq a => Eq (HashSet a) | Note that, in the presence of hash collisions, equal
In general, the lack of extensionality 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 (Vector a) | |
| Eq a => Eq (Maybe a) | Since: base-2.1 |
| Eq a => Eq (Solo a) | |
| Eq a => Eq [a] | |
| Eq (Fixed a) | Since: base-2.1 |
| Eq a => Eq (Arg a b) | Since: base-4.9.0.0 |
| (Eq k, Eq a) => Eq (Map k a) | |
| (Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 |
| Eq (U1 p) | Since: base-4.9.0.0 |
| Eq (V1 p) | Since: base-4.9.0.0 |
| 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 (MVar s a) | |
| Eq (MutVar s a) | |
| 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 (PrimVar s a) | |
| 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 f, Eq a) => Eq (Lift f a) | |
| (Eq k, Eq v) => Eq (HashMap k v) | Note that, in the presence of hash collisions, equal
In general, the lack of extensionality 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 (p a a) => Eq (Join p a) | |
| (Generic1 f, Eq (Rep1 f a)) => Eq (Generically1 f a) | Since: base-4.18.0.0 |
Defined in GHC.Internal.Generics Methods (==) :: Generically1 f a -> Generically1 f a -> Bool # (/=) :: Generically1 f a -> Generically1 f a -> Bool # | |
| 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 (f a), Eq (g a), Eq a) => Eq (These1 f g a) | |
| (Eq a, Eq b, Eq c) => Eq (a, b, c) | |
| (Eq (f a), Eq (g a)) => Eq (Product f g a) | Since: base-4.18.0.0 |
| (Eq (f a), Eq (g a)) => Eq (Sum f g a) | Since: base-4.18.0.0 |
| (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) | |
| Eq (f (g a)) => Eq (Compose f g a) | Since: base-4.18.0.0 |
| Eq (f a) => Eq (Clown f a b) | |
| Eq (p b a) => Eq (Flip p a b) | |
| Eq (g b) => Eq (Joker g a b) | |
| Eq (p a b) => Eq (WrappedBifunctor p a b) | |
Defined in Data.Bifunctor.Wrapped Methods (==) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (/=) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # | |
| 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 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 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) | |
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.
Ord, as defined by the Haskell report, implements a total order and has the
following properties:
- Comparability
x <= y || y <= x=True- Transitivity
- if
x <= y && y <= z=True, thenx <= z=True - Reflexivity
x <= x=True- Antisymmetry
- if
x <= y && y <= x=True, thenx == y=True
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 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: base-4.17.0.0 |
| Ord ByteString | |
Defined in Data.ByteString.Internal.Type 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 IntSet | |
| Ord BigNat | |
| Ord Void | Since: base-4.8.0.0 |
| Ord BlockReason | Since: base-4.3.0.0 |
Defined in GHC.Internal.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.Internal.Conc.Sync | |
| Ord ThreadStatus | Since: base-4.3.0.0 |
Defined in GHC.Internal.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 Version | Since: base-2.1 |
Defined in GHC.Internal.Data.Version | |
| Ord ArithException | Since: base-3.0 |
Defined in GHC.Internal.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 CBool | |
| Ord CChar | |
| Ord CClock | |
| Ord CDouble | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CFloat | |
| Ord CInt | |
| Ord CIntMax | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CIntPtr | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CLLong | |
| Ord CLong | |
| Ord CPtrdiff | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CSChar | |
| Ord CSUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods compare :: CSUSeconds -> CSUSeconds -> Ordering # (<) :: CSUSeconds -> CSUSeconds -> Bool # (<=) :: CSUSeconds -> CSUSeconds -> Bool # (>) :: CSUSeconds -> CSUSeconds -> Bool # (>=) :: CSUSeconds -> CSUSeconds -> Bool # max :: CSUSeconds -> CSUSeconds -> CSUSeconds # min :: CSUSeconds -> CSUSeconds -> CSUSeconds # | |
| Ord CShort | |
| Ord CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types Methods compare :: CSigAtomic -> CSigAtomic -> Ordering # (<) :: CSigAtomic -> CSigAtomic -> Bool # (<=) :: CSigAtomic -> CSigAtomic -> Bool # (>) :: CSigAtomic -> CSigAtomic -> Bool # (>=) :: CSigAtomic -> CSigAtomic -> Bool # max :: CSigAtomic -> CSigAtomic -> CSigAtomic # min :: CSigAtomic -> CSigAtomic -> CSigAtomic # | |
| Ord CSize | |
| Ord CTime | |
| Ord CUChar | |
| Ord CUInt | |
| Ord CUIntMax | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CUIntPtr | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CULLong | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CULong | |
| Ord CUSeconds | |
| Ord CUShort | |
Defined in GHC.Internal.Foreign.C.Types | |
| Ord CWchar | |
| Ord Associativity | Since: base-4.6.0.0 |
Defined in GHC.Internal.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.Internal.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.Internal.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.Internal.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.Internal.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.Internal.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.Internal.IO.Exception | |
| 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 Ordering | |
Defined in GHC.Classes | |
| Ord TyCon | |
| Ord LogLevel | |
Defined in Control.Monad.Logger | |
| Ord LoggedMessage | |
Defined in Control.Monad.Logger.Aeson.Internal Methods compare :: LoggedMessage -> LoggedMessage -> Ordering # (<) :: LoggedMessage -> LoggedMessage -> Bool # (<=) :: LoggedMessage -> LoggedMessage -> Bool # (>) :: LoggedMessage -> LoggedMessage -> Bool # (>=) :: LoggedMessage -> LoggedMessage -> Bool # max :: LoggedMessage -> LoggedMessage -> LoggedMessage # min :: LoggedMessage -> LoggedMessage -> LoggedMessage # | |
| Ord URI | |
| Ord URIAuth | |
| 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 BndrVis | |
Defined in Language.Haskell.TH.Syntax | |
| 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 DocLoc | |
| 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 NamespaceSpecifier | |
Defined in Language.Haskell.TH.Syntax Methods compare :: NamespaceSpecifier -> NamespaceSpecifier -> Ordering # (<) :: NamespaceSpecifier -> NamespaceSpecifier -> Bool # (<=) :: NamespaceSpecifier -> NamespaceSpecifier -> Bool # (>) :: NamespaceSpecifier -> NamespaceSpecifier -> Bool # (>=) :: NamespaceSpecifier -> NamespaceSpecifier -> Bool # max :: NamespaceSpecifier -> NamespaceSpecifier -> NamespaceSpecifier # min :: NamespaceSpecifier -> NamespaceSpecifier -> NamespaceSpecifier # | |
| 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 I8 | |
| Ord Builder | |
Defined in Data.Text.Internal.Builder | |
| Ord B | |
| Ord ShortText | |
| Ord Day | |
| Ord Month | |
| Ord Quarter | |
Defined in Data.Time.Calendar.Quarter | |
| Ord QuarterOfYear | |
Defined in Data.Time.Calendar.Quarter Methods compare :: QuarterOfYear -> QuarterOfYear -> Ordering # (<) :: QuarterOfYear -> QuarterOfYear -> Bool # (<=) :: QuarterOfYear -> QuarterOfYear -> Bool # (>) :: QuarterOfYear -> QuarterOfYear -> Bool # (>=) :: QuarterOfYear -> QuarterOfYear -> Bool # max :: QuarterOfYear -> QuarterOfYear -> QuarterOfYear # min :: QuarterOfYear -> QuarterOfYear -> QuarterOfYear # | |
| Ord DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Ord NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods compare :: NominalDiffTime -> NominalDiffTime -> Ordering # (<) :: NominalDiffTime -> NominalDiffTime -> Bool # (<=) :: NominalDiffTime -> NominalDiffTime -> Bool # (>) :: NominalDiffTime -> NominalDiffTime -> Bool # (>=) :: NominalDiffTime -> NominalDiffTime -> Bool # max :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # min :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # | |
| Ord UTCTime | |
Defined in Data.Time.Clock.Internal.UTCTime | |
| Ord LocalTime | |
Defined in Data.Time.LocalTime.Internal.LocalTime | |
| Ord UnixDiffTime | |
Defined in Data.UnixTime.Types Methods compare :: UnixDiffTime -> UnixDiffTime -> Ordering # (<) :: UnixDiffTime -> UnixDiffTime -> Bool # (<=) :: UnixDiffTime -> UnixDiffTime -> Bool # (>) :: UnixDiffTime -> UnixDiffTime -> Bool # (>=) :: UnixDiffTime -> UnixDiffTime -> Bool # max :: UnixDiffTime -> UnixDiffTime -> UnixDiffTime # min :: UnixDiffTime -> UnixDiffTime -> UnixDiffTime # | |
| Ord UnixTime | |
Defined in Data.UnixTime.Types | |
| 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 Integer | |
| Ord Natural | |
| Ord () | |
| Ord Bool | |
| Ord Char | |
| Ord Double | IEEE 754 IEEE 754-2008, section 5.11 requires that if at least one of arguments of
IEEE 754-2008, section 5.10 defines Thus, users must be extremely cautious when using Moving further, the behaviour of IEEE 754-2008 compliant |
| Ord Float | See |
| Ord Int | |
| Ord Word | |
| Ord v => Ord (KeyMap v) | |
Defined in Data.Aeson.KeyMap | |
| 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 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 (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 (Intersection a) | |
Defined in Data.Set.Internal Methods compare :: Intersection a -> Intersection a -> Ordering # (<) :: Intersection a -> Intersection a -> Bool # (<=) :: Intersection a -> Intersection a -> Bool # (>) :: Intersection a -> Intersection a -> Bool # (>=) :: Intersection a -> Intersection a -> Bool # max :: Intersection a -> Intersection a -> Intersection a # min :: Intersection a -> Intersection a -> Intersection a # | |
| Ord a => Ord (Set a) | |
| Ord a => Ord (Tree a) | Since: containers-0.6.5 |
| 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 a => Ord (NonEmpty a) | Since: base-4.9.0.0 |
| Ord p => Ord (Par1 p) | Since: base-4.7.0.0 |
| Integral a => Ord (Ratio a) | Since: base-2.0.1 |
| Ord a => Ord (Hashed a) | |
Defined in Data.Hashable.Class | |
| 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 (Stream a) | |
Defined in Data.Text.Internal.Fusion.Types | |
| 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 (Vector a) | |
Defined in Data.Vector.Strict | |
| Ord a => Ord (Maybe a) | Since: base-2.1 |
| Ord a => Ord (Solo a) | |
| Ord a => Ord [a] | |
| Ord (Fixed a) | Since: base-2.1 |
| Ord a => Ord (Arg a b) | Since: base-4.9.0.0 |
| (Ord k, Ord v) => Ord (Map k v) | |
| (Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 |
Defined in GHC.Internal.Data.Either | |
| Ord (U1 p) | Since: base-4.7.0.0 |
| Ord (V1 p) | Since: base-4.9.0.0 |
| (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 f, Ord a) => Ord (Lift f a) | |
Defined in Control.Applicative.Lift | |
| (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 (p a a) => Ord (Join p a) | |
Defined in Data.Bifunctor.Join | |
| (Generic1 f, Ord (Rep1 f a)) => Ord (Generically1 f a) | Since: base-4.18.0.0 |
Defined in GHC.Internal.Generics Methods compare :: Generically1 f a -> Generically1 f a -> Ordering # (<) :: Generically1 f a -> Generically1 f a -> Bool # (<=) :: Generically1 f a -> Generically1 f a -> Bool # (>) :: Generically1 f a -> Generically1 f a -> Bool # (>=) :: Generically1 f a -> Generically1 f a -> Bool # max :: Generically1 f a -> Generically1 f a -> Generically1 f a # min :: Generically1 f a -> Generically1 f a -> Generically1 f a # | |
| Ord (f p) => Ord (Rec1 f p) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Generics | |
| Ord (URec (Ptr ()) p) | Since: base-4.9.0.0 |
Defined in GHC.Internal.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.Internal.Generics | |
| Ord (URec Double p) | Since: base-4.9.0.0 |
Defined in GHC.Internal.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.Internal.Generics | |
| Ord (URec Int p) | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics | |
| Ord (URec Word p) | Since: base-4.9.0.0 |
Defined in GHC.Internal.Generics | |
| (Ord (f a), Ord (g a), Ord a) => Ord (These1 f g a) | |
Defined in Data.Functor.These | |
| (Ord a, Ord b, Ord c) => Ord (a, b, c) | |
| (Ord (f a), Ord (g a)) => Ord (Product f g a) | Since: base-4.18.0.0 |
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 # | |
| (Ord (f a), Ord (g a)) => Ord (Sum f g a) | Since: base-4.18.0.0 |
| (Ord (f p), Ord (g p)) => Ord ((f :*: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Generics | |
| (Ord (f p), Ord (g p)) => Ord ((f :+: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Generics | |
| Ord c => Ord (K1 i c p) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Generics | |
| (Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) | |
Defined in GHC.Classes | |
| Ord (f (g a)) => Ord (Compose f g a) | Since: base-4.18.0.0 |
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 a) => Ord (Clown f a b) | |
Defined in Data.Bifunctor.Clown | |
| Ord (p b a) => Ord (Flip p a b) | |
Defined in Data.Bifunctor.Flip | |
| Ord (g b) => Ord (Joker g a b) | |
Defined in Data.Bifunctor.Joker | |
| Ord (p a b) => Ord (WrappedBifunctor p a b) | |
Defined in Data.Bifunctor.Wrapped Methods compare :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Ordering # (<) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (<=) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (>) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (>=) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # max :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> WrappedBifunctor p a b # min :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> WrappedBifunctor p a b # | |
| Ord (f (g p)) => Ord ((f :.: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Generics | |
| Ord (f p) => Ord (M1 i c f p) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Generics | |
| (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 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) # | |
String is an alias for a list of characters.
String constants in Haskell are values of type String.
That means if you write a string literal like "hello world",
it will have the type [Char], which is the same as String.
Note: You can ask the compiler to automatically infer different types
with the -XOverloadedStrings language extension, for example
"hello world" :: Text. See IsString for more information.
Because String is just a list of characters, you can use normal list functions
to do basic string manipulation. See Data.List for operations on lists.
Performance considerations
[Char] is a relatively memory-inefficient type.
It is a linked list of boxed word-size characters, internally it looks something like:
╭─────┬───┬──╮ ╭─────┬───┬──╮ ╭─────┬───┬──╮ ╭────╮
│ (:) │ │ ─┼─>│ (:) │ │ ─┼─>│ (:) │ │ ─┼─>│ [] │
╰─────┴─┼─┴──╯ ╰─────┴─┼─┴──╯ ╰─────┴─┼─┴──╯ ╰────╯
v v v
'a' 'b' 'c'The String "abc" will use 5*3+1 = 16 (in general 5n+1)
words of space in memory.
Furthermore, operations like (++) (string concatenation) are O(n)
(in the left argument).
For historical reasons, the base library uses String in a lot of places
for the conceptual simplicity, but library code dealing with user-data
should use the text
package for Unicode text, or the the
bytestring package
for binary data.
realToFrac :: (Real a, Fractional b) => a -> b #
General coercion to Fractional types.
WARNING: This function goes through the Rational type, which does not have values for NaN for example.
This means it does not round-trip.
For Double it also behaves differently with or without -O0:
Prelude> realToFrac nan -- With -O0 -Infinity Prelude> realToFrac nan NaN
fromIntegral :: (Integral a, Num b) => a -> b #
General coercion from Integral types.
WARNING: This function performs silent truncation if the result type is not at least as big as the argument's type.
class (Num a, Ord a) => Real a where #
Real numbers.
The Haskell report defines no laws for Real, however Real instances
are customarily expected to adhere to the following law:
- Coherence with
fromRational - if the type also implements
Fractional, thenfromRationalis a left inverse fortoRational, i.e.fromRational (toRational i) = i
The law does not hold for Float, Double, CFloat,
CDouble, etc., because these types contain non-finite values,
which cannot be roundtripped through Rational.
Instances
| Real CBool | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CBool -> Rational # | |
| Real CChar | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CChar -> Rational # | |
| Real CClock | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CClock -> Rational # | |
| Real CDouble | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CDouble -> Rational # | |
| Real CFloat | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CFloat -> Rational # | |
| Real CInt | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CInt -> Rational # | |
| Real CIntMax | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CIntMax -> Rational # | |
| Real CIntPtr | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CIntPtr -> Rational # | |
| Real CLLong | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CLLong -> Rational # | |
| Real CLong | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CLong -> Rational # | |
| Real CPtrdiff | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CPtrdiff -> Rational # | |
| Real CSChar | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CSChar -> Rational # | |
| Real CSUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CSUSeconds -> Rational # | |
| Real CShort | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CShort -> Rational # | |
| Real CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CSigAtomic -> Rational # | |
| Real CSize | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CSize -> Rational # | |
| Real CTime | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CTime -> Rational # | |
| Real CUChar | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CUChar -> Rational # | |
| Real CUInt | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CUInt -> Rational # | |
| Real CUIntMax | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CUIntMax -> Rational # | |
| Real CUIntPtr | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CUIntPtr -> Rational # | |
| Real CULLong | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CULLong -> Rational # | |
| Real CULong | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CULong -> Rational # | |
| Real CUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CUSeconds -> Rational # | |
| Real CUShort | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CUShort -> Rational # | |
| Real CWchar | |
Defined in GHC.Internal.Foreign.C.Types Methods toRational :: CWchar -> Rational # | |
| Real Int16 | Since: base-2.1 |
Defined in GHC.Internal.Int Methods toRational :: Int16 -> Rational # | |
| Real Int32 | Since: base-2.1 |
Defined in GHC.Internal.Int Methods toRational :: Int32 -> Rational # | |
| Real Int64 | Since: base-2.1 |
Defined in GHC.Internal.Int Methods toRational :: Int64 -> Rational # | |
| Real Int8 | Since: base-2.1 |
Defined in GHC.Internal.Int Methods toRational :: Int8 -> Rational # | |
| Real Scientific | WARNING: Avoid applying |
Defined in Data.Scientific Methods toRational :: Scientific -> Rational # | |
| Real I8 | |
Defined in Data.Text.Foreign Methods toRational :: I8 -> Rational # | |
| Real DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime Methods toRational :: DiffTime -> Rational # | |
| Real NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods toRational :: NominalDiffTime -> Rational # | |
| Real Integer | Since: base-2.0.1 |
Defined in GHC.Internal.Real Methods toRational :: Integer -> Rational # | |
| Real Natural | Since: base-4.8.0.0 |
Defined in GHC.Internal.Real Methods toRational :: Natural -> Rational # | |
| Real Int | Since: base-2.0.1 |
Defined in GHC.Internal.Real Methods toRational :: Int -> Rational # | |
| Real Word | Since: base-2.1 |
Defined in GHC.Internal.Real Methods toRational :: Word -> Rational # | |
| Integral a => Real (Ratio a) | Since: base-2.0.1 |
Defined in GHC.Internal.Real Methods toRational :: Ratio a -> Rational # | |
| HasResolution a => Real (Fixed a) | Since: base-2.1 |
Defined in Data.Fixed Methods toRational :: Fixed a -> Rational # | |
| Real (f (g a)) => Real (Compose f g a) | Since: base-4.19.0.0 |
Defined in Data.Functor.Compose Methods toRational :: Compose f g a -> Rational # | |
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- Totality of
toRational toRationalis total- Coherence with
toRational - if the type also implements
Real, thenfromRationalis a left inverse fortoRational, i.e.fromRational (toRational i) = i
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 CDouble | |
| Fractional CFloat | |
| Fractional Scientific | WARNING: These methods also compute
|
Defined in Data.Scientific Methods (/) :: Scientific -> Scientific -> Scientific # recip :: Scientific -> Scientific # fromRational :: Rational -> Scientific # | |
| Fractional DiffTime | |
| Fractional NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (/) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # recip :: NominalDiffTime -> NominalDiffTime # fromRational :: Rational -> NominalDiffTime # | |
| RealFloat a => Fractional (Complex a) | Since: base-2.1 |
| Integral a => Fractional (Ratio a) | Since: base-2.0.1 |
| HasResolution a => Fractional (Fixed a) | Since: base-2.1 |
| Fractional a => Fractional (Op a b) | |
| Fractional (f (g a)) => Fractional (Compose f g a) | Since: base-4.20.0.0 |
($) :: (a -> b) -> a -> b infixr 0 #
($)
Applying ($)f and an argument x gives the same result as applying f to x directly. The definition is akin to this:
($) :: (a -> b) -> a -> b ($) f x = f x
This is ida -> a to (a -> b) -> (a -> b) which by the associativity of (->)
is the same as (a -> b) -> a -> b.
On the face of it, this may appear pointless! But it's actually one of the most useful and important operators in Haskell.
The order of operations is very different between ($) and normal function application. Normal function application has precedence 10 - higher than any operator - and associates to the left. So these two definitions are equivalent:
expr = min 5 1 + 5 expr = ((min 5) 1) + 5
($) has precedence 0 (the lowest) and associates to the right, so these are equivalent:
expr = min 5 $ 1 + 5 expr = (min 5) (1 + 5)
Examples
A common use cases of ($) is to avoid parentheses in complex expressions.
For example, instead of using nested parentheses in the following Haskell function:
-- | Sum numbers in a string: strSum "100 5 -7" == 98 strSum ::String->IntstrSum s =sum(mapMaybereadMaybe(wordss))
we can deploy the function application operator:
-- | Sum numbers in a string: strSum "100 5 -7" == 98 strSum ::String->IntstrSum s =sum$mapMaybereadMaybe$wordss
($) is also used as a section (a partially applied operator), in order to indicate that we wish to apply some yet-unspecified function to a given value. For example, to apply the argument 5 to a list of functions:
applyFive :: [Int] applyFive = map ($ 5) [(+1), (2^)] >>> [6, 32]
Technical Remark (Representation Polymorphism)
($) is fully representation-polymorphic. This allows it to also be used with arguments of unlifted and even unboxed kinds, such as unboxed integers:
fastMod :: Int -> Int -> Int fastMod (I# x) (I# m) = I# $ remInt# x m
(++) :: [a] -> [a] -> [a] infixr 5 #
(++) appends 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.
Performance considerations
This function takes linear time in the number of elements of the
first list. Thus it is better to associate repeated
applications of (++) to the right (which is the default behaviour):
xs ++ (ys ++ zs) or simply xs ++ ys ++ zs, but not (xs ++ ys) ++ zs.
For the same reason concat = foldr (++) []
has linear performance, while foldl (++) [] is prone
to quadratic slowdown
Examples
>>>[1, 2, 3] ++ [4, 5, 6][1,2,3,4,5,6]
>>>[] ++ [1, 2, 3][1,2,3]
>>>[3, 2, 1] ++ [][3,2,1]
class Foldable (t :: Type -> Type) where #
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.
Methods
foldMap :: Monoid m => (a -> m) -> t a -> m #
Map each element of the structure into a monoid, and combine the
results with (. This fold is right-associative and lazy in the
accumulator. For strict left-associative folds consider <>)foldMap'
instead.
Examples
Basic usage:
>>>foldMap Sum [1, 3, 5]Sum {getSum = 9}
>>>foldMap Product [1, 3, 5]Product {getProduct = 15}
>>>foldMap (replicate 3) [1, 2, 3][1,1,1,2,2,2,3,3,3]
When a Monoid's ( is lazy in its second argument, <>)foldMap can
return a result even from an unbounded structure. For example, lazy
accumulation enables Data.ByteString.Builder to efficiently serialise
large data structures and produce the output incrementally:
>>>import qualified Data.ByteString.Lazy as L>>>import qualified Data.ByteString.Builder as B>>>let bld :: Int -> B.Builder; bld i = B.intDec i <> B.word8 0x20>>>let lbs = B.toLazyByteString $ foldMap bld [0..]>>>L.take 64 lbs"0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24"
foldr :: (a -> b -> b) -> b -> t a -> b #
Right-associative fold of a structure, lazy in the accumulator.
In the case of lists, foldr, when applied to a binary operator, a
starting value (typically the right-identity of the operator), and a
list, reduces the list using the binary operator, from right to left:
foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)
Note that since the head of the resulting expression is produced by an
application of the operator to the first element of the list, given an
operator lazy in its right argument, foldr can produce a terminating
expression from an unbounded list.
For a general Foldable structure this should be semantically identical
to,
foldr f z =foldrf z .toList
Examples
Basic usage:
>>>foldr (||) False [False, True, False]True
>>>foldr (||) False []False
>>>foldr (\c acc -> acc ++ [c]) "foo" ['a', 'b', 'c', 'd']"foodcba"
Infinite structures
⚠️ Applying foldr to infinite structures usually doesn't terminate.
It may still terminate under one of the following conditions:
- the folding function is short-circuiting
- the folding function is lazy on its second argument
Short-circuiting
( short-circuits on ||)True values, so the following terminates
because there is a True value finitely far from the left side:
>>>foldr (||) False (True : repeat False)True
But the following doesn't terminate:
>>>foldr (||) False (repeat False ++ [True])* Hangs forever *
Laziness in the second argument
Applying foldr to infinite structures terminates when the operator is
lazy in its second argument (the initial accumulator is never used in
this case, and so could be left undefined, but [] is more clear):
>>>take 5 $ foldr (\i acc -> i : fmap (+3) acc) [] (repeat 1)[1,4,7,10,13]
foldl :: (b -> a -> b) -> b -> t a -> b #
Left-associative fold of a structure, lazy in the accumulator. This is rarely what you want, but can work well for structures with efficient right-to-left sequencing and an operator that is lazy in its left argument.
In the case of lists, foldl, when applied to a binary operator, a
starting value (typically the left-identity of the operator), and a
list, reduces the list using the binary operator, from left to right:
foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn
Note that to produce the outermost application of the operator the
entire input list must be traversed. Like all left-associative folds,
foldl will diverge if given an infinite list.
If you want an efficient strict left-fold, you probably want to use
foldl' instead of foldl. The reason for this is that the latter
does not force the inner results (e.g. z `f` x1 in the above
example) before applying them to the operator (e.g. to (`f` x2)).
This results in a thunk chain O(n) elements long, which then must be
evaluated from the outside-in.
For a general Foldable structure this should be semantically identical
to:
foldl f z =foldlf z .toList
Examples
The first example is a strict fold, which in practice is best performed
with foldl'.
>>>foldl (+) 42 [1,2,3,4]52
Though the result below is lazy, the input is reversed before prepending it to the initial accumulator, so corecursion begins only after traversing the entire input string.
>>>foldl (\acc c -> c : acc) "abcd" "efgh""hgfeabcd"
A left fold of a structure that is infinite on the right cannot terminate, even when for any finite input the fold just returns the initial accumulator:
>>>foldl (\a _ -> a) 0 $ repeat 1* Hangs forever *
WARNING: When it comes to lists, you always want to use either foldl' or foldr instead.
foldl' :: (b -> a -> b) -> b -> t a -> b #
Left-associative fold of a structure but with strict application of the operator.
This ensures that each step of the fold is forced to Weak Head Normal
Form before being applied, avoiding the collection of thunks that would
otherwise occur. This is often what you want to strictly reduce a
finite structure to a single strict result (e.g. sum).
For a general Foldable structure this should be semantically identical
to,
foldl' f z =foldl'f z .toList
Since: base-4.6.0.0
Test whether the structure is empty. The default implementation is Left-associative and lazy in both the initial element and the accumulator. Thus optimised for structures where the first element can be accessed in constant time. Structures where this is not the case should have a non-default implementation.
Examples
Basic usage:
>>>null []True
>>>null [1]False
null is expected to terminate even for infinite structures.
The default implementation terminates provided the structure
is bounded on the left (there is a leftmost element).
>>>null [1..]False
Since: base-4.8.0.0
Returns the size/length of a finite structure as an Int. The
default implementation just counts elements starting with the leftmost.
Instances for structures that can compute the element count faster
than via element-by-element counting, should provide a specialised
implementation.
Examples
Basic usage:
>>>length []0
>>>length ['a', 'b', 'c']3>>>length [1..]* Hangs forever *
Since: base-4.8.0.0
elem :: Eq a => a -> t a -> Bool infix 4 #
Does the element occur in the structure?
Note: elem is often used in infix form.
Examples
Basic usage:
>>>3 `elem` []False
>>>3 `elem` [1,2]False
>>>3 `elem` [1,2,3,4,5]True
For infinite structures, the default implementation of elem
terminates if the sought-after value exists at a finite distance
from the left side of the structure:
>>>3 `elem` [1..]True
>>>3 `elem` ([4..] ++ [3])* Hangs forever *
Since: base-4.8.0.0
The sum function computes the sum of the numbers of a structure.
Examples
Basic usage:
>>>sum []0
>>>sum [42]42
>>>sum [1..10]55
>>>sum [4.1, 2.0, 1.7]7.8
>>>sum [1..]* Hangs forever *
Since: base-4.8.0.0
product :: Num a => t a -> a #
The product function computes the product of the numbers of a
structure.
Examples
Basic usage:
>>>product []1
>>>product [42]42
>>>product [1..10]3628800
>>>product [4.1, 2.0, 1.7]13.939999999999998
>>>product [1..]* Hangs forever *
Since: base-4.8.0.0
Instances
| Foldable KeyMap | |
Defined in Data.Aeson.KeyMap Methods fold :: Monoid m => KeyMap m -> m # foldMap :: Monoid m => (a -> m) -> KeyMap a -> m # foldMap' :: Monoid m => (a -> m) -> KeyMap a -> m # foldr :: (a -> b -> b) -> b -> KeyMap a -> b # foldr' :: (a -> b -> b) -> b -> KeyMap a -> b # foldl :: (b -> a -> b) -> b -> KeyMap a -> b # foldl' :: (b -> a -> b) -> b -> KeyMap a -> b # foldr1 :: (a -> a -> a) -> KeyMap a -> a # foldl1 :: (a -> a -> a) -> KeyMap a -> a # elem :: Eq a => a -> KeyMap a -> Bool # maximum :: Ord a => KeyMap a -> a # minimum :: Ord a => KeyMap a -> a # | |
| 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 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 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 SCC | Since: containers-0.5.9 |
Defined in Data.Graph Methods fold :: Monoid m => SCC m -> m # foldMap :: Monoid m => (a -> m) -> SCC a -> m # foldMap' :: Monoid m => (a -> m) -> SCC a -> m # foldr :: (a -> b -> b) -> b -> SCC a -> b # foldr' :: (a -> b -> b) -> b -> SCC a -> b # foldl :: (b -> a -> b) -> b -> SCC a -> b # foldl' :: (b -> a -> b) -> b -> SCC a -> b # foldr1 :: (a -> a -> a) -> SCC a -> a # foldl1 :: (a -> a -> a) -> SCC a -> a # elem :: Eq a => a -> SCC a -> Bool # maximum :: Ord a => SCC 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 | Folds in preorder |
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 NonEmpty | Since: base-4.9.0.0 |
Defined in GHC.Internal.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 First | Since: base-4.8.0.0 |
Defined in GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 Dual | Since: base-4.8.0.0 |
Defined in GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 Par1 | Since: base-4.9.0.0 |
Defined in GHC.Internal.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 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 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 TyVarBndr | |
Defined in Language.Haskell.TH.Syntax Methods fold :: Monoid m => TyVarBndr m -> m # foldMap :: Monoid m => (a -> m) -> TyVarBndr a -> m # foldMap' :: Monoid m => (a -> m) -> TyVarBndr a -> m # foldr :: (a -> b -> b) -> b -> TyVarBndr a -> b # foldr' :: (a -> b -> b) -> b -> TyVarBndr a -> b # foldl :: (b -> a -> b) -> b -> TyVarBndr a -> b # foldl' :: (b -> a -> b) -> b -> TyVarBndr a -> b # foldr1 :: (a -> a -> a) -> TyVarBndr a -> a # foldl1 :: (a -> a -> a) -> TyVarBndr a -> a # toList :: TyVarBndr a -> [a] # length :: TyVarBndr a -> Int # elem :: Eq a => a -> TyVarBndr a -> Bool # maximum :: Ord a => TyVarBndr a -> a # minimum :: Ord a => TyVarBndr 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 Vector | |
Defined in Data.Vector.Strict 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 GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 (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 (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 (Array i) | Since: base-4.8.0.0 |
Defined in GHC.Internal.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 (Either a) | Since: base-4.7.0.0 |
Defined in GHC.Internal.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 GHC.Internal.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 (U1 :: Type -> Type) | Since: base-4.9.0.0 |
Defined in GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 (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 (Lift f) | |
Defined in Control.Applicative.Lift Methods fold :: Monoid m => Lift f m -> m # foldMap :: Monoid m => (a -> m) -> Lift f a -> m # foldMap' :: Monoid m => (a -> m) -> Lift f a -> m # foldr :: (a -> b -> b) -> b -> Lift f a -> b # foldr' :: (a -> b -> b) -> b -> Lift f a -> b # foldl :: (b -> a -> b) -> b -> Lift f a -> b # foldl' :: (b -> a -> b) -> b -> Lift f a -> b # foldr1 :: (a -> a -> a) -> Lift f a -> a # foldl1 :: (a -> a -> a) -> Lift f a -> a # elem :: Eq a => a -> Lift f a -> Bool # maximum :: Ord a => Lift f a -> a # minimum :: Ord a => Lift 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 GHC.Internal.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 # | |
| Bifoldable p => Foldable (Join p) | |
Defined in Data.Bifunctor.Join Methods fold :: Monoid m => Join p m -> m # foldMap :: Monoid m => (a -> m) -> Join p a -> m # foldMap' :: Monoid m => (a -> m) -> Join p a -> m # foldr :: (a -> b -> b) -> b -> Join p a -> b # foldr' :: (a -> b -> b) -> b -> Join p a -> b # foldl :: (b -> a -> b) -> b -> Join p a -> b # foldl' :: (b -> a -> b) -> b -> Join p a -> b # foldr1 :: (a -> a -> a) -> Join p a -> a # foldl1 :: (a -> a -> a) -> Join p a -> a # elem :: Eq a => a -> Join p a -> Bool # maximum :: Ord a => Join p a -> a # minimum :: Ord a => Join p a -> a # | |
| Foldable f => Foldable (Ap f) | Since: base-4.12.0.0 |
Defined in GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 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 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 GHC.Internal.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 GHC.Internal.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 GHC.Internal.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 (Clown f a :: Type -> Type) | |
Defined in Data.Bifunctor.Clown Methods fold :: Monoid m => Clown f a m -> m # foldMap :: Monoid m => (a0 -> m) -> Clown f a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Clown f a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Clown f a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Clown f a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Clown f a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Clown f a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Clown f a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Clown f a a0 -> a0 # toList :: Clown f a a0 -> [a0] # null :: Clown f a a0 -> Bool # length :: Clown f a a0 -> Int # elem :: Eq a0 => a0 -> Clown f a a0 -> Bool # maximum :: Ord a0 => Clown f a a0 -> a0 # minimum :: Ord a0 => Clown f a a0 -> a0 # | |
| 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 g => Foldable (Joker g a) | |
Defined in Data.Bifunctor.Joker Methods fold :: Monoid m => Joker g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Joker g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Joker g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Joker g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Joker g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Joker g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Joker g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Joker g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Joker g a a0 -> a0 # toList :: Joker g a a0 -> [a0] # null :: Joker g a a0 -> Bool # length :: Joker g a a0 -> Int # elem :: Eq a0 => a0 -> Joker g a a0 -> Bool # maximum :: Ord a0 => Joker g a a0 -> a0 # minimum :: Ord a0 => Joker g a a0 -> a0 # | |
| Bifoldable p => Foldable (WrappedBifunctor p a) | |
Defined in Data.Bifunctor.Wrapped Methods fold :: Monoid m => WrappedBifunctor p a m -> m # foldMap :: Monoid m => (a0 -> m) -> WrappedBifunctor p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> WrappedBifunctor p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> WrappedBifunctor p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> WrappedBifunctor p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> WrappedBifunctor p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> WrappedBifunctor p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> WrappedBifunctor p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> WrappedBifunctor p a a0 -> a0 # toList :: WrappedBifunctor p a a0 -> [a0] # null :: WrappedBifunctor p a a0 -> Bool # length :: WrappedBifunctor p a a0 -> Int # elem :: Eq a0 => a0 -> WrappedBifunctor p a a0 -> Bool # maximum :: Ord a0 => WrappedBifunctor p a a0 -> a0 # minimum :: Ord a0 => WrappedBifunctor p a a0 -> a0 # sum :: Num a0 => WrappedBifunctor p a a0 -> a0 # product :: Num a0 => WrappedBifunctor p a a0 -> a0 # | |
| (Foldable f, Foldable g) => Foldable (f :.: g) | Since: base-4.9.0.0 |
Defined in GHC.Internal.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 GHC.Internal.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 # | |
| (Foldable (f a), Foldable (g a)) => Foldable (Product f g a) | |
Defined in Data.Bifunctor.Product Methods fold :: Monoid m => Product f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Product f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Product f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Product f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Product f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Product f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Product f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Product f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Product f g a a0 -> a0 # toList :: Product f g a a0 -> [a0] # null :: Product f g a a0 -> Bool # length :: Product f g a a0 -> Int # elem :: Eq a0 => a0 -> Product f g a a0 -> Bool # maximum :: Ord a0 => Product f g a a0 -> a0 # minimum :: Ord a0 => Product f g 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 # | |
map :: (a -> b) -> [a] -> [b] #
\(\mathcal{O}(n)\). map f xs is the list obtained by applying f to
each element of xs, i.e.,
map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn] map f [x1, x2, ...] == [f x1, f x2, ...]
this means that map id == id
Examples
>>>map (+1) [1, 2, 3][2,3,4]
>>>map id [1, 2, 3][1,2,3]
>>>map (\n -> 3 * n + 1) [1, 2, 3][4,7,10]
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 List, 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
An alternative name for this function is 'bind', but some people may refer to it as 'flatMap', which results from it being equivialent to
\x f ->join(fmapf x) :: Monad m => m a -> (a -> m b) -> m b
which can be seen as mapping a value with
Monad m => m a -> m (m b) and then 'flattening' m (m b) to m b using join.
(>>) :: 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
or in terms of (>>=)
as >>= const bs
Inject a value into the monadic type.
This function should not be different from its default implementation
as pure. The justification for the existence of this function is
merely historic.
Instances
| Monad IResult | |
| Monad Parser | |
| Monad Result | |
| Monad Complex | Since: base-4.9.0.0 |
| 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 Seq | |
| Monad Tree | |
| Monad DNonEmpty | |
| Monad DList | |
| 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 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 Id | |
| Monad Vector | |
| Monad Maybe | Since: base-2.1 |
| Monad Solo | Since: base-4.15 |
| Monad [] | Since: base-2.1 |
| 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 # | |
| Monad (SetM s) | |
| ArrowApply a => Monad (ArrowMonad a) | Since: base-2.1 |
Defined in GHC.Internal.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 (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monad m => Monad (LoggingT m) | |
| Monad m => Monad (NoLoggingT m) | |
Defined in Control.Monad.Logger Methods (>>=) :: NoLoggingT m a -> (a -> NoLoggingT m b) -> NoLoggingT m b # (>>) :: NoLoggingT m a -> NoLoggingT m b -> NoLoggingT m b # return :: a -> NoLoggingT m a # | |
| Monad m => Monad (WriterLoggingT m) | |
Defined in Control.Monad.Logger Methods (>>=) :: WriterLoggingT m a -> (a -> WriterLoggingT m b) -> WriterLoggingT m b # (>>) :: WriterLoggingT m a -> WriterLoggingT m b -> WriterLoggingT m b # return :: a -> WriterLoggingT m a # | |
| Monad m => Monad (ResourceT m) | |
| Semigroup a => Monad (These a) | |
| Monad (IParser t) | |
| Semigroup a => Monad (These a) | |
| Monoid a => Monad ((,) a) | 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 (Kleisli m a) | Since: base-4.14.0.0 |
| Monad f => Monad (Rec1 f) | Since: base-4.9.0.0 |
| Monad (t m) => Monad (LiftingAccum t m) | Since: mtl-2.3 |
Defined in Control.Monad.Accum Methods (>>=) :: LiftingAccum t m a -> (a -> LiftingAccum t m b) -> LiftingAccum t m b # (>>) :: LiftingAccum t m a -> LiftingAccum t m b -> LiftingAccum t m b # return :: a -> LiftingAccum t m a # | |
| Monad (t m) => Monad (LiftingSelect t m) | Since: mtl-2.3 |
Defined in Control.Monad.Select Methods (>>=) :: LiftingSelect t m a -> (a -> LiftingSelect t m b) -> LiftingSelect t m b # (>>) :: LiftingSelect t m a -> LiftingSelect t m b -> LiftingSelect t m b # return :: a -> LiftingSelect t m a # | |
| Monad m => Monad (ReaderT r 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 (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 # | |
| (Monad f, Monad g) => Monad (f :*: g) | Since: base-4.9.0.0 |
| (Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c) | Since: base-4.14.0.0 |
| Monad ((->) r) | Since: base-2.1 |
| (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 f => Monad (M1 i c f) | Since: base-4.9.0.0 |
| 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.
See these articles by School of Haskell or
David Luposchainsky
for an explanation.
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
Examples
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 KeyMap | |
| Functor IResult | |
| Functor Parser | |
| Functor Result | |
| Functor Complex | Since: base-4.9.0.0 |
| 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 ArgDescr | Since: base-4.7.0.0 |
| Functor ArgOrder | Since: base-4.7.0.0 |
| Functor OptDescr | Since: base-4.7.0.0 |
| Functor Flush | |
| Functor SCC | Since: containers-0.5.4 |
| Functor IntMap | |
| Functor Digit | |
| Functor Elem | |
| Functor FingerTree | |
Defined in Data.Sequence.Internal Methods fmap :: (a -> b) -> FingerTree a -> FingerTree b # (<$) :: a -> FingerTree b -> FingerTree a # | |
| Functor Node | |
| Functor Seq | |
| Functor ViewL | |
| Functor ViewR | |
| Functor Tree | |
| Functor View | |
| Functor DNonEmpty | |
| Functor DList | |
| Functor NonEmpty | Since: base-4.9.0.0 |
| Functor STM | Since: base-4.3.0.0 |
| Functor Par1 | Since: base-4.9.0.0 |
| Functor P | Since: base-4.8.0.0 |
Defined in GHC.Internal.Text.ParserCombinators.ReadP | |
| Functor ReadP | Since: base-2.1 |
| Functor IO | Since: base-2.1 |
| Functor Array | |
| Functor SmallArray | |
Defined in Data.Primitive.SmallArray Methods fmap :: (a -> b) -> SmallArray a -> SmallArray b # (<$) :: a -> SmallArray b -> SmallArray a # | |
| Functor Maybe | |
| Functor Q | |
| Functor TyVarBndr | |
| Functor Flat | |
| Functor FlatApp | |
| Functor Vector | |
| Functor Id | |
Defined in Data.Vector.Fusion.Util | |
| Functor Vector | |
Defined in Data.Vector.Strict | |
| Functor Maybe | Since: base-2.1 |
| Functor Solo | Since: base-4.15 |
| Functor [] | Since: base-2.1 |
Defined in GHC.Internal.Base | |
| Monad m => Functor (WrappedMonad m) | Since: base-2.1 |
Defined in Control.Applicative Methods fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b # (<$) :: a -> WrappedMonad m b -> WrappedMonad m a # | |
| Functor (Arg a) | Since: base-4.9.0.0 |
| Monad m => Functor (ZipSource m) | |
| Functor (SetM s) | |
Defined in Data.Graph | |
| Functor (Map k) | |
| Arrow a => Functor (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in GHC.Internal.Control.Arrow Methods fmap :: (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # (<$) :: a0 -> ArrowMonad a b -> ArrowMonad a a0 # | |
| Functor (Either a) | Since: base-3.0 |
| Functor (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (V1 :: Type -> Type) | Since: base-4.9.0.0 |
| Functor m => Functor (LoggingT m) | |
| Functor m => Functor (NoLoggingT m) | |
Defined in Control.Monad.Logger Methods fmap :: (a -> b) -> NoLoggingT m a -> NoLoggingT m b # (<$) :: a -> NoLoggingT m b -> NoLoggingT m a # | |
| Functor m => Functor (WriterLoggingT m) | |
Defined in Control.Monad.Logger Methods fmap :: (a -> b) -> WriterLoggingT m a -> WriterLoggingT m b # (<$) :: a -> WriterLoggingT m b -> WriterLoggingT m a # | |
| Functor m => Functor (ResourceT m) | |
| Functor f => Functor (MaybeApply f) | |
Defined in Data.Functor.Bind.Class Methods fmap :: (a -> b) -> MaybeApply f a -> MaybeApply f b # (<$) :: a -> MaybeApply f b -> MaybeApply f a # | |
| Functor f => Functor (WrappedApplicative f) | |
Defined in Data.Functor.Bind.Class Methods fmap :: (a -> b) -> WrappedApplicative f a -> WrappedApplicative f b # (<$) :: a -> WrappedApplicative f b -> WrappedApplicative f a # | |
| Functor f => Functor (Act f) | |
Defined in Data.Semigroup.Bifoldable | |
| Functor f => Functor (Act f) | |
Defined in Data.Semigroup.Foldable | |
| Functor (Either a) | |
| Functor (These a) | |
| Functor (Pair e) | |
| Functor (IParser t) | |
| Functor (These a) | |
| Functor f => Functor (Lift f) | |
| 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 # (<$) :: a -> Concurrently m b -> Concurrently m a # | |
| Functor (HashMap k) | |
| Functor ((,) a) | Since: base-2.1 |
Defined in GHC.Internal.Base | |
| Arrow a => Functor (WrappedArrow a b) | Since: base-2.1 |
Defined in Control.Applicative Methods fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # (<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
| Bifunctor p => Functor (Join p) | |
| 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 # (<$) :: a -> WhenMissing f x b -> WhenMissing f x a # | |
| Functor m => Functor (Kleisli m a) | Since: base-4.14.0.0 |
| (Generic1 f, Functor (Rep1 f)) => Functor (Generically1 f) | Since: base-4.17.0.0 |
Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> Generically1 f a -> Generically1 f b # (<$) :: a -> Generically1 f b -> Generically1 f a # | |
| 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 |
| Functor (t m) => Functor (LiftingAccum t m) | Since: mtl-2.3 |
Defined in Control.Monad.Accum Methods fmap :: (a -> b) -> LiftingAccum t m a -> LiftingAccum t m b # (<$) :: a -> LiftingAccum t m b -> LiftingAccum t m a # | |
| Functor (t m) => Functor (LiftingSelect t m) | Since: mtl-2.3 |
Defined in Control.Monad.Select Methods fmap :: (a -> b) -> LiftingSelect t m a -> LiftingSelect t m b # (<$) :: a -> LiftingSelect t m b -> LiftingSelect t m a # | |
| Functor f => Functor (Static f a) | |
| (Functor f, Functor g) => Functor (These1 f g) | |
| Functor m => Functor (ReaderT r m) | |
| Monad m => Functor (Bundle m v) | |
Defined in Data.Vector.Fusion.Bundle.Monadic | |
| Functor ((,,) a b) | Since: base-4.14.0.0 |
Defined in GHC.Internal.Base | |
| (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 (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 # (<$) :: a -> WhenMissing f k x b -> WhenMissing f k x a # | |
| (Functor f, Functor g) => Functor (f :*: g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :+: g) | Since: base-4.9.0.0 |
| Functor (K1 i c :: Type -> Type) | Since: base-4.9.0.0 |
| Functor ((,,,) a b c) | Since: base-4.14.0.0 |
Defined in GHC.Internal.Base | |
| Functor ((->) r) | Since: base-2.1 |
Defined in GHC.Internal.Base | |
| (Functor f, Functor g) => Functor (Compose f g) | Since: base-4.9.0.0 |
| Functor (Clown f a :: Type -> Type) | |
| Bifunctor p => Functor (Flip p a) | |
| Functor g => Functor (Joker g a) | |
| Bifunctor p => Functor (WrappedBifunctor p a) | |
Defined in Data.Bifunctor.Wrapped Methods fmap :: (a0 -> b) -> WrappedBifunctor p a a0 -> WrappedBifunctor p a b # (<$) :: a0 -> WrappedBifunctor p a b -> WrappedBifunctor p a a0 # | |
| 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 # (<$) :: a -> WhenMatched f k x y b -> WhenMatched f k x y a # | |
| (Functor f, Functor g) => Functor (f :.: g) | Since: base-4.9.0.0 |
| Functor f => Functor (M1 i c f) | Since: base-4.9.0.0 |
| Functor ((,,,,) a b c d) | Since: base-4.18.0.0 |
Defined in GHC.Internal.Base | |
| (Functor (f a), Functor (g a)) => Functor (Product f g a) | |
| Monad m => Functor (Pipe l i o u m) | |
| Functor ((,,,,,) a b c d e) | Since: base-4.18.0.0 |
Defined in GHC.Internal.Base | |
| (Functor f, Bifunctor p) => Functor (Tannen f p a) | |
| Functor ((,,,,,,) a b c d e f) | Since: base-4.18.0.0 |
Defined in GHC.Internal.Base | |
| (Bifunctor p, Functor g) => Functor (Biff p f g a) | |
class Functor f => Applicative (f :: Type -> Type) where #
A functor with application, providing operations to
A minimal complete definition must include implementations of pure
and of either <*> or liftA2. If it defines both, then they must behave
the same as their default definitions:
(<*>) =liftA2id
liftA2f x y = f<$>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($y)<*>u
The other methods have the following default definitions, which may be overridden with equivalent specialized implementations:
As a consequence of these laws, the Functor instance for f will satisfy
It may be useful to note that supposing
forall x y. p (q x y) = f x . g y
it follows from the above that
liftA2p (liftA2q u v) =liftA2f u .liftA2g v
If f is also a Monad, it should satisfy
(which implies that pure and <*> satisfy the applicative functor laws).
Methods
Lift a value into the Structure.
Examples
>>>pure 1 :: Maybe IntJust 1
>>>pure 'z' :: [Char]"z"
>>>pure (pure ":D") :: Maybe [String]Just [":D"]
(<*>) :: f (a -> b) -> f a -> f b infixl 4 #
Sequential application.
A few functors support an implementation of <*> that is more
efficient than the default one.
Example
Used in combination with (<$>)(<*>)
>>>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
(*>) :: 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 GHC.Internal.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 Complex | Since: base-4.9.0.0 |
| 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 Seq | Since: containers-0.5.4 |
| Applicative Tree | |
| Applicative DNonEmpty | |
Defined in Data.DList.DNonEmpty.Internal | |
| Applicative DList | |
| 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 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 Id | |
| Applicative Vector | |
| Applicative Maybe | Since: base-2.1 |
| Applicative Solo | Since: base-4.15 |
| Applicative [] | Since: base-2.1 |
| 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 # | |
| Monad m => Applicative (ZipSource m) | |
Defined in Data.Conduit.Internal.Conduit | |
| Applicative (SetM s) | |
| Arrow a => Applicative (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in GHC.Internal.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 (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Applicative m => Applicative (LoggingT m) | |
Defined in Control.Monad.Logger | |
| Applicative m => Applicative (NoLoggingT m) | |
Defined in Control.Monad.Logger Methods pure :: a -> NoLoggingT m a # (<*>) :: NoLoggingT m (a -> b) -> NoLoggingT m a -> NoLoggingT m b # liftA2 :: (a -> b -> c) -> NoLoggingT m a -> NoLoggingT m b -> NoLoggingT m c # (*>) :: NoLoggingT m a -> NoLoggingT m b -> NoLoggingT m b # (<*) :: NoLoggingT m a -> NoLoggingT m b -> NoLoggingT m a # | |
| Applicative m => Applicative (WriterLoggingT m) | |
Defined in Control.Monad.Logger Methods pure :: a -> WriterLoggingT m a # (<*>) :: WriterLoggingT m (a -> b) -> WriterLoggingT m a -> WriterLoggingT m b # liftA2 :: (a -> b -> c) -> WriterLoggingT m a -> WriterLoggingT m b -> WriterLoggingT m c # (*>) :: WriterLoggingT m a -> WriterLoggingT m b -> WriterLoggingT m b # (<*) :: WriterLoggingT m a -> WriterLoggingT m b -> WriterLoggingT m a # | |
| Applicative m => Applicative (ResourceT m) | |
Defined in Control.Monad.Trans.Resource.Internal | |
| Apply f => Applicative (MaybeApply f) | |
Defined in Data.Functor.Bind.Class Methods pure :: a -> MaybeApply f a # (<*>) :: MaybeApply f (a -> b) -> MaybeApply f a -> MaybeApply f b # liftA2 :: (a -> b -> c) -> MaybeApply f a -> MaybeApply f b -> MaybeApply f c # (*>) :: MaybeApply f a -> MaybeApply f b -> MaybeApply f b # (<*) :: MaybeApply f a -> MaybeApply f b -> MaybeApply f a # | |
| Applicative f => Applicative (WrappedApplicative f) | |
Defined in Data.Functor.Bind.Class Methods pure :: a -> WrappedApplicative f a # (<*>) :: WrappedApplicative f (a -> b) -> WrappedApplicative f a -> WrappedApplicative f b # liftA2 :: (a -> b -> c) -> WrappedApplicative f a -> WrappedApplicative f b -> WrappedApplicative f c # (*>) :: WrappedApplicative f a -> WrappedApplicative f b -> WrappedApplicative f b # (<*) :: WrappedApplicative f a -> WrappedApplicative f b -> WrappedApplicative f a # | |
| Semigroup a => Applicative (These a) | |
| Applicative (IParser t) | |
| Semigroup a => Applicative (These a) | |
| Applicative f => Applicative (Lift f) | A combination is |
| 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 # | |
| Biapplicative p => Applicative (Join p) | |
| 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 m => Applicative (Kleisli m a) | Since: base-4.14.0.0 |
Defined in GHC.Internal.Control.Arrow | |
| (Generic1 f, Applicative (Rep1 f)) => Applicative (Generically1 f) | Since: base-4.17.0.0 |
Defined in GHC.Internal.Generics Methods pure :: a -> Generically1 f a # (<*>) :: Generically1 f (a -> b) -> Generically1 f a -> Generically1 f b # liftA2 :: (a -> b -> c) -> Generically1 f a -> Generically1 f b -> Generically1 f c # (*>) :: Generically1 f a -> Generically1 f b -> Generically1 f b # (<*) :: Generically1 f a -> Generically1 f b -> Generically1 f a # | |
| Applicative f => Applicative (Rec1 f) | Since: base-4.9.0.0 |
| Applicative (t m) => Applicative (LiftingAccum t m) | Since: mtl-2.3 |
Defined in Control.Monad.Accum Methods pure :: a -> LiftingAccum t m a # (<*>) :: LiftingAccum t m (a -> b) -> LiftingAccum t m a -> LiftingAccum t m b # liftA2 :: (a -> b -> c) -> LiftingAccum t m a -> LiftingAccum t m b -> LiftingAccum t m c # (*>) :: LiftingAccum t m a -> LiftingAccum t m b -> LiftingAccum t m b # (<*) :: LiftingAccum t m a -> LiftingAccum t m b -> LiftingAccum t m a # | |
| Applicative (t m) => Applicative (LiftingSelect t m) | Since: mtl-2.3 |
Defined in Control.Monad.Select Methods pure :: a -> LiftingSelect t m a # (<*>) :: LiftingSelect t m (a -> b) -> LiftingSelect t m a -> LiftingSelect t m b # liftA2 :: (a -> b -> c) -> LiftingSelect t m a -> LiftingSelect t m b -> LiftingSelect t m c # (*>) :: LiftingSelect t m a -> LiftingSelect t m b -> LiftingSelect t m b # (<*) :: LiftingSelect t m a -> LiftingSelect t m b -> LiftingSelect t m a # | |
| Applicative f => Applicative (Static f a) | |
Defined in Data.Semigroupoid.Static | |
| Applicative m => Applicative (ReaderT r m) | |
Defined in Control.Monad.Trans.Reader | |
| (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 (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 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 |
| (Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c) | Since: base-4.14.0.0 |
Defined in GHC.Internal.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 | |
| (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 # | |
| (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 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 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
You can alternatively define mconcat instead of mempty, in which case the
laws are:
- Unit
mconcat(purex) = x- Multiplication
mconcat(joinxss) =mconcat(fmapmconcatxss)- Subclass
mconcat(toListxs) =sconcatxs
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.
Methods
Identity of mappend
Examples
>>>"Hello world" <> mempty"Hello world"
>>>mempty <> [1, 2, 3][1,2,3]
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 ByteArray | Since: base-4.17.0.0 |
| Monoid ByteString | |
Defined in Data.ByteString.Internal.Type Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid IntSet | |
| Monoid Ordering | Since: base-2.1 |
| Monoid Builder | |
| Monoid StrictTextBuilder | |
Defined in Data.Text.Internal.StrictBuilder Methods mappend :: StrictTextBuilder -> StrictTextBuilder -> StrictTextBuilder # mconcat :: [StrictTextBuilder] -> StrictTextBuilder # | |
| Monoid ShortText | |
| Monoid () | Since: base-2.1 |
| Monoid (KeyMap v) | |
| Monoid (IResult a) | |
| Monoid (Parser a) | |
| Monoid (Result a) | |
| Monoid (Comparison a) |
mempty :: Comparison a mempty = Comparison _ _ -> EQ |
Defined in Data.Functor.Contravariant Methods mempty :: Comparison a # mappend :: Comparison a -> Comparison a -> Comparison a # mconcat :: [Comparison a] -> Comparison a # | |
| Monoid (Equivalence a) |
mempty :: Equivalence a mempty = Equivalence _ _ -> True |
Defined in Data.Functor.Contravariant Methods mempty :: Equivalence a # mappend :: Equivalence a -> Equivalence a -> Equivalence a # mconcat :: [Equivalence a] -> Equivalence a # | |
| Monoid (Predicate a) |
mempty :: Predicate a mempty = _ -> True |
| (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 |
| 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 (IntMap a) | |
| Monoid (Seq a) | |
| Monoid (MergeSet a) | |
| Ord a => Monoid (Set a) | |
| Monoid (DList a) | |
| Monoid a => Monoid (STM a) | Since: base-4.17.0.0 |
| (Generic a, Monoid (Rep a ())) => Monoid (Generically a) | Since: base-4.17.0.0 |
Defined in GHC.Internal.Generics Methods mempty :: Generically a # mappend :: Generically a -> Generically a -> Generically a # mconcat :: [Generically a] -> Generically a # | |
| Monoid p => Monoid (Par1 p) | Since: base-4.12.0.0 |
| Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
| 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 |
| Monoid (Validity k) | |
| (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) | |
| 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 (Solo a) | Since: base-4.15 |
| Monoid [a] | Since: base-2.1 |
| Monoid a => Monoid (Op a b) |
mempty :: Op a b mempty = Op _ -> mempty |
| Ord k => Monoid (Map k v) | |
| Monoid (U1 p) | Since: base-4.12.0.0 |
| (Applicative m, Monoid a) => Monoid (LoggingT m a) | |
| (Applicative m, Monoid a) => Monoid (NoLoggingT m a) | |
Defined in Control.Monad.Logger Methods mempty :: NoLoggingT m a # mappend :: NoLoggingT m a -> NoLoggingT m a -> NoLoggingT m a # mconcat :: [NoLoggingT m a] -> NoLoggingT m a # | |
| (Applicative m, Monoid a) => Monoid (WriterLoggingT m a) | |
Defined in Control.Monad.Logger Methods mempty :: WriterLoggingT m a # mappend :: WriterLoggingT m a -> WriterLoggingT m a -> WriterLoggingT m a # mconcat :: [WriterLoggingT m a] -> WriterLoggingT m 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 a, Monoid b) => Monoid (a, b) | Since: base-2.1 |
| Monoid b => Monoid (a -> b) | Since: base-2.1 |
| Monoid (f p) => Monoid (Rec1 f p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b, Monoid c) => Monoid (a, b, c) | Since: base-2.1 |
| (Monoid (f a), Monoid (g a)) => Monoid (Product f g a) | Since: base-4.16.0.0 |
| Monad m => Monoid (ConduitT i o m ()) | |
| (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 |
| (Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d) | Since: base-2.1 |
| Monoid (f (g a)) => Monoid (Compose f g a) | Since: base-4.16.0.0 |
| 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 ()) | |
The class of semigroups (types with an associative binary operation).
Instances should satisfy the following:
You can alternatively define sconcat instead of (<>), in which case the
laws are:
Since: base-4.9.0.0
Methods
(<>) :: a -> a -> a infixr 6 #
An associative operation.
Examples
>>>[1,2,3] <> [4,5,6][1,2,3,4,5,6]
>>>Just [1, 2, 3] <> Just [4, 5, 6]Just [1,2,3,4,5,6]
>>>putStr "Hello, " <> putStrLn "World!"Hello, World!
Instances
| Semigroup ByteArray | Since: base-4.17.0.0 |
| Semigroup ByteString | |
Defined in Data.ByteString.Internal.Type Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString # | |
| Semigroup IntSet | Since: containers-0.5.7 |
| Semigroup Void | Since: base-4.9.0.0 |
| Semigroup Ordering | Since: base-4.9.0.0 |
| Semigroup SeriesElem | Since: monad-logger-aeson-0.3.1.0 |
Defined in Control.Monad.Logger.Aeson.Internal Methods (<>) :: SeriesElem -> SeriesElem -> SeriesElem # sconcat :: NonEmpty SeriesElem -> SeriesElem # stimes :: Integral b => b -> SeriesElem -> SeriesElem # | |
| Semigroup Builder | |
| Semigroup StrictTextBuilder | Concatenation of |
Defined in Data.Text.Internal.StrictBuilder Methods (<>) :: StrictTextBuilder -> StrictTextBuilder -> StrictTextBuilder # sconcat :: NonEmpty StrictTextBuilder -> StrictTextBuilder # stimes :: Integral b => b -> StrictTextBuilder -> StrictTextBuilder # | |
| Semigroup ShortText | |
| Semigroup () | Since: base-4.9.0.0 |
| Semigroup (KeyMap v) | |
| Semigroup (IResult a) | |
| Semigroup (Parser a) | |
| Semigroup (Result a) | |
| Semigroup (FromMaybe b) | |
| Semigroup a => Semigroup (JoinWith a) | |
| Semigroup (NonEmptyDList a) | |
| Semigroup (Comparison a) |
(<>) :: Comparison a -> Comparison a -> Comparison a Comparison cmp <> Comparison cmp' = Comparison a a' -> cmp a a' <> cmp a a' |
Defined in Data.Functor.Contravariant Methods (<>) :: Comparison a -> Comparison a -> Comparison a # sconcat :: NonEmpty (Comparison a) -> Comparison a # stimes :: Integral b => b -> Comparison a -> Comparison a # | |
| Semigroup (Equivalence a) |
(<>) :: Equivalence a -> Equivalence a -> Equivalence a Equivalence equiv <> Equivalence equiv' = Equivalence a b -> equiv a b && equiv' a b |
Defined in Data.Functor.Contravariant Methods (<>) :: Equivalence a -> Equivalence a -> Equivalence a # sconcat :: NonEmpty (Equivalence a) -> Equivalence a # stimes :: Integral b => b -> Equivalence a -> Equivalence a # | |
| Semigroup (Predicate a) |
(<>) :: Predicate a -> Predicate a -> Predicate a Predicate pred <> Predicate pred' = Predicate a -> pred a && pred' a |
| 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 |
| 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 (IntMap a) | Since: containers-0.5.7 |
| Semigroup (Seq a) | Since: containers-0.5.7 |
| Ord a => Semigroup (Intersection a) | |
Defined in Data.Set.Internal Methods (<>) :: Intersection a -> Intersection a -> Intersection a # sconcat :: NonEmpty (Intersection a) -> Intersection a # stimes :: Integral b => b -> Intersection a -> Intersection a # | |
| Semigroup (MergeSet a) | |
| Ord a => Semigroup (Set a) | Since: containers-0.5.7 |
| Semigroup (DNonEmpty a) | |
| Semigroup (DList a) | |
| Semigroup (NonEmpty a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (STM a) | Since: base-4.17.0.0 |
| (Generic a, Semigroup (Rep a ())) => Semigroup (Generically a) | Since: base-4.17.0.0 |
Defined in GHC.Internal.Generics Methods (<>) :: Generically a -> Generically a -> Generically a # sconcat :: NonEmpty (Generically a) -> Generically a # stimes :: Integral b => b -> Generically a -> Generically a # | |
| Semigroup p => Semigroup (Par1 p) | Since: base-4.12.0.0 |
| Semigroup a => Semigroup (IO a) | Since: base-4.10.0.0 |
| 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 (JoinWith a) | |
| Semigroup a => Semigroup (Maybe a) | |
| Semigroup a => Semigroup (Q a) | Since: template-haskell-2.17.0.0 |
| Semigroup (Validity k) | |
| (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 (Vector a) | |
| Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Solo a) | Since: base-4.15 |
| Semigroup [a] | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Op a b) |
(<>) :: Op a b -> Op a b -> Op a b Op f <> Op g = Op a -> f a <> g a |
| Ord k => Semigroup (Map k v) | |
| Semigroup (Either a b) | Since: base-4.9.0.0 |
| Semigroup (U1 p) | Since: base-4.12.0.0 |
| Semigroup (V1 p) | Since: base-4.12.0.0 |
| (Applicative m, Semigroup a) => Semigroup (LoggingT m a) | |
| (Applicative m, Semigroup a) => Semigroup (NoLoggingT m a) | |
Defined in Control.Monad.Logger Methods (<>) :: NoLoggingT m a -> NoLoggingT m a -> NoLoggingT m a # sconcat :: NonEmpty (NoLoggingT m a) -> NoLoggingT m a # stimes :: Integral b => b -> NoLoggingT m a -> NoLoggingT m a # | |
| (Applicative m, Semigroup a) => Semigroup (WriterLoggingT m a) | |
Defined in Control.Monad.Logger Methods (<>) :: WriterLoggingT m a -> WriterLoggingT m a -> WriterLoggingT m a # sconcat :: NonEmpty (WriterLoggingT m a) -> WriterLoggingT m a # stimes :: Integral b => b -> WriterLoggingT m a -> WriterLoggingT m a # | |
| Apply f => Semigroup (Act f a) | |
| Apply f => Semigroup (Act f a) | |
| Alt f => Semigroup (Alt_ f 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 a, Semigroup b) => Semigroup (a, b) | Since: base-4.9.0.0 |
| Semigroup b => Semigroup (a -> b) | Since: base-4.9.0.0 |
| Semigroup (f p) => Semigroup (Rec1 f p) | Since: base-4.12.0.0 |
| (Semigroup a, Semigroup b, Semigroup c) => Semigroup (a, b, c) | Since: base-4.9.0.0 |
| (Semigroup (f a), Semigroup (g a)) => Semigroup (Product f g a) | Since: base-4.16.0.0 |
| Monad m => Semigroup (ConduitT i o m ()) | |
| (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 |
| (Semigroup a, Semigroup b, Semigroup c, Semigroup d) => Semigroup (a, b, c, d) | Since: base-4.9.0.0 |
| Semigroup (f (g a)) => Semigroup (Compose f g a) | Since: base-4.16.0.0 |
| 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 (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
| Traversable KeyMap | |
| Traversable IResult | |
| Traversable Result | |
| Traversable Complex | Since: base-4.9.0.0 |
| Traversable First | Since: base-4.9.0.0 |
| Traversable Last | Since: base-4.9.0.0 |
| Traversable Max | Since: base-4.9.0.0 |
| Traversable Min | Since: base-4.9.0.0 |
| Traversable SCC | Since: containers-0.5.9 |
| Traversable IntMap | Traverses in order of increasing key. |
| Traversable Digit | |
| Traversable Elem | |
| Traversable FingerTree | |
Defined in Data.Sequence.Internal Methods traverse :: Applicative f => (a -> f b) -> FingerTree a -> f (FingerTree b) # sequenceA :: Applicative f => FingerTree (f a) -> f (FingerTree a) # mapM :: Monad m => (a -> m b) -> FingerTree a -> m (FingerTree b) # sequence :: Monad m => FingerTree (m a) -> m (FingerTree a) # | |
| Traversable Node | |
| Traversable Seq | |
| Traversable ViewL | |
| Traversable ViewR | |
| Traversable Tree | |
| Traversable DList | |
| Traversable NonEmpty | Since: base-4.9.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| Traversable Identity | Since: base-4.9.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| Traversable First | Since: base-4.8.0.0 |
| Traversable Last | Since: base-4.8.0.0 |
| Traversable Down | Since: base-4.12.0.0 |
| Traversable Dual | Since: base-4.8.0.0 |
| Traversable Product | Since: base-4.8.0.0 |
| Traversable Sum | Since: base-4.8.0.0 |
| Traversable Par1 | Since: base-4.9.0.0 |
| Traversable Array | |
| Traversable SmallArray | |
Defined in Data.Primitive.SmallArray Methods traverse :: Applicative f => (a -> f b) -> SmallArray a -> f (SmallArray b) # sequenceA :: Applicative f => SmallArray (f a) -> f (SmallArray a) # mapM :: Monad m => (a -> m b) -> SmallArray a -> m (SmallArray b) # sequence :: Monad m => SmallArray (m a) -> m (SmallArray a) # | |
| Traversable Maybe | |
| Traversable TyVarBndr | |
Defined in Language.Haskell.TH.Syntax | |
| Traversable Vector | |
| Traversable Vector | |
Defined in Data.Vector.Strict | |
| Traversable Maybe | Since: base-2.1 |
| Traversable Solo | Since: base-4.15 |
| Traversable [] | Since: base-2.1 |
Defined in GHC.Internal.Data.Traversable | |
| Traversable (Arg a) | Since: base-4.9.0.0 |
| Traversable (Map k) | Traverses in order of increasing key. |
| Ix i => Traversable (Array i) | Since: base-2.1 |
| Traversable (Either a) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| Traversable (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Traversable (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (UAddr :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (UChar :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (UDouble :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (UFloat :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (UInt :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (UWord :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (V1 :: Type -> Type) | Since: base-4.9.0.0 |
| Traversable (Either e) | |
| Traversable (These a) | |
| Traversable (Pair e) | |
| Traversable (These a) | |
| Traversable f => Traversable (Lift f) | |
| Traversable (HashMap k) | |
Defined in Data.HashMap.Internal | |
| Traversable ((,) a) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| Bitraversable p => Traversable (Join p) | |
| Traversable (Const m :: Type -> Type) | Since: base-4.7.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| Traversable f => Traversable (Ap f) | Since: base-4.12.0.0 |
| Traversable f => Traversable (Alt f) | Since: base-4.12.0.0 |
| Traversable f => Traversable (Rec1 f) | Since: base-4.9.0.0 |
| (Traversable f, Traversable g) => Traversable (These1 f g) | |
Defined in Data.Functor.These | |
| (Traversable f, Traversable g) => Traversable (Product f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product | |
| (Traversable f, Traversable g) => Traversable (Sum f g) | Since: base-4.9.0.0 |
| (Traversable f, Traversable g) => Traversable (f :*: g) | Since: base-4.9.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| (Traversable f, Traversable g) => Traversable (f :+: g) | Since: base-4.9.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| Traversable (K1 i c :: Type -> Type) | 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 | |
| Traversable (Clown f a :: Type -> Type) | |
Defined in Data.Bifunctor.Clown | |
| Bitraversable p => Traversable (Flip p a) | |
Defined in Data.Bifunctor.Flip | |
| Traversable g => Traversable (Joker g a) | |
Defined in Data.Bifunctor.Joker | |
| Bitraversable p => Traversable (WrappedBifunctor p a) | |
Defined in Data.Bifunctor.Wrapped Methods traverse :: Applicative f => (a0 -> f b) -> WrappedBifunctor p a a0 -> f (WrappedBifunctor p a b) # sequenceA :: Applicative f => WrappedBifunctor p a (f a0) -> f (WrappedBifunctor p a a0) # mapM :: Monad m => (a0 -> m b) -> WrappedBifunctor p a a0 -> m (WrappedBifunctor p a b) # sequence :: Monad m => WrappedBifunctor p a (m a0) -> m (WrappedBifunctor p a a0) # | |
| (Traversable f, Traversable g) => Traversable (f :.: g) | Since: base-4.9.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| Traversable f => Traversable (M1 i c f) | Since: base-4.9.0.0 |
Defined in GHC.Internal.Data.Traversable | |
| (Traversable (f a), Traversable (g a)) => Traversable (Product f g a) | |
Defined in Data.Bifunctor.Product Methods traverse :: Applicative f0 => (a0 -> f0 b) -> Product f g a a0 -> f0 (Product f g a b) # sequenceA :: Applicative f0 => Product f g a (f0 a0) -> f0 (Product f g a a0) # mapM :: Monad m => (a0 -> m b) -> Product f g a a0 -> m (Product f g a b) # sequence :: Monad m => Product f g a (m a0) -> m (Product f g a a0) # | |
| (Traversable f, Bitraversable p) => Traversable (Tannen f p a) | |
Defined in Data.Bifunctor.Tannen Methods traverse :: Applicative f0 => (a0 -> f0 b) -> Tannen f p a a0 -> f0 (Tannen f p a b) # sequenceA :: Applicative f0 => Tannen f p a (f0 a0) -> f0 (Tannen f p a a0) # mapM :: Monad m => (a0 -> m b) -> Tannen f p a a0 -> m (Tannen f p a b) # sequence :: Monad m => Tannen f p a (m a0) -> m (Tannen f p a a0) # | |
| (Bitraversable p, Traversable g) => Traversable (Biff p f g a) | |
Defined in Data.Bifunctor.Biff Methods traverse :: Applicative f0 => (a0 -> f0 b) -> Biff p f g a a0 -> f0 (Biff p f g a b) # sequenceA :: Applicative f0 => Biff p f g a (f0 a0) -> f0 (Biff p f g a a0) # mapM :: Monad m => (a0 -> m b) -> Biff p f g a a0 -> m (Biff p f g a b) # sequence :: Monad m => Biff p f g a (m a0) -> m (Biff p f g a a0) # | |
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]
Examples
>>>filter odd [1, 2, 3][1,3]
>>>filter (\l -> length l > 3) ["Hello", ", ", "World", "!"]["Hello","World"]
>>>filter (/= 3) [1, 2, 3, 4, 3, 2, 1][1,2,4,2,1]
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
| Bifoldable Either | Since: base-4.10.0.0 | ||||
| Bifoldable1 Either | |||||
Defined in Data.Bifoldable1 | |||||
| Bifunctor Either | Since: base-4.8.0.0 | ||||
| Bitraversable Either | Since: base-4.10.0.0 | ||||
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) # | |||||
| Eq2 Either | Since: base-4.9.0.0 | ||||
| Ord2 Either | Since: base-4.9.0.0 | ||||
Defined in Data.Functor.Classes | |||||
| Read2 Either | 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 (Either a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Either a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Either a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Either a b] # | |||||
| Show2 Either | Since: base-4.9.0.0 | ||||
| Hashable2 Either | |||||
Defined in Data.Hashable.Class | |||||
| Bitraversable1 Either | |||||
Defined in Data.Semigroup.Traversable.Class Methods bitraverse1 :: Apply f => (a -> f b) -> (c -> f d) -> Either a c -> f (Either b d) # bisequence1 :: Apply f => Either (f a) (f b) -> f (Either a b) # | |||||
| Generic1 (Either a :: Type -> Type) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| MonadError e (Either e) | |||||
Defined in Control.Monad.Error.Class | |||||
| (Lift a, Lift b) => Lift (Either a b :: Type) | |||||
| Eq a => Eq1 (Either a) | Since: base-4.9.0.0 | ||||
| Ord a => Ord1 (Either a) | Since: base-4.9.0.0 | ||||
Defined in Data.Functor.Classes | |||||
| Read a => Read1 (Either a) | Since: base-4.9.0.0 | ||||
Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Either a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Either a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Either a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Either a a0] # | |||||
| Show a => Show1 (Either a) | Since: base-4.9.0.0 | ||||
| Applicative (Either e) | Since: base-3.0 | ||||
| Functor (Either a) | Since: base-3.0 | ||||
| Monad (Either e) | Since: base-4.4.0.0 | ||||
| Foldable (Either a) | Since: base-4.7.0.0 | ||||
Defined in GHC.Internal.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 # | |||||
| Traversable (Either a) | Since: base-4.7.0.0 | ||||
Defined in GHC.Internal.Data.Traversable | |||||
| Hashable a => Hashable1 (Either a) | |||||
Defined in Data.Hashable.Class | |||||
| Alt (Either a) | |||||
| Apply (Either a) | |||||
| Bind (Either a) | |||||
| Extend (Either a) | |||||
| MonadBaseControl (Either e) (Either e) | |||||
| Semigroup (Either a b) | Since: base-4.9.0.0 | ||||
| Generic (Either a b) | |||||
Defined in GHC.Internal.Generics Associated Types
| |||||
| (Read a, Read b) => Read (Either a b) | Since: base-3.0 | ||||
| (Show a, Show b) => Show (Either a b) | Since: base-3.0 | ||||
| (Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 | ||||
| (Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 | ||||
Defined in GHC.Internal.Data.Either | |||||
| (Hashable a, Hashable b) => Hashable (Either a b) | |||||
Defined in Data.Hashable.Class | |||||
| type Rep1 (Either a :: Type -> Type) | Since: base-4.6.0.0 | ||||
Defined in GHC.Internal.Generics type Rep1 (Either a :: Type -> Type) = D1 ('MetaData "Either" "GHC.Internal.Data.Either" "ghc-internal" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1)) | |||||
| type StM (Either e) a | |||||
Defined in Control.Monad.Trans.Control | |||||
| type Rep (Either a b) | Since: base-4.6.0.0 | ||||
Defined in GHC.Internal.Generics type Rep (Either a b) = D1 ('MetaData "Either" "GHC.Internal.Data.Either" "ghc-internal" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 b))) | |||||
Identity function.
id x = x
This function might seem useless at first glance, but it can be very useful in a higher order context.
Examples
>>>length $ filter id [True, True, False, True]3
>>>Just (Just 3) >>= idJust 3
>>>foldr id 0 [(^3), (*5), (+2)]1000
(<$>) :: 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)
The value of seq a ba 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 ba 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.
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.
Laziness
>>>takeWhile (const False) undefined*** Exception: Prelude.undefined
>>>takeWhile (const False) (undefined : undefined)[]
>>>take 1 (takeWhile (const True) (1 : undefined))[1]
Examples
>>>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
It is an instance of the more general genericTake,
in which n may be of any integral type.
Laziness
>>>take 0 undefined[]>>>take 2 (1 : 2 : undefined)[1,2]
Examples
>>>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][]
const x y always evaluates to x, ignoring its second argument.
const x = \_ -> x
This function might seem useless at first glance, but it can be very useful in a higher order context.
Examples
>>>const 42 "hello"42
>>>map (const 42) [0..3][42,42,42,42]
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]
zip :: [a] -> [b] -> [(a, b)] #
\(\mathcal{O}(\min(m,n))\). zip takes two lists and returns a list of
corresponding pairs.
zip is right-lazy:
>>>zip [] undefined[]>>>zip undefined []*** Exception: Prelude.undefined ...
zip is capable of list fusion, but it is restricted to its
first list argument and its resulting list.
Examples
>>>zip [1, 2, 3] ['a', 'b', 'c'][(1,'a'),(2,'b'),(3,'c')]
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..] [][]
print :: Show a => a -> IO () #
The print function outputs a value of any printable type to the
standard output device.
Printable types are those that are instances of class Show; print
converts values to strings for output using the show operation and
adds a newline.
For example, a program to print the first 20 integers and their powers of 2 could be written as:
main = print ([(n, 2^n) | n <- [0..19]])
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)- Coherence with
toInteger - if the type also implements
Integral, thenfromIntegeris a left inverse fortoInteger, i.e.fromInteger (toInteger i) == i
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 CBool | |
| Num CChar | |
| Num CClock | |
| Num CDouble | |
| Num CFloat | |
| Num CInt | |
| Num CIntMax | |
| Num CIntPtr | |
| Num CLLong | |
| Num CLong | |
| Num CPtrdiff | |
| Num CSChar | |
| Num CSUSeconds | |
Defined in GHC.Internal.Foreign.C.Types Methods (+) :: CSUSeconds -> CSUSeconds -> CSUSeconds # (-) :: CSUSeconds -> CSUSeconds -> CSUSeconds # (*) :: CSUSeconds -> CSUSeconds -> CSUSeconds # negate :: CSUSeconds -> CSUSeconds # abs :: CSUSeconds -> CSUSeconds # signum :: CSUSeconds -> CSUSeconds # fromInteger :: Integer -> CSUSeconds # | |
| Num CShort | |
| Num CSigAtomic | |
Defined in GHC.Internal.Foreign.C.Types Methods (+) :: CSigAtomic -> CSigAtomic -> CSigAtomic # (-) :: CSigAtomic -> CSigAtomic -> CSigAtomic # (*) :: CSigAtomic -> CSigAtomic -> CSigAtomic # negate :: CSigAtomic -> CSigAtomic # abs :: CSigAtomic -> CSigAtomic # signum :: CSigAtomic -> CSigAtomic # fromInteger :: Integer -> CSigAtomic # | |
| Num CSize | |
| Num CTime | |
| Num CUChar | |
| Num CUInt | |
| Num CUIntMax | |
| Num CUIntPtr | |
| Num CULLong | |
| Num CULong | |
| Num CUSeconds | |
Defined in GHC.Internal.Foreign.C.Types | |
| Num CUShort | |
| Num CWchar | |
| 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 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 I8 | |
| Num Size | |
| Num B | |
| Num DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Num NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (+) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (-) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (*) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # negate :: NominalDiffTime -> NominalDiffTime # abs :: NominalDiffTime -> NominalDiffTime # signum :: NominalDiffTime -> NominalDiffTime # fromInteger :: Integer -> NominalDiffTime # | |
| Num Size | |
| 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 (Max a) | Since: base-4.9.0.0 |
| Num a => Num (Min a) | Since: base-4.9.0.0 |
| Integral a => Num (Ratio a) | Since: base-2.0.1 |
| HasResolution a => Num (Fixed a) | Multiplication is not associative or distributive:
Since: base-2.1 |
| Num a => Num (Op a b) | |
| Num (f (g a)) => Num (Compose f g a) | Since: base-4.19.0.0 |
Defined in Data.Functor.Compose Methods (+) :: Compose f g a -> Compose f g a -> Compose f g a # (-) :: Compose f g a -> Compose f g a -> Compose f g a # (*) :: Compose f g a -> Compose f g a -> Compose f g a # negate :: Compose f g a -> Compose f g a # abs :: Compose f g a -> Compose f g a # signum :: Compose f g a -> Compose f g a # fromInteger :: Integer -> Compose f g a # | |
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
| Floating CDouble | |
| Floating CFloat | |
| Floating Double | Since: base-2.1 |
| Floating Float | Since: base-2.1 |
| RealFloat a => Floating (Complex a) | Since: base-2.1 |
Defined in Data.Complex Methods exp :: Complex a -> Complex a # log :: Complex a -> Complex a # sqrt :: Complex a -> Complex a # (**) :: Complex a -> Complex a -> Complex a # logBase :: Complex a -> Complex a -> Complex a # sin :: Complex a -> Complex a # cos :: Complex a -> Complex a # tan :: Complex a -> Complex a # asin :: Complex a -> Complex a # acos :: Complex a -> Complex a # atan :: Complex a -> Complex a # sinh :: Complex a -> Complex a # cosh :: Complex a -> Complex a # tanh :: Complex a -> Complex a # asinh :: Complex a -> Complex a # acosh :: Complex a -> Complex a # atanh :: Complex a -> Complex a # log1p :: Complex a -> Complex a # expm1 :: Complex a -> Complex a # | |
| Floating a => Floating (Op a b) | |
| Floating (f (g a)) => Floating (Compose f g a) | Since: base-4.20.0.0 |
Defined in Data.Functor.Compose Methods exp :: Compose f g a -> Compose f g a # log :: Compose f g a -> Compose f g a # sqrt :: Compose f g a -> Compose f g a # (**) :: Compose f g a -> Compose f g a -> Compose f g a # logBase :: Compose f g a -> Compose f g a -> Compose f g a # sin :: Compose f g a -> Compose f g a # cos :: Compose f g a -> Compose f g a # tan :: Compose f g a -> Compose f g a # asin :: Compose f g a -> Compose f g a # acos :: Compose f g a -> Compose f g a # atan :: Compose f g a -> Compose f g a # sinh :: Compose f g a -> Compose f g a # cosh :: Compose f g a -> Compose f g a # tanh :: Compose f g a -> Compose f g a # asinh :: Compose f g a -> Compose f g a # acosh :: Compose f g a -> Compose f g a # atanh :: Compose f g a -> Compose f g a # log1p :: Compose f g a -> Compose f g a # expm1 :: Compose f g a -> Compose f g a # | |
class (RealFrac a, Floating a) => RealFloat a where #
Efficient, machine-independent access to the components of a floating-point number.
Minimal complete definition
floatRadix, floatDigits, floatRange, decodeFloat, encodeFloat, isNaN, isInfinite, isDenormalized, isNegativeZero, isIEEE
Methods
floatRadix :: a -> Integer #
a constant function, returning the radix of the representation
(often 2)
floatDigits :: a -> Int #
a constant function, returning the number of digits of
floatRadix in the significand
floatRange :: a -> (Int, Int) #
a constant function, returning the lowest and highest values the exponent may assume
decodeFloat :: a -> (Integer, Int) #
The function decodeFloat applied to a real floating-point
number returns the significand expressed as an Integer and an
appropriately scaled exponent (an Int). If decodeFloat x(m,n), then x is equal in value to m*b^^n, where b
is the floating-point radix, and furthermore, either m and n
are both zero or else b^(d-1) <= , where abs m < b^dd is
the value of floatDigits xdecodeFloat 0 = (0,0)decodeFloat (-0.0) = (0,0)decodeFloat xisNaN xisInfinite xTrue.
encodeFloat :: Integer -> Int -> a #
encodeFloat performs the inverse of decodeFloat in the
sense that for finite x with the exception of -0.0,
uncurry encodeFloat (decodeFloat x) = xencodeFloat m nm*b^^n (or ±Infinity if overflow
occurs); usually the closer, but if m contains too many bits,
the result may be rounded in the wrong direction.
exponent corresponds to the second component of decodeFloat.
exponent 0 = 0x,
exponent x = snd (decodeFloat x) + floatDigits xx is a finite floating-point number, it is equal in value to
significand x * b ^^ exponent xb is the
floating-point radix.
The behaviour is unspecified on infinite or NaN values.
significand :: a -> a #
The first component of decodeFloat, scaled to lie in the open
interval (-1,1), either 0.0 or of absolute value >= 1/b,
where b is the floating-point radix.
The behaviour is unspecified on infinite or NaN values.
scaleFloat :: Int -> a -> a #
multiplies a floating-point number by an integer power of the radix
True if the argument is an IEEE "not-a-number" (NaN) value
isInfinite :: a -> Bool #
True if the argument is an IEEE infinity or negative infinity
isDenormalized :: a -> Bool #
True if the argument is too small to be represented in
normalized format
isNegativeZero :: a -> Bool #
True if the argument is an IEEE negative zero
True if the argument is an IEEE floating point number
a version of arctangent taking two real floating-point arguments.
For real floating x and y, atan2 y x(x,y). atan2 y x-pi,
pi]. It follows the Common Lisp semantics for the origin when
signed zeroes are supported. atan2 y 1y in a type
that is RealFloat, should return the same value as atan yatan2 is provided, but implementors
can provide a more accurate implementation.
Instances
| RealFloat CDouble | |
Defined in GHC.Internal.Foreign.C.Types Methods floatRadix :: CDouble -> Integer # floatDigits :: CDouble -> Int # floatRange :: CDouble -> (Int, Int) # decodeFloat :: CDouble -> (Integer, Int) # encodeFloat :: Integer -> Int -> CDouble # significand :: CDouble -> CDouble # scaleFloat :: Int -> CDouble -> CDouble # isInfinite :: CDouble -> Bool # isDenormalized :: CDouble -> Bool # isNegativeZero :: CDouble -> Bool # | |
| RealFloat CFloat | |
Defined in GHC.Internal.Foreign.C.Types Methods floatRadix :: CFloat -> Integer # floatDigits :: CFloat -> Int # floatRange :: CFloat -> (Int, Int) # decodeFloat :: CFloat -> (Integer, Int) # encodeFloat :: Integer -> Int -> CFloat # significand :: CFloat -> CFloat # scaleFloat :: Int -> CFloat -> CFloat # isInfinite :: CFloat -> Bool # isDenormalized :: CFloat -> Bool # isNegativeZero :: CFloat -> Bool # | |
| RealFloat Double | Since: base-2.1 |
Defined in GHC.Internal.Float Methods floatRadix :: Double -> Integer # floatDigits :: Double -> Int # floatRange :: Double -> (Int, Int) # decodeFloat :: Double -> (Integer, Int) # encodeFloat :: Integer -> Int -> Double # significand :: Double -> Double # scaleFloat :: Int -> Double -> Double # isInfinite :: Double -> Bool # isDenormalized :: Double -> Bool # isNegativeZero :: Double -> Bool # | |
| RealFloat Float | Since: base-2.1 |
Defined in GHC.Internal.Float Methods floatRadix :: Float -> Integer # floatDigits :: Float -> Int # floatRange :: Float -> (Int, Int) # decodeFloat :: Float -> (Integer, Int) # encodeFloat :: Integer -> Int -> Float # significand :: Float -> Float # scaleFloat :: Int -> Float -> Float # isInfinite :: Float -> Bool # isDenormalized :: Float -> Bool # isNegativeZero :: Float -> Bool # | |
| RealFloat (f (g a)) => RealFloat (Compose f g a) | Since: base-4.20.0.0 |
Defined in Data.Functor.Compose Methods floatRadix :: Compose f g a -> Integer # floatDigits :: Compose f g a -> Int # floatRange :: Compose f g a -> (Int, Int) # decodeFloat :: Compose f g a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Compose f g a # exponent :: Compose f g a -> Int # significand :: Compose f g a -> Compose f g a # scaleFloat :: Int -> Compose f g a -> Compose f g a # isNaN :: Compose f g a -> Bool # isInfinite :: Compose f g a -> Bool # isDenormalized :: Compose f g a -> Bool # isNegativeZero :: Compose f g a -> Bool # | |
curry :: ((a, b) -> c) -> a -> b -> c #
Convert an uncurried function to a curried function.
Examples
>>>curry fst 1 21
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]
error :: HasCallStack => [Char] -> a #
error stops execution and displays an error message.
errorWithoutStackTrace :: [Char] -> a #
A variant of error that does not produce a stack trace.
Since: base-4.9.0.0
undefined :: HasCallStack => a #
(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1 #
Same as >>=, but with the arguments interchanged.
as >>= f == f =<< as
(.) :: (b -> c) -> (a -> b) -> a -> c infixr 9 #
Right to left function composition.
(f . g) x = f (g x)
f . id = f = id . f
Examples
>>>map ((*2) . length) [[], [0, 1, 2], [0]][0,6,2]
>>>foldr (.) id [(+1), (*3), (^3)] 225
>>>let (...) = (.).(.) in ((*2)...(+)) 5 1030
flip :: (a -> b -> c) -> b -> a -> c #
flip ff.
flip f x y = f y x
flip . flip = id
Examples
>>>flip (++) "hello" "world""worldhello"
>>>let (.>) = flip (.) in (+1) .> show $ 5"6"
($!) :: (a -> b) -> a -> b infixr 0 #
Strict (call-by-value) application operator. It takes a function and an argument, evaluates the argument to weak head normal form (WHNF), then calls the function with that value.
until :: (a -> Bool) -> (a -> a) -> a -> a #
until p ff until p holds.
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 GHC.Internal.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""
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
Examples
>>>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"]
>>>take 10 (scanl (+) 0 [1..])[0,1,3,6,10,15,21,28,36,45]
>>>take 1 (scanl undefined 'a' undefined)"a"
scanl1 :: (a -> a -> a) -> [a] -> [a] #
\(\mathcal{O}(n)\). scanl1 is a variant of scanl that has no starting
value argument:
scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
Examples
>>>scanl1 (+) [1..4][1,3,6,10]
>>>scanl1 (+) [][]
>>>scanl1 (-) [1..4][1,-1,-4,-8]
>>>scanl1 (&&) [True, False, True, True][True,False,False,False]
>>>scanl1 (||) [False, False, True, True][False,False,True,True]
>>>take 10 (scanl1 (+) [1..])[1,3,6,10,15,21,28,36,45,55]
>>>take 1 (scanl1 undefined ('a' : undefined))"a"
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.
Examples
>>>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
scanr1 :: (a -> a -> a) -> [a] -> [a] #
\(\mathcal{O}(n)\). scanr1 is a variant of scanr that has no starting
value argument.
Examples
>>>scanr1 (+) [1..4][10,9,7,4]
>>>scanr1 (+) [][]
>>>scanr1 (-) [1..4][-2,3,-1,4]
>>>scanr1 (&&) [True, False, True, True][False,False,True,True]
>>>scanr1 (||) [True, True, False, False][True,True,False,False]
>>>force $ scanr1 (+) [1..]*** Exception: stack overflow
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), ...]
Laziness
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 1 $ iterate undefined 42[42]
Examples
>>>take 10 $ iterate not True[True,False,True,False,True,False,True,False,True,False]
>>>take 10 $ iterate (+3) 42[42,45,48,51,54,57,60,63,66,69]
iterate id == :repeat
>>>take 10 $ iterate id 1[1,1,1,1,1,1,1,1,1,1]
repeat x is an infinite list, with x the value of every element.
Examples
>>>take 10 $ repeat 17[17,17,17,17,17,17,17,17,17, 17]
>>>repeat undefined[*** Exception: Prelude.undefined
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.
Examples
>>>replicate 0 True[]
>>>replicate (-1) True[]
>>>replicate 4 True[True,True,True,True]
drop n xs returns the suffix of xs
after the first n elements, or [] if n >= .length xs
It is an instance of the more general genericDrop,
in which n may be of any integral type.
Examples
>>>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]
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 is an instance of the more general genericSplitAt,
in which n may be of any integral type.
Laziness
It is equivalent to (
unless take n xs, drop n xs)n is _|_:
splitAt _|_ xs = _|_, not (_|_, _|_)).
The first component of the tuple is produced lazily:
>>>fst (splitAt 0 undefined)[]
>>>take 1 (fst (splitAt 10 (1 : undefined)))[1]
Examples
>>>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])
span :: (a -> Bool) -> [a] -> ([a], [a]) #
span, applied to a predicate p and a list xs, returns a tuple where
first element is the longest prefix (possibly empty) of xs of elements that
satisfy p and second element is the remainder of the list:
span p xs is equivalent to (, even if takeWhile p xs, dropWhile p xs)p is _|_.
Laziness
>>>span undefined []([],[])>>>fst (span (const False) undefined)*** Exception: Prelude.undefined>>>fst (span (const False) (undefined : undefined))[]>>>take 1 (fst (span (const True) (1 : undefined)))[1]
span produces the first component of the tuple lazily:
>>>take 10 (fst (span (const True) [1..]))[1,2,3,4,5,6,7,8,9,10]
Examples
>>>span (< 3) [1,2,3,4,1,2,3,4]([1,2],[3,4,1,2,3,4])
>>>span (< 9) [1,2,3]([1,2,3],[])
>>>span (< 0) [1,2,3]([],[1,2,3])
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 p is equivalent to span (not . p)(,
even if takeWhile (not . p) xs, dropWhile (not . p) xs)p is _|_.
Laziness
>>>break undefined []([],[])
>>>fst (break (const True) undefined)*** Exception: Prelude.undefined
>>>fst (break (const True) (undefined : undefined))[]
>>>take 1 (fst (break (const False) (1 : undefined)))[1]
break produces the first component of the tuple lazily:
>>>take 10 (fst (break (const False) [1..]))[1,2,3,4,5,6,7,8,9,10]
Examples
>>>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],[])
\(\mathcal{O}(n)\). reverse xs returns the elements of xs in reverse order.
xs must be finite.
Laziness
reverse is lazy in its elements.
>>>head (reverse [undefined, 1])1
>>>reverse (1 : 2 : undefined)*** Exception: Prelude.undefined
Examples
>>>reverse [][]
>>>reverse [42][42]
>>>reverse [2,5,7][7,5,2]
>>>reverse [1..]* Hangs forever *
and :: Foldable t => t Bool -> Bool #
and returns the conjunction of a container of Bools. For the
result to be True, the container must be finite; False, however,
results from a False value finitely far from the left end.
Examples
Basic usage:
>>>and []True
>>>and [True]True
>>>and [False]False
>>>and [True, True, False]False
>>>and (False : repeat True) -- Infinite list [False,True,True,True,...False
>>>and (repeat True)* Hangs forever *
or :: Foldable t => t Bool -> Bool #
or returns the disjunction of a container of Bools. For the
result to be False, the container must be finite; True, however,
results from a True value finitely far from the left end.
Examples
Basic usage:
>>>or []False
>>>or [True]True
>>>or [False]False
>>>or [True, True, False]True
>>>or (True : repeat False) -- Infinite list [True,False,False,False,...True
>>>or (repeat False)* Hangs forever *
any :: Foldable t => (a -> Bool) -> t a -> Bool #
Determines whether any element of the structure satisfies the predicate.
Examples
Basic usage:
>>>any (> 3) []False
>>>any (> 3) [1,2]False
>>>any (> 3) [1,2,3,4,5]True
>>>any (> 3) [1..]True
>>>any (> 3) [0, -1..]* Hangs forever *
all :: Foldable t => (a -> Bool) -> t a -> Bool #
Determines whether all elements of the structure satisfy the predicate.
Examples
Basic usage:
>>>all (> 3) []True
>>>all (> 3) [1,2]False
>>>all (> 3) [1,2,3,4,5]False
>>>all (> 3) [1..]False
>>>all (> 3) [4..]* Hangs forever *
notElem :: (Foldable t, Eq a) => a -> t a -> Bool infix 4 #
notElem is the negation of elem.
Examples
Basic usage:
>>>3 `notElem` []True
>>>3 `notElem` [1,2]True
>>>3 `notElem` [1,2,3,4,5]False
For infinite structures, notElem terminates if the value exists at a
finite distance from the left side of the structure:
>>>3 `notElem` [1..]False
>>>3 `notElem` ([4..] ++ [3])* Hangs forever *
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]