License | BSD-style |
---|---|
Maintainer | Vincent Hanquez <vincent@snarc.org> |
Stability | experimental |
Portability | portable |
Safe Haskell | Safe-Inferred |
Language | Haskell2010 |
Foundation
Description
I tried to picture clusters of information As they moved through the computer What do they look like?
Alternative Prelude
Synopsis
- ($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- ($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- (&&) :: Bool -> Bool -> Bool
- (||) :: Bool -> Bool -> Bool
- (.) :: forall (b :: k) (c :: k) (a :: k). Category cat => cat b c -> cat a b -> cat a c
- not :: Bool -> Bool
- otherwise :: Bool
- data Tuple2 a b = Tuple2 !a !b
- data Tuple3 a b c = Tuple3 !a !b !c
- data Tuple4 a b c d = Tuple4 !a !b !c !d
- class Fstable a where
- type ProductFirst a
- fst :: a -> ProductFirst a
- class Sndable a where
- type ProductSecond a
- snd :: a -> ProductSecond a
- class Thdable a where
- type ProductThird a
- thd :: a -> ProductThird a
- id :: forall (a :: k). Category cat => cat a a
- maybe :: b -> (a -> b) -> Maybe a -> b
- either :: (a -> c) -> (b -> c) -> Either a b -> c
- flip :: (a -> b -> c) -> b -> a -> c
- const :: a -> b -> a
- error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => String -> a
- putStr :: String -> IO ()
- putStrLn :: String -> IO ()
- getArgs :: IO [String]
- uncurry :: (a -> b -> c) -> (a, b) -> c
- curry :: ((a, b) -> c) -> a -> b -> c
- swap :: (a, b) -> (b, a)
- until :: (a -> Bool) -> (a -> a) -> a -> a
- asTypeOf :: a -> a -> a
- undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a
- seq :: forall {r :: RuntimeRep} a (b :: TYPE r). a -> b -> b
- class NormalForm a
- deepseq :: NormalForm a => a -> b -> b
- force :: NormalForm a => a -> a
- class Show a
- show :: Show a => a -> String
- class Eq a => Ord a where
- class Eq 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 Functor (f :: Type -> Type) where
- class Integral a where
- fromInteger :: Integer -> a
- class Fractional a where
- fromRational :: Rational -> a
- class HasNegation a where
- negate :: a -> a
- class Bifunctor (p :: Type -> Type -> Type) where
- class Functor f => Applicative (f :: Type -> Type) where
- class Applicative m => Monad (m :: Type -> Type) where
- (=<<) :: Monad m => (a -> m b) -> m a -> m b
- class IsString a where
- fromString :: String -> a
- class IsList l where
- class (Integral a, Eq a, Ord a) => IsIntegral a where
- class IsIntegral a => IsNatural a where
- class Signed a where
- class Additive a where
- class Subtractive a where
- type Difference a
- (-) :: a -> a -> Difference a
- class Multiplicative a where
- class (Additive a, Multiplicative a) => IDivisible a where
- class Multiplicative a => Divisible a where
- (/) :: a -> a -> a
- data Maybe a
- data Ordering
- data Bool
- data Char
- data Char7
- data IO a
- data Either a b
- data Int8
- data Int16
- data Int32
- data Int64
- data Word8
- data Word16
- data Word32
- data Word64
- data Word
- data Word128
- data Word256
- data Int
- data Integer
- data Natural
- type Rational = Ratio Integer
- data Float
- data Double
- newtype CountOf ty = CountOf Int
- newtype Offset ty = Offset Int
- toCount :: Int -> CountOf ty
- fromCount :: CountOf ty -> Int
- data UArray ty
- class Eq ty => PrimType ty
- data Array a
- data String
- (^^) :: (Fractional a, Integral b) => a -> b -> a
- fromIntegral :: (Integral a, Num b) => a -> b
- realToFrac :: (Real a, Fractional b) => a -> b
- class Semigroup a
- class Semigroup a => Monoid a where
- (<>) :: Semigroup a => a -> a -> a
- class (IsList c, Item c ~ Element c) => Collection c where
- null :: c -> Bool
- length :: c -> CountOf (Element c)
- elem :: forall a. (Eq a, a ~ Element c) => Element c -> c -> Bool
- notElem :: forall a. (Eq a, a ~ Element c) => Element c -> c -> Bool
- maximum :: forall a. (Ord a, a ~ Element c) => NonEmpty c -> Element c
- minimum :: forall a. (Ord a, a ~ Element c) => NonEmpty c -> Element c
- any :: (Element c -> Bool) -> c -> Bool
- all :: (Element c -> Bool) -> c -> Bool
- and :: (Collection col, Element col ~ Bool) => col -> Bool
- or :: (Collection col, Element col ~ Bool) => col -> Bool
- class (IsList c, Item c ~ Element c, Monoid c, Collection c) => Sequential c where
- take :: CountOf (Element c) -> c -> c
- revTake :: CountOf (Element c) -> c -> c
- drop :: CountOf (Element c) -> c -> c
- revDrop :: CountOf (Element c) -> c -> c
- splitAt :: CountOf (Element c) -> c -> (c, c)
- revSplitAt :: CountOf (Element c) -> c -> (c, c)
- splitOn :: (Element c -> Bool) -> c -> [c]
- break :: (Element c -> Bool) -> c -> (c, c)
- breakEnd :: (Element c -> Bool) -> c -> (c, c)
- breakElem :: Eq (Element c) => Element c -> c -> (c, c)
- takeWhile :: (Element c -> Bool) -> c -> c
- dropWhile :: (Element c -> Bool) -> c -> c
- intersperse :: Element c -> c -> c
- intercalate :: Monoid (Item c) => Element c -> c -> Element c
- span :: (Element c -> Bool) -> c -> (c, c)
- spanEnd :: (Element c -> Bool) -> c -> (c, c)
- filter :: (Element c -> Bool) -> c -> c
- partition :: (Element c -> Bool) -> c -> (c, c)
- reverse :: c -> c
- uncons :: c -> Maybe (Element c, c)
- unsnoc :: c -> Maybe (c, Element c)
- snoc :: c -> Element c -> c
- cons :: Element c -> c -> c
- find :: (Element c -> Bool) -> c -> Maybe (Element c)
- sortBy :: (Element c -> Element c -> Ordering) -> c -> c
- singleton :: Element c -> c
- head :: NonEmpty c -> Element c
- last :: NonEmpty c -> Element c
- tail :: NonEmpty c -> c
- init :: NonEmpty c -> c
- replicate :: CountOf (Element c) -> Element c -> c
- isPrefixOf :: Eq (Element c) => c -> c -> Bool
- isSuffixOf :: Eq (Element c) => c -> c -> Bool
- isInfixOf :: Eq (Element c) => c -> c -> Bool
- stripPrefix :: Eq (Element c) => c -> c -> Maybe c
- stripSuffix :: Eq (Element c) => c -> c -> Maybe c
- data NonEmpty a
- nonEmpty :: Collection c => c -> Maybe (NonEmpty c)
- class Foldable collection where
- mapMaybe :: (a -> Maybe b) -> [a] -> [b]
- catMaybes :: [Maybe a] -> [a]
- fromMaybe :: a -> Maybe a -> a
- isJust :: Maybe a -> Bool
- isNothing :: Maybe a -> Bool
- listToMaybe :: [a] -> Maybe a
- maybeToList :: Maybe a -> [a]
- partitionEithers :: [Either a b] -> ([a], [b])
- lefts :: [Either a b] -> [a]
- rights :: [Either a b] -> [b]
- on :: (b -> b -> c) -> (a -> b) -> a -> a -> c
- (<$>) :: Functor f => (a -> b) -> f a -> f b
- (<|>) :: Alternative f => f a -> f a -> f a
- (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
- class (Typeable e, Show e) => Exception e where
- toException :: e -> SomeException
- fromException :: SomeException -> Maybe e
- displayException :: e -> String
- class Typeable (a :: k)
- data SomeException
- data IOException
- data Proxy (t :: k) = Proxy
- asProxyTypeOf :: a -> proxy a -> a
- data Partial a
- partial :: a -> Partial a
- data PartialError
- fromPartial :: Partial a -> a
- ifThenElse :: Bool -> a -> a -> a
- type LString = String
Standard
Operators
($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0 #
Application operator. This operator is redundant, since ordinary
application (f x)
means the same as (f
. However, $
x)$
has
low, right-associative binding precedence, so it sometimes allows
parentheses to be omitted; for example:
f $ g $ h x = f (g (h x))
It is also useful in higher-order situations, such as
,
or map
($
0) xs
.zipWith
($
) fs xs
Note that (
is levity-polymorphic in its result type, so that
$
)foo
where $
Truefoo :: Bool -> Int#
is well-typed.
($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (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.
(.) :: forall (b :: k) (c :: k) (a :: k). Category cat => cat b c -> cat a b -> cat a c infixr 9 #
morphism composition
Functions
Strict tuple (a,b)
Constructors
Tuple2 !a !b |
Instances
Nthable 1 (Tuple2 a b) Source # | |
Nthable 2 (Tuple2 a b) Source # | |
(Data a, Data b) => Data (Tuple2 a b) Source # | |
Defined in Foundation.Tuple Methods gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> Tuple2 a b -> c (Tuple2 a b) # gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Tuple2 a b) # toConstr :: Tuple2 a b -> Constr # dataTypeOf :: Tuple2 a b -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Tuple2 a b)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Tuple2 a b)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Tuple2 a b -> Tuple2 a b # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Tuple2 a b -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Tuple2 a b -> r # gmapQ :: (forall d. Data d => d -> u) -> Tuple2 a b -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Tuple2 a b -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Tuple2 a b -> m (Tuple2 a b) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Tuple2 a b -> m (Tuple2 a b) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Tuple2 a b -> m (Tuple2 a b) # | |
Generic (Tuple2 a b) Source # | |
(Show a, Show b) => Show (Tuple2 a b) Source # | |
(NormalForm a, NormalForm b) => NormalForm (Tuple2 a b) Source # | |
Defined in Foundation.Tuple Methods toNormalForm :: Tuple2 a b -> () # | |
(Hashable a, Hashable b) => Hashable (Tuple2 a b) Source # | |
Fstable (Tuple2 a b) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (Tuple2 a b) Source # | |
Sndable (Tuple2 a b) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (Tuple2 a b) Source # | |
(Eq a, Eq b) => Eq (Tuple2 a b) Source # | |
(Ord a, Ord b) => Ord (Tuple2 a b) Source # | |
type NthTy 1 (Tuple2 a b) Source # | |
Defined in Foundation.Tuple.Nth | |
type NthTy 2 (Tuple2 a b) Source # | |
Defined in Foundation.Tuple.Nth | |
type Rep (Tuple2 a b) Source # | |
Defined in Foundation.Tuple type Rep (Tuple2 a b) = D1 ('MetaData "Tuple2" "Foundation.Tuple" "foundation-0.0.30-9BPNbqL9YFL1YXPlNJAt6G" 'False) (C1 ('MetaCons "Tuple2" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 b))) | |
type ProductFirst (Tuple2 a b) Source # | |
Defined in Foundation.Tuple | |
type ProductSecond (Tuple2 a b) Source # | |
Defined in Foundation.Tuple |
Strict tuple (a,b,c)
Constructors
Tuple3 !a !b !c |
Instances
Nthable 1 (Tuple3 a b c) Source # | |
Nthable 2 (Tuple3 a b c) Source # | |
Nthable 3 (Tuple3 a b c) Source # | |
(Data a, Data b, Data c) => Data (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Methods gfoldl :: (forall d b0. Data d => c0 (d -> b0) -> d -> c0 b0) -> (forall g. g -> c0 g) -> Tuple3 a b c -> c0 (Tuple3 a b c) # gunfold :: (forall b0 r. Data b0 => c0 (b0 -> r) -> c0 r) -> (forall r. r -> c0 r) -> Constr -> c0 (Tuple3 a b c) # toConstr :: Tuple3 a b c -> Constr # dataTypeOf :: Tuple3 a b c -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c0 (t d)) -> Maybe (c0 (Tuple3 a b c)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c0 (t d e)) -> Maybe (c0 (Tuple3 a b c)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Tuple3 a b c -> Tuple3 a b c # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Tuple3 a b c -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Tuple3 a b c -> r # gmapQ :: (forall d. Data d => d -> u) -> Tuple3 a b c -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Tuple3 a b c -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Tuple3 a b c -> m (Tuple3 a b c) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Tuple3 a b c -> m (Tuple3 a b c) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Tuple3 a b c -> m (Tuple3 a b c) # | |
Generic (Tuple3 a b c) Source # | |
(Show a, Show b, Show c) => Show (Tuple3 a b c) Source # | |
(NormalForm a, NormalForm b, NormalForm c) => NormalForm (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Methods toNormalForm :: Tuple3 a b c -> () # | |
(Hashable a, Hashable b, Hashable c) => Hashable (Tuple3 a b c) Source # | |
Fstable (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (Tuple3 a b c) Source # | |
Sndable (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (Tuple3 a b c) Source # | |
Thdable (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductThird (Tuple3 a b c) Source # | |
(Eq a, Eq b, Eq c) => Eq (Tuple3 a b c) Source # | |
(Ord a, Ord b, Ord c) => Ord (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple | |
type NthTy 1 (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple.Nth | |
type NthTy 2 (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple.Nth | |
type NthTy 3 (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple.Nth | |
type Rep (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple type Rep (Tuple3 a b c) = D1 ('MetaData "Tuple3" "Foundation.Tuple" "foundation-0.0.30-9BPNbqL9YFL1YXPlNJAt6G" 'False) (C1 ('MetaCons "Tuple3" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a) :*: (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 b) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 c)))) | |
type ProductFirst (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple | |
type ProductSecond (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple | |
type ProductThird (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple |
Strict tuple (a,b,c,d)
Constructors
Tuple4 !a !b !c !d |
Instances
Nthable 1 (Tuple4 a b c d) Source # | |
Nthable 2 (Tuple4 a b c d) Source # | |
Nthable 3 (Tuple4 a b c d) Source # | |
Nthable 4 (Tuple4 a b c d) Source # | |
(Data a, Data b, Data c, Data d) => Data (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Methods gfoldl :: (forall d0 b0. Data d0 => c0 (d0 -> b0) -> d0 -> c0 b0) -> (forall g. g -> c0 g) -> Tuple4 a b c d -> c0 (Tuple4 a b c d) # gunfold :: (forall b0 r. Data b0 => c0 (b0 -> r) -> c0 r) -> (forall r. r -> c0 r) -> Constr -> c0 (Tuple4 a b c d) # toConstr :: Tuple4 a b c d -> Constr # dataTypeOf :: Tuple4 a b c d -> DataType # dataCast1 :: Typeable t => (forall d0. Data d0 => c0 (t d0)) -> Maybe (c0 (Tuple4 a b c d)) # dataCast2 :: Typeable t => (forall d0 e. (Data d0, Data e) => c0 (t d0 e)) -> Maybe (c0 (Tuple4 a b c d)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Tuple4 a b c d -> Tuple4 a b c d # gmapQl :: (r -> r' -> r) -> r -> (forall d0. Data d0 => d0 -> r') -> Tuple4 a b c d -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d0. Data d0 => d0 -> r') -> Tuple4 a b c d -> r # gmapQ :: (forall d0. Data d0 => d0 -> u) -> Tuple4 a b c d -> [u] # gmapQi :: Int -> (forall d0. Data d0 => d0 -> u) -> Tuple4 a b c d -> u # gmapM :: Monad m => (forall d0. Data d0 => d0 -> m d0) -> Tuple4 a b c d -> m (Tuple4 a b c d) # gmapMp :: MonadPlus m => (forall d0. Data d0 => d0 -> m d0) -> Tuple4 a b c d -> m (Tuple4 a b c d) # gmapMo :: MonadPlus m => (forall d0. Data d0 => d0 -> m d0) -> Tuple4 a b c d -> m (Tuple4 a b c d) # | |
Generic (Tuple4 a b c d) Source # | |
(Show a, Show b, Show c, Show d) => Show (Tuple4 a b c d) Source # | |
(NormalForm a, NormalForm b, NormalForm c, NormalForm d) => NormalForm (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Methods toNormalForm :: Tuple4 a b c d -> () # | |
(Hashable a, Hashable b, Hashable c, Hashable d) => Hashable (Tuple4 a b c d) Source # | |
Fstable (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (Tuple4 a b c d) Source # | |
Sndable (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (Tuple4 a b c d) Source # | |
Thdable (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductThird (Tuple4 a b c d) Source # | |
(Eq a, Eq b, Eq c, Eq d) => Eq (Tuple4 a b c d) Source # | |
(Ord a, Ord b, Ord c, Ord d) => Ord (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Methods compare :: Tuple4 a b c d -> Tuple4 a b c d -> Ordering # (<) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # (<=) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # (>) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # (>=) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # | |
type NthTy 1 (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple.Nth | |
type NthTy 2 (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple.Nth | |
type NthTy 3 (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple.Nth | |
type NthTy 4 (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple.Nth | |
type Rep (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple type Rep (Tuple4 a b c d) = D1 ('MetaData "Tuple4" "Foundation.Tuple" "foundation-0.0.30-9BPNbqL9YFL1YXPlNJAt6G" 'False) (C1 ('MetaCons "Tuple4" 'PrefixI 'False) ((S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 b)) :*: (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 c) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 d)))) | |
type ProductFirst (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple | |
type ProductSecond (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple | |
type ProductThird (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple |
class Fstable a where Source #
Class of product types that have a first element
Associated Types
type ProductFirst a Source #
Methods
fst :: a -> ProductFirst a Source #
Instances
Fstable (Tuple2 a b) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (Tuple2 a b) Source # | |
Fstable (a, b) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (a, b) Source # Methods fst :: (a, b) -> ProductFirst (a, b) Source # | |
Fstable (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (Tuple3 a b c) Source # | |
Fstable (a, b, c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (a, b, c) Source # Methods fst :: (a, b, c) -> ProductFirst (a, b, c) Source # | |
Fstable (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (Tuple4 a b c d) Source # | |
Fstable (a, b, c, d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductFirst (a, b, c, d) Source # Methods fst :: (a, b, c, d) -> ProductFirst (a, b, c, d) Source # |
class Sndable a where Source #
Class of product types that have a second element
Associated Types
type ProductSecond a Source #
Methods
snd :: a -> ProductSecond a Source #
Instances
Sndable (Tuple2 a b) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (Tuple2 a b) Source # | |
Sndable (a, b) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (a, b) Source # Methods snd :: (a, b) -> ProductSecond (a, b) Source # | |
Sndable (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (Tuple3 a b c) Source # | |
Sndable (a, b, c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (a, b, c) Source # Methods snd :: (a, b, c) -> ProductSecond (a, b, c) Source # | |
Sndable (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (Tuple4 a b c d) Source # | |
Sndable (a, b, c, d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductSecond (a, b, c, d) Source # Methods snd :: (a, b, c, d) -> ProductSecond (a, b, c, d) Source # |
class Thdable a where Source #
Class of product types that have a third element
Associated Types
type ProductThird a Source #
Methods
thd :: a -> ProductThird a Source #
Instances
Thdable (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductThird (Tuple3 a b c) Source # | |
Thdable (a, b, c) Source # | |
Defined in Foundation.Tuple Associated Types type ProductThird (a, b, c) Source # Methods thd :: (a, b, c) -> ProductThird (a, b, c) Source # | |
Thdable (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductThird (Tuple4 a b c d) Source # | |
Thdable (a, b, c, d) Source # | |
Defined in Foundation.Tuple Associated Types type ProductThird (a, b, c, d) Source # Methods thd :: (a, b, c, d) -> ProductThird (a, b, c, d) Source # |
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 Nothing
False
Read an integer from a string using readMaybe
. If we succeed,
return twice the integer; that is, apply (*2)
to it. If instead
we fail to parse an integer, return 0
by default:
>>>
import Text.Read ( readMaybe )
>>>
maybe 0 (*2) (readMaybe "5")
10>>>
maybe 0 (*2) (readMaybe "")
0
Apply show
to a Maybe Int
. If we have Just n
, we want to show
the underlying Int
n
. But if we have Nothing
, we return the
empty string instead of (for example) "Nothing":
>>>
maybe "" show (Just 5)
"5">>>
maybe "" show Nothing
""
either :: (a -> c) -> (b -> c) -> Either a b -> c #
Case analysis for the Either
type.
If the value is
, apply the first function to Left
aa
;
if it is
, apply the second function to Right
bb
.
Examples
We create two values of type
, one using the
Either
String
Int
Left
constructor and another using the Right
constructor. Then
we apply "either" the length
function (if we have a String
)
or the "times-two" function (if we have an Int
):
>>>
let s = Left "foo" :: Either String Int
>>>
let n = Right 3 :: Either String Int
>>>
either length (*2) s
3>>>
either length (*2) n
6
flip :: (a -> b -> c) -> b -> a -> c #
takes its (first) two arguments in the reverse order of flip
ff
.
>>>
flip (++) "hello" "world"
"worldhello"
const x
is a unary function which evaluates to x
for all inputs.
>>>
const 42 "hello"
42
>>>
map (const 42) [0..3]
[42,42,42,42]
error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => String -> a #
stop execution and displays an error message
Returns a list of the program's command line arguments (not including the program name).
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]
until :: (a -> Bool) -> (a -> a) -> a -> a #
yields the result of applying until
p ff
until p
holds.
undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a #
seq :: forall {r :: RuntimeRep} a (b :: TYPE r). a -> b -> b infixr 0 #
The value of seq a b
is bottom if a
is bottom, and
otherwise equal to b
. In other words, it evaluates the first
argument a
to weak head normal form (WHNF). seq
is usually
introduced to improve performance by avoiding unneeded laziness.
A note on evaluation order: the expression seq a b
does
not guarantee that a
will be evaluated before b
.
The only guarantee given by seq
is that the both a
and b
will be evaluated before seq
returns a value.
In particular, this means that b
may be evaluated before
a
. If you need to guarantee a specific order of evaluation,
you must use the function pseq
from the "parallel" package.
class NormalForm a #
Data that can be fully evaluated in Normal Form
Minimal complete definition
Instances
deepseq :: NormalForm a => a -> b -> b #
force :: NormalForm a => a -> a #
Type classes
Conversion of values to readable String
s.
Derived instances of Show
have the following properties, which
are compatible with derived instances of Read
:
- The result of
show
is 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
showsPrec
will produce infix applications of the constructor. - the representation will be enclosed in parentheses if the
precedence of the top-level constructor in
x
is less thand
(associativity is ignored). Thus, ifd
is0
then the result is never surrounded in parentheses; ifd
is11
it is always surrounded in parentheses, unless it is an atomic expression. - If the constructor is defined using record syntax, then
show
will 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 = 5
Note that right-associativity of :^:
is ignored. For example,
produces the stringshow
(Leaf 1 :^: Leaf 2 :^: Leaf 3)"Leaf 1 :^: (Leaf 2 :^: Leaf 3)"
.
Instances
show :: Show a => a -> String #
Use the Show class to create a String.
Note that this is not efficient, since an intermediate [Char] is going to be created before turning into a real String.
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 <= x
x < y
=x <= y && x /= y
x > y
=y < x
x < y
=compare x y == LT
x > y
=compare x y == GT
x == y
=compare x y == EQ
min x y == if x <= y then x else y
=True
max 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 All | Since: base-2.1 |
Ord Any | Since: base-2.1 |
Ord SomeTypeRep | |
Defined in Data.Typeable.Internal Methods compare :: SomeTypeRep -> SomeTypeRep -> Ordering # (<) :: SomeTypeRep -> SomeTypeRep -> Bool # (<=) :: SomeTypeRep -> SomeTypeRep -> Bool # (>) :: SomeTypeRep -> SomeTypeRep -> Bool # (>=) :: SomeTypeRep -> SomeTypeRep -> Bool # max :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep # min :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep # | |
Ord Version | Since: base-2.1 |
Ord CBool | |
Ord CChar | |
Ord CClock | |
Ord CDouble | |
Ord CFloat | |
Ord CInt | |
Ord CIntMax | |
Ord CIntPtr | |
Ord CLLong | |
Ord CLong | |
Ord CPtrdiff | |
Defined in Foreign.C.Types | |
Ord CSChar | |
Ord CSUSeconds | |
Defined in 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 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 Foreign.C.Types | |
Ord CUIntPtr | |
Defined in Foreign.C.Types | |
Ord CULLong | |
Ord CULong | |
Ord CUSeconds | |
Ord CUShort | |
Ord CWchar | |
Ord IntPtr | |
Ord WordPtr | |
Ord BlockReason | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync Methods compare :: BlockReason -> BlockReason -> Ordering # (<) :: BlockReason -> BlockReason -> Bool # (<=) :: BlockReason -> BlockReason -> Bool # (>) :: BlockReason -> BlockReason -> Bool # (>=) :: BlockReason -> BlockReason -> Bool # max :: BlockReason -> BlockReason -> BlockReason # min :: BlockReason -> BlockReason -> BlockReason # | |
Ord ThreadId | Since: base-4.2.0.0 |
Defined in GHC.Conc.Sync | |
Ord ThreadStatus | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync Methods compare :: ThreadStatus -> ThreadStatus -> Ordering # (<) :: ThreadStatus -> ThreadStatus -> Bool # (<=) :: ThreadStatus -> ThreadStatus -> Bool # (>) :: ThreadStatus -> ThreadStatus -> Bool # (>=) :: ThreadStatus -> ThreadStatus -> Bool # max :: ThreadStatus -> ThreadStatus -> ThreadStatus # min :: ThreadStatus -> ThreadStatus -> ThreadStatus # | |
Ord ErrorCall | Since: base-4.7.0.0 |
Ord ArithException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods compare :: ArithException -> ArithException -> Ordering # (<) :: ArithException -> ArithException -> Bool # (<=) :: ArithException -> ArithException -> Bool # (>) :: ArithException -> ArithException -> Bool # (>=) :: ArithException -> ArithException -> Bool # max :: ArithException -> ArithException -> ArithException # min :: ArithException -> ArithException -> ArithException # | |
Ord Associativity | Since: base-4.6.0.0 |
Defined in GHC.Generics Methods compare :: Associativity -> Associativity -> Ordering # (<) :: Associativity -> Associativity -> Bool # (<=) :: Associativity -> Associativity -> Bool # (>) :: Associativity -> Associativity -> Bool # (>=) :: Associativity -> Associativity -> Bool # max :: Associativity -> Associativity -> Associativity # min :: Associativity -> Associativity -> Associativity # | |
Ord DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: DecidedStrictness -> DecidedStrictness -> Ordering # (<) :: DecidedStrictness -> DecidedStrictness -> Bool # (<=) :: DecidedStrictness -> DecidedStrictness -> Bool # (>) :: DecidedStrictness -> DecidedStrictness -> Bool # (>=) :: DecidedStrictness -> DecidedStrictness -> Bool # max :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # min :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # | |
Ord Fixity | Since: base-4.6.0.0 |
Ord SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: SourceStrictness -> SourceStrictness -> Ordering # (<) :: SourceStrictness -> SourceStrictness -> Bool # (<=) :: SourceStrictness -> SourceStrictness -> Bool # (>) :: SourceStrictness -> SourceStrictness -> Bool # (>=) :: SourceStrictness -> SourceStrictness -> Bool # max :: SourceStrictness -> SourceStrictness -> SourceStrictness # min :: SourceStrictness -> SourceStrictness -> SourceStrictness # | |
Ord SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: SourceUnpackedness -> SourceUnpackedness -> Ordering # (<) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (<=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # max :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # min :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # | |
Ord SeekMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Device | |
Ord ArrayException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods compare :: ArrayException -> ArrayException -> Ordering # (<) :: ArrayException -> ArrayException -> Bool # (<=) :: ArrayException -> ArrayException -> Bool # (>) :: ArrayException -> ArrayException -> Bool # (>=) :: ArrayException -> ArrayException -> Bool # max :: ArrayException -> ArrayException -> ArrayException # min :: ArrayException -> ArrayException -> ArrayException # | |
Ord AsyncException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods compare :: AsyncException -> AsyncException -> Ordering # (<) :: AsyncException -> AsyncException -> Bool # (<=) :: AsyncException -> AsyncException -> Bool # (>) :: AsyncException -> AsyncException -> Bool # (>=) :: AsyncException -> AsyncException -> Bool # max :: AsyncException -> AsyncException -> AsyncException # min :: AsyncException -> AsyncException -> AsyncException # | |
Ord ExitCode | |
Defined in GHC.IO.Exception | |
Ord BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods compare :: BufferMode -> BufferMode -> Ordering # (<) :: BufferMode -> BufferMode -> Bool # (<=) :: BufferMode -> BufferMode -> Bool # (>) :: BufferMode -> BufferMode -> Bool # (>=) :: BufferMode -> BufferMode -> Bool # max :: BufferMode -> BufferMode -> BufferMode # min :: BufferMode -> BufferMode -> BufferMode # | |
Ord Newline | Since: base-4.3.0.0 |
Ord NewlineMode | Since: base-4.3.0.0 |
Defined in GHC.IO.Handle.Types Methods compare :: NewlineMode -> NewlineMode -> Ordering # (<) :: NewlineMode -> NewlineMode -> Bool # (<=) :: NewlineMode -> NewlineMode -> Bool # (>) :: NewlineMode -> NewlineMode -> Bool # (>=) :: NewlineMode -> NewlineMode -> Bool # max :: NewlineMode -> NewlineMode -> NewlineMode # min :: NewlineMode -> NewlineMode -> NewlineMode # | |
Ord IOMode | Since: base-4.2.0.0 |
Ord Int16 | Since: base-2.1 |
Ord Int32 | Since: base-2.1 |
Ord Int64 | Since: base-2.1 |
Ord Int8 | Since: base-2.1 |
Ord SomeChar | |
Defined in GHC.TypeLits | |
Ord SomeSymbol | Since: base-4.7.0.0 |
Defined in GHC.TypeLits Methods compare :: SomeSymbol -> SomeSymbol -> Ordering # (<) :: SomeSymbol -> SomeSymbol -> Bool # (<=) :: SomeSymbol -> SomeSymbol -> Bool # (>) :: SomeSymbol -> SomeSymbol -> Bool # (>=) :: SomeSymbol -> SomeSymbol -> Bool # max :: SomeSymbol -> SomeSymbol -> SomeSymbol # min :: SomeSymbol -> SomeSymbol -> SomeSymbol # | |
Ord SomeNat | Since: base-4.7.0.0 |
Ord GeneralCategory | Since: base-2.1 |
Defined in GHC.Unicode Methods compare :: GeneralCategory -> GeneralCategory -> Ordering # (<) :: GeneralCategory -> GeneralCategory -> Bool # (<=) :: GeneralCategory -> GeneralCategory -> Bool # (>) :: GeneralCategory -> GeneralCategory -> Bool # (>=) :: GeneralCategory -> GeneralCategory -> Bool # max :: GeneralCategory -> GeneralCategory -> GeneralCategory # min :: GeneralCategory -> GeneralCategory -> GeneralCategory # | |
Ord Word16 | Since: base-2.1 |
Ord Word32 | Since: base-2.1 |
Ord Word64 | Since: base-2.1 |
Ord Word8 | Since: base-2.1 |
Ord CBlkCnt | |
Ord CBlkSize | |
Defined in System.Posix.Types | |
Ord CCc | |
Ord CClockId | |
Defined in System.Posix.Types | |
Ord CDev | |
Ord CFsBlkCnt | |
Ord CFsFilCnt | |
Ord CGid | |
Ord CId | |
Ord CIno | |
Ord CKey | |
Ord CMode | |
Ord CNfds | |
Ord CNlink | |
Ord COff | |
Ord CPid | |
Ord CRLim | |
Ord CSocklen | |
Defined in System.Posix.Types | |
Ord CSpeed | |
Ord CSsize | |
Ord CTcflag | |
Ord CTimer | |
Ord CUid | |
Ord Fd | |
Ord Encoding | |
Defined in Basement.String | |
Ord UTF32_Invalid | |
Defined in Basement.String.Encoding.UTF32 Methods compare :: UTF32_Invalid -> UTF32_Invalid -> Ordering # (<) :: UTF32_Invalid -> UTF32_Invalid -> Bool # (<=) :: UTF32_Invalid -> UTF32_Invalid -> Bool # (>) :: UTF32_Invalid -> UTF32_Invalid -> Bool # (>=) :: UTF32_Invalid -> UTF32_Invalid -> Bool # | |
Ord AsciiString | |
Defined in Basement.Types.AsciiString Methods compare :: AsciiString -> AsciiString -> Ordering # (<) :: AsciiString -> AsciiString -> Bool # (<=) :: AsciiString -> AsciiString -> Bool # (>) :: AsciiString -> AsciiString -> Bool # (>=) :: AsciiString -> AsciiString -> Bool # max :: AsciiString -> AsciiString -> AsciiString # min :: AsciiString -> AsciiString -> AsciiString # | |
Ord Char7 | |
Ord FileSize | |
Defined in Basement.Types.OffsetSize | |
Ord Addr | |
Ord Word128 | |
Defined in Basement.Types.Word128 | |
Ord Word256 | |
Defined in Basement.Types.Word256 | |
Ord String | |
Ord Bitmap Source # | |
Ord Escaping Source # | |
Defined in Foundation.Format.CSV.Types | |
Ord IPv4 Source # | |
Ord IPv6 Source # | |
Ord Arch Source # | |
Ord OS Source # | |
Ord NanoSeconds Source # | |
Defined in Foundation.Time.Types Methods compare :: NanoSeconds -> NanoSeconds -> Ordering # (<) :: NanoSeconds -> NanoSeconds -> Bool # (<=) :: NanoSeconds -> NanoSeconds -> Bool # (>) :: NanoSeconds -> NanoSeconds -> Bool # (>=) :: NanoSeconds -> NanoSeconds -> Bool # max :: NanoSeconds -> NanoSeconds -> NanoSeconds # min :: NanoSeconds -> NanoSeconds -> NanoSeconds # | |
Ord Seconds Source # | |
Defined in Foundation.Time.Types | |
Ord UUID Source # | |
Ord FilePath Source # | |
Defined in Foundation.VFS.FilePath | |
Ord Ordering | |
Defined in GHC.Classes | |
Ord TyCon | |
Ord Integer | |
Ord Natural | |
Ord () | |
Ord Bool | |
Ord Char | |
Ord Double | Note that due to the presence of
Also note that, due to the same,
|
Ord Float | Note that due to the presence of
Also note that, due to the same,
|
Ord Int | |
Ord Word | |
Ord a => Ord (ZipList a) | Since: base-4.7.0.0 |
Ord a => Ord (Identity a) | Since: base-4.8.0.0 |
Defined in Data.Functor.Identity | |
Ord a => Ord (First a) | Since: base-2.1 |
Ord a => Ord (Last a) | Since: base-2.1 |
Ord a => Ord (Down a) | Since: base-4.6.0.0 |
Ord a => Ord (First a) | Since: base-4.9.0.0 |
Ord a => Ord (Last a) | Since: base-4.9.0.0 |
Ord a => Ord (Max a) | Since: base-4.9.0.0 |
Ord a => Ord (Min a) | Since: base-4.9.0.0 |
Ord m => Ord (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods compare :: WrappedMonoid m -> WrappedMonoid m -> Ordering # (<) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (<=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (>) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (>=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # max :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # min :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # | |
Ord a => Ord (Dual a) | Since: base-2.1 |
Ord a => Ord (Product a) | Since: base-2.1 |
Ord a => Ord (Sum a) | Since: base-2.1 |
Ord (ForeignPtr a) | Since: base-2.1 |
Defined in GHC.ForeignPtr Methods compare :: ForeignPtr a -> ForeignPtr a -> Ordering # (<) :: ForeignPtr a -> ForeignPtr a -> Bool # (<=) :: ForeignPtr a -> ForeignPtr a -> Bool # (>) :: ForeignPtr a -> ForeignPtr a -> Bool # (>=) :: ForeignPtr a -> ForeignPtr a -> Bool # max :: ForeignPtr a -> ForeignPtr a -> ForeignPtr a # min :: ForeignPtr a -> ForeignPtr a -> ForeignPtr a # | |
Ord p => Ord (Par1 p) | Since: base-4.7.0.0 |
Ord (FunPtr a) | |
Defined in GHC.Ptr | |
Ord (Ptr a) | Since: base-2.1 |
Integral a => Ord (Ratio a) | Since: base-2.0.1 |
Ord (Bits n) | |
(PrimType ty, Ord ty) => Ord (Block ty) | |
Defined in Basement.Block.Base | |
Ord (Zn n) | |
Ord (Zn64 n) | |
Ord a => Ord (Array a) | |
(ByteSwap a, Ord a) => Ord (BE a) | |
(ByteSwap a, Ord a) => Ord (LE a) | |
Ord (FinalPtr a) | |
Ord (CountOf ty) | |
Defined in Basement.Types.OffsetSize | |
Ord (Offset ty) | |
(PrimType ty, Ord ty) => Ord (UArray ty) | |
(PrimType ty, Ord ty) => Ord (ChunkedUArray ty) Source # | |
Defined in Foundation.Array.Chunked.Unboxed Methods compare :: ChunkedUArray ty -> ChunkedUArray ty -> Ordering # (<) :: ChunkedUArray ty -> ChunkedUArray ty -> Bool # (<=) :: ChunkedUArray ty -> ChunkedUArray ty -> Bool # (>) :: ChunkedUArray ty -> ChunkedUArray ty -> Bool # (>=) :: ChunkedUArray ty -> ChunkedUArray ty -> Bool # max :: ChunkedUArray ty -> ChunkedUArray ty -> ChunkedUArray ty # min :: ChunkedUArray ty -> ChunkedUArray ty -> ChunkedUArray ty # | |
Ord a => Ord (DList a) Source # | |
Defined in Foundation.List.DList | |
Ord a => Ord (NonEmpty a) | Since: base-4.9.0.0 |
Ord a => Ord (Maybe a) | Since: base-2.1 |
Ord a => Ord (a) | |
Ord a => Ord [a] | |
(Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 |
Ord (Proxy s) | Since: base-4.7.0.0 |
Ord a => Ord (Arg a b) | Since: base-4.9.0.0 |
Ord (TypeRep a) | Since: base-4.4.0.0 |
(Ix i, Ord e) => Ord (Array i e) | Since: base-2.1 |
Ord (U1 p) | Since: base-4.7.0.0 |
Ord (V1 p) | Since: base-4.9.0.0 |
(PrimType a, Ord a) => Ord (BlockN n a) | |
Defined in Basement.Sized.Block | |
Ord a => Ord (ListN n a) | |
(Ord a, Ord b) => Ord (These a b) | |
(Ord a, Ord b) => Ord (Tuple2 a b) Source # | |
(Ord a, Ord b) => Ord (a, b) | |
Ord a => Ord (Const a b) | Since: base-4.9.0.0 |
Ord (f a) => Ord (Ap f a) | Since: base-4.12.0.0 |
Ord (f a) => Ord (Alt f a) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
Ord (Coercion a b) | Since: base-4.7.0.0 |
Defined in Data.Type.Coercion | |
Ord (a :~: b) | Since: base-4.7.0.0 |
Defined in Data.Type.Equality | |
Ord (f p) => Ord (Rec1 f p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
Ord (URec (Ptr ()) p) | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: URec (Ptr ()) p -> URec (Ptr ()) p -> Ordering # (<) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (<=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # max :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p # min :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p # | |
Ord (URec Char p) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
Ord (URec Double p) | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods compare :: URec Double p -> URec Double p -> Ordering # (<) :: URec Double p -> URec Double p -> Bool # (<=) :: URec Double p -> URec Double p -> Bool # (>) :: URec Double p -> URec Double p -> Bool # (>=) :: URec Double p -> URec Double p -> Bool # | |
Ord (URec Float p) | |
Defined in GHC.Generics | |
Ord (URec Int p) | Since: base-4.9.0.0 |
Ord (URec Word p) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
(Ord a, Ord b, Ord c) => Ord (Tuple3 a b c) Source # | |
Defined in Foundation.Tuple | |
(Ord a, Ord b, Ord c) => Ord (a, b, c) | |
Ord (a :~~: b) | Since: base-4.10.0.0 |
(Ord (f p), Ord (g p)) => Ord ((f :*: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
(Ord (f p), Ord (g p)) => Ord ((f :+: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
Ord c => Ord (K1 i c p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
(Ord a, Ord b, Ord c, Ord d) => Ord (Tuple4 a b c d) Source # | |
Defined in Foundation.Tuple Methods compare :: Tuple4 a b c d -> Tuple4 a b c d -> Ordering # (<) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # (<=) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # (>) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # (>=) :: Tuple4 a b c d -> Tuple4 a b c d -> Bool # | |
(Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) | |
Defined in GHC.Classes | |
Ord (f (g p)) => Ord ((f :.: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
Ord (f p) => Ord (M1 i c f p) | Since: base-4.7.0.0 |
(Ord 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 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 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 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) # |
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 Constr | Equality of constructors Since: base-4.0.0.0 |
Eq ConstrRep | Since: base-4.0.0.0 |
Eq DataRep | Since: base-4.0.0.0 |
Eq Fixity | Since: base-4.0.0.0 |
Eq All | Since: base-2.1 |
Eq Any | Since: base-2.1 |
Eq SomeTypeRep | |
Defined in Data.Typeable.Internal | |
Eq Version | Since: base-2.1 |
Eq Errno | Since: base-2.1 |
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 Foreign.C.Types | |
Eq CShort | |
Eq CSigAtomic | |
Defined in 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 IntPtr | |
Eq WordPtr | |
Eq BlockReason | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync | |
Eq ThreadId | Since: base-4.2.0.0 |
Eq ThreadStatus | Since: base-4.3.0.0 |
Defined in GHC.Conc.Sync | |
Eq ErrorCall | Since: base-4.7.0.0 |
Eq ArithException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods (==) :: ArithException -> ArithException -> Bool # (/=) :: ArithException -> ArithException -> Bool # | |
Eq SpecConstrAnnotation | Since: base-4.3.0.0 |
Defined in GHC.Exts Methods (==) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool # (/=) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool # | |
Eq Associativity | Since: base-4.6.0.0 |
Defined in GHC.Generics Methods (==) :: Associativity -> Associativity -> Bool # (/=) :: Associativity -> Associativity -> Bool # | |
Eq DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: DecidedStrictness -> DecidedStrictness -> Bool # (/=) :: DecidedStrictness -> DecidedStrictness -> Bool # | |
Eq Fixity | Since: base-4.6.0.0 |
Eq SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: SourceStrictness -> SourceStrictness -> Bool # (/=) :: SourceStrictness -> SourceStrictness -> Bool # | |
Eq SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # | |
Eq MaskingState | Since: base-4.3.0.0 |
Defined in GHC.IO | |
Eq IODeviceType | Since: base-4.2.0.0 |
Defined in GHC.IO.Device | |
Eq SeekMode | Since: base-4.2.0.0 |
Eq CodingProgress | Since: base-4.4.0.0 |
Defined in GHC.IO.Encoding.Types Methods (==) :: CodingProgress -> CodingProgress -> Bool # (/=) :: CodingProgress -> CodingProgress -> Bool # | |
Eq ArrayException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods (==) :: ArrayException -> ArrayException -> Bool # (/=) :: ArrayException -> ArrayException -> Bool # | |
Eq AsyncException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods (==) :: AsyncException -> AsyncException -> Bool # (/=) :: AsyncException -> AsyncException -> Bool # | |
Eq ExitCode | |
Eq IOErrorType | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception | |
Eq IOException | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception | |
Eq HandlePosn | Since: base-4.1.0.0 |
Defined in GHC.IO.Handle | |
Eq BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
Eq Handle | Since: base-4.1.0.0 |
Eq Newline | Since: base-4.2.0.0 |
Eq NewlineMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
Eq IOMode | Since: base-4.2.0.0 |
Eq Int16 | Since: base-2.1 |
Eq Int32 | Since: base-2.1 |
Eq Int64 | Since: base-2.1 |
Eq Int8 | Since: base-2.1 |
Eq IoSubSystem | |
Defined in GHC.RTS.Flags | |
Eq SrcLoc | Since: base-4.9.0.0 |
Eq SomeChar | |
Eq SomeSymbol | Since: base-4.7.0.0 |
Defined in GHC.TypeLits | |
Eq SomeNat | Since: base-4.7.0.0 |
Eq GeneralCategory | Since: base-2.1 |
Defined in GHC.Unicode Methods (==) :: GeneralCategory -> GeneralCategory -> Bool # (/=) :: GeneralCategory -> GeneralCategory -> Bool # | |
Eq Word16 | Since: base-2.1 |
Eq Word32 | Since: base-2.1 |
Eq Word64 | Since: base-2.1 |
Eq Word8 | Since: base-2.1 |
Eq CBlkCnt | |
Eq CBlkSize | |
Eq CCc | |
Eq CClockId | |
Eq CDev | |
Eq CFsBlkCnt | |
Eq CFsFilCnt | |
Eq CGid | |
Eq CId | |
Eq CIno | |
Eq CKey | |
Eq CMode | |
Eq CNfds | |
Eq CNlink | |
Eq COff | |
Eq CPid | |
Eq CRLim | |
Eq CSocklen | |
Eq CSpeed | |
Eq CSsize | |
Eq CTcflag | |
Eq CTimer | |
Eq CUid | |
Eq Fd | |
Eq Endianness | |
Defined in Basement.Endianness | |
Eq OutOfBoundOperation | |
Defined in Basement.Exception Methods (==) :: OutOfBoundOperation -> OutOfBoundOperation -> Bool # (/=) :: OutOfBoundOperation -> OutOfBoundOperation -> Bool # | |
Eq RecastDestinationSize | |
Defined in Basement.Exception Methods (==) :: RecastDestinationSize -> RecastDestinationSize -> Bool # (/=) :: RecastDestinationSize -> RecastDestinationSize -> Bool # | |
Eq RecastSourceSize | |
Defined in Basement.Exception Methods (==) :: RecastSourceSize -> RecastSourceSize -> Bool # (/=) :: RecastSourceSize -> RecastSourceSize -> Bool # | |
Eq Encoding | |
Eq ASCII7_Invalid | |
Eq ISO_8859_1_Invalid | |
Eq UTF16_Invalid | |
Eq UTF32_Invalid | |
Eq AsciiString | |
Defined in Basement.Types.AsciiString | |
Eq Char7 | |
Eq FileSize | |
Eq Addr | |
Eq Word128 | |
Eq Word256 | |
Eq String | |
Eq CM | |
Eq ValidationFailure | |
Defined in Basement.UTF8.Types Methods (==) :: ValidationFailure -> ValidationFailure -> Bool # (/=) :: ValidationFailure -> ValidationFailure -> Bool # | |
Eq Bitmap Source # | |
Eq CSV Source # | |
Eq Escaping Source # | |
Eq Field Source # | |
Eq Row Source # | |
Eq IPv4 Source # | |
Eq IPv6 Source # | |
Eq Sign Source # | |
Eq And Source # | |
Eq Condition Source # | |
Eq PartialError Source # | |
Defined in Foundation.Partial | |
Eq Arch Source # | |
Eq OS Source # | |
Eq NanoSeconds Source # | |
Defined in Foundation.Time.Types | |
Eq Seconds Source # | |
Eq UUID Source # | |
Eq FileName Source # | |
Eq FilePath Source # | |
Eq Relativity Source # | |
Defined in Foundation.VFS.FilePath | |
Eq Module | |
Eq Ordering | |
Eq TrName | |
Eq TyCon | |
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 a => Eq (ZipList a) | Since: base-4.7.0.0 |
Eq a => Eq (And a) | Since: base-4.16 |
Eq a => Eq (Iff a) | Since: base-4.16 |
Eq a => Eq (Ior a) | Since: base-4.16 |
Eq a => Eq (Xor a) | Since: base-4.16 |
Eq a => Eq (Identity a) | Since: base-4.8.0.0 |
Eq a => Eq (First a) | Since: base-2.1 |
Eq a => Eq (Last a) | Since: base-2.1 |
Eq a => Eq (Down a) | Since: base-4.6.0.0 |
Eq a => Eq (First a) | Since: base-4.9.0.0 |
Eq a => Eq (Last a) | Since: base-4.9.0.0 |
Eq a => Eq (Max a) | Since: base-4.9.0.0 |
Eq a => Eq (Min a) | Since: base-4.9.0.0 |
Eq m => Eq (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods (==) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (/=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # | |
Eq a => Eq (Dual a) | Since: base-2.1 |
Eq a => Eq (Product a) | Since: base-2.1 |
Eq a => Eq (Sum a) | Since: base-2.1 |
Eq (TVar a) | Since: base-4.8.0.0 |
Eq (ForeignPtr a) | Since: base-2.1 |
Defined in GHC.ForeignPtr | |
Eq p => Eq (Par1 p) | Since: base-4.7.0.0 |
Eq (IORef a) | Pointer equality. Since: base-4.0.0.0 |
Eq (FunPtr a) | |
Eq (Ptr a) | Since: base-2.1 |
Eq a => Eq (Ratio a) | Since: base-2.1 |
Eq (Bits n) | |
(PrimType ty, Eq ty) => Eq (Block ty) | |
Eq (Zn n) | |
Eq (Zn64 n) | |
Eq a => Eq (Array a) | |
Eq a => Eq (BE a) | |
Eq a => Eq (LE a) | |
Eq (FinalPtr a) | |
Eq a => Eq (NonEmpty a) | |
Eq (CountOf ty) | |
Eq (Offset ty) | |
(PrimType ty, Eq ty) => Eq (UArray ty) | |
PrimType ty => Eq (ChunkedUArray ty) Source # | |
Defined in Foundation.Array.Chunked.Unboxed Methods (==) :: ChunkedUArray ty -> ChunkedUArray ty -> Bool # (/=) :: ChunkedUArray ty -> ChunkedUArray ty -> Bool # | |
Eq a => Eq (DList a) Source # | |
Eq a => Eq (NonEmpty a) | Since: base-4.9.0.0 |
Eq a => Eq (Maybe a) | Since: base-2.1 |
Eq a => Eq (a) | |
Eq a => Eq [a] | |
(Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 |
Eq (Proxy s) | Since: base-4.7.0.0 |
Eq a => Eq (Arg a b) | Since: base-4.9.0.0 |
Eq (TypeRep a) | Since: base-2.1 |
(Ix i, Eq e) => Eq (Array i e) | Since: base-2.1 |
Eq (U1 p) | Since: base-4.9.0.0 |
Eq (V1 p) | Since: base-4.9.0.0 |
PrimType a => Eq (BlockN n a) | |
Eq a => Eq (ListN n a) | |
(Eq a, Eq b) => Eq (These a b) | |
(Eq a, Eq b) => Eq (Tuple2 a b) Source # | |
(Eq a, Eq b) => Eq (a, b) | |
Eq a => Eq (Const a b) | Since: base-4.9.0.0 |
Eq (f a) => Eq (Ap f a) | Since: base-4.12.0.0 |
Eq (f a) => Eq (Alt f a) | Since: base-4.8.0.0 |
Eq (Coercion a b) | Since: base-4.7.0.0 |
Eq (a :~: b) | Since: base-4.7.0.0 |
Eq (OrderingI a b) | |
Eq (STArray s i e) | Since: base-2.1 |
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 a, Eq b, Eq c) => Eq (Tuple3 a b c) Source # | |
(Eq a, Eq b, Eq c) => Eq (a, b, c) | |
Eq (a :~~: b) | Since: base-4.10.0.0 |
(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 (Tuple4 a b c d) Source # | |
(Eq a, Eq b, Eq c, Eq d) => Eq (a, b, c, d) | |
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 a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f) | |
(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 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 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
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
andsucc
maxBound
should result in a runtime error.pred
minBound
fromEnum
andtoEnum
should give a runtime error if the result value is not representable in the result type. For example,
is an error.toEnum
7 ::Bool
enumFrom
andenumFromThen
should 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 = minBound
Methods
the successor of a value. For numeric types, succ
adds 1.
the predecessor of a value. For numeric types, pred
subtracts 1.
Convert from an Int
.
Convert to an Int
.
It is implementation-dependent what fromEnum
returns when
applied to a value that is too large to fit in an Int
.
Used in Haskell's translation of [n..]
with [n..] = enumFrom n
,
a possible implementation being enumFrom n = n : enumFrom (succ n)
.
For example:
enumFrom 4 :: [Integer] = [4,5,6,7,...]
enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]
enumFromThen :: a -> a -> [a] #
Used in Haskell's translation of [n,n'..]
with [n,n'..] = enumFromThen n n'
, a possible implementation being
enumFromThen n n' = n : n' : worker (f x) (f x n')
,
worker s v = v : worker s (s v)
, x = fromEnum n' - fromEnum n
and
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y
For example:
enumFromThen 4 6 :: [Integer] = [4,6,8,10...]
enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]
enumFromTo :: a -> a -> [a] #
Used in Haskell's translation of [n..m]
with
[n..m] = enumFromTo n m
, a possible implementation being
enumFromTo n m
| n <= m = n : enumFromTo (succ n) m
| otherwise = []
.
For example:
enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
enumFromTo 42 1 :: [Integer] = []
enumFromThenTo :: a -> a -> a -> [a] #
Used in Haskell's translation of [n,n'..m]
with
[n,n'..m] = enumFromThenTo n n' m
, a possible implementation
being enumFromThenTo n n' m = worker (f x) (c x) n m
,
x = fromEnum n' - fromEnum n
, c x = bool (>=) ((x 0)
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y
and
worker s c v m
| c v m = v : worker s c (s v) m
| otherwise = []
For example:
enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]
enumFromThenTo 6 8 2 :: [Int] = []
Instances
class Functor (f :: Type -> Type) where #
A type f
is a Functor if it provides a function fmap
which, given any types a
and b
lets you apply any function from (a -> b)
to turn an f a
into an f b
, preserving the
structure of f
. Furthermore f
needs to adhere to the following:
Note, that the second law follows from the free theorem of the type fmap
and
the first law, so you need only check that the former condition holds.
Minimal complete definition
Methods
fmap :: (a -> b) -> f a -> f b #
fmap
is used to apply a function of type (a -> b)
to a value of type f a
,
where f is a functor, to produce a value of type f b
.
Note that for any type constructor with more than one parameter (e.g., Either
),
only the last type parameter can be modified with fmap
(e.g., b
in `Either a b`).
Some type constructors with two parameters or more have a
instance that allows
both the last and the penultimate parameters to be mapped over.Bifunctor
Examples
Convert from a
to a Maybe
IntMaybe String
using show
:
>>>
fmap show Nothing
Nothing>>>
fmap show (Just 3)
Just "3"
Convert from an
to 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 ZipList | Since: base-2.1 |
Functor Handler | Since: base-4.6.0.0 |
Functor Identity | Since: base-4.8.0.0 |
Functor First | Since: base-4.8.0.0 |
Functor Last | Since: base-4.8.0.0 |
Functor Down | Since: base-4.11.0.0 |
Functor First | Since: base-4.9.0.0 |
Functor Last | Since: base-4.9.0.0 |
Functor Max | Since: base-4.9.0.0 |
Functor Min | Since: base-4.9.0.0 |
Functor Dual | Since: base-4.8.0.0 |
Functor Product | Since: base-4.8.0.0 |
Functor Sum | Since: base-4.8.0.0 |
Functor STM | Since: base-4.3.0.0 |
Functor Par1 | Since: base-4.9.0.0 |
Functor P | Since: base-4.8.0.0 |
Defined in Text.ParserCombinators.ReadP | |
Functor ReadP | Since: base-2.1 |
Functor Array | |
Functor Gen Source # | |
Functor Check Source # | |
Functor DList Source # | |
Functor Partial Source # | |
Functor IO | Since: base-2.1 |
Functor NonEmpty | Since: base-4.9.0.0 |
Functor Maybe | Since: base-2.1 |
Functor Solo | Since: base-4.15 |
Functor [] | Since: base-2.1 |
Monad m => Functor (WrappedMonad m) | Since: base-2.1 |
Defined in Control.Applicative Methods fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b # (<$) :: a -> WrappedMonad m b -> WrappedMonad m a # | |
Arrow a => Functor (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in Control.Arrow Methods fmap :: (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # (<$) :: a0 -> ArrowMonad a b -> ArrowMonad a a0 # | |
Functor (Either a) | Since: base-3.0 |
Functor (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Functor (Arg a) | Since: base-4.9.0.0 |
Functor (Array i) | Since: base-2.1 |
Functor (U1 :: Type -> Type) | Since: base-4.9.0.0 |
Functor (V1 :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Functor (ST s) | Since: base-2.1 |
Functor m => Functor (ResourceT m) Source # | |
Functor (Parser input) Source # | |
Functor (Result input) Source # | |
Functor (MonadRandomState gen) Source # | |
Defined in Foundation.Random.DRG Methods fmap :: (a -> b) -> MonadRandomState gen a -> MonadRandomState gen b # (<$) :: a -> MonadRandomState gen b -> MonadRandomState gen a # | |
Functor ((,) a) | Since: base-2.1 |
Arrow a => Functor (WrappedArrow a b) | Since: base-2.1 |
Defined in Control.Applicative Methods fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # (<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
Functor m => Functor (Kleisli m a) | Since: base-4.14.0.0 |
Functor (Const m :: Type -> Type) | Since: base-2.1 |
Functor f => Functor (Ap f) | Since: base-4.12.0.0 |
Functor f => Functor (Alt f) | Since: base-4.8.0.0 |
Functor f => Functor (Rec1 f) | Since: base-4.9.0.0 |
Functor (URec (Ptr ()) :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Functor (URec Char :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Functor (URec Double :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Functor (URec Float :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Functor (URec Int :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Functor (URec Word :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Monad m => Functor (Reader r m) | |
Monad m => Functor (State s m) | |
Monad m => Functor (ZipSink i m) Source # | |
Functor m => Functor (ExceptT e m) Source # | |
Functor m => Functor (ReaderT r m) Source # | |
Functor m => Functor (StateT s m) Source # | |
Functor ((,,) a b) | Since: base-4.14.0.0 |
(Functor f, Functor g) => Functor (f :*: g) | Since: base-4.9.0.0 |
(Functor f, Functor g) => Functor (f :+: g) | Since: base-4.9.0.0 |
Functor (K1 i c :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Functor (Conduit i o m) Source # | |
Functor ((,,,) a b c) | Since: base-4.14.0.0 |
Functor ((->) r) | Since: base-2.1 |
(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 |
Monad state => Functor (Builder collection mutCollection step state err) | |
Integral Literal support
e.g. 123 :: Integer 123 :: Word8
Methods
fromInteger :: Integer -> a #
Instances
class Fractional a where #
Fractional Literal support
e.g. 1.2 :: Double 0.03 :: Float
Methods
fromRational :: Rational -> a #
Instances
Fractional CDouble | |
Defined in Basement.Compat.NumLiteral Methods fromRational :: Rational -> CDouble # | |
Fractional CFloat | |
Defined in Basement.Compat.NumLiteral Methods fromRational :: Rational -> CFloat # | |
Fractional Rational | |
Defined in Basement.Compat.NumLiteral Methods fromRational :: Rational -> Rational # | |
Fractional Double | |
Defined in Basement.Compat.NumLiteral Methods fromRational :: Rational -> Double # | |
Fractional Float | |
Defined in Basement.Compat.NumLiteral Methods fromRational :: Rational -> Float # |
class HasNegation a where #
Negation support
e.g. -(f x)
Instances
class Bifunctor (p :: Type -> Type -> Type) where #
A bifunctor is a type constructor that takes
two type arguments and is a functor in both arguments. That
is, unlike with Functor
, a type constructor such as Either
does not need to be partially applied for a Bifunctor
instance, and the methods in this class permit mapping
functions over the Left
value or the Right
value,
or both at the same time.
Formally, the class Bifunctor
represents a bifunctor
from Hask
-> Hask
.
Intuitively it is a bifunctor where both the first and second arguments are covariant.
You can define a Bifunctor
by either defining bimap
or by
defining both first
and second
.
If you supply bimap
, you should ensure that:
bimap
id
id
≡id
If you supply first
and second
, ensure:
first
id
≡id
second
id
≡id
If you supply both, you should also ensure:
bimap
f g ≡first
f.
second
g
These ensure by parametricity:
bimap
(f.
g) (h.
i) ≡bimap
f h.
bimap
g ifirst
(f.
g) ≡first
f.
first
gsecond
(f.
g) ≡second
f.
second
g
Since: base-4.8.0.0
Methods
bimap :: (a -> b) -> (c -> d) -> p a c -> p b d #
Map over both arguments at the same time.
bimap
f g ≡first
f.
second
g
Examples
>>>
bimap toUpper (+1) ('j', 3)
('J',4)
>>>
bimap toUpper (+1) (Left 'j')
Left 'J'
>>>
bimap toUpper (+1) (Right 3)
Right 4
Instances
Bifunctor Either | Since: base-4.8.0.0 |
Bifunctor Arg | Since: base-4.9.0.0 |
Bifunctor (,) | Since: base-4.8.0.0 |
Bifunctor (Const :: Type -> Type -> Type) | Since: base-4.8.0.0 |
Bifunctor ((,,) x1) | Since: base-4.8.0.0 |
Bifunctor (K1 i :: Type -> Type -> Type) | Since: base-4.9.0.0 |
Bifunctor ((,,,) x1 x2) | Since: base-4.8.0.0 |
Bifunctor ((,,,,) x1 x2 x3) | Since: base-4.8.0.0 |
Bifunctor ((,,,,,) x1 x2 x3 x4) | Since: base-4.8.0.0 |
Bifunctor ((,,,,,,) x1 x2 x3 x4 x5) | Since: base-4.8.0.0 |
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:
(<*>
) =liftA2
id
liftA2
f x y = f<$>
x<*>
y
Further, any definition must satisfy the following:
- Identity
pure
id
<*>
v = v- Composition
pure
(.)<*>
u<*>
v<*>
w = u<*>
(v<*>
w)- Homomorphism
pure
f<*>
pure
x =pure
(f x)- Interchange
u
<*>
pure
y =pure
($
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
liftA2
p (liftA2
q u v) =liftA2
f u .liftA2
g v
If f
is also a Monad
, it should satisfy
(which implies that pure
and <*>
satisfy the applicative functor laws).
Methods
Lift a value.
(<*>) :: f (a -> b) -> f a -> f b infixl 4 #
Sequential application.
A few functors support an implementation of <*>
that is more
efficient than the default one.
Example
Used in combination with (
, <$>
)(
can be used to build a record.<*>
)
>>>
data MyState = MyState {arg1 :: Foo, arg2 :: Bar, arg3 :: Baz}
>>>
produceFoo :: Applicative f => f Foo
>>>
produceBar :: Applicative f => f Bar
>>>
produceBaz :: Applicative f => f Baz
>>>
mkState :: Applicative f => f MyState
>>>
mkState = MyState <$> produceFoo <*> produceBar <*> produceBaz
liftA2 :: (a -> b -> c) -> f a -> f b -> f c #
Lift a binary function to actions.
Some functors support an implementation of liftA2
that is more
efficient than the default one. In particular, if fmap
is an
expensive operation, it is likely better to use liftA2
than to
fmap
over the structure and then use <*>
.
This became a typeclass method in 4.10.0.0. Prior to that, it was
a function defined in terms of <*>
and fmap
.
Example
>>>
liftA2 (,) (Just 3) (Just 5)
Just (3,5)
(*>) :: f a -> f b -> f b infixl 4 #
Sequence actions, discarding the value of the first argument.
Examples
If used in conjunction with the Applicative instance for Maybe
,
you can chain Maybe computations, with a possible "early return"
in case of Nothing
.
>>>
Just 2 *> Just 3
Just 3
>>>
Nothing *> Just 3
Nothing
Of course a more interesting use case would be to have effectful computations instead of just returning pure values.
>>>
import Data.Char
>>>
import Text.ParserCombinators.ReadP
>>>
let p = string "my name is " *> munch1 isAlpha <* eof
>>>
readP_to_S p "my name is Simon"
[("Simon","")]
(<*) :: f a -> f b -> f a infixl 4 #
Sequence actions, discarding the value of the second argument.
Instances
Applicative ZipList | f <$> ZipList xs1 <*> ... <*> ZipList xsN = ZipList (zipWithN f xs1 ... xsN) where (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <*> ZipList "567" <*> ZipList [1..] = ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..]) = ZipList {getZipList = ["a5","b6b6","c7c7c7"]} Since: base-2.1 |
Applicative Identity | Since: base-4.8.0.0 |
Applicative First | Since: base-4.8.0.0 |
Applicative Last | Since: base-4.8.0.0 |
Applicative Down | Since: base-4.11.0.0 |
Applicative First | Since: base-4.9.0.0 |
Applicative Last | Since: base-4.9.0.0 |
Applicative Max | Since: base-4.9.0.0 |
Applicative Min | Since: base-4.9.0.0 |
Applicative Dual | Since: base-4.8.0.0 |
Applicative Product | Since: base-4.8.0.0 |
Applicative Sum | Since: base-4.8.0.0 |
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 Gen Source # | |
Applicative Check Source # | |
Applicative DList Source # | |
Applicative Partial Source # | |
Applicative IO | Since: base-2.1 |
Applicative NonEmpty | Since: base-4.9.0.0 |
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 # | |
Arrow a => Applicative (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in Control.Arrow Methods pure :: a0 -> ArrowMonad a a0 # (<*>) :: ArrowMonad a (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # liftA2 :: (a0 -> b -> c) -> ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a c # (*>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # (<*) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a a0 # | |
Applicative (Either e) | Since: base-3.0 |
Applicative (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Applicative (U1 :: Type -> Type) | Since: base-4.9.0.0 |
Applicative (ST s) | Since: base-4.4.0.0 |
Applicative m => Applicative (ResourceT m) Source # | |
Defined in Foundation.Conduit.Internal | |
ParserSource input => Applicative (Parser input) Source # | |
Defined in Foundation.Parser | |
Applicative (MonadRandomState gen) Source # | |
Defined in Foundation.Random.DRG Methods pure :: a -> MonadRandomState gen a # (<*>) :: MonadRandomState gen (a -> b) -> MonadRandomState gen a -> MonadRandomState gen b # liftA2 :: (a -> b -> c) -> MonadRandomState gen a -> MonadRandomState gen b -> MonadRandomState gen c # (*>) :: MonadRandomState gen a -> MonadRandomState gen b -> MonadRandomState gen b # (<*) :: MonadRandomState gen a -> MonadRandomState gen b -> MonadRandomState gen a # | |
Monoid a => Applicative ((,) a) | For tuples, the ("hello ", (+15)) <*> ("world!", 2002) ("hello world!",2017) Since: base-2.1 |
Arrow a => Applicative (WrappedArrow a b) | Since: base-2.1 |
Defined in Control.Applicative Methods pure :: a0 -> WrappedArrow a b a0 # (<*>) :: WrappedArrow a b (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # liftA2 :: (a0 -> b0 -> c) -> WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b c # (*>) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b b0 # (<*) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
Applicative m => Applicative (Kleisli m a) | Since: base-4.14.0.0 |
Defined in Control.Arrow | |
Monoid m => Applicative (Const m :: Type -> Type) | Since: base-2.0.1 |
Applicative f => Applicative (Ap f) | Since: base-4.12.0.0 |
Applicative f => Applicative (Alt f) | Since: base-4.8.0.0 |
Applicative f => Applicative (Rec1 f) | Since: base-4.9.0.0 |
Monad m => Applicative (Reader r m) | |
Defined in Basement.Compat.MonadTrans | |
Monad m => Applicative (State s m) | |
Defined in Basement.Compat.MonadTrans | |
Monad m => Applicative (ZipSink i m) Source # | |
Defined in Foundation.Conduit.Internal | |
Monad m => Applicative (ExceptT e m) Source # | |
Defined in Foundation.Monad.Except | |
Applicative m => Applicative (ReaderT r m) Source # | |
Defined in Foundation.Monad.Reader | |
(Applicative m, Monad m) => Applicative (StateT s m) Source # | |
Defined in Foundation.Monad.State | |
(Monoid a, Monoid b) => Applicative ((,,) a b) | Since: base-4.14.0.0 |
(Applicative f, Applicative g) => Applicative (f :*: g) | Since: base-4.9.0.0 |
Monoid c => Applicative (K1 i c :: Type -> Type) | Since: base-4.12.0.0 |
Applicative (Conduit i o m) Source # | |
Defined in Foundation.Conduit.Internal Methods pure :: a -> Conduit i o m a # (<*>) :: Conduit i o m (a -> b) -> Conduit i o m a -> Conduit i o m b # liftA2 :: (a -> b -> c) -> Conduit i o m a -> Conduit i o m b -> Conduit i o m c # (*>) :: Conduit i o m a -> Conduit i o m b -> Conduit i o m b # (<*) :: Conduit i o m a -> Conduit i o m b -> Conduit i o m a # | |
(Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c) | Since: base-4.14.0.0 |
Defined in GHC.Base | |
Applicative ((->) r) | Since: base-2.1 |
(Applicative f, Applicative g) => Applicative (f :.: g) | Since: base-4.9.0.0 |
Applicative f => Applicative (M1 i c f) | Since: base-4.9.0.0 |
Monad state => Applicative (Builder collection mutCollection step state err) | |
Defined in Basement.MutableBuilder Methods pure :: a -> Builder collection mutCollection step state err a # (<*>) :: Builder collection mutCollection step state err (a -> b) -> Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b # liftA2 :: (a -> b -> c) -> Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err c # (*>) :: Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err b # (<*) :: Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err a # |
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
return
a>>=
k = k a- Right identity
m
>>=
return
= m- Associativity
m
>>=
(\x -> k x>>=
h) = (m>>=
k)>>=
h
Furthermore, the Monad
and Applicative
operations should relate as follows:
The above laws imply:
and that pure
and (<*>
) satisfy the applicative functor laws.
The instances of Monad
for lists, Maybe
and IO
defined in the Prelude satisfy these laws.
Minimal complete definition
Methods
(>>=) :: m a -> (a -> m b) -> m b infixl 1 #
Sequentially compose two actions, passing any value produced by the first as an argument to the second.
'as
' can be understood as the >>=
bsdo
expression
do a <- as bs a
(>>) :: m a -> m b -> m b infixl 1 #
Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.
'as
' can be understood as the >>
bsdo
expression
do as bs
Inject a value into the monadic type.
Instances
Monad Identity | Since: base-4.8.0.0 |
Monad First | Since: base-4.8.0.0 |
Monad Last | Since: base-4.8.0.0 |
Monad Down | Since: base-4.11.0.0 |
Monad First | Since: base-4.9.0.0 |
Monad Last | Since: base-4.9.0.0 |
Monad Max | Since: base-4.9.0.0 |
Monad Min | Since: base-4.9.0.0 |
Monad Dual | Since: base-4.8.0.0 |
Monad Product | Since: base-4.8.0.0 |
Monad Sum | Since: base-4.8.0.0 |
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 Gen Source # | |
Monad Check Source # | |
Monad DList Source # | |
Monad Partial Source # | |
Monad IO | Since: base-2.1 |
Monad NonEmpty | Since: base-4.9.0.0 |
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 # | |
ArrowApply a => Monad (ArrowMonad a) | Since: base-2.1 |
Defined in Control.Arrow Methods (>>=) :: ArrowMonad a a0 -> (a0 -> ArrowMonad a b) -> ArrowMonad a b # (>>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # return :: a0 -> ArrowMonad a a0 # | |
Monad (Either e) | Since: base-4.4.0.0 |
Monad (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Monad (U1 :: Type -> Type) | Since: base-4.9.0.0 |
Monad (ST s) | Since: base-2.1 |
Monad m => Monad (ResourceT m) Source # | |
ParserSource input => Monad (Parser input) Source # | |
Monad (MonadRandomState gen) Source # | |
Defined in Foundation.Random.DRG Methods (>>=) :: MonadRandomState gen a -> (a -> MonadRandomState gen b) -> MonadRandomState gen b # (>>) :: MonadRandomState gen a -> MonadRandomState gen b -> MonadRandomState gen b # return :: a -> MonadRandomState gen a # | |
Monoid a => Monad ((,) a) | Since: base-4.9.0.0 |
Monad m => Monad (Kleisli m a) | Since: base-4.14.0.0 |
Monad f => Monad (Ap f) | Since: base-4.12.0.0 |
Monad f => Monad (Alt f) | Since: base-4.8.0.0 |
Monad f => Monad (Rec1 f) | Since: base-4.9.0.0 |
Monad m => Monad (Reader r m) | |
Monad m => Monad (State r m) | |
Monad m => Monad (ExceptT e m) Source # | |
Monad m => Monad (ReaderT r m) Source # | |
(Functor m, Monad m) => Monad (StateT s m) Source # | |
(Monoid a, Monoid b) => Monad ((,,) a b) | Since: base-4.14.0.0 |
(Monad f, Monad g) => Monad (f :*: g) | Since: base-4.9.0.0 |
Monad (Conduit i o m) Source # | |
(Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c) | Since: base-4.14.0.0 |
Monad ((->) r) | Since: base-2.1 |
Monad f => Monad (M1 i c f) | Since: base-4.9.0.0 |
Monad state => Monad (Builder collection mutCollection step state err) | |
Defined in Basement.MutableBuilder Methods (>>=) :: Builder collection mutCollection step state err a -> (a -> Builder collection mutCollection step state err b) -> Builder collection mutCollection step state err b # (>>) :: Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err b # return :: a -> Builder collection mutCollection step state err a # |
(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1 #
Same as >>=
, but with the arguments interchanged.
Class for string-like datastructures; used by the overloaded string extension (-XOverloadedStrings in GHC).
Methods
fromString :: String -> a #
Instances
IsString AsciiString | |
Defined in Basement.Types.AsciiString Methods fromString :: String -> AsciiString # | |
IsString String | |
Defined in Basement.UTF8.Base Methods fromString :: String0 -> String # | |
IsString IPv4 Source # | |
Defined in Foundation.Network.IPv4 Methods fromString :: String -> IPv4 # | |
IsString IPv6 Source # | |
Defined in Foundation.Network.IPv6 Methods fromString :: String -> IPv6 # | |
IsString FileName Source # | |
Defined in Foundation.VFS.FilePath Methods fromString :: String -> FileName # | |
IsString FilePath Source # | |
Defined in Foundation.VFS.FilePath Methods fromString :: String -> FilePath # | |
IsString a => IsString (Identity a) | Since: base-4.9.0.0 |
Defined in Data.String Methods fromString :: String -> Identity a # | |
a ~ Char => IsString [a] |
Since: base-2.1 |
Defined in Data.String Methods fromString :: String -> [a] # | |
IsString a => IsString (Const a b) | Since: base-4.9.0.0 |
Defined in Data.String Methods fromString :: String -> Const a b # |
The IsList
class and its methods are intended to be used in
conjunction with the OverloadedLists extension.
Since: base-4.7.0.0
Methods
The fromList
function constructs the structure l
from the given
list of Item l
fromListN :: Int -> [Item l] -> l #
The fromListN
function takes the input list's length and potentially
uses it to construct the structure l
more efficiently compared to
fromList
. If the given number does not equal to the input list's length
the behaviour of fromListN
is not specified.
fromListN (length xs) xs == fromList xs
The toList
function extracts a list of Item l
from the structure l
.
It should satisfy fromList . toList = id.
Instances
Numeric type classes
class (Integral a, Eq a, Ord a) => IsIntegral a where #
Number literals, convertible through the generic Integer type.
all number are Enum'erable, meaning that you can move to next element
Instances
class IsIntegral a => IsNatural a where #
Non Negative Number literals, convertible through the generic Natural type
Instances
types that have sign and can be made absolute
Represent class of things that can be added together, contains a neutral element and is commutative.
x + azero = x azero + x = x x + y = y + x
Instances
class Subtractive a where #
Represent class of things that can be subtracted.
Note that the result is not necessary of the same type as the operand depending on the actual type.
For example:
(-) :: Int -> Int -> Int (-) :: DateTime -> DateTime -> Seconds (-) :: Ptr a -> Ptr a -> PtrDiff (-) :: Natural -> Natural -> Maybe Natural
Associated Types
type Difference a #
Methods
(-) :: a -> a -> Difference a infixl 6 #
Instances
class Multiplicative a where #
Represent class of things that can be multiplied together
x * midentity = x midentity * x = x
Methods
Identity element over multiplication
Multiplication of 2 elements that result in another element
(^) :: (IsNatural n, Enum n, IDivisible n) => a -> n -> a infixr 8 #
Raise to power, repeated multiplication e.g. > a ^ 2 = a * a > a ^ 10 = (a ^ 5) * (a ^ 5) .. (^) :: (IsNatural n) => a -> n -> a
Instances
class (Additive a, Multiplicative a) => IDivisible a where #
Represent types that supports an euclidian division
(x ‘div‘ y) * y + (x ‘mod‘ y) == x
Instances
class Multiplicative a => Divisible a where #
Support for division between same types
This is likely to change to represent specific mathematic divisions
Data types
The Maybe
type encapsulates an optional value. A value of type
either contains a value of type Maybe
aa
(represented as
),
or it is empty (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
MonadFail Maybe | Since: base-4.9.0.0 |
Defined in Control.Monad.Fail | |
MonadFix Maybe | Since: base-2.1 |
Defined in Control.Monad.Fix | |
Foldable Maybe | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
Traversable Maybe | Since: base-2.1 |
Alternative Maybe | Since: base-2.1 |
Applicative Maybe | Since: base-2.1 |
Functor Maybe | Since: base-2.1 |
Monad Maybe | Since: base-2.1 |
MonadPlus Maybe | Since: base-2.1 |
MonadFailure Maybe | |
Generic1 Maybe | |
Data a => Data (Maybe a) | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Maybe a -> c (Maybe a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Maybe a) # toConstr :: Maybe a -> Constr # dataTypeOf :: Maybe a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Maybe a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Maybe a)) # gmapT :: (forall b. Data b => b -> b) -> Maybe a -> Maybe a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r # gmapQ :: (forall d. Data d => d -> u) -> Maybe a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Maybe a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # | |
Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
Generic (Maybe a) | |
SingKind a => SingKind (Maybe a) | Since: base-4.9.0.0 |
Defined in GHC.Generics Associated Types type DemoteRep (Maybe a) | |
Read a => Read (Maybe a) | Since: base-2.1 |
Show a => Show (Maybe a) | Since: base-2.1 |
NormalForm a => NormalForm (Maybe a) | |
Defined in Basement.NormalForm Methods toNormalForm :: Maybe a -> () # | |
Arbitrary a => Arbitrary (Maybe a) Source # | |
IsField a => IsField (Maybe a) Source # | |
Eq a => Eq (Maybe a) | Since: base-2.1 |
Ord a => Ord (Maybe a) | Since: base-2.1 |
SingI ('Nothing :: Maybe a) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
SingI a2 => SingI ('Just a2 :: Maybe a1) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
From (Maybe a) (Either () a) | |
Defined in Basement.From | |
type Failure Maybe | |
Defined in Basement.Monad | |
type Rep1 Maybe | Since: base-4.6.0.0 |
type DemoteRep (Maybe a) | |
Defined in GHC.Generics | |
type Rep (Maybe a) | Since: base-4.6.0.0 |
Defined in GHC.Generics | |
data Sing (b :: Maybe a) | |
Instances
Data Ordering | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Ordering -> c Ordering # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Ordering # toConstr :: Ordering -> Constr # dataTypeOf :: Ordering -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Ordering) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Ordering) # gmapT :: (forall b. Data b => b -> b) -> Ordering -> Ordering # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Ordering -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Ordering -> r # gmapQ :: (forall d. Data d => d -> u) -> Ordering -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Ordering -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering # | |
Monoid Ordering | Since: base-2.1 |
Semigroup Ordering | Since: base-4.9.0.0 |
Bounded Ordering | Since: base-2.1 |
Enum Ordering | Since: base-2.1 |
Generic Ordering | |
Ix Ordering | Since: base-2.1 |
Defined in GHC.Ix Methods range :: (Ordering, Ordering) -> [Ordering] # index :: (Ordering, Ordering) -> Ordering -> Int # unsafeIndex :: (Ordering, Ordering) -> Ordering -> Int # inRange :: (Ordering, Ordering) -> Ordering -> Bool # rangeSize :: (Ordering, Ordering) -> Int # unsafeRangeSize :: (Ordering, Ordering) -> Int # | |
Read Ordering | Since: base-2.1 |
Show Ordering | Since: base-2.1 |
Eq Ordering | |
Ord Ordering | |
Defined in GHC.Classes | |
type Rep Ordering | Since: base-4.6.0.0 |
Instances
Data Bool | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Bool -> c Bool # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Bool # dataTypeOf :: Bool -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Bool) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Bool) # gmapT :: (forall b. Data b => b -> b) -> Bool -> Bool # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Bool -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Bool -> r # gmapQ :: (forall d. Data d => d -> u) -> Bool -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Bool -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Bool -> m Bool # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Bool -> m Bool # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Bool -> m Bool # | |
Storable Bool | Since: base-2.1 |
Defined in Foreign.Storable | |
Bits Bool | Interpret Since: base-4.7.0.0 |
Defined in GHC.Bits Methods (.&.) :: Bool -> Bool -> Bool # (.|.) :: Bool -> Bool -> Bool # complement :: Bool -> Bool # shift :: Bool -> Int -> Bool # rotate :: Bool -> Int -> Bool # setBit :: Bool -> Int -> Bool # clearBit :: Bool -> Int -> Bool # complementBit :: Bool -> Int -> Bool # testBit :: Bool -> Int -> Bool # bitSizeMaybe :: Bool -> Maybe Int # shiftL :: Bool -> Int -> Bool # unsafeShiftL :: Bool -> Int -> Bool # shiftR :: Bool -> Int -> Bool # unsafeShiftR :: Bool -> Int -> Bool # rotateL :: Bool -> Int -> Bool # | |
FiniteBits Bool | Since: base-4.7.0.0 |
Defined in GHC.Bits Methods finiteBitSize :: Bool -> Int # countLeadingZeros :: Bool -> Int # countTrailingZeros :: Bool -> Int # | |
Bounded Bool | Since: base-2.1 |
Enum Bool | Since: base-2.1 |
Generic Bool | |
SingKind Bool | Since: base-4.9.0.0 |
Defined in GHC.Generics Associated Types type DemoteRep Bool | |
Ix Bool | Since: base-2.1 |
Read Bool | Since: base-2.1 |
Show Bool | Since: base-2.1 |
BitOps Bool | |
FiniteBitsOps Bool | |
NormalForm Bool | |
Defined in Basement.NormalForm Methods toNormalForm :: Bool -> () # | |
Arbitrary Bool Source # | |
IsProperty Bool Source # | |
IsField Bool Source # | |
Eq Bool | |
Ord Bool | |
SingI 'False | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
SingI 'True | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
IsProperty (String, Bool) Source # | |
type DemoteRep Bool | |
Defined in GHC.Generics | |
type Rep Bool | Since: base-4.6.0.0 |
data Sing (a :: Bool) | |
The character type Char
is an enumeration whose values represent
Unicode (or equivalently ISO/IEC 10646) code points (i.e. characters, see
http://www.unicode.org/ for details). This set extends the ISO 8859-1
(Latin-1) character set (the first 256 characters), which is itself an extension
of the ASCII character set (the first 128 characters). A character literal in
Haskell has type Char
.
To convert a Char
to or from the corresponding Int
value defined
by Unicode, use toEnum
and fromEnum
from the
Enum
class respectively (or equivalently ord
and
chr
).
Instances
Data Char | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Char -> c Char # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Char # dataTypeOf :: Char -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Char) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Char) # gmapT :: (forall b. Data b => b -> b) -> Char -> Char # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Char -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Char -> r # gmapQ :: (forall d. Data d => d -> u) -> Char -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Char -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Char -> m Char # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Char -> m Char # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Char -> m Char # | |
Storable Char | Since: base-2.1 |
Defined in Foreign.Storable | |
Bounded Char | Since: base-2.1 |
Enum Char | Since: base-2.1 |
Ix Char | Since: base-2.1 |
Read Char | Since: base-2.1 |
Show Char | Since: base-2.1 |
IsChar Char | Since: base-2.1 |
PrintfArg Char | Since: base-2.1 |
Defined in Text.Printf | |
NormalForm Char | |
Defined in Basement.NormalForm Methods toNormalForm :: Char -> () # | |
Subtractive Char | |
Defined in Basement.Numerical.Subtractive Associated Types type Difference Char # | |
PrimMemoryComparable Char | |
Defined in Basement.PrimType | |
PrimType Char | |
Defined in Basement.PrimType Methods primSizeInBytes :: Proxy Char -> CountOf Word8 # primShiftToBytes :: Proxy Char -> Int # primBaUIndex :: ByteArray# -> Offset Char -> Char # primMbaURead :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Char -> prim Char # primMbaUWrite :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Char -> Char -> prim () # primAddrIndex :: Addr# -> Offset Char -> Char # primAddrRead :: PrimMonad prim => Addr# -> Offset Char -> prim Char # primAddrWrite :: PrimMonad prim => Addr# -> Offset Char -> Char -> prim () # | |
Arbitrary Char Source # | |
Storable Char Source # | |
StorableFixed Char Source # | |
IsField Char Source # | |
Eq Char | |
Ord Char | |
Generic1 (URec Char :: k -> Type) | |
Foldable (UChar :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UChar m -> m # foldMap :: Monoid m => (a -> m) -> UChar a -> m # foldMap' :: Monoid m => (a -> m) -> UChar a -> m # foldr :: (a -> b -> b) -> b -> UChar a -> b # foldr' :: (a -> b -> b) -> b -> UChar a -> b # foldl :: (b -> a -> b) -> b -> UChar a -> b # foldl' :: (b -> a -> b) -> b -> UChar a -> b # foldr1 :: (a -> a -> a) -> UChar a -> a # foldl1 :: (a -> a -> a) -> UChar a -> a # elem :: Eq a => a -> UChar a -> Bool # maximum :: Ord a => UChar a -> a # minimum :: Ord a => UChar a -> a # | |
Traversable (UChar :: Type -> Type) | Since: base-4.9.0.0 |
IsField [Char] Source # | |
Functor (URec Char :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Generic (URec Char p) | |
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.Generics | |
type NatNumMaxBound Char | |
Defined in Basement.Nat | |
type Difference Char | |
Defined in Basement.Numerical.Subtractive | |
type PrimSize Char | |
Defined in Basement.PrimType | |
data URec Char (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
type Compare (a :: Char) (b :: Char) | |
Defined in Data.Type.Ord | |
type Rep1 (URec Char :: k -> Type) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
type Rep (URec Char p) | Since: base-4.9.0.0 |
Defined in GHC.Generics |
ASCII value between 0x0 and 0x7f
Instances
Show Char7 | |
NormalForm Char7 | |
Defined in Basement.NormalForm Methods toNormalForm :: Char7 -> () # | |
PrimType Char7 | |
Defined in Basement.PrimType Methods primSizeInBytes :: Proxy Char7 -> CountOf Word8 # primShiftToBytes :: Proxy Char7 -> Int # primBaUIndex :: ByteArray# -> Offset Char7 -> Char7 # primMbaURead :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Char7 -> prim Char7 # primMbaUWrite :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Char7 -> Char7 -> prim () # primAddrIndex :: Addr# -> Offset Char7 -> Char7 # primAddrRead :: PrimMonad prim => Addr# -> Offset Char7 -> prim Char7 # primAddrWrite :: PrimMonad prim => Addr# -> Offset Char7 -> Char7 -> prim () # | |
Arbitrary Char7 Source # | |
Eq Char7 | |
Ord Char7 | |
type NatNumMaxBound Char7 | |
Defined in Basement.Nat | |
type PrimSize Char7 | |
Defined in Basement.PrimType |
A value of type
is a computation which, when performed,
does some I/O before returning 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
MonadFail IO | Since: base-4.9.0.0 |
Defined in Control.Monad.Fail | |
MonadFix IO | Since: base-2.1 |
Defined in Control.Monad.Fix | |
MonadIO IO | Since: base-4.9.0.0 |
Defined in Control.Monad.IO.Class | |
Alternative IO | 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 | Since: base-4.9.0.0 |
PrimMonad IO | |
Defined in Basement.Monad Methods primitive :: (State# (PrimState IO) -> (# State# (PrimState IO), a #)) -> IO a # primThrow :: Exception e => e -> IO a # unPrimMonad :: IO a -> State# (PrimState IO) -> (# State# (PrimState IO), a #) # primVarNew :: a -> IO (PrimVar IO a) # primVarRead :: PrimVar IO a -> IO a # primVarWrite :: PrimVar IO a -> a -> IO () # | |
MonadBracket IO Source # | |
Defined in Foundation.Monad.Exception Methods generalBracket :: IO a -> (a -> b -> IO ignored1) -> (a -> SomeException -> IO ignored2) -> (a -> IO b) -> IO b Source # | |
MonadCatch IO Source # | |
MonadThrow IO Source # | |
MonadRandom IO Source # | |
Defined in Foundation.Random.Class | |
Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
Semigroup a => Semigroup (IO a) | Since: base-4.10.0.0 |
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 | |
type PrimState IO | |
Defined in Basement.Monad | |
type PrimVar IO | |
Defined in Basement.Monad |
The Either
type represents values with two possibilities: a value of
type
is either Either
a b
or Left
a
.Right
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
is the type of values which can be either
a Either
String
Int
String
or an Int
. The Left
constructor can be used only on
String
s, and the Right
constructor can be used only on Int
s:
>>>
let s = Left "foo" :: Either String Int
>>>
s
Left "foo">>>
let n = Right 3 :: Either String Int
>>>
n
Right 3>>>
:type s
s :: Either String Int>>>
:type n
n :: 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) s
Left "foo">>>
fmap (*2) n
Right 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 Int
s.
>>>
:{
let parseMultiple :: Either String Int parseMultiple = do x <- parseEither '1' y <- parseEither '2' return (x + y)>>>
:}
>>>
parseMultiple
Right 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)>>>
:}
>>>
parseMultiple
Left "parse error"
Instances
Bifunctor Either | Since: base-4.8.0.0 |
Generic1 (Either a :: Type -> Type) | |
MonadFix (Either e) | Since: base-4.3.0.0 |
Defined in Control.Monad.Fix | |
Foldable (Either a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # toList :: Either a a0 -> [a0] # length :: Either a a0 -> Int # elem :: Eq a0 => a0 -> Either a a0 -> Bool # maximum :: Ord a0 => Either a a0 -> a0 # minimum :: Ord a0 => Either a a0 -> a0 # | |
Traversable (Either a) | Since: base-4.7.0.0 |
Defined in Data.Traversable | |
Applicative (Either e) | Since: base-3.0 |
Functor (Either a) | Since: base-3.0 |
Monad (Either e) | Since: base-4.4.0.0 |
MonadFailure (Either a) | |
From (Maybe a) (Either () a) | |
Defined in Basement.From | |
(Data a, Data b) => Data (Either a b) | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> Either a b -> c (Either a b) # gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Either a b) # toConstr :: Either a b -> Constr # dataTypeOf :: Either a b -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Either a b)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Either a b)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Either a b -> Either a b # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r # gmapQ :: (forall d. Data d => d -> u) -> Either a b -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Either a b -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # | |
Semigroup (Either a b) | Since: base-4.9.0.0 |
Generic (Either a b) | |
(Read a, Read b) => Read (Either a b) | Since: base-3.0 |
(Show a, Show b) => Show (Either a b) | Since: base-3.0 |
(NormalForm l, NormalForm r) => NormalForm (Either l r) | |
Defined in Basement.NormalForm Methods toNormalForm :: Either l r -> () # | |
(Arbitrary l, Arbitrary r) => Arbitrary (Either l r) Source # | |
(Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 |
(Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 |
From (Either a b) (These a b) | |
Defined in Basement.From | |
type Rep1 (Either a :: Type -> Type) | Since: base-4.6.0.0 |
Defined in GHC.Generics type Rep1 (Either a :: Type -> Type) = D1 ('MetaData "Either" "Data.Either" "base" '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 Failure (Either a) | |
Defined in Basement.Monad | |
type Rep (Either a b) | Since: base-4.6.0.0 |
Defined in GHC.Generics type Rep (Either a b) = D1 ('MetaData "Either" "Data.Either" "base" '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))) |
Numbers
8-bit signed integer type
Instances
16-bit signed integer type
Instances
32-bit signed integer type
Instances
64-bit signed integer type
Instances
8-bit unsigned integer type
Instances
16-bit unsigned integer type
Instances
32-bit unsigned integer type
Instances
64-bit unsigned integer type
Instances
Instances
128 bits Word
Instances
256 bits Word
Instances
A fixed-precision integer type with at least the range [-2^29 .. 2^29-1]
.
The exact range for a given implementation can be determined by using
minBound
and maxBound
from the Bounded
class.
Instances
Arbitrary precision integers. In contrast with fixed-size integral types
such as Int
, the Integer
type represents the entire infinite range of
integers.
Integers are stored in a kind of sign-magnitude form, hence do not expect two's complement form when using bit operations.
If the value is small (fit into an Int
), IS
constructor is used.
Otherwise Integer
and IN
constructors are used to store a BigNat
representing respectively the positive or the negative value magnitude.
Invariant: Integer
and IN
are used iff value doesn't fit in IS
Instances
Natural number
Invariant: numbers <= 0xffffffffffffffff use the NS
constructor
Instances
Single-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE single-precision type.
Instances
Data Float | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Float -> c Float # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Float # dataTypeOf :: Float -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Float) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Float) # gmapT :: (forall b. Data b => b -> b) -> Float -> Float # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Float -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Float -> r # gmapQ :: (forall d. Data d => d -> u) -> Float -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Float -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Float -> m Float # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Float -> m Float # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Float -> m Float # | |
Storable Float | Since: base-2.1 |
Floating Float | Since: base-2.1 |
RealFloat Float | Since: base-2.1 |
Defined in GHC.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 |
PrintfArg Float | Since: base-2.1 |
Defined in Text.Printf | |
Fractional Float | |
Defined in Basement.Compat.NumLiteral Methods fromRational :: Rational -> Float # | |
HasNegation Float | |
Defined in Basement.Compat.NumLiteral | |
Integral Float | |
Defined in Basement.Compat.NumLiteral Methods fromInteger :: Integer -> Float # | |
NormalForm Float | |
Defined in Basement.NormalForm Methods toNormalForm :: Float -> () # | |
Additive Float | |
Divisible Float | |
Multiplicative Float | |
Subtractive Float | |
Defined in Basement.Numerical.Subtractive Associated Types type Difference Float # | |
PrimType Float | |
Defined in Basement.PrimType Methods primSizeInBytes :: Proxy Float -> CountOf Word8 # primShiftToBytes :: Proxy Float -> Int # primBaUIndex :: ByteArray# -> Offset Float -> Float # primMbaURead :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Float -> prim Float # primMbaUWrite :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Float -> Float -> prim () # primAddrIndex :: Addr# -> Offset Float -> Float # primAddrRead :: PrimMonad prim => Addr# -> Offset Float -> prim Float # primAddrWrite :: PrimMonad prim => Addr# -> Offset Float -> Float -> prim () # | |
Arbitrary Float Source # | |
Storable Float Source # | |
StorableFixed Float Source # | |
Trigonometry Float Source # | |
Defined in Foundation.Math.Trigonometry Methods sin :: Float -> Float Source # cos :: Float -> Float Source # tan :: Float -> Float Source # asin :: Float -> Float Source # acos :: Float -> Float Source # atan :: Float -> Float Source # sinh :: Float -> Float Source # cosh :: Float -> Float Source # tanh :: Float -> Float Source # asinh :: Float -> Float Source # | |
IntegralRounding Float Source # | |
Signed Float Source # | |
FloatingPoint Float Source # | |
Eq Float | Note that due to the presence of
Also note that
|
Ord Float | Note that due to the presence of
Also note that, due to the same,
|
Generic1 (URec Float :: k -> Type) | |
Foldable (UFloat :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # | |
Traversable (UFloat :: Type -> Type) | Since: base-4.9.0.0 |
Functor (URec Float :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Generic (URec Float p) | |
Show (URec Float p) | |
Eq (URec Float p) | |
Ord (URec Float p) | |
Defined in GHC.Generics | |
type Difference Float | |
Defined in Basement.Numerical.Subtractive | |
type PrimSize Float | |
Defined in Basement.PrimType | |
data URec Float (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
type Rep1 (URec Float :: k -> Type) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
type Rep (URec Float p) | |
Defined in GHC.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
Data Double | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Double -> c Double # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Double # toConstr :: Double -> Constr # dataTypeOf :: Double -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Double) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Double) # gmapT :: (forall b. Data b => b -> b) -> Double -> Double # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Double -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Double -> r # gmapQ :: (forall d. Data d => d -> u) -> Double -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Double -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Double -> m Double # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Double -> m Double # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Double -> m Double # | |
Storable Double | Since: base-2.1 |
Floating Double | Since: base-2.1 |
RealFloat Double | Since: base-2.1 |
Defined in GHC.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 |
PrintfArg Double | Since: base-2.1 |
Defined in Text.Printf | |
Fractional Double | |
Defined in Basement.Compat.NumLiteral Methods fromRational :: Rational -> Double # | |
HasNegation Double | |
Defined in Basement.Compat.NumLiteral | |
Integral Double | |
Defined in Basement.Compat.NumLiteral Methods fromInteger :: Integer -> Double # | |
NormalForm Double | |
Defined in Basement.NormalForm Methods toNormalForm :: Double -> () # | |
Additive Double | |
Divisible Double | |
Multiplicative Double | |
Subtractive Double | |
Defined in Basement.Numerical.Subtractive Associated Types type Difference Double # | |
PrimType Double | |
Defined in Basement.PrimType Methods primSizeInBytes :: Proxy Double -> CountOf Word8 # primShiftToBytes :: Proxy Double -> Int # primBaUIndex :: ByteArray# -> Offset Double -> Double # primMbaURead :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Double -> prim Double # primMbaUWrite :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Double -> Double -> prim () # primAddrIndex :: Addr# -> Offset Double -> Double # primAddrRead :: PrimMonad prim => Addr# -> Offset Double -> prim Double # primAddrWrite :: PrimMonad prim => Addr# -> Offset Double -> Double -> prim () # | |
Arbitrary Double Source # | |
Storable Double Source # | |
StorableFixed Double Source # | |
IsField Double Source # | |
Trigonometry Double Source # | |
Defined in Foundation.Math.Trigonometry Methods sin :: Double -> Double Source # cos :: Double -> Double Source # tan :: Double -> Double Source # asin :: Double -> Double Source # acos :: Double -> Double Source # atan :: Double -> Double Source # sinh :: Double -> Double Source # cosh :: Double -> Double Source # tanh :: Double -> Double Source # asinh :: Double -> Double Source # | |
IntegralRounding Double Source # | |
Signed Double Source # | |
FloatingPoint Double Source # | |
Eq Double | Note that due to the presence of
Also note that
|
Ord Double | Note that due to the presence of
Also note that, due to the same,
|
Generic1 (URec Double :: k -> Type) | |
Foldable (UDouble :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UDouble m -> m # foldMap :: Monoid m => (a -> m) -> UDouble a -> m # foldMap' :: Monoid m => (a -> m) -> UDouble a -> m # foldr :: (a -> b -> b) -> b -> UDouble a -> b # foldr' :: (a -> b -> b) -> b -> UDouble a -> b # foldl :: (b -> a -> b) -> b -> UDouble a -> b # foldl' :: (b -> a -> b) -> b -> UDouble a -> b # foldr1 :: (a -> a -> a) -> UDouble a -> a # foldl1 :: (a -> a -> a) -> UDouble a -> a # elem :: Eq a => a -> UDouble a -> Bool # maximum :: Ord a => UDouble a -> a # minimum :: Ord a => UDouble a -> a # | |
Traversable (UDouble :: Type -> Type) | Since: base-4.9.0.0 |
Functor (URec Double :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Generic (URec Double p) | |
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.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 # | |
type Difference Double | |
Defined in Basement.Numerical.Subtractive | |
type PrimSize Double | |
Defined in Basement.PrimType | |
data URec Double (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
type Rep1 (URec Double :: k -> Type) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
type Rep (URec Double p) | Since: base-4.9.0.0 |
Defined in GHC.Generics |
CountOf of a data structure.
More specifically, it represents the number of elements of type ty
that fit
into the data structure.
>>>
length (fromList ['a', 'b', 'c', '🌟']) :: CountOf Char
CountOf 4
Same caveats as Offset
apply here.
Instances
Offset in a data structure consisting of elements of type ty
.
Int is a terrible backing type which is hard to get away from, considering that GHC/Haskell are mostly using this for offset. Trying to bring some sanity by a lightweight wrapping.
Instances
Collection types
An array of type built on top of GHC primitive.
The elements need to have fixed sized and the representation is a packed contiguous array in memory that can easily be passed to foreign interface
Instances
Represent the accessor for types that can be stored in the UArray and MUArray.
Types need to be a instance of storable and have fixed sized.
Minimal complete definition
primSizeInBytes, primShiftToBytes, primBaUIndex, primMbaURead, primMbaUWrite, primAddrIndex, primAddrRead, primAddrWrite
Instances
Array of a
Instances
Opaque packed array of characters in the UTF8 encoding
Instances
Numeric functions
(^^) :: (Fractional a, Integral b) => a -> b -> a infixr 8 #
raise a number to an integral power
fromIntegral :: (Integral a, Num b) => a -> b #
general coercion from integral types
realToFrac :: (Real a, Fractional b) => a -> b #
general coercion to fractional types
Monoids
The class of semigroups (types with an associative binary operation).
Instances should satisfy the following:
Since: base-4.9.0.0
Minimal complete definition
Instances
Semigroup All | Since: base-4.9.0.0 |
Semigroup Any | Since: base-4.9.0.0 |
Semigroup Builder | |
Semigroup Builder | |
Semigroup AsciiString | |
Defined in Basement.Types.AsciiString Methods (<>) :: AsciiString -> AsciiString -> AsciiString # sconcat :: NonEmpty AsciiString -> AsciiString # stimes :: Integral b => b -> AsciiString -> AsciiString # | |
Semigroup String | |
Semigroup Bitmap Source # | |
Semigroup CSV Source # | |
Semigroup Row Source # | |
Semigroup FileName Source # | |
Semigroup Ordering | Since: base-4.9.0.0 |
Semigroup () | Since: base-4.9.0.0 |
Bits a => Semigroup (And a) | Since: base-4.16 |
FiniteBits a => Semigroup (Iff a) | This constraint is arguably
too strong. However, as some types (such as Since: base-4.16 |
Bits a => Semigroup (Ior a) | Since: base-4.16 |
Bits a => Semigroup (Xor a) | Since: base-4.16 |
Semigroup a => Semigroup (Identity a) | Since: base-4.9.0.0 |
Semigroup (First a) | Since: base-4.9.0.0 |
Semigroup (Last a) | Since: base-4.9.0.0 |
Semigroup a => Semigroup (Down a) | Since: base-4.11.0.0 |
Semigroup (First a) | Since: base-4.9.0.0 |
Semigroup (Last a) | Since: base-4.9.0.0 |
Ord a => Semigroup (Max a) | Since: base-4.9.0.0 |
Ord a => Semigroup (Min a) | Since: base-4.9.0.0 |
Monoid m => Semigroup (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods (<>) :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # sconcat :: NonEmpty (WrappedMonoid m) -> WrappedMonoid m # stimes :: Integral b => b -> WrappedMonoid m -> WrappedMonoid m # | |
Semigroup a => Semigroup (Dual a) | Since: base-4.9.0.0 |
Semigroup (Endo a) | Since: base-4.9.0.0 |
Num a => Semigroup (Product a) | Since: base-4.9.0.0 |
Num a => Semigroup (Sum a) | Since: base-4.9.0.0 |
Semigroup p => Semigroup (Par1 p) | Since: base-4.12.0.0 |
PrimType ty => Semigroup (Block ty) | |
Semigroup (Array a) | |
Semigroup (CountOf ty) | |
PrimType ty => Semigroup (UArray ty) | |
Semigroup (ChunkedUArray a) Source # | |
Defined in Foundation.Array.Chunked.Unboxed Methods (<>) :: ChunkedUArray a -> ChunkedUArray a -> ChunkedUArray a # sconcat :: NonEmpty (ChunkedUArray a) -> ChunkedUArray a # stimes :: Integral b => b -> ChunkedUArray a -> ChunkedUArray a # | |
Semigroup (DList a) Source # | |
Semigroup a => Semigroup (IO a) | Since: base-4.10.0.0 |
Semigroup (NonEmpty a) | Since: base-4.9.0.0 |
Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
Semigroup a => Semigroup (a) | Since: base-4.15 |
Semigroup [a] | Since: base-4.9.0.0 |
Semigroup (Either a b) | Since: base-4.9.0.0 |
Semigroup (Proxy s) | Since: base-4.9.0.0 |
Semigroup (U1 p) | Since: base-4.12.0.0 |
Semigroup (V1 p) | Since: base-4.12.0.0 |
Semigroup a => Semigroup (ST s a) | Since: base-4.11.0.0 |
Semigroup b => Semigroup (a -> b) | Since: base-4.9.0.0 |
(Semigroup a, Semigroup b) => Semigroup (a, b) | Since: base-4.9.0.0 |
Semigroup a => Semigroup (Const a b) | Since: base-4.9.0.0 |
(Applicative f, Semigroup a) => Semigroup (Ap f a) | Since: base-4.12.0.0 |
Alternative f => Semigroup (Alt f a) | Since: base-4.9.0.0 |
Semigroup (f p) => Semigroup (Rec1 f p) | Since: base-4.12.0.0 |
(Semigroup a, Semigroup b, Semigroup c) => Semigroup (a, b, c) | Since: base-4.9.0.0 |
(Semigroup (f p), Semigroup (g p)) => Semigroup ((f :*: g) p) | Since: base-4.12.0.0 |
Semigroup c => Semigroup (K1 i c p) | Since: base-4.12.0.0 |
(Semigroup a, Semigroup b, Semigroup c, Semigroup d) => Semigroup (a, b, c, d) | Since: base-4.9.0.0 |
Semigroup (f (g p)) => Semigroup ((f :.: g) p) | Since: base-4.12.0.0 |
Semigroup (f p) => Semigroup (M1 i c f p) | Since: base-4.12.0.0 |
(Semigroup a, Semigroup b, Semigroup c, Semigroup d, Semigroup e) => Semigroup (a, b, c, d, e) | Since: base-4.9.0.0 |
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)<>
zSemigroup
law)- Concatenation
mconcat
=foldr
(<>
)mempty
The method names refer to the monoid of lists under concatenation, but there are many other instances.
Some types can be viewed as a monoid in more than one way,
e.g. both addition and multiplication on numbers.
In such cases we often define newtype
s and make those instances
of Monoid
, e.g. Sum
and Product
.
NOTE: Semigroup
is a superclass of Monoid
since base-4.11.0.0.
Minimal complete definition
Methods
Identity of mappend
>>>
"Hello world" <> mempty
"Hello world"
An associative operation
NOTE: This method is redundant and has the default
implementation
since base-4.11.0.0.
Should it be implemented manually, since 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 All | Since: base-2.1 |
Monoid Any | Since: base-2.1 |
Monoid Builder | |
Monoid Builder | |
Monoid AsciiString | |
Defined in Basement.Types.AsciiString Methods mempty :: AsciiString # mappend :: AsciiString -> AsciiString -> AsciiString # mconcat :: [AsciiString] -> AsciiString # | |
Monoid String | |
Monoid Bitmap Source # | |
Monoid CSV Source # | |
Monoid Row Source # | |
Monoid FileName Source # | |
Monoid Ordering | Since: base-2.1 |
Monoid () | Since: base-2.1 |
FiniteBits a => Monoid (And a) | This constraint is arguably too strong. However,
as some types (such as Since: base-4.16 |
FiniteBits a => Monoid (Iff a) | This constraint is arguably
too strong. However, as some types (such as Since: base-4.16 |
Bits a => Monoid (Ior a) | Since: base-4.16 |
Bits a => Monoid (Xor a) | Since: base-4.16 |
Monoid a => Monoid (Identity a) | Since: base-4.9.0.0 |
Monoid (First a) | Since: base-2.1 |
Monoid (Last a) | Since: base-2.1 |
Monoid a => Monoid (Down a) | Since: base-4.11.0.0 |
(Ord a, Bounded a) => Monoid (Max a) | Since: base-4.9.0.0 |
(Ord a, Bounded a) => Monoid (Min a) | Since: base-4.9.0.0 |
Monoid m => Monoid (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods mempty :: WrappedMonoid m # mappend :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # mconcat :: [WrappedMonoid m] -> WrappedMonoid m # | |
Monoid a => Monoid (Dual a) | Since: base-2.1 |
Monoid (Endo a) | Since: base-2.1 |
Num a => Monoid (Product a) | Since: base-2.1 |
Num a => Monoid (Sum a) | Since: base-2.1 |
Monoid p => Monoid (Par1 p) | Since: base-4.12.0.0 |
PrimType ty => Monoid (Block ty) | |
Monoid (Array a) | |
Monoid (CountOf ty) | |
PrimType ty => Monoid (UArray ty) | |
Monoid (ChunkedUArray a) Source # | |
Defined in Foundation.Array.Chunked.Unboxed Methods mempty :: ChunkedUArray a # mappend :: ChunkedUArray a -> ChunkedUArray a -> ChunkedUArray a # mconcat :: [ChunkedUArray a] -> ChunkedUArray a # | |
Monoid (DList a) Source # | |
Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
Monoid a => Monoid (a) | Since: base-4.15 |
Monoid [a] | Since: base-2.1 |
Monoid (Proxy s) | Since: base-4.7.0.0 |
Monoid (U1 p) | Since: base-4.12.0.0 |
Monoid a => Monoid (ST s a) | Since: base-4.11.0.0 |
Monoid b => Monoid (a -> b) | Since: base-2.1 |
(Monoid a, Monoid b) => Monoid (a, b) | Since: base-2.1 |
Monoid a => Monoid (Const a b) | Since: base-4.9.0.0 |
(Applicative f, Monoid a) => Monoid (Ap f a) | Since: base-4.12.0.0 |
Alternative f => Monoid (Alt f a) | Since: base-4.8.0.0 |
Monoid (f p) => Monoid (Rec1 f p) | Since: base-4.12.0.0 |
(Monoid a, Monoid b, Monoid c) => Monoid (a, b, c) | Since: base-2.1 |
(Monoid (f p), Monoid (g p)) => Monoid ((f :*: g) p) | Since: base-4.12.0.0 |
Monoid c => Monoid (K1 i c p) | Since: base-4.12.0.0 |
(Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d) | Since: base-2.1 |
Monoid (f (g p)) => Monoid ((f :.: g) p) | Since: base-4.12.0.0 |
Monoid (f p) => Monoid (M1 i c f p) | Since: base-4.12.0.0 |
(Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e) | Since: base-2.1 |
(<>) :: Semigroup a => a -> a -> a infixr 6 #
An associative operation.
>>>
[1,2,3] <> [4,5,6]
[1,2,3,4,5,6]
Collection
class (IsList c, Item c ~ Element c) => Collection c where Source #
A set of methods for ordered colection
Methods
Check if a collection is empty
length :: c -> CountOf (Element c) Source #
Length of a collection (number of Element c)
elem :: forall a. (Eq a, a ~ Element c) => Element c -> c -> Bool Source #
Check if a collection contains a specific element
This is the inverse of notElem
.
notElem :: forall a. (Eq a, a ~ Element c) => Element c -> c -> Bool Source #
Check if a collection does *not* contain a specific element
This is the inverse of elem
.
maximum :: forall a. (Ord a, a ~ Element c) => NonEmpty c -> Element c Source #
Get the maximum element of a collection
minimum :: forall a. (Ord a, a ~ Element c) => NonEmpty c -> Element c Source #
Get the minimum element of a collection
any :: (Element c -> Bool) -> c -> Bool Source #
Determine is any elements of the collection satisfy the predicate
all :: (Element c -> Bool) -> c -> Bool Source #
Determine is all elements of the collection satisfy the predicate
Instances
and :: (Collection col, Element col ~ Bool) => col -> Bool Source #
Return True if all the elements in the collection are True
or :: (Collection col, Element col ~ Bool) => col -> Bool Source #
Return True if at least one element in the collection is True
class (IsList c, Item c ~ Element c, Monoid c, Collection c) => Sequential c where Source #
A set of methods for ordered colection
Minimal complete definition
(take, drop | splitAt), (revTake, revDrop | revSplitAt), splitOn, (break | span), (breakEnd | spanEnd), intersperse, filter, reverse, uncons, unsnoc, snoc, cons, find, sortBy, singleton, replicate
Methods
take :: CountOf (Element c) -> c -> c Source #
Take the first @n elements of a collection
revTake :: CountOf (Element c) -> c -> c Source #
Take the last @n elements of a collection
drop :: CountOf (Element c) -> c -> c Source #
Drop the first @n elements of a collection
revDrop :: CountOf (Element c) -> c -> c Source #
Drop the last @n elements of a collection
splitAt :: CountOf (Element c) -> c -> (c, c) Source #
Split the collection at the @n'th elements
revSplitAt :: CountOf (Element c) -> c -> (c, c) Source #
Split the collection at the @n'th elements from the end
splitOn :: (Element c -> Bool) -> c -> [c] Source #
Split on a specific elements returning a list of colletion
break :: (Element c -> Bool) -> c -> (c, c) Source #
Split a collection when the predicate return true
breakEnd :: (Element c -> Bool) -> c -> (c, c) Source #
Split a collection when the predicate return true starting from the end of the collection
breakElem :: Eq (Element c) => Element c -> c -> (c, c) Source #
Split a collection at the given element
takeWhile :: (Element c -> Bool) -> c -> c Source #
Return the longest prefix in the collection that satisfy the predicate
dropWhile :: (Element c -> Bool) -> c -> c Source #
Return the longest prefix in the collection that satisfy the predicate
intersperse :: Element c -> c -> c Source #
The intersperse
function takes an element and a list and
`intersperses' that element between the elements of the list.
For example,
intersperse ',' "abcde" == "a,b,c,d,e"
intercalate :: Monoid (Item c) => Element c -> c -> Element c Source #
intercalate
xs xss
is equivalent to (
.
It inserts the list mconcat
(intersperse
xs xss))xs
in between the lists in xss
and concatenates the
result.
span :: (Element c -> Bool) -> c -> (c, c) Source #
Split a collection while the predicate return true
spanEnd :: (Element c -> Bool) -> c -> (c, c) Source #
Split a collection while the predicate return true starting from the end of the collection
filter :: (Element c -> Bool) -> c -> c Source #
Filter all the elements that satisfy the predicate
partition :: (Element c -> Bool) -> c -> (c, c) Source #
Partition the elements that satisfy the predicate and those that don't
Reverse a collection
uncons :: c -> Maybe (Element c, c) Source #
Decompose a collection into its first element and the remaining collection. If the collection is empty, returns Nothing.
unsnoc :: c -> Maybe (c, Element c) Source #
Decompose a collection into a collection without its last element, and the last element If the collection is empty, returns Nothing.
snoc :: c -> Element c -> c Source #
Prepend an element to an ordered collection
cons :: Element c -> c -> c Source #
Append an element to an ordered collection
find :: (Element c -> Bool) -> c -> Maybe (Element c) Source #
Find an element in an ordered collection
sortBy :: (Element c -> Element c -> Ordering) -> c -> c Source #
Sort an ordered collection using the specified order function
singleton :: Element c -> c Source #
Create a collection with a single element
head :: NonEmpty c -> Element c Source #
get the first element of a non-empty collection
last :: NonEmpty c -> Element c Source #
get the last element of a non-empty collection
tail :: NonEmpty c -> c Source #
Extract the elements after the first element of a non-empty collection.
init :: NonEmpty c -> c Source #
Extract the elements before the last element of a non-empty collection.
replicate :: CountOf (Element c) -> Element c -> c Source #
Create a collection where the element in parameter is repeated N time
isPrefixOf :: Eq (Element c) => c -> c -> Bool Source #
Takes two collections and returns True iff the first collection is a prefix of the second.
default isPrefixOf :: Eq c => c -> c -> Bool Source #
isSuffixOf :: Eq (Element c) => c -> c -> Bool Source #
Takes two collections and returns True iff the first collection is a suffix of the second.
default isSuffixOf :: Eq c => c -> c -> Bool Source #
isInfixOf :: Eq (Element c) => c -> c -> Bool Source #
Takes two collections and returns True iff the first collection is an infix of the second.
stripPrefix :: Eq (Element c) => c -> c -> Maybe c Source #
Try to strip a prefix from a collection
stripSuffix :: Eq (Element c) => c -> c -> Maybe c Source #
Try to strip a suffix from a collection
Instances
NonEmpty property for any Collection
Instances
IsList c => IsList (NonEmpty c) | |
Show a => Show (NonEmpty a) | |
Collection c => Collection (NonEmpty c) Source # | |
Defined in Foundation.Collection.Collection Methods null :: NonEmpty c -> Bool Source # length :: NonEmpty c -> CountOf (Element (NonEmpty c)) Source # elem :: (Eq a, a ~ Element (NonEmpty c)) => Element (NonEmpty c) -> NonEmpty c -> Bool Source # notElem :: (Eq a, a ~ Element (NonEmpty c)) => Element (NonEmpty c) -> NonEmpty c -> Bool Source # maximum :: (Ord a, a ~ Element (NonEmpty c)) => NonEmpty (NonEmpty c) -> Element (NonEmpty c) Source # minimum :: (Ord a, a ~ Element (NonEmpty c)) => NonEmpty (NonEmpty c) -> Element (NonEmpty c) Source # any :: (Element (NonEmpty c) -> Bool) -> NonEmpty c -> Bool Source # all :: (Element (NonEmpty c) -> Bool) -> NonEmpty c -> Bool Source # | |
Eq a => Eq (NonEmpty a) | |
type Item (NonEmpty c) | |
Defined in Basement.NonEmpty | |
type Element (NonEmpty a) Source # | |
Defined in Foundation.Collection.Element |
nonEmpty :: Collection c => c -> Maybe (NonEmpty c) Source #
Smart constructor to create a NonEmpty collection
If the collection is empty, then Nothing is returned Otherwise, the collection is wrapped in the NonEmpty property
Folds
class Foldable collection where Source #
Give the ability to fold a collection on itself
Methods
foldl' :: (a -> Element collection -> a) -> a -> collection -> a Source #
Left-associative fold of a structure.
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. This means that foldl' will diverge if given an infinite list.
Note that Foundation only provides foldl
`, a strict version of foldl
because
the lazy version is seldom useful.
Left-associative fold of a structure with strict application of the operator.
foldr :: (Element collection -> a -> a) -> a -> collection -> a Source #
Right-associative fold of a structure.
foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)
foldr' :: (Element collection -> a -> a) -> a -> collection -> a Source #
Right-associative fold of a structure, but with strict application of the operator.
Instances
Foldable Bitmap Source # | |
PrimType ty => Foldable (Block ty) Source # | |
Foldable (Array ty) Source # | |
PrimType ty => Foldable (UArray ty) Source # | |
PrimType ty => Foldable (ChunkedUArray ty) Source # | |
Defined in Foundation.Array.Chunked.Unboxed Methods foldl' :: (a -> Element (ChunkedUArray ty) -> a) -> a -> ChunkedUArray ty -> a Source # foldr :: (Element (ChunkedUArray ty) -> a -> a) -> a -> ChunkedUArray ty -> a Source # foldr' :: (Element (ChunkedUArray ty) -> a -> a) -> a -> ChunkedUArray ty -> a Source # | |
Foldable (DList a) Source # | |
Foldable [a] Source # | |
PrimType ty => Foldable (BlockN n ty) Source # | |
Foldable (ListN n a) Source # | |
Maybe
mapMaybe :: (a -> Maybe b) -> [a] -> [b] #
The mapMaybe
function is a version of map
which can throw
out elements. In particular, the functional argument returns
something of type
. If this is Maybe
bNothing
, no element
is added on to the result list. If it is
, then Just
bb
is
included in the result list.
Examples
Using
is a shortcut for mapMaybe
f x
in most cases:catMaybes
$ map
f x
>>>
import Text.Read ( readMaybe )
>>>
let readMaybeInt = readMaybe :: String -> Maybe Int
>>>
mapMaybe readMaybeInt ["1", "Foo", "3"]
[1,3]>>>
catMaybes $ map readMaybeInt ["1", "Foo", "3"]
[1,3]
If we map the Just
constructor, the entire list should be returned:
>>>
mapMaybe Just [1,2,3]
[1,2,3]
catMaybes :: [Maybe a] -> [a] #
The catMaybes
function takes a list of Maybe
s and returns
a list of all the Just
values.
Examples
Basic usage:
>>>
catMaybes [Just 1, Nothing, Just 3]
[1,3]
When constructing a list of Maybe
values, catMaybes
can be used
to return all of the "success" results (if the list is the result
of a map
, then mapMaybe
would be more appropriate):
>>>
import Text.Read ( readMaybe )
>>>
[readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[Just 1,Nothing,Just 3]>>>
catMaybes $ [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[1,3]
fromMaybe :: a -> Maybe a -> a #
The fromMaybe
function takes a default value and a Maybe
value. If the Maybe
is Nothing
, it returns the default value;
otherwise, it returns the value contained in the Maybe
.
Examples
Basic usage:
>>>
fromMaybe "" (Just "Hello, World!")
"Hello, World!"
>>>
fromMaybe "" Nothing
""
Read an integer from a string using readMaybe
. If we fail to
parse an integer, we want to return 0
by default:
>>>
import Text.Read ( readMaybe )
>>>
fromMaybe 0 (readMaybe "5")
5>>>
fromMaybe 0 (readMaybe "")
0
listToMaybe :: [a] -> Maybe a #
The listToMaybe
function returns Nothing
on an empty list
or
where Just
aa
is the first element of the list.
Examples
Basic usage:
>>>
listToMaybe []
Nothing
>>>
listToMaybe [9]
Just 9
>>>
listToMaybe [1,2,3]
Just 1
Composing maybeToList
with listToMaybe
should be the identity
on singleton/empty lists:
>>>
maybeToList $ listToMaybe [5]
[5]>>>
maybeToList $ listToMaybe []
[]
But not on lists with more than one element:
>>>
maybeToList $ listToMaybe [1,2,3]
[1]
maybeToList :: Maybe a -> [a] #
The maybeToList
function returns an empty list when given
Nothing
or a singleton list when given Just
.
Examples
Basic usage:
>>>
maybeToList (Just 7)
[7]
>>>
maybeToList Nothing
[]
One can use maybeToList
to avoid pattern matching when combined
with a function that (safely) works on lists:
>>>
import Text.Read ( readMaybe )
>>>
sum $ maybeToList (readMaybe "3")
3>>>
sum $ maybeToList (readMaybe "")
0
Either
partitionEithers :: [Either a b] -> ([a], [b]) #
Partitions a list of Either
into two lists.
All the Left
elements are extracted, in order, to the first
component of the output. Similarly the Right
elements are extracted
to the second component of the output.
Examples
Basic usage:
>>>
let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]
>>>
partitionEithers list
(["foo","bar","baz"],[3,7])
The pair returned by
should be the same
pair as partitionEithers
x(
:lefts
x, rights
x)
>>>
let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]
>>>
partitionEithers list == (lefts list, rights list)
True
Function
Applicative
(<$>) :: 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, <$>
is function
application lifted over a Functor
.
Examples
Convert from a
to a Maybe
Int
using Maybe
String
show
:
>>>
show <$> Nothing
Nothing>>>
show <$> Just 3
Just "3"
Convert from an
to an
Either
Int
Int
Either
Int
String
using show
:
>>>
show <$> Left 17
Left 17>>>
show <$> Right 17
Right "17"
Double each element of a list:
>>>
(*2) <$> [1,2,3]
[2,4,6]
Apply even
to the second element of a pair:
>>>
even <$> (2,2)
(2,True)
(<|>) :: Alternative f => f a -> f a -> f a infixl 3 #
An associative binary operation
Monad
(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c infixr 1 #
Left-to-right composition of Kleisli arrows.
'(bs
' can be understood as the >=>
cs) ado
expression
do b <- bs a cs b
Exceptions
class (Typeable e, Show e) => Exception e where #
Any type that you wish to throw or catch as an exception must be an
instance of the Exception
class. The simplest case is a new exception
type directly below the root:
data MyException = ThisException | ThatException deriving Show instance Exception MyException
The default method definitions in the Exception
class do what we need
in this case. You can now throw and catch ThisException
and
ThatException
as exceptions:
*Main> throw ThisException `catch` \e -> putStrLn ("Caught " ++ show (e :: MyException)) Caught ThisException
In more complicated examples, you may wish to define a whole hierarchy of exceptions:
--------------------------------------------------------------------- -- Make the root exception type for all the exceptions in a compiler data SomeCompilerException = forall e . Exception e => SomeCompilerException e instance Show SomeCompilerException where show (SomeCompilerException e) = show e instance Exception SomeCompilerException compilerExceptionToException :: Exception e => e -> SomeException compilerExceptionToException = toException . SomeCompilerException compilerExceptionFromException :: Exception e => SomeException -> Maybe e compilerExceptionFromException x = do SomeCompilerException a <- fromException x cast a --------------------------------------------------------------------- -- Make a subhierarchy for exceptions in the frontend of the compiler data SomeFrontendException = forall e . Exception e => SomeFrontendException e instance Show SomeFrontendException where show (SomeFrontendException e) = show e instance Exception SomeFrontendException where toException = compilerExceptionToException fromException = compilerExceptionFromException frontendExceptionToException :: Exception e => e -> SomeException frontendExceptionToException = toException . SomeFrontendException frontendExceptionFromException :: Exception e => SomeException -> Maybe e frontendExceptionFromException x = do SomeFrontendException a <- fromException x cast a --------------------------------------------------------------------- -- Make an exception type for a particular frontend compiler exception data MismatchedParentheses = MismatchedParentheses deriving Show instance Exception MismatchedParentheses where toException = frontendExceptionToException fromException = frontendExceptionFromException
We can now catch a MismatchedParentheses
exception as
MismatchedParentheses
, SomeFrontendException
or
SomeCompilerException
, but not other types, e.g. IOException
:
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: MismatchedParentheses)) Caught MismatchedParentheses *Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeFrontendException)) Caught MismatchedParentheses *Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeCompilerException)) Caught MismatchedParentheses *Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: IOException)) *** Exception: MismatchedParentheses
Minimal complete definition
Nothing
Methods
toException :: e -> SomeException #
fromException :: SomeException -> Maybe e #
displayException :: e -> String #
Render this exception value in a human-friendly manner.
Default implementation:
.show
Since: base-4.8.0.0
Instances
The class Typeable
allows a concrete representation of a type to
be calculated.
Minimal complete definition
typeRep#
data SomeException #
The SomeException
type is the root of the exception type hierarchy.
When an exception of type e
is thrown, behind the scenes it is
encapsulated in a SomeException
.
Instances
Exception SomeException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods toException :: SomeException -> SomeException # fromException :: SomeException -> Maybe SomeException # displayException :: SomeException -> String # | |
Show SomeException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS # show :: SomeException -> String # showList :: [SomeException] -> ShowS # |
data IOException #
Exceptions that occur in the IO
monad.
An IOException
records a more specific error type, a descriptive
string and maybe the handle that was used when the error was
flagged.
Instances
Exception IOException | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception Methods toException :: IOException -> SomeException # fromException :: SomeException -> Maybe IOException # displayException :: IOException -> String # | |
Show IOException | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception Methods showsPrec :: Int -> IOException -> ShowS # show :: IOException -> String # showList :: [IOException] -> ShowS # | |
Eq IOException | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception |
Proxy
Proxy
is a type that holds no data, but has a phantom parameter of
arbitrary type (or even kind). Its use is to provide type information, even
though there is no value available of that type (or it may be too costly to
create one).
Historically,
is a safer alternative to the
Proxy
:: Proxy
a
idiom.undefined
:: a
>>>
Proxy :: Proxy (Void, Int -> Int)
Proxy
Proxy can even hold types of higher kinds,
>>>
Proxy :: Proxy Either
Proxy
>>>
Proxy :: Proxy Functor
Proxy
>>>
Proxy :: Proxy complicatedStructure
Proxy
Constructors
Proxy |
Instances
Generic1 (Proxy :: k -> Type) | |
Foldable (Proxy :: TYPE LiftedRep -> Type) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # | |
Traversable (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Alternative (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
Applicative (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Functor (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Monad (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
MonadPlus (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
Data t => Data (Proxy t) | Since: base-4.7.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Proxy t -> c (Proxy t) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Proxy t) # toConstr :: Proxy t -> Constr # dataTypeOf :: Proxy t -> DataType # dataCast1 :: Typeable t0 => (forall d. Data d => c (t0 d)) -> Maybe (c (Proxy t)) # dataCast2 :: Typeable t0 => (forall d e. (Data d, Data e) => c (t0 d e)) -> Maybe (c (Proxy t)) # gmapT :: (forall b. Data b => b -> b) -> Proxy t -> Proxy t # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Proxy t -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Proxy t -> r # gmapQ :: (forall d. Data d => d -> u) -> Proxy t -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Proxy t -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) # | |
Monoid (Proxy s) | Since: base-4.7.0.0 |
Semigroup (Proxy s) | Since: base-4.9.0.0 |
Bounded (Proxy t) | Since: base-4.7.0.0 |
Enum (Proxy s) | Since: base-4.7.0.0 |
Generic (Proxy t) | |
Ix (Proxy s) | Since: base-4.7.0.0 |
Defined in Data.Proxy | |
Read (Proxy t) | Since: base-4.7.0.0 |
Show (Proxy s) | Since: base-4.7.0.0 |
Eq (Proxy s) | Since: base-4.7.0.0 |
Ord (Proxy s) | Since: base-4.7.0.0 |
type Rep1 (Proxy :: k -> Type) | Since: base-4.6.0.0 |
type Rep (Proxy t) | Since: base-4.6.0.0 |
asProxyTypeOf :: a -> proxy a -> a #
asProxyTypeOf
is a type-restricted version of const
.
It is usually used as an infix operator, and its typing forces its first
argument (which is usually overloaded) to have the same type as the tag
of the second.
>>>
import Data.Word
>>>
:type asProxyTypeOf 123 (Proxy :: Proxy Word8)
asProxyTypeOf 123 (Proxy :: Proxy Word8) :: Word8
Note the lower-case proxy
in the definition. This allows any type
constructor with just one argument to be passed to the function, for example
we could also write
>>>
import Data.Word
>>>
:type asProxyTypeOf 123 (Just (undefined :: Word8))
asProxyTypeOf 123 (Just (undefined :: Word8)) :: Word8
Partial
Partialiality wrapper.
partial :: a -> Partial a Source #
Create a value that is partial. this can only be
unwrap using the fromPartial
function
data PartialError Source #
An error related to the evaluation of a Partial value that failed.
it contains the name of the function and the reason for failure
Instances
Exception PartialError Source # | |
Defined in Foundation.Partial Methods toException :: PartialError -> SomeException # fromException :: SomeException -> Maybe PartialError # displayException :: PartialError -> String # | |
Show PartialError Source # | |
Defined in Foundation.Partial Methods showsPrec :: Int -> PartialError -> ShowS # show :: PartialError -> String # showList :: [PartialError] -> ShowS # | |
Eq PartialError Source # | |
Defined in Foundation.Partial |
fromPartial :: Partial a -> a Source #
Dewrap a possible partial value
ifThenElse :: Bool -> a -> a -> a #
for support of if .. then .. else