| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
OpenSuse.Prelude
Synopsis
- (++) :: [a] -> [a] -> [a]
- seq :: forall (r :: RuntimeRep) a (b :: TYPE r). a -> b -> b
- filter :: (a -> Bool) -> [a] -> [a]
- zip :: [a] -> [b] -> [(a, b)]
- print :: Show a => a -> IO ()
- fst :: (a, b) -> a
- snd :: (a, b) -> b
- otherwise :: Bool
- map :: (a -> b) -> [a] -> [b]
- ($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- fromIntegral :: (Integral a, Num b) => a -> b
- realToFrac :: (Real a, Fractional b) => a -> b
- class Bounded a where
- class Enum a where
- succ :: a -> a
- pred :: a -> a
- toEnum :: Int -> a
- fromEnum :: a -> Int
- enumFrom :: a -> [a]
- enumFromThen :: a -> a -> [a]
- enumFromTo :: a -> a -> [a]
- enumFromThenTo :: a -> a -> a -> [a]
- class Eq a where
- class Fractional a => Floating a where
- class Num a => Fractional a where
- (/) :: a -> a -> a
- recip :: a -> a
- fromRational :: Rational -> a
- class (Real a, Enum a) => Integral a where
- class Applicative m => Monad (m :: Type -> Type) where
- class Functor (f :: Type -> Type) where
- class Num a where
- class Eq a => Ord a where
- class Read a where
- class (Num a, Ord a) => Real a where
- toRational :: a -> Rational
- class (RealFrac a, Floating a) => RealFloat a where
- floatRadix :: a -> Integer
- floatDigits :: a -> Int
- floatRange :: a -> (Int, Int)
- decodeFloat :: a -> (Integer, Int)
- encodeFloat :: Integer -> Int -> a
- exponent :: a -> Int
- significand :: a -> a
- scaleFloat :: Int -> a -> a
- isNaN :: a -> Bool
- isInfinite :: a -> Bool
- isDenormalized :: a -> Bool
- isNegativeZero :: a -> Bool
- isIEEE :: a -> Bool
- atan2 :: a -> a -> a
- class (Real a, Fractional a) => RealFrac a where
- class Show a where
- class Monad m => MonadFail (m :: Type -> Type)
- class Functor f => Applicative (f :: Type -> Type) where
- class Foldable (t :: Type -> Type) where
- foldMap :: Monoid m => (a -> m) -> t a -> m
- foldr :: (a -> b -> b) -> b -> t a -> b
- foldl :: (b -> a -> b) -> b -> t a -> b
- foldr1 :: (a -> a -> a) -> t a -> a
- foldl1 :: (a -> a -> a) -> t a -> a
- null :: t a -> Bool
- length :: t a -> Int
- elem :: Eq a => a -> t a -> Bool
- maximum :: Ord a => t a -> a
- minimum :: Ord a => t a -> a
- sum :: Num a => t a -> a
- product :: Num a => t a -> a
- class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where
- traverse :: Applicative f => (a -> f b) -> t a -> f (t b)
- sequenceA :: Applicative f => t (f a) -> f (t a)
- mapM :: Monad m => (a -> m b) -> t a -> m (t b)
- sequence :: Monad m => t (m a) -> m (t a)
- class Semigroup a
- class Semigroup a => Monoid a where
- data Bool
- data Char
- data Double
- data Float
- data Int
- data Integer
- data Maybe a
- data Ordering
- type Rational = Ratio Integer
- data IO a
- data Word
- data Either a b
- type String = [Char]
- (<$>) :: Functor f => (a -> b) -> f a -> f b
- const :: a -> b -> a
- (.) :: (b -> c) -> (a -> b) -> a -> c
- id :: a -> a
- mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
- readIO :: Read a => String -> IO a
- readLn :: Read a => IO a
- appendFile :: FilePath -> String -> IO ()
- writeFile :: FilePath -> String -> IO ()
- readFile :: FilePath -> IO String
- interact :: (String -> String) -> IO ()
- getContents :: IO String
- getLine :: IO String
- getChar :: IO Char
- putStrLn :: String -> IO ()
- putStr :: String -> IO ()
- putChar :: Char -> IO ()
- ioError :: IOError -> IO a
- type FilePath = String
- userError :: String -> IOError
- type IOError = IOException
- notElem :: (Foldable t, Eq a) => a -> t a -> Bool
- all :: Foldable t => (a -> Bool) -> t a -> Bool
- any :: Foldable t => (a -> Bool) -> t a -> Bool
- or :: Foldable t => t Bool -> Bool
- and :: Foldable t => t Bool -> Bool
- concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
- concat :: Foldable t => t [a] -> [a]
- sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
- unwords :: [String] -> String
- words :: String -> [String]
- unlines :: [String] -> String
- lines :: String -> [String]
- read :: Read a => String -> a
- reads :: Read a => ReadS a
- either :: (a -> c) -> (b -> c) -> Either a b -> c
- lex :: ReadS String
- readParen :: Bool -> ReadS a -> ReadS a
- type ReadS a = String -> [(a, String)]
- lcm :: Integral a => a -> a -> a
- gcd :: Integral a => a -> a -> a
- (^^) :: (Fractional a, Integral b) => a -> b -> a
- (^) :: (Num a, Integral b) => a -> b -> a
- odd :: Integral a => a -> Bool
- even :: Integral a => a -> Bool
- showParen :: Bool -> ShowS -> ShowS
- showString :: String -> ShowS
- showChar :: Char -> ShowS
- shows :: Show a => a -> ShowS
- type ShowS = String -> String
- unzip3 :: [(a, b, c)] -> ([a], [b], [c])
- unzip :: [(a, b)] -> ([a], [b])
- zipWith3 :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d]
- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
- zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
- (!!) :: [a] -> Int -> a
- lookup :: Eq a => a -> [(a, b)] -> Maybe b
- reverse :: [a] -> [a]
- break :: (a -> Bool) -> [a] -> ([a], [a])
- span :: (a -> Bool) -> [a] -> ([a], [a])
- splitAt :: Int -> [a] -> ([a], [a])
- drop :: Int -> [a] -> [a]
- take :: Int -> [a] -> [a]
- dropWhile :: (a -> Bool) -> [a] -> [a]
- takeWhile :: (a -> Bool) -> [a] -> [a]
- cycle :: [a] -> [a]
- replicate :: Int -> a -> [a]
- repeat :: a -> [a]
- iterate :: (a -> a) -> a -> [a]
- scanr1 :: (a -> a -> a) -> [a] -> [a]
- scanr :: (a -> b -> b) -> b -> [a] -> [b]
- scanl1 :: (a -> a -> a) -> [a] -> [a]
- scanl :: (b -> a -> b) -> b -> [a] -> [b]
- init :: [a] -> [a]
- last :: [a] -> a
- tail :: [a] -> [a]
- head :: [a] -> a
- maybe :: b -> (a -> b) -> Maybe a -> b
- uncurry :: (a -> b -> c) -> (a, b) -> c
- curry :: ((a, b) -> c) -> a -> b -> c
- subtract :: Num a => a -> a -> a
- asTypeOf :: a -> a -> a
- until :: (a -> Bool) -> (a -> a) -> a -> a
- ($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- flip :: (a -> b -> c) -> b -> a -> c
- (=<<) :: Monad m => (a -> m b) -> m a -> m b
- undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a
- errorWithoutStackTrace :: forall (r :: RuntimeRep) (a :: TYPE r). [Char] -> a
- error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => [Char] -> a
- (&&) :: Bool -> Bool -> Bool
- (||) :: Bool -> Bool -> Bool
- not :: Bool -> Bool
- guard :: Alternative f => Bool -> f ()
- join :: Monad m => m (m a) -> m a
- class Applicative m => Monad (m :: Type -> Type) where
- class Functor (f :: Type -> Type) where
- class Monad m => MonadFail (m :: Type -> Type)
- mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)
- sequence :: (Traversable t, Monad m) => t (m a) -> m (t a)
- forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m ()
- mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
- mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a
- (<$!>) :: Monad m => (a -> b) -> m a -> m b
- unless :: Applicative f => Bool -> f () -> f ()
- replicateM_ :: Applicative m => Int -> m a -> m ()
- replicateM :: Applicative m => Int -> m a -> m [a]
- foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m ()
- foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b
- zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m ()
- zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c]
- mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])
- forever :: Applicative f => f a -> f b
- (<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c
- (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
- filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a]
- forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b)
- msum :: (Foldable t, MonadPlus m) => t (m a) -> m a
- sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
- void :: Functor f => f a -> f ()
- ap :: Monad m => m (a -> b) -> m a -> m b
- liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r
- liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r
- liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r
- liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r
- liftM :: Monad m => (a1 -> r) -> m a1 -> m r
- when :: Applicative f => Bool -> f () -> f ()
- (=<<) :: Monad m => (a -> m b) -> m a -> m b
- class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type) where
- firstJustM :: Monad m => (a -> m (Maybe b)) -> [a] -> m (Maybe b)
- findM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a)
- andM :: Monad m => [m Bool] -> m Bool
- orM :: Monad m => [m Bool] -> m Bool
- allM :: Monad m => (a -> m Bool) -> [a] -> m Bool
- anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool
- (&&^) :: Monad m => m Bool -> m Bool -> m Bool
- (||^) :: Monad m => m Bool -> m Bool -> m Bool
- notM :: Functor m => m Bool -> m Bool
- ifM :: Monad m => m Bool -> m a -> m a -> m a
- unlessM :: Monad m => m Bool -> m () -> m ()
- whenM :: Monad m => m Bool -> m () -> m ()
- untilJustM :: Monad m => m (Maybe a) -> m a
- whileJustM :: (Monad m, Monoid a) => m (Maybe a) -> m a
- whileM :: Monad m => m Bool -> m ()
- loopM :: Monad m => (a -> m (Either a b)) -> a -> m b
- loop :: (a -> Either a b) -> a -> b
- mapMaybeM :: Monad m => (a -> m (Maybe b)) -> [a] -> m [b]
- mconcatMapM :: (Monad m, Monoid b) => (a -> m b) -> [a] -> m b
- concatForM :: Monad m => [a] -> (a -> m [b]) -> m [b]
- concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b]
- partitionM :: Monad m => (a -> m Bool) -> [a] -> m ([a], [a])
- fold1M_ :: (Partial, Monad m) => (a -> a -> m a) -> [a] -> m ()
- fold1M :: (Partial, Monad m) => (a -> a -> m a) -> [a] -> m a
- eitherM :: Monad m => (a -> m c) -> (b -> m c) -> m (Either a b) -> m c
- fromMaybeM :: Monad m => m a -> m (Maybe a) -> m a
- maybeM :: Monad m => m b -> (a -> m b) -> m (Maybe a) -> m b
- unit :: m () -> m ()
- whenMaybeM :: Monad m => m Bool -> m a -> m (Maybe a)
- whenMaybe :: Applicative m => Bool -> m a -> m (Maybe a)
- pureIf :: Alternative m => Bool -> a -> m a
- whenJustM :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()
- whenJust :: Applicative m => Maybe a -> (a -> m ()) -> m ()
- module Control.Monad.Fail
- class Monad m => MonadIO (m :: Type -> Type) where
- class Semigroup a => Monoid a where
- class Semigroup a where
- data Word8
- class Generic a
- data Natural
- data Text
- type LazyText = Text
- data ByteString
- type LazyByteString = ByteString
- packText :: String -> Text
- unpackText :: Text -> String
- runParser :: Stream s Identity t => Parsec s u a -> u -> SourceName -> s -> Either ParseError a
- runParserT :: Stream s m t => ParsecT s u m a -> u -> SourceName -> s -> m (Either ParseError a)
- parse :: (Stream input Identity Char, HasParser a) => ErrorContext -> input -> a
- parseM :: (MonadFail m, Stream input m Char, HasParser a) => ErrorContext -> input -> m a
- type CharParser st input (m :: Type -> Type) a = Stream st m Char => ParsecT st input m a
- class HasParser a where
- parser :: forall st input (m :: Type -> Type). CharParser st input m a
- type ErrorContext = String
- prettyShow :: Pretty a => a -> String
- class Pretty a where
- data Doc
- class ToJSON a
- class FromJSON a
- class IsString a where
- fromString :: String -> a
- data UTCTime = UTCTime {
- utctDay :: Day
- utctDayTime :: DiffTime
- data DiffTime
- data Set a
- class NFData a
- class Binary t
- class Eq a => Hashable a
- fromMaybe :: a -> Maybe a -> a
Standard Prelude
(++) :: [a] -> [a] -> [a] infixr 5 #
Append two lists, i.e.,
[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn] [x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]
If the first list is not finite, the result is the first list.
seq :: forall (r :: RuntimeRep) a (b :: TYPE r). a -> b -> b infixr 0 #
The value of seq a b is bottom if a is bottom, and
otherwise equal to b. In other words, it evaluates the first
argument a to weak head normal form (WHNF). seq is usually
introduced to improve performance by avoiding unneeded laziness.
A note on evaluation order: the expression seq a b does
not guarantee that a will be evaluated before b.
The only guarantee given by seq is that the both a
and b will be evaluated before seq returns a value.
In particular, this means that b may be evaluated before
a. If you need to guarantee a specific order of evaluation,
you must use the function pseq from the "parallel" package.
filter :: (a -> Bool) -> [a] -> [a] #
\(\mathcal{O}(n)\). filter, applied to a predicate and a list, returns
the list of those elements that satisfy the predicate; i.e.,
filter p xs = [ x | x <- xs, p x]
>>>filter odd [1, 2, 3][1,3]
zip :: [a] -> [b] -> [(a, b)] #
\(\mathcal{O}(\min(m,n))\). zip takes two lists and returns a list of
corresponding pairs.
zip [1, 2] ['a', 'b'] = [(1, 'a'), (2, 'b')]
If one input list is short, excess elements of the longer list are discarded:
zip [1] ['a', 'b'] = [(1, 'a')] zip [1, 2] ['a'] = [(1, 'a')]
zip is right-lazy:
zip [] _|_ = [] zip _|_ [] = _|_
zip is capable of list fusion, but it is restricted to its
first list argument and its resulting list.
print :: Show a => a -> IO () #
The print function outputs a value of any printable type to the
standard output device.
Printable types are those that are instances of class Show; print
converts values to strings for output using the show operation and
adds a newline.
For example, a program to print the first 20 integers and their powers of 2 could be written as:
main = print ([(n, 2^n) | n <- [0..19]])
map :: (a -> b) -> [a] -> [b] #
\(\mathcal{O}(n)\). map f xs is the list obtained by applying f to
each element of xs, i.e.,
map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn] map f [x1, x2, ...] == [f x1, f x2, ...]
>>>map (+1) [1, 2, 3]
($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0 #
Application operator. This operator is redundant, since ordinary
application (f x) means the same as (f . However, $ x)$ has
low, right-associative binding precedence, so it sometimes allows
parentheses to be omitted; for example:
f $ g $ h x = f (g (h x))
It is also useful in higher-order situations, such as map ($ 0) xszipWith ($) fs xs
Note that ( is levity-polymorphic in its result type, so that
$)foo where $ Truefoo :: Bool -> Int# is well-typed.
fromIntegral :: (Integral a, Num b) => a -> b #
general coercion from integral types
realToFrac :: (Real a, Fractional b) => a -> b #
general coercion to fractional types
The Bounded class is used to name the upper and lower limits of a
type. Ord is not a superclass of Bounded since types that are not
totally ordered may also have upper and lower bounds.
The Bounded class may be derived for any enumeration type;
minBound is the first constructor listed in the data declaration
and maxBound is the last.
Bounded may also be derived for single-constructor datatypes whose
constituent types are in Bounded.
Instances
| Bounded Bool | Since: base-2.1 |
| Bounded Char | Since: base-2.1 |
| Bounded Int | Since: base-2.1 |
| Bounded Ordering | Since: base-2.1 |
| Bounded Word | Since: base-2.1 |
| Bounded Word8 | Since: base-2.1 |
| Bounded Word16 | Since: base-2.1 |
| Bounded Word32 | Since: base-2.1 |
| Bounded Word64 | Since: base-2.1 |
| Bounded VecCount | Since: base-4.10.0.0 |
| Bounded VecElem | Since: base-4.10.0.0 |
| Bounded () | Since: base-2.1 |
| Bounded All | Since: base-2.1 |
| Bounded Any | Since: base-2.1 |
| Bounded Associativity | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded GeneralCategory | Since: base-2.1 |
Defined in GHC.Unicode | |
| Bounded TimeSpec | |
| Bounded Extension | |
| Bounded a => Bounded (Solo a) | |
| Bounded a => Bounded (Min a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Max a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (First a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Last a) | Since: base-4.9.0.0 |
| Bounded m => Bounded (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| Bounded a => Bounded (Identity a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Dual a) | Since: base-2.1 |
| Bounded a => Bounded (Sum a) | Since: base-2.1 |
| Bounded a => Bounded (Product a) | Since: base-2.1 |
| (Bounded a, Bounded b) => Bounded (a, b) | Since: base-2.1 |
| (Bounded a, Bounded b) => Bounded (Pair a b) | |
| (Bounded a, Bounded b, Bounded c) => Bounded (a, b, c) | Since: base-2.1 |
| Bounded a => Bounded (Const a b) | Since: base-4.9.0.0 |
| (Applicative f, Bounded a) => Bounded (Ap f a) | Since: base-4.12.0.0 |
| Bounded b => Bounded (Tagged s b) | |
| (Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g) => Bounded (a, b, c, d, e, f, g) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h) => Bounded (a, b, c, d, e, f, g, h) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i) => Bounded (a, b, c, d, e, f, g, h, i) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j) => Bounded (a, b, c, d, e, f, g, h, i, j) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k) => Bounded (a, b, c, d, e, f, g, h, i, j, k) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | Since: base-2.1 |
Class Enum defines operations on sequentially ordered types.
The enumFrom... methods are used in Haskell's translation of
arithmetic sequences.
Instances of Enum may be derived for any enumeration type (types
whose constructors have no fields). The nullary constructors are
assumed to be numbered left-to-right by fromEnum from 0 through n-1.
See Chapter 10 of the Haskell Report for more details.
For any type that is an instance of class Bounded as well as Enum,
the following should hold:
- The calls
succmaxBoundpredminBound fromEnumandtoEnumshould give a runtime error if the result value is not representable in the result type. For example,toEnum7 ::BoolenumFromandenumFromThenshould be defined with an implicit bound, thus:
enumFrom x = enumFromTo x maxBound
enumFromThen x y = enumFromThenTo x y bound
where
bound | fromEnum y >= fromEnum x = maxBound
| otherwise = minBoundMethods
the successor of a value. For numeric types, succ adds 1.
the predecessor of a value. For numeric types, pred subtracts 1.
Convert from an Int.
Convert to an Int.
It is implementation-dependent what fromEnum returns when
applied to a value that is too large to fit in an Int.
Used in Haskell's translation of [n..] with [n..] = enumFrom n,
a possible implementation being enumFrom n = n : enumFrom (succ n).
For example:
enumFrom 4 :: [Integer] = [4,5,6,7,...]
enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]
enumFromThen :: a -> a -> [a] #
Used in Haskell's translation of [n,n'..]
with [n,n'..] = enumFromThen n n', a possible implementation being
enumFromThen n n' = n : n' : worker (f x) (f x n'),
worker s v = v : worker s (s v), x = fromEnum n' - fromEnum n and
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y
For example:
enumFromThen 4 6 :: [Integer] = [4,6,8,10...]
enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]
enumFromTo :: a -> a -> [a] #
Used in Haskell's translation of [n..m] with
[n..m] = enumFromTo n m, a possible implementation being
enumFromTo n m
| n <= m = n : enumFromTo (succ n) m
| otherwise = [].
For example:
enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
enumFromTo 42 1 :: [Integer] = []
enumFromThenTo :: a -> a -> a -> [a] #
Used in Haskell's translation of [n,n'..m] with
[n,n'..m] = enumFromThenTo n n' m, a possible implementation
being enumFromThenTo n n' m = worker (f x) (c x) n m,
x = fromEnum n' - fromEnum n, c x = bool (>=) ((x 0)
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y and
worker s c v m
| c v m = v : worker s c (s v) m
| otherwise = []
For example:
enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]
enumFromThenTo 6 8 2 :: [Int] = []
Instances
The Eq class defines equality (==) and inequality (/=).
All the basic datatypes exported by the Prelude are instances of Eq,
and Eq may be derived for any datatype whose constituents are also
instances of Eq.
The Haskell Report defines no laws for Eq. However, == is customarily
expected to implement an equivalence relationship where two values comparing
equal are indistinguishable by "public" functions, with a "public" function
being one not allowing to see implementation details. For example, for a
type representing non-normalised natural numbers modulo 100, a "public"
function doesn't make the difference between 1 and 201. It is expected to
have the following properties:
Instances
| Eq 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 Integer | |
| Eq Natural | Since: base-4.8.0.0 |
| Eq Ordering | |
| Eq Word | |
| Eq Word8 | Since: base-2.1 |
| Eq Word16 | Since: base-2.1 |
| Eq Word32 | Since: base-2.1 |
| Eq Word64 | Since: base-2.1 |
| Eq Exp | |
| Eq Match | |
| Eq Clause | |
| Eq Pat | |
| Eq Type | |
| Eq Dec | |
| Eq Name | |
| Eq FunDep | |
| Eq InjectivityAnn | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: InjectivityAnn -> InjectivityAnn -> Bool # (/=) :: InjectivityAnn -> InjectivityAnn -> Bool # | |
| Eq Overlap | |
| Eq () | |
| Eq TyCon | |
| Eq Module | |
| Eq TrName | |
| Eq Version | Since: base-2.1 |
| Eq StdGen | |
| Eq Scientific | Scientific numbers can be safely compared for equality. No magnitude |
Defined in Data.Scientific | |
| Eq UTCTime | |
| Eq ByteString | |
Defined in Data.ByteString.Internal | |
| Eq ByteString | |
Defined in Data.ByteString.Lazy.Internal | |
| Eq JSONPathElement | |
Defined in Data.Aeson.Types.Internal Methods (==) :: JSONPathElement -> JSONPathElement -> Bool # (/=) :: JSONPathElement -> JSONPathElement -> Bool # | |
| Eq Value | |
| Eq DotNetTime | |
Defined in Data.Aeson.Types.Internal | |
| Eq SumEncoding | |
Defined in Data.Aeson.Types.Internal | |
| Eq Key | |
| Eq Handle | Since: base-4.1.0.0 |
| Eq Void | Since: base-4.8.0.0 |
| Eq SpecConstrAnnotation | Since: base-4.3.0.0 |
Defined in GHC.Exts Methods (==) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool # (/=) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool # | |
| Eq Constr | Equality of constructors Since: base-4.0.0.0 |
| Eq DataRep | Since: base-4.0.0.0 |
| Eq ConstrRep | Since: base-4.0.0.0 |
| Eq Fixity | Since: base-4.0.0.0 |
| Eq AsyncException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods (==) :: AsyncException -> AsyncException -> Bool # (/=) :: AsyncException -> AsyncException -> Bool # | |
| Eq ArrayException | Since: base-4.2.0.0 |
Defined in GHC.IO.Exception Methods (==) :: ArrayException -> ArrayException -> Bool # (/=) :: ArrayException -> ArrayException -> Bool # | |
| Eq ExitCode | |
| Eq IOErrorType | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception | |
| Eq BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
| Eq Newline | Since: base-4.2.0.0 |
| Eq NewlineMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
| Eq MaskingState | Since: base-4.3.0.0 |
Defined in GHC.IO | |
| Eq IOException | Since: base-4.1.0.0 |
Defined in GHC.IO.Exception | |
| Eq All | Since: base-2.1 |
| Eq Any | Since: base-2.1 |
| Eq Fixity | Since: base-4.6.0.0 |
| Eq Associativity | Since: base-4.6.0.0 |
Defined in GHC.Generics Methods (==) :: Associativity -> Associativity -> Bool # (/=) :: Associativity -> Associativity -> Bool # | |
| Eq SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # | |
| Eq SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: SourceStrictness -> SourceStrictness -> Bool # (/=) :: SourceStrictness -> SourceStrictness -> Bool # | |
| Eq DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods (==) :: DecidedStrictness -> DecidedStrictness -> Bool # (/=) :: DecidedStrictness -> DecidedStrictness -> Bool # | |
| Eq SomeSymbol | Since: base-4.7.0.0 |
Defined in GHC.TypeLits | |
| Eq Lexeme | Since: base-2.1 |
| Eq Number | Since: base-4.6.0.0 |
| Eq GeneralCategory | Since: base-2.1 |
Defined in GHC.Unicode Methods (==) :: GeneralCategory -> GeneralCategory -> Bool # (/=) :: GeneralCategory -> GeneralCategory -> Bool # | |
| Eq SrcLoc | Since: base-4.9.0.0 |
| Eq ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods (==) :: ShortByteString -> ShortByteString -> Bool # (/=) :: ShortByteString -> ShortByteString -> Bool # | |
| Eq Clock | |
| Eq TimeSpec | |
| Eq IntSet | |
| Eq ByteArray | |
| Eq Extension | |
| Eq ForeignSrcLang | |
Defined in GHC.ForeignSrcLang.Type Methods (==) :: ForeignSrcLang -> ForeignSrcLang -> Bool # (/=) :: ForeignSrcLang -> ForeignSrcLang -> Bool # | |
| Eq TimeOfDay | |
| Eq NameAddr | |
| Eq BigNat | |
| Eq Backtracking | |
Defined in Options.Applicative.Types | |
| Eq ParserPrefs | |
Defined in Options.Applicative.Types | |
| Eq OptName | |
| Eq OptVisibility | |
Defined in Options.Applicative.Types Methods (==) :: OptVisibility -> OptVisibility -> Bool # (/=) :: OptVisibility -> OptVisibility -> Bool # | |
| Eq ArgPolicy | |
| Eq ArgumentReachability | |
Defined in Options.Applicative.Types Methods (==) :: ArgumentReachability -> ArgumentReachability -> Bool # (/=) :: ArgumentReachability -> ArgumentReachability -> Bool # | |
| Eq AltNodeType | |
Defined in Options.Applicative.Types | |
| Eq LayoutOptions | |
Defined in Prettyprinter.Internal Methods (==) :: LayoutOptions -> LayoutOptions -> Bool # (/=) :: LayoutOptions -> LayoutOptions -> Bool # | |
| Eq PageWidth | |
| Eq FusionDepth | |
Defined in Prettyprinter.Internal | |
| Eq Message | |
| Eq ParseError | |
Defined in Text.Parsec.Error | |
| Eq SourcePos | |
| Eq PrettyLevel | |
Defined in Text.PrettyPrint.HughesPJClass | |
| Eq Doc | |
| Eq TextDetails | |
Defined in Text.PrettyPrint.Annotated.HughesPJ | |
| Eq Style | |
| Eq Mode | |
| Eq ModName | |
| Eq PkgName | |
| Eq Module | |
| Eq OccName | |
| Eq NameFlavour | |
Defined in Language.Haskell.TH.Syntax | |
| Eq NameSpace | |
| Eq Loc | |
| Eq Info | |
| Eq ModuleInfo | |
Defined in Language.Haskell.TH.Syntax | |
| Eq Fixity | |
| Eq FixityDirection | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: FixityDirection -> FixityDirection -> Bool # (/=) :: FixityDirection -> FixityDirection -> Bool # | |
| Eq Lit | |
| Eq Bytes | |
| Eq Body | |
| Eq Guard | |
| Eq Stmt | |
| Eq Range | |
| Eq DerivClause | |
Defined in Language.Haskell.TH.Syntax | |
| Eq DerivStrategy | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: DerivStrategy -> DerivStrategy -> Bool # (/=) :: DerivStrategy -> DerivStrategy -> Bool # | |
| Eq TypeFamilyHead | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (/=) :: TypeFamilyHead -> TypeFamilyHead -> Bool # | |
| Eq TySynEqn | |
| Eq Foreign | |
| Eq Callconv | |
| Eq Safety | |
| Eq Pragma | |
| Eq Inline | |
| Eq RuleMatch | |
| Eq Phases | |
| Eq RuleBndr | |
| Eq AnnTarget | |
| Eq SourceUnpackedness | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # | |
| Eq SourceStrictness | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: SourceStrictness -> SourceStrictness -> Bool # (/=) :: SourceStrictness -> SourceStrictness -> Bool # | |
| Eq DecidedStrictness | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: DecidedStrictness -> DecidedStrictness -> Bool # (/=) :: DecidedStrictness -> DecidedStrictness -> Bool # | |
| Eq Con | |
| Eq Bang | |
| Eq PatSynDir | |
| Eq PatSynArgs | |
Defined in Language.Haskell.TH.Syntax | |
| Eq TyVarBndr | |
| Eq FamilyResultSig | |
Defined in Language.Haskell.TH.Syntax Methods (==) :: FamilyResultSig -> FamilyResultSig -> Bool # (/=) :: FamilyResultSig -> FamilyResultSig -> Bool # | |
| Eq TyLit | |
| Eq Role | |
| Eq AnnLookup | |
| Eq ShortText | |
| Eq TimeLocale | |
Defined in Data.Time.Format.Locale | |
| Eq LocalTime | |
| Eq TimeZone | |
| Eq UniversalTime | |
Defined in Data.Time.Clock.Internal.UniversalTime Methods (==) :: UniversalTime -> UniversalTime -> Bool # (/=) :: UniversalTime -> UniversalTime -> Bool # | |
| Eq NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (==) :: NominalDiffTime -> NominalDiffTime -> Bool # (/=) :: NominalDiffTime -> NominalDiffTime -> Bool # | |
| Eq DiffTime | |
| Eq Day | |
| Eq Permissions | |
Defined in Turtle.Prelude | |
| Eq Size | |
| Eq Line | |
| Eq UnpackedUUID | |
| Eq UUID | |
| Eq Pos | |
| Eq More | |
| Eq DI | |
| Eq DL | |
| Eq B | |
| Eq EMailAddress Source # | |
Defined in OpenSuse.Types.EMailAddress | |
| Eq Entry Source # | |
| Eq ChangeLog Source # | |
| Eq Issue Source # | |
| Eq ProjectId Source # | |
| Eq RequestId Source # | |
| Eq a => Eq [a] | |
| Eq a => Eq (Maybe a) | Since: base-2.1 |
| Eq a => Eq (Ratio a) | Since: base-2.1 |
| Eq p => Eq (Par1 p) | Since: base-4.7.0.0 |
| Eq a => Eq (Solo a) | |
| Eq (Encoding' a) | |
| Eq a => Eq (IResult a) | |
| Eq a => Eq (Result a) | |
| Eq v => Eq (KeyMap v) | |
| Eq a => Eq (Complex a) | Since: base-2.1 |
| Eq a => Eq (Min a) | Since: base-4.9.0.0 |
| Eq a => Eq (Max a) | Since: base-4.9.0.0 |
| Eq a => Eq (First a) | Since: base-4.9.0.0 |
| Eq a => Eq (Last a) | Since: base-4.9.0.0 |
| Eq 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 (Option a) | Since: base-4.9.0.0 |
| Eq a => Eq (ZipList a) | Since: base-4.7.0.0 |
| 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 (Dual a) | Since: base-2.1 |
| Eq a => Eq (Sum a) | Since: base-2.1 |
| Eq a => Eq (Product a) | Since: base-2.1 |
| Eq a => Eq (NonEmpty a) | Since: base-4.9.0.0 |
| Eq a => Eq (IntMap a) | |
| Eq a => Eq (Tree a) | |
| Eq a => Eq (Seq a) | |
| Eq a => Eq (ViewL a) | |
| Eq a => Eq (ViewR a) | |
| Eq a => Eq (Set a) | |
| Eq (MutableByteArray s) | |
Defined in Data.Array.Byte Methods (==) :: MutableByteArray s -> MutableByteArray s -> Bool # (/=) :: MutableByteArray s -> MutableByteArray s -> Bool # | |
| Eq1 f => Eq (Fix f) | |
| (Functor f, Eq1 f) => Eq (Mu f) | |
| (Functor f, Eq1 f) => Eq (Nu f) | |
| Eq a => Eq (DNonEmpty a) | |
| Eq a => Eq (DList a) | |
| Eq a => Eq (Hashed a) | Uses precomputed hash to detect inequality faster |
| Eq ann => Eq (SimpleDocStream ann) | |
Defined in Prettyprinter.Internal Methods (==) :: SimpleDocStream ann -> SimpleDocStream ann -> Bool # (/=) :: SimpleDocStream ann -> SimpleDocStream ann -> Bool # | |
| Eq (Doc a) | |
| Eq a => Eq (AnnotDetails a) | |
Defined in Text.PrettyPrint.Annotated.HughesPJ Methods (==) :: AnnotDetails a -> AnnotDetails a -> Bool # (/=) :: AnnotDetails a -> AnnotDetails a -> Bool # | |
| Eq a => Eq (Span a) | |
| (Eq a, Prim a) => Eq (PrimArray a) | Since: primitive-0.6.4.0 |
| Eq a => Eq (SmallArray a) | |
Defined in Data.Primitive.SmallArray | |
| Eq a => Eq (Array a) | |
| Eq g => Eq (AtomicGen g) | |
| Eq g => Eq (IOGen g) | |
| Eq g => Eq (STGen g) | |
| Eq g => Eq (TGen g) | |
| Eq g => Eq (StateGen g) | |
| Eq a => Eq (Maybe a) | |
| Eq a => Eq (HashSet a) | Note that, in the presence of hash collisions, equal
In general, the lack of extensionality can be observed with any function that depends on the key ordering, such as folds and traversals. |
| (Storable a, Eq a) => Eq (Vector a) | |
| (Prim a, Eq a) => Eq (Vector a) | |
| Eq a => Eq (Vector a) | |
| (Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 |
| Eq (V1 p) | Since: base-4.9.0.0 |
| Eq (U1 p) | Since: base-4.9.0.0 |
| (Eq a, Eq b) => Eq (a, b) | |
| (Eq a, Eq b) => Eq (PolyDiff a b) | |
| (Eq k, Eq a) => Eq (Map k a) | |
| (Eq k, Eq v) => Eq (HashMap k v) | Note that, in the presence of hash collisions, equal
In general, the lack of extensionality can be observed with any function that depends on the key ordering, such as folds and traversals. |
| (Ix i, Eq e) => Eq (Array i e) | Since: base-2.1 |
| Eq a => Eq (Arg a b) | Since: base-4.9.0.0 |
| Eq (MutablePrimArray s a) | |
Defined in Data.Primitive.PrimArray Methods (==) :: MutablePrimArray s a -> MutablePrimArray s a -> Bool # (/=) :: MutablePrimArray s a -> MutablePrimArray s a -> Bool # | |
| Eq (SmallMutableArray s a) | |
Defined in Data.Primitive.SmallArray Methods (==) :: SmallMutableArray s a -> SmallMutableArray s a -> Bool # (/=) :: SmallMutableArray s a -> SmallMutableArray s a -> Bool # | |
| Eq (MutableArray s a) | |
Defined in Data.Primitive.Array Methods (==) :: MutableArray s a -> MutableArray s a -> Bool # (/=) :: MutableArray s a -> MutableArray s a -> Bool # | |
| (Eq a, Eq b) => Eq (These a b) | |
| (Eq a, Eq b) => Eq (Pair a b) | |
| (Eq a, Eq b) => Eq (These a b) | |
| (Eq a, Eq b) => Eq (Either a b) | |
| (Eq k, Eq v) => Eq (Leaf k v) | |
| 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 (a, b, c) | |
| Eq (STArray s i e) | Since: base-2.1 |
| 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 (p a a) => Eq (Join p a) | |
| (Eq e, Eq1 m, Eq a) => Eq (ExceptT e m a) | |
| (Eq e, Eq1 m, Eq a) => Eq (ErrorT e m a) | |
| Eq b => Eq (Tagged s b) | |
| (Eq (f a), Eq (g a), Eq a) => Eq (These1 f g a) | |
| Eq c => Eq (K1 i c p) | Since: base-4.7.0.0 |
| (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 a, Eq b, Eq c, Eq d) => Eq (a, b, c, d) | |
| (Eq1 f, Eq1 g, Eq a) => Eq (Product f g a) | Since: base-4.9.0.0 |
| (Eq1 f, Eq1 g, Eq a) => Eq (Sum f g a) | Since: base-4.9.0.0 |
| Eq (f p) => Eq (M1 i c f p) | Since: base-4.7.0.0 |
| Eq (f (g p)) => Eq ((f :.: g) p) | Since: base-4.7.0.0 |
| (Eq a, Eq b, Eq c, Eq d, Eq e) => Eq (a, b, c, d, e) | |
| (Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a) | Since: base-4.9.0.0 |
| Eq (p a b) => Eq (WrappedBifunctor p a b) | |
Defined in Data.Bifunctor.Wrapped Methods (==) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (/=) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # | |
| Eq (g b) => Eq (Joker g a b) | |
| Eq (p b a) => Eq (Flip p a b) | |
| Eq (f a) => Eq (Clown f a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f) | |
| (Eq (p a b), Eq (q a b)) => Eq (Sum p q a b) | |
| (Eq (f a b), Eq (g a b)) => Eq (Product f g a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g) => Eq (a, b, c, d, e, f, g) | |
| Eq (f (p a b)) => Eq (Tannen f p a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq 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 (p (f a) (g b)) => Eq (Biff p f g a b) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j) => Eq (a, b, c, d, e, f, g, h, i, j) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k) => Eq (a, b, c, d, e, f, g, h, i, j, k) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l) => Eq (a, b, c, d, e, f, g, h, i, j, k, l) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | |
| (Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n, Eq o) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | |
class Fractional a => Floating a where #
Trigonometric and hyperbolic functions and related functions.
The Haskell Report defines no laws for Floating. However, (, +)(
and *)exp are customarily expected to define an exponential field and have
the following properties:
exp (a + b)=exp a * exp bexp (fromInteger 0)=fromInteger 1
Minimal complete definition
pi, exp, log, sin, cos, asin, acos, atan, sinh, cosh, asinh, acosh, atanh
Instances
class Num a => Fractional a where #
Fractional numbers, supporting real division.
The Haskell Report defines no laws for Fractional. However, ( and
+)( are customarily expected to define a division ring and have the
following properties:*)
recipgives the multiplicative inversex * recip x=recip x * x=fromInteger 1
Note that it isn't customarily expected that a type instance of
Fractional implement a field. However, all instances in base do.
Minimal complete definition
fromRational, (recip | (/))
Methods
Fractional division.
Reciprocal fraction.
fromRational :: Rational -> a #
Conversion from a Rational (that is Ratio IntegerfromRational
to a value of type Rational, so such literals have type
(.Fractional a) => a
Instances
| Fractional Scientific | WARNING: These methods also compute
|
Defined in Data.Scientific Methods (/) :: Scientific -> Scientific -> Scientific # recip :: Scientific -> Scientific # fromRational :: Rational -> Scientific # | |
| Fractional NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (/) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # recip :: NominalDiffTime -> NominalDiffTime # fromRational :: Rational -> NominalDiffTime # | |
| Fractional DiffTime | |
| Integral a => Fractional (Ratio a) | Since: base-2.0.1 |
| RealFloat a => Fractional (Complex a) | Since: base-2.1 |
| Fractional a => Fractional (Identity a) | Since: base-4.9.0.0 |
| Fractional a => Fractional (Managed a) | |
| Fractional b => Fractional (Fold a b) | |
| Fractional a => Fractional (Const a b) | Since: base-4.9.0.0 |
| (Monad m, Fractional b) => Fractional (FoldM m a b) | |
| Fractional a => Fractional (Tagged s a) | |
class (Real a, Enum a) => Integral a where #
Integral numbers, supporting integer division.
The Haskell Report defines no laws for Integral. However, Integral
instances are customarily expected to define a Euclidean domain and have the
following properties for the div/mod and quot/rem pairs, given
suitable Euclidean functions f and g:
x=y * quot x y + rem x ywithrem x y=fromInteger 0org (rem x y)<g yx=y * div x y + mod x ywithmod x y=fromInteger 0orf (mod x y)<f y
An example of a suitable Euclidean function, for Integer's instance, is
abs.
Methods
quot :: a -> a -> a infixl 7 #
integer division truncated toward zero
integer remainder, satisfying
(x `quot` y)*y + (x `rem` y) == x
integer division truncated toward negative infinity
integer modulus, satisfying
(x `div` y)*y + (x `mod` y) == x
conversion to Integer
Instances
| Integral Int | Since: base-2.0.1 |
| Integral Integer | Since: base-2.0.1 |
Defined in GHC.Real | |
| Integral Natural | Since: base-4.8.0.0 |
Defined in GHC.Real | |
| Integral Word | Since: base-2.1 |
| Integral Word8 | Since: base-2.1 |
| Integral Word16 | Since: base-2.1 |
| Integral Word32 | Since: base-2.1 |
| Integral Word64 | Since: base-2.1 |
| Integral TimeSpec | |
Defined in System.Clock | |
| Integral a => Integral (Identity a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Identity Methods quot :: Identity a -> Identity a -> Identity a # rem :: Identity a -> Identity a -> Identity a # div :: Identity a -> Identity a -> Identity a # mod :: Identity a -> Identity a -> Identity a # quotRem :: Identity a -> Identity a -> (Identity a, Identity a) # divMod :: Identity a -> Identity a -> (Identity a, Identity a) # | |
| Integral a => Integral (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods quot :: Const a b -> Const a b -> Const a b # rem :: Const a b -> Const a b -> Const a b # div :: Const a b -> Const a b -> Const a b # mod :: Const a b -> Const a b -> Const a b # quotRem :: Const a b -> Const a b -> (Const a b, Const a b) # divMod :: Const a b -> Const a b -> (Const a b, Const a b) # | |
| Integral a => Integral (Tagged s a) | |
Defined in Data.Tagged Methods quot :: Tagged s a -> Tagged s a -> Tagged s a # rem :: Tagged s a -> Tagged s a -> Tagged s a # div :: Tagged s a -> Tagged s a -> Tagged s a # mod :: Tagged s a -> Tagged s a -> Tagged s a # quotRem :: Tagged s a -> Tagged s a -> (Tagged s a, Tagged s a) # divMod :: Tagged s a -> Tagged s a -> (Tagged s a, Tagged s 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
returna>>=k = k a- Right identity
m>>=return= m- Associativity
m>>=(\x -> k x>>=h) = (m>>=k)>>=h
Furthermore, the Monad and Applicative operations should relate as follows:
The above laws imply:
and that pure and (<*>) satisfy the applicative functor laws.
The instances of Monad for lists, Maybe and IO
defined in the Prelude satisfy these laws.
Minimal complete definition
Methods
(>>=) :: m a -> (a -> m b) -> m b infixl 1 #
Sequentially compose two actions, passing any value produced by the first as an argument to the second.
'as ' can be understood as the >>= bsdo expression
do a <- as bs a
(>>) :: m a -> m b -> m b infixl 1 #
Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.
'as ' can be understood as the >> bsdo expression
do as bs
Inject a value into the monadic type.
Instances
| Monad [] | Since: base-2.1 |
| Monad Maybe | Since: base-2.1 |
| Monad IO | Since: base-2.1 |
| Monad Par1 | Since: base-4.9.0.0 |
| Monad Q | |
| Monad Solo | |
| Monad IResult | |
| Monad Result | |
| Monad Parser | |
| Monad Complex | Since: base-4.9.0.0 |
| Monad Min | Since: base-4.9.0.0 |
| Monad Max | Since: base-4.9.0.0 |
| Monad First | Since: base-4.9.0.0 |
| Monad Last | Since: base-4.9.0.0 |
| Monad Option | Since: base-4.9.0.0 |
| Monad Identity | Since: base-4.8.0.0 |
| Monad First | Since: base-4.8.0.0 |
| Monad Last | Since: base-4.8.0.0 |
| Monad Dual | Since: base-4.8.0.0 |
| Monad Sum | Since: base-4.8.0.0 |
| Monad Product | Since: base-4.8.0.0 |
| Monad ReadPrec | Since: base-2.1 |
| Monad ReadP | Since: base-2.1 |
| Monad NonEmpty | Since: base-4.9.0.0 |
| Monad PutM | |
| Monad Get | |
| Monad Tree | |
| Monad Seq | |
| Monad DNonEmpty | |
| Monad DList | |
| Monad Managed | |
| Monad ReadM | |
| Monad ParserM | |
| Monad ParserResult | |
Defined in Options.Applicative.Types Methods (>>=) :: ParserResult a -> (a -> ParserResult b) -> ParserResult b # (>>) :: ParserResult a -> ParserResult b -> ParserResult b # return :: a -> ParserResult a # | |
| Monad SmallArray | |
Defined in Data.Primitive.SmallArray Methods (>>=) :: SmallArray a -> (a -> SmallArray b) -> SmallArray b # (>>) :: SmallArray a -> SmallArray b -> SmallArray b # return :: a -> SmallArray a # | |
| Monad Array | |
| Monad Shell | |
| Monad Pattern | |
| Monad Vector | |
| Monad P | Since: base-2.1 |
| Monad (Either e) | Since: base-4.4.0.0 |
| Monad (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monoid a => Monad ((,) a) | Since: base-4.9.0.0 |
| 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 # | |
| Semigroup a => Monad (These a) | |
| Semigroup a => Monad (These a) | |
| Monad (Parser i) | |
| Monad f => Monad (Rec1 f) | Since: base-4.9.0.0 |
| (Monoid a, Monoid b) => Monad ((,,) a b) | Since: base-4.14.0.0 |
| 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 |
| (Applicative f, Monad f) => Monad (WhenMissing f x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMissing f x a -> (a -> WhenMissing f x b) -> WhenMissing f x b # (>>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # return :: a -> WhenMissing f x a # | |
| Monad m => Monad (ExceptT e m) | |
| (Monad m, Error e) => Monad (ErrorT e m) | |
| Monad (Tagged s) | |
| Monad ((->) r :: Type -> Type) | Since: base-2.1 |
| (Monad f, Monad g) => Monad (f :*: g) | Since: base-4.9.0.0 |
| (Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c) | Since: base-4.14.0.0 |
| (Monad f, Monad g) => Monad (Product f g) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Monad (WhenMatched f x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMatched f x y a -> (a -> WhenMatched f x y b) -> WhenMatched f x y b # (>>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # return :: a -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Monad (WhenMissing f k x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMissing f k x a -> (a -> WhenMissing f k x b) -> WhenMissing f k x b # (>>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # return :: a -> WhenMissing f k x a # | |
| Monad (ParsecT s u m) | |
| Monad f => Monad (M1 i c f) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Monad (WhenMatched f k x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMatched f k x y a -> (a -> WhenMatched f k x y b) -> WhenMatched f k x y b # (>>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # return :: a -> WhenMatched f k x y a # | |
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 #
Using ApplicativeDo: 'fmap f asdo expression
do a <- as pure (f a)
with an inferred Functor constraint.
Instances
| Functor [] | Since: base-2.1 |
| Functor Maybe | Since: base-2.1 |
| Functor IO | Since: base-2.1 |
| Functor Par1 | Since: base-4.9.0.0 |
| Functor Q | |
| Functor Solo | |
| Functor FromJSONKeyFunction | Only law abiding up to interpretation |
Defined in Data.Aeson.Types.FromJSON Methods fmap :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b # (<$) :: a -> FromJSONKeyFunction b -> FromJSONKeyFunction a # | |
| Functor IResult | |
| Functor Result | |
| Functor Parser | |
| Functor KeyMap | |
| Functor Complex | Since: base-4.9.0.0 |
| Functor Min | Since: base-4.9.0.0 |
| Functor Max | Since: base-4.9.0.0 |
| Functor First | Since: base-4.9.0.0 |
| Functor Last | Since: base-4.9.0.0 |
| Functor Option | Since: base-4.9.0.0 |
| Functor ZipList | Since: base-2.1 |
| Functor Identity | Since: base-4.8.0.0 |
| Functor First | Since: base-4.8.0.0 |
| Functor Last | Since: base-4.8.0.0 |
| Functor Dual | Since: base-4.8.0.0 |
| Functor Sum | Since: base-4.8.0.0 |
| Functor Product | Since: base-4.8.0.0 |
| Functor ReadPrec | Since: base-2.1 |
| Functor ReadP | Since: base-2.1 |
| Functor NonEmpty | Since: base-4.9.0.0 |
| Functor PutM | |
| Functor Decoder | |
| Functor Get | |
| Functor IntMap | |
| Functor Tree | |
| Functor Seq | |
| Functor FingerTree | |
Defined in Data.Sequence.Internal Methods fmap :: (a -> b) -> FingerTree a -> FingerTree b # (<$) :: a -> FingerTree b -> FingerTree a # | |
| Functor Digit | |
| Functor Node | |
| Functor Elem | |
| Functor ViewL | |
| Functor ViewR | |
| Functor DNonEmpty | |
| Functor DList | |
| Functor Managed | |
| Functor ParserInfo | |
Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserInfo a -> ParserInfo b # (<$) :: a -> ParserInfo b -> ParserInfo a # | |
| Functor Option | |
| Functor ReadM | |
| Functor CReader | |
| Functor OptReader | |
| Functor Parser | |
| Functor ParserM | |
| Functor ParserFailure | |
Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserFailure a -> ParserFailure b # (<$) :: a -> ParserFailure b -> ParserFailure a # | |
| Functor ParserResult | |
Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserResult a -> ParserResult b # (<$) :: a -> ParserResult b -> ParserResult a # | |
| Functor SimpleDocStream | Alter the document’s annotations. This instance makes |
Defined in Prettyprinter.Internal Methods fmap :: (a -> b) -> SimpleDocStream a -> SimpleDocStream b # (<$) :: a -> SimpleDocStream b -> SimpleDocStream a # | |
| Functor Consumed | |
| Functor Doc | |
| Functor AnnotDetails | |
Defined in Text.PrettyPrint.Annotated.HughesPJ Methods fmap :: (a -> b) -> AnnotDetails a -> AnnotDetails b # (<$) :: a -> AnnotDetails b -> AnnotDetails a # | |
| Functor Span | |
| Functor Doc | Alter the document’s annotations. This instance makes |
| Functor SmallArray | |
Defined in Data.Primitive.SmallArray Methods fmap :: (a -> b) -> SmallArray a -> SmallArray b # (<$) :: a -> SmallArray b -> SmallArray a # | |
| Functor Array | |
| Functor Maybe | |
| Functor Shell | |
| Functor Pattern | |
| Functor Vector | |
| Functor P | Since: base-4.8.0.0 |
Defined in Text.ParserCombinators.ReadP | |
| Functor FlattenResult | |
Defined in Prettyprinter.Internal | |
| Functor (Either a) | Since: base-3.0 |
| Functor (V1 :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Functor ((,) a) | Since: base-2.1 |
| Functor (Tagged2 s) | |
Defined in Data.Aeson.Types.Generic | |
| Functor (Map k) | |
| Functor (HashMap k) | |
| Functor (Array i) | Since: base-2.1 |
| Functor (Arg a) | Since: base-4.9.0.0 |
| 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 (Fold a) | |
| Functor (These a) | |
| Functor (Pair e) | |
| Functor (These a) | |
| Functor (Either a) | |
| Functor (IResult i) | |
Defined in Data.Attoparsec.Internal.Types | |
| Functor (Parser i) | |
Defined in Data.Attoparsec.Internal.Types | |
| Functor f => Functor (Rec1 f) | Since: base-4.9.0.0 |
| Functor (URec Char :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Double :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Float :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Int :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Word :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec (Ptr ()) :: Type -> Type) | Since: base-4.9.0.0 |
| Functor ((,,) a b) | Since: base-4.14.0.0 |
| 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 # (<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
| Functor m => Functor (Kleisli m a) | Since: base-4.14.0.0 |
| Functor (Const m :: Type -> Type) | Since: base-2.1 |
| Functor f => Functor (Ap f) | Since: base-4.12.0.0 |
| Functor f => Functor (Alt f) | Since: base-4.8.0.0 |
| Bifunctor p => Functor (Join p) | |
| (Applicative f, Monad f) => Functor (WhenMissing f x) | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods fmap :: (a -> b) -> WhenMissing f x a -> WhenMissing f x b # (<$) :: a -> WhenMissing f x b -> WhenMissing f x a # | |
| Functor m => Functor (ExceptT e m) | |
| Functor m => Functor (FoldM m a) | |
| Functor m => Functor (ErrorT e m) | |
| Functor (Reply s u) | |
| Functor (Tagged s) | |
| (Functor f, Functor g) => Functor (These1 f g) | |
| Functor ((->) r :: Type -> Type) | Since: base-2.1 |
| Functor (K1 i c :: Type -> Type) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :+: g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :*: g) | Since: base-4.9.0.0 |
| Functor ((,,,) a b c) | Since: base-4.14.0.0 |
| (Functor f, Functor g) => Functor (Product f g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (Sum f g) | Since: base-4.9.0.0 |
| Functor f => Functor (WhenMatched f x y) | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods fmap :: (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b # (<$) :: a -> WhenMatched f x y b -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Functor (WhenMissing f k x) | Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods fmap :: (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # (<$) :: a -> WhenMissing f k x b -> WhenMissing f k x a # | |
| Functor (ParsecT s u m) | |
| Functor f => Functor (M1 i c f) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :.: g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (Compose f g) | Since: base-4.9.0.0 |
| Bifunctor p => Functor (WrappedBifunctor p a) | |
Defined in Data.Bifunctor.Wrapped Methods fmap :: (a0 -> b) -> WrappedBifunctor p a a0 -> WrappedBifunctor p a b # (<$) :: a0 -> WrappedBifunctor p a b -> WrappedBifunctor p a a0 # | |
| Functor g => Functor (Joker g a) | |
| Bifunctor p => Functor (Flip p a) | |
| Functor (Clown f a :: Type -> Type) | |
| Functor f => Functor (WhenMatched f k x y) | Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods fmap :: (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # (<$) :: a -> WhenMatched f k x y b -> WhenMatched f k x y a # | |
| (Functor (f a), Functor (g a)) => Functor (Sum f g a) | |
| (Functor (f a), Functor (g a)) => Functor (Product f g a) | |
| (Functor f, Bifunctor p) => Functor (Tannen f p a) | |
| (Bifunctor p, Functor g) => Functor (Biff p f g a) | |
Basic numeric class.
The Haskell Report defines no laws for Num. However, ( and +)( are
customarily expected to define a ring and have the following properties:*)
- Associativity of
(+) (x + y) + z=x + (y + z)- Commutativity of
(+) x + y=y + xfromInteger0x + fromInteger 0=xnegategives the additive inversex + negate x=fromInteger 0- Associativity of
(*) (x * y) * z=x * (y * z)fromInteger1x * fromInteger 1=xandfromInteger 1 * x=x- Distributivity of
(with respect to*)(+) a * (b + c)=(a * b) + (a * c)and(b + c) * a=(b * a) + (c * a)
Note that it isn't customarily expected that a type instance of both Num
and Ord implement an ordered ring. Indeed, in base only Integer and
Rational do.
Methods
Unary negation.
Absolute value.
Sign of a number.
The functions abs and signum should satisfy the law:
abs x * signum x == x
For real numbers, the signum is either -1 (negative), 0 (zero)
or 1 (positive).
fromInteger :: Integer -> a #
Conversion from an Integer.
An integer literal represents the application of the function
fromInteger to the appropriate value of type Integer,
so such literals have type (.Num a) => a
Instances
| Num Int | Since: base-2.1 |
| Num Integer | Since: base-2.1 |
| Num Natural | Note that Since: base-4.8.0.0 |
| Num Word | Since: base-2.1 |
| Num Word8 | Since: base-2.1 |
| Num Word16 | Since: base-2.1 |
| Num Word32 | Since: base-2.1 |
| Num Word64 | Since: base-2.1 |
| Num Scientific | WARNING: |
Defined in Data.Scientific Methods (+) :: Scientific -> Scientific -> Scientific # (-) :: Scientific -> Scientific -> Scientific # (*) :: Scientific -> Scientific -> Scientific # negate :: Scientific -> Scientific # abs :: Scientific -> Scientific # signum :: Scientific -> Scientific # fromInteger :: Integer -> Scientific # | |
| Num TimeSpec | |
| Num NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (+) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (-) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (*) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # negate :: NominalDiffTime -> NominalDiffTime # abs :: NominalDiffTime -> NominalDiffTime # signum :: NominalDiffTime -> NominalDiffTime # fromInteger :: Integer -> NominalDiffTime # | |
| Num DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Num Size | |
| Num Pos | |
| Num B | |
| Integral a => Num (Ratio a) | Since: base-2.0.1 |
| RealFloat a => Num (Complex a) | Since: base-2.1 |
| Num a => Num (Min a) | Since: base-4.9.0.0 |
| Num a => Num (Max a) | Since: base-4.9.0.0 |
| Num a => Num (Identity a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Identity | |
| Num a => Num (Sum a) | Since: base-4.7.0.0 |
| Num a => Num (Product a) | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| Num a => Num (Managed a) | |
Defined in Control.Monad.Managed | |
| Monoid a => Num (Shell a) | Shell forms a semiring, this is the closest approximation |
| Monoid a => Num (Pattern a) | Pattern forms a semiring, this is the closest approximation |
Defined in Turtle.Pattern | |
| Num b => Num (Fold a b) | |
| Num a => Num (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| (Applicative f, Num a) => Num (Ap f a) | Since: base-4.12.0.0 |
| Num (f a) => Num (Alt f a) | Since: base-4.8.0.0 |
| (Monad m, Num b) => Num (FoldM m a b) | |
Defined in Control.Foldl Methods (+) :: FoldM m a b -> FoldM m a b -> FoldM m a b # (-) :: FoldM m a b -> FoldM m a b -> FoldM m a b # (*) :: FoldM m a b -> FoldM m a b -> FoldM m a b # negate :: FoldM m a b -> FoldM m a b # abs :: FoldM m a b -> FoldM m a b # signum :: FoldM m a b -> FoldM m a b # fromInteger :: Integer -> FoldM m a b # | |
| Num a => Num (Tagged s a) | |
Defined in Data.Tagged | |
The Ord class is used for totally ordered datatypes.
Instances of Ord can be derived for any user-defined datatype whose
constituent types are in Ord. The declared order of the constructors in
the data declaration determines the ordering in derived Ord instances. The
Ordering datatype allows a single comparison to determine the precise
ordering of two objects.
The Haskell Report defines no laws for Ord. However, <= is customarily
expected to implement a non-strict partial order and have the following
properties:
- Transitivity
- if
x <= y && y <= z=True, thenx <= z=True - Reflexivity
x <= x=True- Antisymmetry
- if
x <= y && y <= x=True, thenx == y=True
Note that the following operator interactions are expected to hold:
x >= y=y <= xx < y=x <= y && x /= yx > y=y < xx < y=compare x y == LTx > y=compare x y == GTx == y=compare x y == EQmin x y == if x <= y then x else y=Truemax x y == if x >= y then x else y=True
Note that (7.) and (8.) do not require min and max to return either of
their arguments. The result is merely required to equal one of the
arguments in terms of (==).
Minimal complete definition: either compare or <=.
Using compare can be more efficient for complex types.
Methods
compare :: a -> a -> Ordering #
(<) :: a -> a -> Bool infix 4 #
(<=) :: a -> a -> Bool infix 4 #
(>) :: a -> a -> Bool infix 4 #
Instances
| Ord 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 Integer | |
| Ord Natural | Since: base-4.8.0.0 |
| Ord Ordering | |
Defined in GHC.Classes | |
| Ord Word | |
| Ord Word8 | Since: base-2.1 |
| Ord Word16 | Since: base-2.1 |
| Ord Word32 | Since: base-2.1 |
| Ord Word64 | Since: base-2.1 |
| Ord Exp | |
| Ord Match | |
| Ord Clause | |
| Ord Pat | |
| Ord Type | |
| Ord Dec | |
| Ord Name | |
| Ord FunDep | |
| Ord InjectivityAnn | |
Defined in Language.Haskell.TH.Syntax Methods compare :: InjectivityAnn -> InjectivityAnn -> Ordering # (<) :: InjectivityAnn -> InjectivityAnn -> Bool # (<=) :: InjectivityAnn -> InjectivityAnn -> Bool # (>) :: InjectivityAnn -> InjectivityAnn -> Bool # (>=) :: InjectivityAnn -> InjectivityAnn -> Bool # max :: InjectivityAnn -> InjectivityAnn -> InjectivityAnn # min :: InjectivityAnn -> InjectivityAnn -> InjectivityAnn # | |
| Ord Overlap | |
Defined in Language.Haskell.TH.Syntax | |
| Ord () | |
| Ord TyCon | |
| Ord Version | Since: base-2.1 |
| Ord Scientific | Scientific numbers can be safely compared for ordering. No magnitude |
Defined in Data.Scientific Methods compare :: Scientific -> Scientific -> Ordering # (<) :: Scientific -> Scientific -> Bool # (<=) :: Scientific -> Scientific -> Bool # (>) :: Scientific -> Scientific -> Bool # (>=) :: Scientific -> Scientific -> Bool # max :: Scientific -> Scientific -> Scientific # min :: Scientific -> Scientific -> Scientific # | |
| Ord UTCTime | |
Defined in Data.Time.Clock.Internal.UTCTime | |
| Ord ByteString | |
Defined in Data.ByteString.Internal Methods compare :: ByteString -> ByteString -> Ordering # (<) :: ByteString -> ByteString -> Bool # (<=) :: ByteString -> ByteString -> Bool # (>) :: ByteString -> ByteString -> Bool # (>=) :: ByteString -> ByteString -> Bool # max :: ByteString -> ByteString -> ByteString # min :: ByteString -> ByteString -> ByteString # | |
| Ord ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods compare :: ByteString -> ByteString -> Ordering # (<) :: ByteString -> ByteString -> Bool # (<=) :: ByteString -> ByteString -> Bool # (>) :: ByteString -> ByteString -> Bool # (>=) :: ByteString -> ByteString -> Bool # max :: ByteString -> ByteString -> ByteString # min :: ByteString -> ByteString -> ByteString # | |
| Ord JSONPathElement | |
Defined in Data.Aeson.Types.Internal Methods compare :: JSONPathElement -> JSONPathElement -> Ordering # (<) :: JSONPathElement -> JSONPathElement -> Bool # (<=) :: JSONPathElement -> JSONPathElement -> Bool # (>) :: JSONPathElement -> JSONPathElement -> Bool # (>=) :: JSONPathElement -> JSONPathElement -> Bool # max :: JSONPathElement -> JSONPathElement -> JSONPathElement # min :: JSONPathElement -> JSONPathElement -> JSONPathElement # | |
| Ord Value | The ordering is total, consistent with Since: aeson-1.5.2.0 |
| Ord DotNetTime | |
Defined in Data.Aeson.Types.Internal Methods compare :: DotNetTime -> DotNetTime -> Ordering # (<) :: DotNetTime -> DotNetTime -> Bool # (<=) :: DotNetTime -> DotNetTime -> Bool # (>) :: DotNetTime -> DotNetTime -> Bool # (>=) :: DotNetTime -> DotNetTime -> Bool # max :: DotNetTime -> DotNetTime -> DotNetTime # min :: DotNetTime -> DotNetTime -> DotNetTime # | |
| Ord Key | |
| Ord Void | Since: base-4.8.0.0 |
| 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 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 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 All | Since: base-2.1 |
| Ord Any | Since: base-2.1 |
| Ord Fixity | Since: base-4.6.0.0 |
| 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 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 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 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 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 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 ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods compare :: ShortByteString -> ShortByteString -> Ordering # (<) :: ShortByteString -> ShortByteString -> Bool # (<=) :: ShortByteString -> ShortByteString -> Bool # (>) :: ShortByteString -> ShortByteString -> Bool # (>=) :: ShortByteString -> ShortByteString -> Bool # max :: ShortByteString -> ShortByteString -> ShortByteString # min :: ShortByteString -> ShortByteString -> ShortByteString # | |
| Ord TimeSpec | |
Defined in System.Clock | |
| Ord IntSet | |
| Ord ByteArray | Non-lexicographic ordering. This compares the lengths of the byte arrays first and uses a lexicographic ordering if the lengths are equal. Subject to change between major versions. |
| Ord TimeOfDay | |
Defined in Data.Time.LocalTime.Internal.TimeOfDay | |
| Ord BigNat | |
| Ord OptName | |
Defined in Options.Applicative.Types | |
| Ord OptVisibility | |
Defined in Options.Applicative.Types Methods compare :: OptVisibility -> OptVisibility -> Ordering # (<) :: OptVisibility -> OptVisibility -> Bool # (<=) :: OptVisibility -> OptVisibility -> Bool # (>) :: OptVisibility -> OptVisibility -> Bool # (>=) :: OptVisibility -> OptVisibility -> Bool # max :: OptVisibility -> OptVisibility -> OptVisibility # min :: OptVisibility -> OptVisibility -> OptVisibility # | |
| Ord ArgPolicy | |
| Ord LayoutOptions | |
Defined in Prettyprinter.Internal Methods compare :: LayoutOptions -> LayoutOptions -> Ordering # (<) :: LayoutOptions -> LayoutOptions -> Bool # (<=) :: LayoutOptions -> LayoutOptions -> Bool # (>) :: LayoutOptions -> LayoutOptions -> Bool # (>=) :: LayoutOptions -> LayoutOptions -> Bool # max :: LayoutOptions -> LayoutOptions -> LayoutOptions # min :: LayoutOptions -> LayoutOptions -> LayoutOptions # | |
| Ord PageWidth | |
| Ord FusionDepth | |
Defined in Prettyprinter.Internal Methods compare :: FusionDepth -> FusionDepth -> Ordering # (<) :: FusionDepth -> FusionDepth -> Bool # (<=) :: FusionDepth -> FusionDepth -> Bool # (>) :: FusionDepth -> FusionDepth -> Bool # (>=) :: FusionDepth -> FusionDepth -> Bool # max :: FusionDepth -> FusionDepth -> FusionDepth # min :: FusionDepth -> FusionDepth -> FusionDepth # | |
| Ord Message | |
| Ord SourcePos | |
| Ord PrettyLevel | |
Defined in Text.PrettyPrint.HughesPJClass Methods compare :: PrettyLevel -> PrettyLevel -> Ordering # (<) :: PrettyLevel -> PrettyLevel -> Bool # (<=) :: PrettyLevel -> PrettyLevel -> Bool # (>) :: PrettyLevel -> PrettyLevel -> Bool # (>=) :: PrettyLevel -> PrettyLevel -> Bool # max :: PrettyLevel -> PrettyLevel -> PrettyLevel # min :: PrettyLevel -> PrettyLevel -> PrettyLevel # | |
| Ord ModName | |
Defined in Language.Haskell.TH.Syntax | |
| Ord PkgName | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Module | |
| Ord OccName | |
Defined in Language.Haskell.TH.Syntax | |
| Ord NameFlavour | |
Defined in Language.Haskell.TH.Syntax Methods compare :: NameFlavour -> NameFlavour -> Ordering # (<) :: NameFlavour -> NameFlavour -> Bool # (<=) :: NameFlavour -> NameFlavour -> Bool # (>) :: NameFlavour -> NameFlavour -> Bool # (>=) :: NameFlavour -> NameFlavour -> Bool # max :: NameFlavour -> NameFlavour -> NameFlavour # min :: NameFlavour -> NameFlavour -> NameFlavour # | |
| Ord NameSpace | |
| Ord Loc | |
| Ord Info | |
| Ord ModuleInfo | |
Defined in Language.Haskell.TH.Syntax Methods compare :: ModuleInfo -> ModuleInfo -> Ordering # (<) :: ModuleInfo -> ModuleInfo -> Bool # (<=) :: ModuleInfo -> ModuleInfo -> Bool # (>) :: ModuleInfo -> ModuleInfo -> Bool # (>=) :: ModuleInfo -> ModuleInfo -> Bool # max :: ModuleInfo -> ModuleInfo -> ModuleInfo # min :: ModuleInfo -> ModuleInfo -> ModuleInfo # | |
| Ord Fixity | |
| Ord FixityDirection | |
Defined in Language.Haskell.TH.Syntax Methods compare :: FixityDirection -> FixityDirection -> Ordering # (<) :: FixityDirection -> FixityDirection -> Bool # (<=) :: FixityDirection -> FixityDirection -> Bool # (>) :: FixityDirection -> FixityDirection -> Bool # (>=) :: FixityDirection -> FixityDirection -> Bool # max :: FixityDirection -> FixityDirection -> FixityDirection # min :: FixityDirection -> FixityDirection -> FixityDirection # | |
| Ord Lit | |
| Ord Bytes | |
| Ord Body | |
| Ord Guard | |
| Ord Stmt | |
| Ord Range | |
| Ord DerivClause | |
Defined in Language.Haskell.TH.Syntax Methods compare :: DerivClause -> DerivClause -> Ordering # (<) :: DerivClause -> DerivClause -> Bool # (<=) :: DerivClause -> DerivClause -> Bool # (>) :: DerivClause -> DerivClause -> Bool # (>=) :: DerivClause -> DerivClause -> Bool # max :: DerivClause -> DerivClause -> DerivClause # min :: DerivClause -> DerivClause -> DerivClause # | |
| Ord DerivStrategy | |
Defined in Language.Haskell.TH.Syntax Methods compare :: DerivStrategy -> DerivStrategy -> Ordering # (<) :: DerivStrategy -> DerivStrategy -> Bool # (<=) :: DerivStrategy -> DerivStrategy -> Bool # (>) :: DerivStrategy -> DerivStrategy -> Bool # (>=) :: DerivStrategy -> DerivStrategy -> Bool # max :: DerivStrategy -> DerivStrategy -> DerivStrategy # min :: DerivStrategy -> DerivStrategy -> DerivStrategy # | |
| Ord TypeFamilyHead | |
Defined in Language.Haskell.TH.Syntax Methods compare :: TypeFamilyHead -> TypeFamilyHead -> Ordering # (<) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (<=) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (>) :: TypeFamilyHead -> TypeFamilyHead -> Bool # (>=) :: TypeFamilyHead -> TypeFamilyHead -> Bool # max :: TypeFamilyHead -> TypeFamilyHead -> TypeFamilyHead # min :: TypeFamilyHead -> TypeFamilyHead -> TypeFamilyHead # | |
| Ord TySynEqn | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Foreign | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Callconv | |
Defined in Language.Haskell.TH.Syntax | |
| Ord Safety | |
| Ord Pragma | |
| Ord Inline | |
| Ord RuleMatch | |
| Ord Phases | |
| Ord RuleBndr | |
Defined in Language.Haskell.TH.Syntax | |
| Ord AnnTarget | |
| Ord SourceUnpackedness | |
Defined in Language.Haskell.TH.Syntax Methods compare :: SourceUnpackedness -> SourceUnpackedness -> Ordering # (<) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (<=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # max :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # min :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # | |
| Ord SourceStrictness | |
Defined in Language.Haskell.TH.Syntax Methods compare :: SourceStrictness -> SourceStrictness -> Ordering # (<) :: SourceStrictness -> SourceStrictness -> Bool # (<=) :: SourceStrictness -> SourceStrictness -> Bool # (>) :: SourceStrictness -> SourceStrictness -> Bool # (>=) :: SourceStrictness -> SourceStrictness -> Bool # max :: SourceStrictness -> SourceStrictness -> SourceStrictness # min :: SourceStrictness -> SourceStrictness -> SourceStrictness # | |
| Ord DecidedStrictness | |
Defined in Language.Haskell.TH.Syntax Methods compare :: DecidedStrictness -> DecidedStrictness -> Ordering # (<) :: DecidedStrictness -> DecidedStrictness -> Bool # (<=) :: DecidedStrictness -> DecidedStrictness -> Bool # (>) :: DecidedStrictness -> DecidedStrictness -> Bool # (>=) :: DecidedStrictness -> DecidedStrictness -> Bool # max :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # min :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # | |
| Ord Con | |
| Ord Bang | |
| Ord PatSynDir | |
| Ord PatSynArgs | |
Defined in Language.Haskell.TH.Syntax Methods compare :: PatSynArgs -> PatSynArgs -> Ordering # (<) :: PatSynArgs -> PatSynArgs -> Bool # (<=) :: PatSynArgs -> PatSynArgs -> Bool # (>) :: PatSynArgs -> PatSynArgs -> Bool # (>=) :: PatSynArgs -> PatSynArgs -> Bool # max :: PatSynArgs -> PatSynArgs -> PatSynArgs # min :: PatSynArgs -> PatSynArgs -> PatSynArgs # | |
| Ord TyVarBndr | |
| Ord FamilyResultSig | |
Defined in Language.Haskell.TH.Syntax Methods compare :: FamilyResultSig -> FamilyResultSig -> Ordering # (<) :: FamilyResultSig -> FamilyResultSig -> Bool # (<=) :: FamilyResultSig -> FamilyResultSig -> Bool # (>) :: FamilyResultSig -> FamilyResultSig -> Bool # (>=) :: FamilyResultSig -> FamilyResultSig -> Bool # max :: FamilyResultSig -> FamilyResultSig -> FamilyResultSig # min :: FamilyResultSig -> FamilyResultSig -> FamilyResultSig # | |
| Ord TyLit | |
| Ord Role | |
| Ord AnnLookup | |
| Ord ShortText | |
| Ord TimeLocale | |
Defined in Data.Time.Format.Locale Methods compare :: TimeLocale -> TimeLocale -> Ordering # (<) :: TimeLocale -> TimeLocale -> Bool # (<=) :: TimeLocale -> TimeLocale -> Bool # (>) :: TimeLocale -> TimeLocale -> Bool # (>=) :: TimeLocale -> TimeLocale -> Bool # max :: TimeLocale -> TimeLocale -> TimeLocale # min :: TimeLocale -> TimeLocale -> TimeLocale # | |
| Ord LocalTime | |
Defined in Data.Time.LocalTime.Internal.LocalTime | |
| Ord TimeZone | |
Defined in Data.Time.LocalTime.Internal.TimeZone | |
| Ord UniversalTime | |
Defined in Data.Time.Clock.Internal.UniversalTime Methods compare :: UniversalTime -> UniversalTime -> Ordering # (<) :: UniversalTime -> UniversalTime -> Bool # (<=) :: UniversalTime -> UniversalTime -> Bool # (>) :: UniversalTime -> UniversalTime -> Bool # (>=) :: UniversalTime -> UniversalTime -> Bool # max :: UniversalTime -> UniversalTime -> UniversalTime # min :: UniversalTime -> UniversalTime -> UniversalTime # | |
| Ord NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods compare :: NominalDiffTime -> NominalDiffTime -> Ordering # (<) :: NominalDiffTime -> NominalDiffTime -> Bool # (<=) :: NominalDiffTime -> NominalDiffTime -> Bool # (>) :: NominalDiffTime -> NominalDiffTime -> Bool # (>=) :: NominalDiffTime -> NominalDiffTime -> Bool # max :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # min :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # | |
| Ord DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Ord Day | |
| Ord Permissions | |
Defined in Turtle.Prelude Methods compare :: Permissions -> Permissions -> Ordering # (<) :: Permissions -> Permissions -> Bool # (<=) :: Permissions -> Permissions -> Bool # (>) :: Permissions -> Permissions -> Bool # (>=) :: Permissions -> Permissions -> Bool # max :: Permissions -> Permissions -> Permissions # min :: Permissions -> Permissions -> Permissions # | |
| Ord Size | |
| Ord Line | |
| Ord UnpackedUUID | |
Defined in Data.UUID.Types.Internal | |
| Ord UUID | |
| Ord Pos | |
| Ord DL | |
| Ord B | |
| Ord EMailAddress Source # | |
Defined in OpenSuse.Types.EMailAddress Methods compare :: EMailAddress -> EMailAddress -> Ordering # (<) :: EMailAddress -> EMailAddress -> Bool # (<=) :: EMailAddress -> EMailAddress -> Bool # (>) :: EMailAddress -> EMailAddress -> Bool # (>=) :: EMailAddress -> EMailAddress -> Bool # max :: EMailAddress -> EMailAddress -> EMailAddress # min :: EMailAddress -> EMailAddress -> EMailAddress # | |
| Ord Entry Source # | |
| Ord ChangeLog Source # | |
| Ord Issue Source # | |
| Ord ProjectId Source # | |
| Ord RequestId Source # | |
| Ord a => Ord [a] | |
| Ord a => Ord (Maybe a) | Since: base-2.1 |
| Integral a => Ord (Ratio a) | Since: base-2.0.1 |
| Ord p => Ord (Par1 p) | Since: base-4.7.0.0 |
| Ord a => Ord (Solo a) | |
| Ord (Encoding' a) | |
Defined in Data.Aeson.Encoding.Internal | |
| Ord v => Ord (KeyMap v) | |
Defined in Data.Aeson.KeyMap | |
| Ord a => Ord (Min a) | Since: base-4.9.0.0 |
| Ord a => Ord (Max a) | Since: base-4.9.0.0 |
| Ord a => Ord (First a) | Since: base-4.9.0.0 |
| Ord a => Ord (Last a) | Since: base-4.9.0.0 |
| Ord 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 (Option a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| 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 (Dual a) | Since: base-2.1 |
| Ord a => Ord (Sum a) | Since: base-2.1 |
| Ord a => Ord (Product a) | Since: base-2.1 |
| Ord a => Ord (NonEmpty a) | Since: base-4.9.0.0 |
| Ord a => Ord (IntMap a) | |
Defined in Data.IntMap.Internal | |
| Ord a => Ord (Tree a) | Since: containers-0.6.5 |
| Ord a => Ord (Seq a) | |
| Ord a => Ord (ViewL a) | |
Defined in Data.Sequence.Internal | |
| Ord a => Ord (ViewR a) | |
Defined in Data.Sequence.Internal | |
| Ord a => Ord (Set a) | |
| Ord1 f => Ord (Fix f) | |
| (Functor f, Ord1 f) => Ord (Mu f) | |
| (Functor f, Ord1 f) => Ord (Nu f) | |
| Ord a => Ord (DNonEmpty a) | |
Defined in Data.DList.DNonEmpty.Internal | |
| Ord a => Ord (DList a) | |
| Ord a => Ord (Hashed a) | |
Defined in Data.Hashable.Class | |
| Ord ann => Ord (SimpleDocStream ann) | |
Defined in Prettyprinter.Internal Methods compare :: SimpleDocStream ann -> SimpleDocStream ann -> Ordering # (<) :: SimpleDocStream ann -> SimpleDocStream ann -> Bool # (<=) :: SimpleDocStream ann -> SimpleDocStream ann -> Bool # (>) :: SimpleDocStream ann -> SimpleDocStream ann -> Bool # (>=) :: SimpleDocStream ann -> SimpleDocStream ann -> Bool # max :: SimpleDocStream ann -> SimpleDocStream ann -> SimpleDocStream ann # min :: SimpleDocStream ann -> SimpleDocStream ann -> SimpleDocStream ann # | |
| (Ord a, Prim a) => Ord (PrimArray a) | Lexicographic ordering. Subject to change between major versions. Since: primitive-0.6.4.0 |
Defined in Data.Primitive.PrimArray | |
| Ord a => Ord (SmallArray a) | Lexicographic ordering. Subject to change between major versions. |
Defined in Data.Primitive.SmallArray Methods compare :: SmallArray a -> SmallArray a -> Ordering # (<) :: SmallArray a -> SmallArray a -> Bool # (<=) :: SmallArray a -> SmallArray a -> Bool # (>) :: SmallArray a -> SmallArray a -> Bool # (>=) :: SmallArray a -> SmallArray a -> Bool # max :: SmallArray a -> SmallArray a -> SmallArray a # min :: SmallArray a -> SmallArray a -> SmallArray a # | |
| Ord a => Ord (Array a) | Lexicographic ordering. Subject to change between major versions. |
Defined in Data.Primitive.Array | |
| Ord g => Ord (AtomicGen g) | |
Defined in System.Random.Stateful | |
| Ord g => Ord (IOGen g) | |
Defined in System.Random.Stateful | |
| Ord g => Ord (STGen g) | |
Defined in System.Random.Stateful | |
| Ord g => Ord (TGen g) | |
| Ord g => Ord (StateGen g) | |
Defined in System.Random.Internal | |
| Ord a => Ord (Maybe a) | |
| Ord a => Ord (HashSet a) | |
| (Storable a, Ord a) => Ord (Vector a) | |
Defined in Data.Vector.Storable | |
| (Prim a, Ord a) => Ord (Vector a) | |
Defined in Data.Vector.Primitive | |
| Ord a => Ord (Vector a) | |
Defined in Data.Vector | |
| (Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 |
| Ord (V1 p) | Since: base-4.9.0.0 |
| Ord (U1 p) | Since: base-4.7.0.0 |
| (Ord a, Ord b) => Ord (a, b) | |
| (Ord k, Ord v) => Ord (Map k v) | |
| (Ord k, Ord v) => Ord (HashMap k v) | The ordering is total and consistent with the |
Defined in Data.HashMap.Internal | |
| (Ix i, Ord e) => Ord (Array i e) | Since: base-2.1 |
| Ord a => Ord (Arg a b) | Since: base-4.9.0.0 |
| (Ord a, Ord b) => Ord (These a b) | |
| (Ord a, Ord b) => Ord (Pair a b) | |
Defined in Data.Strict.Tuple | |
| (Ord a, Ord b) => Ord (These a b) | |
| (Ord a, Ord b) => Ord (Either a b) | |
| 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 (a, b, c) | |
| 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 (p a a) => Ord (Join p a) | |
Defined in Data.Bifunctor.Join | |
| (Ord e, Ord1 m, Ord a) => Ord (ExceptT e m a) | |
Defined in Control.Monad.Trans.Except Methods compare :: ExceptT e m a -> ExceptT e m a -> Ordering # (<) :: ExceptT e m a -> ExceptT e m a -> Bool # (<=) :: ExceptT e m a -> ExceptT e m a -> Bool # (>) :: ExceptT e m a -> ExceptT e m a -> Bool # (>=) :: ExceptT e m a -> ExceptT e m a -> Bool # | |
| (Ord e, Ord1 m, Ord a) => Ord (ErrorT e m a) | |
Defined in Control.Monad.Trans.Error | |
| Ord b => Ord (Tagged s b) | |
| (Ord (f a), Ord (g a), Ord a) => Ord (These1 f g a) | |
Defined in Data.Functor.These | |
| Ord c => Ord (K1 i c 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 (f p), Ord (g p)) => Ord ((f :*: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
| (Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d) | |
Defined in GHC.Classes | |
| (Ord1 f, Ord1 g, Ord a) => Ord (Product f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product Methods compare :: Product f g a -> Product f g a -> Ordering # (<) :: Product f g a -> Product f g a -> Bool # (<=) :: Product f g a -> Product f g a -> Bool # (>) :: Product f g a -> Product f g a -> Bool # (>=) :: Product f g a -> Product f g a -> Bool # | |
| (Ord1 f, Ord1 g, Ord a) => Ord (Sum f g a) | Since: base-4.9.0.0 |
| Ord (f p) => Ord (M1 i c f p) | Since: base-4.7.0.0 |
| Ord (f (g p)) => Ord ((f :.: g) p) | Since: base-4.7.0.0 |
Defined in GHC.Generics | |
| (Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e) -> (a, b, c, d, e) -> Ordering # (<) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (<=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (>=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # max :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # min :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # | |
| (Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods compare :: Compose f g a -> Compose f g a -> Ordering # (<) :: Compose f g a -> Compose f g a -> Bool # (<=) :: Compose f g a -> Compose f g a -> Bool # (>) :: Compose f g a -> Compose f g a -> Bool # (>=) :: Compose f g a -> Compose f g a -> Bool # | |
| Ord (p a b) => Ord (WrappedBifunctor p a b) | |
Defined in Data.Bifunctor.Wrapped Methods compare :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Ordering # (<) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (<=) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (>) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # (>=) :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> Bool # max :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> WrappedBifunctor p a b # min :: WrappedBifunctor p a b -> WrappedBifunctor p a b -> WrappedBifunctor p a b # | |
| Ord (g b) => Ord (Joker g a b) | |
Defined in Data.Bifunctor.Joker | |
| Ord (p b a) => Ord (Flip p a b) | |
Defined in Data.Bifunctor.Flip | |
| Ord (f a) => Ord (Clown f a b) | |
Defined in Data.Bifunctor.Clown | |
| (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 (p a b), Ord (q a b)) => Ord (Sum p q a b) | |
Defined in Data.Bifunctor.Sum | |
| (Ord (f a b), Ord (g a b)) => Ord (Product f g a b) | |
Defined in Data.Bifunctor.Product Methods compare :: Product f g a b -> Product f g a b -> Ordering # (<) :: Product f g a b -> Product f g a b -> Bool # (<=) :: Product f g a b -> Product f g a b -> Bool # (>) :: Product f g a b -> Product f g a b -> Bool # (>=) :: Product f g a b -> Product f g a b -> Bool # max :: Product f g a b -> Product f g a b -> Product f g a b # min :: Product f g a b -> Product f g a b -> Product f g a b # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord 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 (f (p a b)) => Ord (Tannen f p a b) | |
Defined in Data.Bifunctor.Tannen Methods compare :: Tannen f p a b -> Tannen f p a b -> Ordering # (<) :: Tannen f p a b -> Tannen f p a b -> Bool # (<=) :: Tannen f p a b -> Tannen f p a b -> Bool # (>) :: Tannen f p a b -> Tannen f p a b -> Bool # (>=) :: Tannen f p a b -> Tannen f p a b -> Bool # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord 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 (p (f a) (g b)) => Ord (Biff p f g a b) | |
Defined in Data.Bifunctor.Biff Methods compare :: Biff p f g a b -> Biff p f g a b -> Ordering # (<) :: Biff p f g a b -> Biff p f g a b -> Bool # (<=) :: Biff p f g a b -> Biff p f g a b -> Bool # (>) :: Biff p f g a b -> Biff p f g a b -> Bool # (>=) :: Biff p f g a b -> Biff p f g a b -> Bool # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j) => Ord (a, b, c, d, e, f, g, h, i, j) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) # min :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k) => Ord (a, b, c, d, e, f, g, h, i, j, k) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) # min :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l) => Ord (a, b, c, d, e, f, g, h, i, j, k, l) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) # min :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # | |
| (Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n, Ord o) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | |
Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # | |
Parsing of Strings, producing values.
Derived instances of Read make the following assumptions, which
derived instances of Show obey:
- If the constructor is defined to be an infix operator, then the
derived
Readinstance will parse only infix applications of the constructor (not the prefix form). - Associativity is not used to reduce the occurrence of parentheses, although precedence may be.
- If the constructor is defined using record syntax, the derived
Readwill parse only the record-syntax form, and furthermore, the fields must be given in the same order as the original declaration. - The derived
Readinstance allows arbitrary Haskell whitespace between tokens of the input string. Extra parentheses are also allowed.
For example, given the declarations
infixr 5 :^: data Tree a = Leaf a | Tree a :^: Tree a
the derived instance of Read in Haskell 2010 is equivalent to
instance (Read a) => Read (Tree a) where
readsPrec d r = readParen (d > app_prec)
(\r -> [(Leaf m,t) |
("Leaf",s) <- lex r,
(m,t) <- readsPrec (app_prec+1) s]) r
++ readParen (d > up_prec)
(\r -> [(u:^:v,w) |
(u,s) <- readsPrec (up_prec+1) r,
(":^:",t) <- lex s,
(v,w) <- readsPrec (up_prec+1) t]) r
where app_prec = 10
up_prec = 5Note that right-associativity of :^: is unused.
The derived instance in GHC is equivalent to
instance (Read a) => Read (Tree a) where
readPrec = parens $ (prec app_prec $ do
Ident "Leaf" <- lexP
m <- step readPrec
return (Leaf m))
+++ (prec up_prec $ do
u <- step readPrec
Symbol ":^:" <- lexP
v <- step readPrec
return (u :^: v))
where app_prec = 10
up_prec = 5
readListPrec = readListPrecDefaultWhy do both readsPrec and readPrec exist, and why does GHC opt to
implement readPrec in derived Read instances instead of readsPrec?
The reason is that readsPrec is based on the ReadS type, and although
ReadS is mentioned in the Haskell 2010 Report, it is not a very efficient
parser data structure.
readPrec, on the other hand, is based on a much more efficient ReadPrec
datatype (a.k.a "new-style parsers"), but its definition relies on the use
of the RankNTypes language extension. Therefore, readPrec (and its
cousin, readListPrec) are marked as GHC-only. Nevertheless, it is
recommended to use readPrec instead of readsPrec whenever possible
for the efficiency improvements it brings.
As mentioned above, derived Read instances in GHC will implement
readPrec instead of readsPrec. The default implementations of
readsPrec (and its cousin, readList) will simply use readPrec under
the hood. If you are writing a Read instance by hand, it is recommended
to write it like so:
instanceReadT wherereadPrec= ...readListPrec=readListPrecDefault
Methods
Arguments
| :: Int | the operator precedence of the enclosing
context (a number from |
| -> ReadS a |
attempts to parse a value from the front of the string, returning a list of (parsed value, remaining string) pairs. If there is no successful parse, the returned list is empty.
Derived instances of Read and Show satisfy the following:
That is, readsPrec parses the string produced by
showsPrec, and delivers the value that
showsPrec started with.
Instances
| Read Bool | Since: base-2.1 |
| Read Char | Since: base-2.1 |
| Read Double | Since: base-2.1 |
| Read Float | Since: base-2.1 |
| Read Int | Since: base-2.1 |
| Read Integer | Since: base-2.1 |
| Read Natural | Since: base-4.8.0.0 |
| Read Ordering | Since: base-2.1 |
| Read Word | Since: base-4.5.0.0 |
| Read Word8 | Since: base-2.1 |
| Read Word16 | Since: base-2.1 |
| Read Word32 | Since: base-2.1 |
| Read Word64 | Since: base-2.1 |
| Read () | Since: base-2.1 |
| Read Version | Since: base-2.1 |
| Read Scientific | Supports the skipping of parentheses and whitespaces. Example: > read " ( (( -1.0e+3 ) ))" :: Scientific -1000.0 (Note: This |
Defined in Data.Scientific Methods readsPrec :: Int -> ReadS Scientific # readList :: ReadS [Scientific] # readPrec :: ReadPrec Scientific # readListPrec :: ReadPrec [Scientific] # | |
| Read ByteString | |
Defined in Data.ByteString.Internal Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] # | |
| Read ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] # | |
| Read Value | |
| Read DotNetTime | |
Defined in Data.Aeson.Types.Internal Methods readsPrec :: Int -> ReadS DotNetTime # readList :: ReadS [DotNetTime] # readPrec :: ReadPrec DotNetTime # readListPrec :: ReadPrec [DotNetTime] # | |
| Read Key | |
| Read Void | Reading a Since: base-4.8.0.0 |
| Read ExitCode | |
| Read BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS BufferMode # readList :: ReadS [BufferMode] # readPrec :: ReadPrec BufferMode # readListPrec :: ReadPrec [BufferMode] # | |
| Read Newline | Since: base-4.3.0.0 |
| Read NewlineMode | Since: base-4.3.0.0 |
Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS NewlineMode # readList :: ReadS [NewlineMode] # readPrec :: ReadPrec NewlineMode # readListPrec :: ReadPrec [NewlineMode] # | |
| Read All | Since: base-2.1 |
| Read Any | Since: base-2.1 |
| Read Fixity | Since: base-4.6.0.0 |
| Read Associativity | Since: base-4.6.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS Associativity # readList :: ReadS [Associativity] # | |
| Read SourceUnpackedness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS SourceUnpackedness # readList :: ReadS [SourceUnpackedness] # | |
| Read SourceStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS SourceStrictness # readList :: ReadS [SourceStrictness] # | |
| Read DecidedStrictness | Since: base-4.9.0.0 |
Defined in GHC.Generics Methods readsPrec :: Int -> ReadS DecidedStrictness # readList :: ReadS [DecidedStrictness] # | |
| Read SomeSymbol | Since: base-4.7.0.0 |
Defined in GHC.TypeLits Methods readsPrec :: Int -> ReadS SomeSymbol # readList :: ReadS [SomeSymbol] # readPrec :: ReadPrec SomeSymbol # readListPrec :: ReadPrec [SomeSymbol] # | |
| Read Lexeme | Since: base-2.1 |
| Read GeneralCategory | Since: base-2.1 |
Defined in GHC.Read Methods readsPrec :: Int -> ReadS GeneralCategory # readList :: ReadS [GeneralCategory] # | |
| Read ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods readsPrec :: Int -> ReadS ShortByteString # readList :: ReadS [ShortByteString] # | |
| Read Clock | |
| Read TimeSpec | |
| Read IntSet | |
| Read ShortText | |
| Read Permissions | |
Defined in Turtle.Prelude Methods readsPrec :: Int -> ReadS Permissions # readList :: ReadS [Permissions] # readPrec :: ReadPrec Permissions # readListPrec :: ReadPrec [Permissions] # | |
| Read UnpackedUUID | |
| Read UUID | |
| Read a => Read [a] | Since: base-2.1 |
| Read a => Read (Maybe a) | Since: base-2.1 |
| (Integral a, Read a) => Read (Ratio a) | Since: base-2.1 |
| Read p => Read (Par1 p) | Since: base-4.7.0.0 |
| Read a => Read (Solo a) | |
| Read v => Read (KeyMap v) | |
| Read a => Read (Complex a) | Since: base-2.1 |
| Read a => Read (Min a) | Since: base-4.9.0.0 |
| Read a => Read (Max a) | Since: base-4.9.0.0 |
| Read a => Read (First a) | Since: base-4.9.0.0 |
| Read a => Read (Last a) | Since: base-4.9.0.0 |
| Read m => Read (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (WrappedMonoid m) # readList :: ReadS [WrappedMonoid m] # readPrec :: ReadPrec (WrappedMonoid m) # readListPrec :: ReadPrec [WrappedMonoid m] # | |
| Read a => Read (Option a) | Since: base-4.9.0.0 |
| Read a => Read (ZipList a) | Since: base-4.7.0.0 |
| Read a => Read (Identity a) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| Read a => Read (First a) | Since: base-2.1 |
| Read a => Read (Last a) | Since: base-2.1 |
| Read a => Read (Dual a) | Since: base-2.1 |
| Read a => Read (Sum a) | Since: base-2.1 |
| Read a => Read (Product a) | Since: base-2.1 |
| Read a => Read (NonEmpty a) | Since: base-4.11.0.0 |
| Read e => Read (IntMap e) | |
| Read a => Read (Tree a) | |
| Read a => Read (Seq a) | |
| Read a => Read (ViewL a) | |
| Read a => Read (ViewR a) | |
| (Read a, Ord a) => Read (Set a) | |
| Read1 f => Read (Fix f) | |
| (Functor f, Read1 f) => Read (Mu f) | |
| (Functor f, Read1 f) => Read (Nu f) | |
| Read a => Read (DNonEmpty a) | |
| Read a => Read (DList a) | |
| Read a => Read (SmallArray a) | |
Defined in Data.Primitive.SmallArray Methods readsPrec :: Int -> ReadS (SmallArray a) # readList :: ReadS [SmallArray a] # readPrec :: ReadPrec (SmallArray a) # readListPrec :: ReadPrec [SmallArray a] # | |
| Read a => Read (Array a) | |
| Read a => Read (Maybe a) | |
| (Eq a, Hashable a, Read a) => Read (HashSet a) | |
| (Read a, Storable a) => Read (Vector a) | |
| (Read a, Prim a) => Read (Vector a) | |
| Read a => Read (Vector a) | |
| (Read a, Read b) => Read (Either a b) | Since: base-3.0 |
| Read (V1 p) | Since: base-4.9.0.0 |
| Read (U1 p) | Since: base-4.9.0.0 |
| (Read a, Read b) => Read (a, b) | Since: base-2.1 |
| (Ord k, Read k, Read e) => Read (Map k e) | |
| (Eq k, Hashable k, Read k, Read e) => Read (HashMap k e) | |
| (Ix a, Read a, Read b) => Read (Array a b) | Since: base-2.1 |
| (Read a, Read b) => Read (Arg a b) | Since: base-4.9.0.0 |
| (Read a, Read b) => Read (These a b) | |
| (Read a, Read b) => Read (Pair a b) | |
| (Read a, Read b) => Read (These a b) | |
| (Read a, Read b) => Read (Either a b) | |
| Read (f p) => Read (Rec1 f p) | Since: base-4.7.0.0 |
| (Read a, Read b, Read c) => Read (a, b, c) | Since: base-2.1 |
| Read a => Read (Const a b) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| Read (f a) => Read (Ap f a) | Since: base-4.12.0.0 |
| Read (f a) => Read (Alt f a) | Since: base-4.8.0.0 |
| Read (p a a) => Read (Join p a) | |
| (Read e, Read1 m, Read a) => Read (ExceptT e m a) | |
| (Read e, Read1 m, Read a) => Read (ErrorT e m a) | |
| Read b => Read (Tagged s b) | |
| (Read (f a), Read (g a), Read a) => Read (These1 f g a) | |
| Read c => Read (K1 i c p) | Since: base-4.7.0.0 |
| (Read (f p), Read (g p)) => Read ((f :+: g) p) | Since: base-4.7.0.0 |
| (Read (f p), Read (g p)) => Read ((f :*: g) p) | Since: base-4.7.0.0 |
| (Read a, Read b, Read c, Read d) => Read (a, b, c, d) | Since: base-2.1 |
| (Read1 f, Read1 g, Read a) => Read (Product f g a) | Since: base-4.9.0.0 |
| (Read1 f, Read1 g, Read a) => Read (Sum f g a) | Since: base-4.9.0.0 |
| Read (f p) => Read (M1 i c f p) | Since: base-4.7.0.0 |
| Read (f (g p)) => Read ((f :.: g) p) | Since: base-4.7.0.0 |
| (Read a, Read b, Read c, Read d, Read e) => Read (a, b, c, d, e) | Since: base-2.1 |
| (Read1 f, Read1 g, Read a) => Read (Compose f g a) | Since: base-4.9.0.0 |
| Read (p a b) => Read (WrappedBifunctor p a b) | |
Defined in Data.Bifunctor.Wrapped Methods readsPrec :: Int -> ReadS (WrappedBifunctor p a b) # readList :: ReadS [WrappedBifunctor p a b] # readPrec :: ReadPrec (WrappedBifunctor p a b) # readListPrec :: ReadPrec [WrappedBifunctor p a b] # | |
| Read (g b) => Read (Joker g a b) | |
| Read (p b a) => Read (Flip p a b) | |
| Read (f a) => Read (Clown f a b) | |
| (Read a, Read b, Read c, Read d, Read e, Read f) => Read (a, b, c, d, e, f) | Since: base-2.1 |
| (Read (p a b), Read (q a b)) => Read (Sum p q a b) | |
| (Read (f a b), Read (g a b)) => Read (Product f g a b) | |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g) => Read (a, b, c, d, e, f, g) | Since: base-2.1 |
| Read (f (p a b)) => Read (Tannen f p a b) | |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h) => Read (a, b, c, d, e, f, g, h) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i) => Read (a, b, c, d, e, f, g, h, i) | Since: base-2.1 |
| Read (p (f a) (g b)) => Read (Biff p f g a b) | |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j) => Read (a, b, c, d, e, f, g, h, i, j) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k) => Read (a, b, c, d, e, f, g, h, i, j, k) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l) => Read (a, b, c, d, e, f, g, h, i, j, k, l) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m, Read n) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m, n) | Since: base-2.1 |
| (Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m, Read n, Read o) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) | Since: base-2.1 |
Defined in GHC.Read | |
class (Num a, Ord a) => Real a where #
Methods
toRational :: a -> Rational #
the rational equivalent of its real argument with full precision
Instances
| Real Int | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Int -> Rational # | |
| Real Integer | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Integer -> Rational # | |
| Real Natural | Since: base-4.8.0.0 |
Defined in GHC.Real Methods toRational :: Natural -> Rational # | |
| Real Word | Since: base-2.1 |
Defined in GHC.Real Methods toRational :: Word -> Rational # | |
| Real Word8 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word8 -> Rational # | |
| Real Word16 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word16 -> Rational # | |
| Real Word32 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word32 -> Rational # | |
| Real Word64 | Since: base-2.1 |
Defined in GHC.Word Methods toRational :: Word64 -> Rational # | |
| Real Scientific | WARNING: Avoid applying |
Defined in Data.Scientific Methods toRational :: Scientific -> Rational # | |
| Real TimeSpec | |
Defined in System.Clock Methods toRational :: TimeSpec -> Rational # | |
| Real NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods toRational :: NominalDiffTime -> Rational # | |
| Real DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime Methods toRational :: DiffTime -> Rational # | |
| Integral a => Real (Ratio a) | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Ratio a -> Rational # | |
| Real a => Real (Identity a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Identity Methods toRational :: Identity a -> Rational # | |
| Real a => Real (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods toRational :: Const a b -> Rational # | |
| Real a => Real (Tagged s a) | |
Defined in Data.Tagged Methods toRational :: Tagged s a -> Rational # | |
class (RealFrac a, Floating a) => RealFloat a where #
Efficient, machine-independent access to the components of a floating-point number.
Minimal complete definition
floatRadix, floatDigits, floatRange, decodeFloat, encodeFloat, isNaN, isInfinite, isDenormalized, isNegativeZero, isIEEE
Methods
floatRadix :: a -> Integer #
a constant function, returning the radix of the representation
(often 2)
floatDigits :: a -> Int #
a constant function, returning the number of digits of
floatRadix in the significand
floatRange :: a -> (Int, Int) #
a constant function, returning the lowest and highest values the exponent may assume
decodeFloat :: a -> (Integer, Int) #
The function decodeFloat applied to a real floating-point
number returns the significand expressed as an Integer and an
appropriately scaled exponent (an Int). If decodeFloat x(m,n), then x is equal in value to m*b^^n, where b
is the floating-point radix, and furthermore, either m and n
are both zero or else b^(d-1) <= , where abs m < b^dd is
the value of floatDigits xdecodeFloat 0 = (0,0)decodeFloat (-0.0) = (0,0)decodeFloat xisNaN xisInfinite xTrue.
encodeFloat :: Integer -> Int -> a #
encodeFloat performs the inverse of decodeFloat in the
sense that for finite x with the exception of -0.0,
uncurry encodeFloat (decodeFloat x) = xencodeFloat m nm*b^^n (or ±Infinity if overflow
occurs); usually the closer, but if m contains too many bits,
the result may be rounded in the wrong direction.
exponent corresponds to the second component of decodeFloat.
exponent 0 = 0x,
exponent x = snd (decodeFloat x) + floatDigits xx is a finite floating-point number, it is equal in value to
significand x * b ^^ exponent xb is the
floating-point radix.
The behaviour is unspecified on infinite or NaN values.
significand :: a -> a #
The first component of decodeFloat, scaled to lie in the open
interval (-1,1), either 0.0 or of absolute value >= 1/b,
where b is the floating-point radix.
The behaviour is unspecified on infinite or NaN values.
scaleFloat :: Int -> a -> a #
multiplies a floating-point number by an integer power of the radix
True if the argument is an IEEE "not-a-number" (NaN) value
isInfinite :: a -> Bool #
True if the argument is an IEEE infinity or negative infinity
isDenormalized :: a -> Bool #
True if the argument is too small to be represented in
normalized format
isNegativeZero :: a -> Bool #
True if the argument is an IEEE negative zero
True if the argument is an IEEE floating point number
a version of arctangent taking two real floating-point arguments.
For real floating x and y, atan2 y x(x,y). atan2 y x-pi,
pi]. It follows the Common Lisp semantics for the origin when
signed zeroes are supported. atan2 y 1y in a type
that is RealFloat, should return the same value as atan yatan2 is provided, but implementors
can provide a more accurate implementation.
Instances
class (Real a, Fractional a) => RealFrac a where #
Extracting components of fractions.
Minimal complete definition
Methods
properFraction :: Integral b => a -> (b, a) #
The function properFraction takes a real fractional number x
and returns a pair (n,f) such that x = n+f, and:
nis an integral number with the same sign asx; andfis a fraction with the same type and sign asx, and with absolute value less than1.
The default definitions of the ceiling, floor, truncate
and round functions are in terms of properFraction.
truncate :: Integral b => a -> b #
truncate xx between zero and x
round :: Integral b => a -> b #
round xx;
the even integer if x is equidistant between two integers
ceiling :: Integral b => a -> b #
ceiling xx
floor :: Integral b => a -> b #
floor xx
Instances
| RealFrac Scientific | WARNING: the methods of the |
Defined in Data.Scientific Methods properFraction :: Integral b => Scientific -> (b, Scientific) # truncate :: Integral b => Scientific -> b # round :: Integral b => Scientific -> b # ceiling :: Integral b => Scientific -> b # floor :: Integral b => Scientific -> b # | |
| RealFrac NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods properFraction :: Integral b => NominalDiffTime -> (b, NominalDiffTime) # truncate :: Integral b => NominalDiffTime -> b # round :: Integral b => NominalDiffTime -> b # ceiling :: Integral b => NominalDiffTime -> b # floor :: Integral b => NominalDiffTime -> b # | |
| RealFrac DiffTime | |
| Integral a => RealFrac (Ratio a) | Since: base-2.0.1 |
| RealFrac a => RealFrac (Identity a) | Since: base-4.9.0.0 |
| RealFrac a => RealFrac (Const a b) | Since: base-4.9.0.0 |
| RealFrac a => RealFrac (Tagged s a) | |
Conversion of values to readable Strings.
Derived instances of Show have the following properties, which
are compatible with derived instances of Read:
- The result of
showis a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used. - If the constructor is defined to be an infix operator, then
showsPrecwill produce infix applications of the constructor. - the representation will be enclosed in parentheses if the
precedence of the top-level constructor in
xis less thand(associativity is ignored). Thus, ifdis0then the result is never surrounded in parentheses; ifdis11it is always surrounded in parentheses, unless it is an atomic expression. - If the constructor is defined using record syntax, then
showwill produce the record-syntax form, with the fields given in the same order as the original declaration.
For example, given the declarations
infixr 5 :^: data Tree a = Leaf a | Tree a :^: Tree a
the derived instance of Show is equivalent to
instance (Show a) => Show (Tree a) where
showsPrec d (Leaf m) = showParen (d > app_prec) $
showString "Leaf " . showsPrec (app_prec+1) m
where app_prec = 10
showsPrec d (u :^: v) = showParen (d > up_prec) $
showsPrec (up_prec+1) u .
showString " :^: " .
showsPrec (up_prec+1) v
where up_prec = 5Note that right-associativity of :^: is ignored. For example,
show(Leaf 1 :^: Leaf 2 :^: Leaf 3)"Leaf 1 :^: (Leaf 2 :^: Leaf 3)".
Methods
Arguments
| :: Int | the operator precedence of the enclosing
context (a number from |
| -> a | the value to be converted to a |
| -> ShowS |
Convert a value to a readable String.
showsPrec should satisfy the law
showsPrec d x r ++ s == showsPrec d x (r ++ s)
Derived instances of Read and Show satisfy the following:
That is, readsPrec parses the string produced by
showsPrec, and delivers the value that showsPrec started with.
Instances
class Monad m => MonadFail (m :: Type -> Type) #
When a value is bound in do-notation, the pattern on the left
hand side of <- might not match. In this case, this class
provides a function to recover.
A Monad without a MonadFail instance may only be used in conjunction
with pattern that always match, such as newtypes, tuples, data types with
only a single data constructor, and irrefutable patterns (~pat).
Instances of MonadFail should satisfy the following law: fail s should
be a left zero for >>=,
fail s >>= f = fail s
If your Monad is also MonadPlus, a popular definition is
fail _ = mzero
Since: base-4.9.0.0
Minimal complete definition
Instances
class Functor f => Applicative (f :: Type -> Type) where #
A functor with application, providing operations to
A minimal complete definition must include implementations of pure
and of either <*> or liftA2. If it defines both, then they must behave
the same as their default definitions:
(<*>) =liftA2id
liftA2f x y = f<$>x<*>y
Further, any definition must satisfy the following:
- Identity
pureid<*>v = v- Composition
pure(.)<*>u<*>v<*>w = u<*>(v<*>w)- Homomorphism
puref<*>purex =pure(f x)- Interchange
u
<*>purey =pure($y)<*>u
The other methods have the following default definitions, which may be overridden with equivalent specialized implementations:
As a consequence of these laws, the Functor instance for f will satisfy
It may be useful to note that supposing
forall x y. p (q x y) = f x . g y
it follows from the above that
liftA2p (liftA2q u v) =liftA2f u .liftA2g v
If f is also a Monad, it should satisfy
(which implies that pure and <*> satisfy the applicative functor laws).
Methods
Lift a value.
(<*>) :: f (a -> b) -> f a -> f b infixl 4 #
Sequential application.
A few functors support an implementation of <*> that is more
efficient than the default one.
Using ApplicativeDo: 'fs ' can be understood as
the <*> asdo expression
do f <- fs a <- as pure (f a)
(*>) :: f a -> f b -> f b infixl 4 #
Sequence actions, discarding the value of the first argument.
'as ' can be understood as the *> bsdo expression
do as bs
This is a tad complicated for our ApplicativeDo extension
which will give it a Monad constraint. For an Applicative
constraint we write it of the form
do _ <- as b <- bs pure b
(<*) :: f a -> f b -> f a infixl 4 #
Sequence actions, discarding the value of the second argument.
Using ApplicativeDo: 'as ' can be understood as
the <* bsdo expression
do a <- as bs pure a
Instances
| Applicative [] | Since: base-2.1 |
| Applicative Maybe | Since: base-2.1 |
| Applicative IO | Since: base-2.1 |
| Applicative Par1 | Since: base-4.9.0.0 |
| Applicative Q | |
| Applicative Solo | |
| Applicative IResult | |
| Applicative Result | |
| Applicative Parser | |
| Applicative Complex | Since: base-4.9.0.0 |
| Applicative Min | Since: base-4.9.0.0 |
| Applicative Max | Since: base-4.9.0.0 |
| Applicative First | Since: base-4.9.0.0 |
| Applicative Last | Since: base-4.9.0.0 |
| Applicative Option | Since: base-4.9.0.0 |
| Applicative ZipList | f <$> ZipList xs1 <*> ... <*> ZipList xsN
= ZipList (zipWithN f xs1 ... xsN)where (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <*> ZipList "567" <*> ZipList [1..]
= ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..])
= ZipList {getZipList = ["a5","b6b6","c7c7c7"]}Since: base-2.1 |
| 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 Dual | Since: base-4.8.0.0 |
| Applicative Sum | Since: base-4.8.0.0 |
| Applicative Product | Since: base-4.8.0.0 |
| Applicative ReadPrec | Since: base-4.6.0.0 |
| Applicative ReadP | Since: base-4.6.0.0 |
| Applicative NonEmpty | Since: base-4.9.0.0 |
| Applicative PutM | |
| Applicative Get | |
| Applicative Tree | |
| Applicative Seq | Since: containers-0.5.4 |
| Applicative DNonEmpty | |
Defined in Data.DList.DNonEmpty.Internal | |
| Applicative DList | |
| Applicative Managed | |
| Applicative ReadM | |
| Applicative Parser | |
| Applicative ParserM | |
| Applicative ParserResult | |
Defined in Options.Applicative.Types Methods pure :: a -> ParserResult a # (<*>) :: ParserResult (a -> b) -> ParserResult a -> ParserResult b # liftA2 :: (a -> b -> c) -> ParserResult a -> ParserResult b -> ParserResult c # (*>) :: ParserResult a -> ParserResult b -> ParserResult b # (<*) :: ParserResult a -> ParserResult b -> ParserResult a # | |
| Applicative SmallArray | |
Defined in Data.Primitive.SmallArray Methods pure :: a -> SmallArray a # (<*>) :: SmallArray (a -> b) -> SmallArray a -> SmallArray b # liftA2 :: (a -> b -> c) -> SmallArray a -> SmallArray b -> SmallArray c # (*>) :: SmallArray a -> SmallArray b -> SmallArray b # (<*) :: SmallArray a -> SmallArray b -> SmallArray a # | |
| Applicative Array | |
| Applicative Shell | |
| Applicative Pattern | |
| Applicative Vector | |
| Applicative P | Since: base-4.5.0.0 |
| Applicative (Either e) | Since: base-3.0 |
| Applicative (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monoid a => Applicative ((,) a) | For tuples, the ("hello ", (+15)) <*> ("world!", 2002)
("hello world!",2017)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 (Fold a) | |
| Semigroup a => Applicative (These a) | |
| Semigroup a => Applicative (These a) | |
| Applicative (Parser i) | |
| Applicative f => Applicative (Rec1 f) | Since: base-4.9.0.0 |
| (Monoid a, Monoid b) => Applicative ((,,) a b) | Since: base-4.14.0.0 |
| 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 |
| Biapplicative p => Applicative (Join p) | |
| (Applicative f, Monad f) => Applicative (WhenMissing f x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods pure :: a -> WhenMissing f x a # (<*>) :: WhenMissing f x (a -> b) -> WhenMissing f x a -> WhenMissing f x b # liftA2 :: (a -> b -> c) -> WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x c # (*>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # (<*) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x a # | |
| (Functor m, Monad m) => Applicative (ExceptT e m) | |
Defined in Control.Monad.Trans.Except | |
| Applicative m => Applicative (FoldM m a) | |
| (Functor m, Monad m) => Applicative (ErrorT e m) | |
Defined in Control.Monad.Trans.Error | |
| Applicative (Tagged s) | |
| Applicative ((->) r :: Type -> Type) | Since: base-2.1 |
| Monoid c => Applicative (K1 i c :: Type -> Type) | Since: base-4.12.0.0 |
| (Applicative f, Applicative g) => Applicative (f :*: g) | Since: base-4.9.0.0 |
| (Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c) | Since: base-4.14.0.0 |
Defined in GHC.Base | |
| (Applicative f, Applicative g) => Applicative (Product f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product | |
| (Monad f, Applicative f) => Applicative (WhenMatched f x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods pure :: a -> WhenMatched f x y a # (<*>) :: WhenMatched f x y (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b # liftA2 :: (a -> b -> c) -> WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y c # (*>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # (<*) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Applicative (WhenMissing f k x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods pure :: a -> WhenMissing f k x a # (<*>) :: WhenMissing f k x (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # liftA2 :: (a -> b -> c) -> WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x c # (*>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # (<*) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x a # | |
| Applicative (ParsecT s u m) | |
Defined in Text.Parsec.Prim Methods pure :: a -> ParsecT s u m a # (<*>) :: ParsecT s u m (a -> b) -> ParsecT s u m a -> ParsecT s u m b # liftA2 :: (a -> b -> c) -> ParsecT s u m a -> ParsecT s u m b -> ParsecT s u m c # (*>) :: ParsecT s u m a -> ParsecT s u m b -> ParsecT s u m b # (<*) :: ParsecT s u m a -> ParsecT s u m b -> ParsecT s u m a # | |
| Applicative f => Applicative (M1 i c f) | Since: base-4.9.0.0 |
| (Applicative f, Applicative g) => Applicative (f :.: g) | Since: base-4.9.0.0 |
| (Applicative f, Applicative g) => Applicative (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Monad f, Applicative f) => Applicative (WhenMatched f k x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods pure :: a -> WhenMatched f k x y a # (<*>) :: WhenMatched f k x y (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # liftA2 :: (a -> b -> c) -> WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y c # (*>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # (<*) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y a # | |
class Foldable (t :: Type -> Type) where #
Data structures that can be folded.
For example, given a data type
data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)
a suitable instance would be
instance Foldable Tree where foldMap f Empty = mempty foldMap f (Leaf x) = f x foldMap f (Node l k r) = foldMap f l `mappend` f k `mappend` foldMap f r
This is suitable even for abstract types, as the monoid is assumed
to satisfy the monoid laws. Alternatively, one could define foldr:
instance Foldable Tree where foldr f z Empty = z foldr f z (Leaf x) = f x z foldr f z (Node l k r) = foldr f (f k (foldr f z r)) l
Foldable instances are expected to satisfy the following laws:
foldr f z t = appEndo (foldMap (Endo . f) t ) z
foldl f z t = appEndo (getDual (foldMap (Dual . Endo . flip f) t)) z
fold = foldMap id
length = getSum . foldMap (Sum . const 1)
sum, product, maximum, and minimum should all be essentially
equivalent to foldMap forms, such as
sum = getSum . foldMap Sum
but may be less defined.
If the type is also a Functor instance, it should satisfy
foldMap f = fold . fmap f
which implies that
foldMap f . fmap g = foldMap (f . g)
Methods
foldMap :: Monoid m => (a -> m) -> t a -> m #
Map each element of the structure to a monoid, and combine the results.
foldr :: (a -> b -> b) -> b -> t a -> b #
Right-associative fold of a structure.
In the case of lists, foldr, when applied to a binary operator, a
starting value (typically the right-identity of the operator), and a
list, reduces the list using the binary operator, from right to left:
foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)
Note that, since the head of the resulting expression is produced by
an application of the operator to the first element of the list,
foldr can produce a terminating expression from an infinite list.
For a general Foldable structure this should be semantically identical
to,
foldr f z =foldrf z .toList
foldl :: (b -> a -> b) -> b -> t a -> b #
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.
Also note that if you want an efficient left-fold, you probably want to
use foldl' instead of foldl. The reason for this is that latter does
not force the "inner" results (e.g. z `f` x1 in the above example)
before applying them to the operator (e.g. to (`f` x2)). This results
in a thunk chain \(\mathcal{O}(n)\) elements long, which then must be
evaluated from the outside-in.
For a general Foldable structure this should be semantically identical
to,
foldl f z =foldlf z .toList
foldr1 :: (a -> a -> a) -> t a -> a #
A variant of foldr that has no base case,
and thus may only be applied to non-empty structures.
foldr1f =foldr1f .toList
foldl1 :: (a -> a -> a) -> t a -> a #
A variant of foldl that has no base case,
and thus may only be applied to non-empty structures.
foldl1f =foldl1f .toList
Test whether the structure is empty. The default implementation is optimized for structures that are similar to cons-lists, because there is no general way to do better.
Since: base-4.8.0.0
Returns the size/length of a finite structure as an Int. The
default implementation is optimized for structures that are similar to
cons-lists, because there is no general way to do better.
Since: base-4.8.0.0
elem :: Eq a => a -> t a -> Bool infix 4 #
Does the element occur in the structure?
Since: base-4.8.0.0
maximum :: Ord a => t a -> a #
The largest element of a non-empty structure.
Since: base-4.8.0.0
minimum :: Ord a => t a -> a #
The least element of a non-empty structure.
Since: base-4.8.0.0
The sum function computes the sum of the numbers of a structure.
Since: base-4.8.0.0
product :: Num a => t a -> a #
The product function computes the product of the numbers of a
structure.
Since: base-4.8.0.0
Instances
| Foldable [] | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => [m] -> m # foldMap :: Monoid m => (a -> m) -> [a] -> m # foldMap' :: Monoid m => (a -> m) -> [a] -> m # foldr :: (a -> b -> b) -> b -> [a] -> b # foldr' :: (a -> b -> b) -> b -> [a] -> b # foldl :: (b -> a -> b) -> b -> [a] -> b # foldl' :: (b -> a -> b) -> b -> [a] -> b # foldr1 :: (a -> a -> a) -> [a] -> a # foldl1 :: (a -> a -> a) -> [a] -> a # elem :: Eq a => a -> [a] -> Bool # maximum :: Ord a => [a] -> a # | |
| Foldable Maybe | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Foldable Par1 | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Par1 m -> m # foldMap :: Monoid m => (a -> m) -> Par1 a -> m # foldMap' :: Monoid m => (a -> m) -> Par1 a -> m # foldr :: (a -> b -> b) -> b -> Par1 a -> b # foldr' :: (a -> b -> b) -> b -> Par1 a -> b # foldl :: (b -> a -> b) -> b -> Par1 a -> b # foldl' :: (b -> a -> b) -> b -> Par1 a -> b # foldr1 :: (a -> a -> a) -> Par1 a -> a # foldl1 :: (a -> a -> a) -> Par1 a -> a # elem :: Eq a => a -> Par1 a -> Bool # maximum :: Ord a => Par1 a -> a # | |
| Foldable Solo | |
Defined in Data.Tuple.Solo Methods fold :: Monoid m => Solo m -> m # foldMap :: Monoid m => (a -> m) -> Solo a -> m # foldMap' :: Monoid m => (a -> m) -> Solo a -> m # foldr :: (a -> b -> b) -> b -> Solo a -> b # foldr' :: (a -> b -> b) -> b -> Solo a -> b # foldl :: (b -> a -> b) -> b -> Solo a -> b # foldl' :: (b -> a -> b) -> b -> Solo a -> b # foldr1 :: (a -> a -> a) -> Solo a -> a # foldl1 :: (a -> a -> a) -> Solo a -> a # elem :: Eq a => a -> Solo a -> Bool # maximum :: Ord a => Solo a -> a # | |
| Foldable IResult | |
Defined in Data.Aeson.Types.Internal Methods fold :: Monoid m => IResult m -> m # foldMap :: Monoid m => (a -> m) -> IResult a -> m # foldMap' :: Monoid m => (a -> m) -> IResult a -> m # foldr :: (a -> b -> b) -> b -> IResult a -> b # foldr' :: (a -> b -> b) -> b -> IResult a -> b # foldl :: (b -> a -> b) -> b -> IResult a -> b # foldl' :: (b -> a -> b) -> b -> IResult a -> b # foldr1 :: (a -> a -> a) -> IResult a -> a # foldl1 :: (a -> a -> a) -> IResult a -> a # elem :: Eq a => a -> IResult a -> Bool # maximum :: Ord a => IResult a -> a # minimum :: Ord a => IResult a -> a # | |
| Foldable Result | |
Defined in Data.Aeson.Types.Internal Methods fold :: Monoid m => Result m -> m # foldMap :: Monoid m => (a -> m) -> Result a -> m # foldMap' :: Monoid m => (a -> m) -> Result a -> m # foldr :: (a -> b -> b) -> b -> Result a -> b # foldr' :: (a -> b -> b) -> b -> Result a -> b # foldl :: (b -> a -> b) -> b -> Result a -> b # foldl' :: (b -> a -> b) -> b -> Result a -> b # foldr1 :: (a -> a -> a) -> Result a -> a # foldl1 :: (a -> a -> a) -> Result a -> a # elem :: Eq a => a -> Result a -> Bool # maximum :: Ord a => Result a -> a # minimum :: Ord a => Result a -> a # | |
| Foldable KeyMap | |
Defined in Data.Aeson.KeyMap Methods fold :: Monoid m => KeyMap m -> m # foldMap :: Monoid m => (a -> m) -> KeyMap a -> m # foldMap' :: Monoid m => (a -> m) -> KeyMap a -> m # foldr :: (a -> b -> b) -> b -> KeyMap a -> b # foldr' :: (a -> b -> b) -> b -> KeyMap a -> b # foldl :: (b -> a -> b) -> b -> KeyMap a -> b # foldl' :: (b -> a -> b) -> b -> KeyMap a -> b # foldr1 :: (a -> a -> a) -> KeyMap a -> a # foldl1 :: (a -> a -> a) -> KeyMap a -> a # elem :: Eq a => a -> KeyMap a -> Bool # maximum :: Ord a => KeyMap a -> a # minimum :: Ord a => KeyMap a -> a # | |
| Foldable Complex | Since: base-4.9.0.0 |
Defined in Data.Complex Methods fold :: Monoid m => Complex m -> m # foldMap :: Monoid m => (a -> m) -> Complex a -> m # foldMap' :: Monoid m => (a -> m) -> Complex a -> m # foldr :: (a -> b -> b) -> b -> Complex a -> b # foldr' :: (a -> b -> b) -> b -> Complex a -> b # foldl :: (b -> a -> b) -> b -> Complex a -> b # foldl' :: (b -> a -> b) -> b -> Complex a -> b # foldr1 :: (a -> a -> a) -> Complex a -> a # foldl1 :: (a -> a -> a) -> Complex a -> a # elem :: Eq a => a -> Complex a -> Bool # maximum :: Ord a => Complex a -> a # minimum :: Ord a => Complex a -> a # | |
| Foldable Min | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Min m -> m # foldMap :: Monoid m => (a -> m) -> Min a -> m # foldMap' :: Monoid m => (a -> m) -> Min a -> m # foldr :: (a -> b -> b) -> b -> Min a -> b # foldr' :: (a -> b -> b) -> b -> Min a -> b # foldl :: (b -> a -> b) -> b -> Min a -> b # foldl' :: (b -> a -> b) -> b -> Min a -> b # foldr1 :: (a -> a -> a) -> Min a -> a # foldl1 :: (a -> a -> a) -> Min a -> a # elem :: Eq a => a -> Min a -> Bool # maximum :: Ord a => Min a -> a # | |
| Foldable Max | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Max m -> m # foldMap :: Monoid m => (a -> m) -> Max a -> m # foldMap' :: Monoid m => (a -> m) -> Max a -> m # foldr :: (a -> b -> b) -> b -> Max a -> b # foldr' :: (a -> b -> b) -> b -> Max a -> b # foldl :: (b -> a -> b) -> b -> Max a -> b # foldl' :: (b -> a -> b) -> b -> Max a -> b # foldr1 :: (a -> a -> a) -> Max a -> a # foldl1 :: (a -> a -> a) -> Max a -> a # elem :: Eq a => a -> Max a -> Bool # maximum :: Ord a => Max a -> a # | |
| Foldable First | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Foldable Last | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Foldable Option | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Option m -> m # foldMap :: Monoid m => (a -> m) -> Option a -> m # foldMap' :: Monoid m => (a -> m) -> Option a -> m # foldr :: (a -> b -> b) -> b -> Option a -> b # foldr' :: (a -> b -> b) -> b -> Option a -> b # foldl :: (b -> a -> b) -> b -> Option a -> b # foldl' :: (b -> a -> b) -> b -> Option a -> b # foldr1 :: (a -> a -> a) -> Option a -> a # foldl1 :: (a -> a -> a) -> Option a -> a # elem :: Eq a => a -> Option a -> Bool # maximum :: Ord a => Option a -> a # minimum :: Ord a => Option a -> a # | |
| Foldable ZipList | Since: base-4.9.0.0 |
Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # | |
| Foldable Identity | Since: base-4.8.0.0 |
Defined in Data.Functor.Identity Methods fold :: Monoid m => Identity m -> m # foldMap :: Monoid m => (a -> m) -> Identity a -> m # foldMap' :: Monoid m => (a -> m) -> Identity a -> m # foldr :: (a -> b -> b) -> b -> Identity a -> b # foldr' :: (a -> b -> b) -> b -> Identity a -> b # foldl :: (b -> a -> b) -> b -> Identity a -> b # foldl' :: (b -> a -> b) -> b -> Identity a -> b # foldr1 :: (a -> a -> a) -> Identity a -> a # foldl1 :: (a -> a -> a) -> Identity a -> a # elem :: Eq a => a -> Identity a -> Bool # maximum :: Ord a => Identity a -> a # minimum :: Ord a => Identity a -> a # | |
| Foldable First | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Foldable Last | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Foldable Dual | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Dual m -> m # foldMap :: Monoid m => (a -> m) -> Dual a -> m # foldMap' :: Monoid m => (a -> m) -> Dual a -> m # foldr :: (a -> b -> b) -> b -> Dual a -> b # foldr' :: (a -> b -> b) -> b -> Dual a -> b # foldl :: (b -> a -> b) -> b -> Dual a -> b # foldl' :: (b -> a -> b) -> b -> Dual a -> b # foldr1 :: (a -> a -> a) -> Dual a -> a # foldl1 :: (a -> a -> a) -> Dual a -> a # elem :: Eq a => a -> Dual a -> Bool # maximum :: Ord a => Dual a -> a # | |
| Foldable Sum | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Sum m -> m # foldMap :: Monoid m => (a -> m) -> Sum a -> m # foldMap' :: Monoid m => (a -> m) -> Sum a -> m # foldr :: (a -> b -> b) -> b -> Sum a -> b # foldr' :: (a -> b -> b) -> b -> Sum a -> b # foldl :: (b -> a -> b) -> b -> Sum a -> b # foldl' :: (b -> a -> b) -> b -> Sum a -> b # foldr1 :: (a -> a -> a) -> Sum a -> a # foldl1 :: (a -> a -> a) -> Sum a -> a # elem :: Eq a => a -> Sum a -> Bool # maximum :: Ord a => Sum a -> a # | |
| Foldable Product | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Product m -> m # foldMap :: Monoid m => (a -> m) -> Product a -> m # foldMap' :: Monoid m => (a -> m) -> Product a -> m # foldr :: (a -> b -> b) -> b -> Product a -> b # foldr' :: (a -> b -> b) -> b -> Product a -> b # foldl :: (b -> a -> b) -> b -> Product a -> b # foldl' :: (b -> a -> b) -> b -> Product a -> b # foldr1 :: (a -> a -> a) -> Product a -> a # foldl1 :: (a -> a -> a) -> Product a -> a # elem :: Eq a => a -> Product a -> Bool # maximum :: Ord a => Product a -> a # minimum :: Ord a => Product a -> a # | |
| Foldable Down | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m # foldMap :: Monoid m => (a -> m) -> Down a -> m # foldMap' :: Monoid m => (a -> m) -> Down a -> m # foldr :: (a -> b -> b) -> b -> Down a -> b # foldr' :: (a -> b -> b) -> b -> Down a -> b # foldl :: (b -> a -> b) -> b -> Down a -> b # foldl' :: (b -> a -> b) -> b -> Down a -> b # foldr1 :: (a -> a -> a) -> Down a -> a # foldl1 :: (a -> a -> a) -> Down a -> a # elem :: Eq a => a -> Down a -> Bool # maximum :: Ord a => Down a -> a # | |
| Foldable NonEmpty | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => NonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m # foldr :: (a -> b -> b) -> b -> NonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b # foldl :: (b -> a -> b) -> b -> NonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b # foldr1 :: (a -> a -> a) -> NonEmpty a -> a # foldl1 :: (a -> a -> a) -> NonEmpty a -> a # elem :: Eq a => a -> NonEmpty a -> Bool # maximum :: Ord a => NonEmpty a -> a # minimum :: Ord a => NonEmpty a -> a # | |
| Foldable IntMap | Folds in order of increasing key. |
Defined in Data.IntMap.Internal Methods fold :: Monoid m => IntMap m -> m # foldMap :: Monoid m => (a -> m) -> IntMap a -> m # foldMap' :: Monoid m => (a -> m) -> IntMap a -> m # foldr :: (a -> b -> b) -> b -> IntMap a -> b # foldr' :: (a -> b -> b) -> b -> IntMap a -> b # foldl :: (b -> a -> b) -> b -> IntMap a -> b # foldl' :: (b -> a -> b) -> b -> IntMap a -> b # foldr1 :: (a -> a -> a) -> IntMap a -> a # foldl1 :: (a -> a -> a) -> IntMap a -> a # elem :: Eq a => a -> IntMap a -> Bool # maximum :: Ord a => IntMap a -> a # minimum :: Ord a => IntMap a -> a # | |
| Foldable Tree | |
Defined in Data.Tree Methods fold :: Monoid m => Tree m -> m # foldMap :: Monoid m => (a -> m) -> Tree a -> m # foldMap' :: Monoid m => (a -> m) -> Tree a -> m # foldr :: (a -> b -> b) -> b -> Tree a -> b # foldr' :: (a -> b -> b) -> b -> Tree a -> b # foldl :: (b -> a -> b) -> b -> Tree a -> b # foldl' :: (b -> a -> b) -> b -> Tree a -> b # foldr1 :: (a -> a -> a) -> Tree a -> a # foldl1 :: (a -> a -> a) -> Tree a -> a # elem :: Eq a => a -> Tree a -> Bool # maximum :: Ord a => Tree a -> a # | |
| Foldable Seq | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Seq m -> m # foldMap :: Monoid m => (a -> m) -> Seq a -> m # foldMap' :: Monoid m => (a -> m) -> Seq a -> m # foldr :: (a -> b -> b) -> b -> Seq a -> b # foldr' :: (a -> b -> b) -> b -> Seq a -> b # foldl :: (b -> a -> b) -> b -> Seq a -> b # foldl' :: (b -> a -> b) -> b -> Seq a -> b # foldr1 :: (a -> a -> a) -> Seq a -> a # foldl1 :: (a -> a -> a) -> Seq a -> a # elem :: Eq a => a -> Seq a -> Bool # maximum :: Ord a => Seq a -> a # | |
| Foldable FingerTree | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => FingerTree m -> m # foldMap :: Monoid m => (a -> m) -> FingerTree a -> m # foldMap' :: Monoid m => (a -> m) -> FingerTree a -> m # foldr :: (a -> b -> b) -> b -> FingerTree a -> b # foldr' :: (a -> b -> b) -> b -> FingerTree a -> b # foldl :: (b -> a -> b) -> b -> FingerTree a -> b # foldl' :: (b -> a -> b) -> b -> FingerTree a -> b # foldr1 :: (a -> a -> a) -> FingerTree a -> a # foldl1 :: (a -> a -> a) -> FingerTree a -> a # toList :: FingerTree a -> [a] # null :: FingerTree a -> Bool # length :: FingerTree a -> Int # elem :: Eq a => a -> FingerTree a -> Bool # maximum :: Ord a => FingerTree a -> a # minimum :: Ord a => FingerTree a -> a # sum :: Num a => FingerTree a -> a # product :: Num a => FingerTree a -> a # | |
| Foldable Digit | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Digit m -> m # foldMap :: Monoid m => (a -> m) -> Digit a -> m # foldMap' :: Monoid m => (a -> m) -> Digit a -> m # foldr :: (a -> b -> b) -> b -> Digit a -> b # foldr' :: (a -> b -> b) -> b -> Digit a -> b # foldl :: (b -> a -> b) -> b -> Digit a -> b # foldl' :: (b -> a -> b) -> b -> Digit a -> b # foldr1 :: (a -> a -> a) -> Digit a -> a # foldl1 :: (a -> a -> a) -> Digit a -> a # elem :: Eq a => a -> Digit a -> Bool # maximum :: Ord a => Digit a -> a # minimum :: Ord a => Digit a -> a # | |
| Foldable Node | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Node m -> m # foldMap :: Monoid m => (a -> m) -> Node a -> m # foldMap' :: Monoid m => (a -> m) -> Node a -> m # foldr :: (a -> b -> b) -> b -> Node a -> b # foldr' :: (a -> b -> b) -> b -> Node a -> b # foldl :: (b -> a -> b) -> b -> Node a -> b # foldl' :: (b -> a -> b) -> b -> Node a -> b # foldr1 :: (a -> a -> a) -> Node a -> a # foldl1 :: (a -> a -> a) -> Node a -> a # elem :: Eq a => a -> Node a -> Bool # maximum :: Ord a => Node a -> a # | |
| Foldable Elem | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Elem m -> m # foldMap :: Monoid m => (a -> m) -> Elem a -> m # foldMap' :: Monoid m => (a -> m) -> Elem a -> m # foldr :: (a -> b -> b) -> b -> Elem a -> b # foldr' :: (a -> b -> b) -> b -> Elem a -> b # foldl :: (b -> a -> b) -> b -> Elem a -> b # foldl' :: (b -> a -> b) -> b -> Elem a -> b # foldr1 :: (a -> a -> a) -> Elem a -> a # foldl1 :: (a -> a -> a) -> Elem a -> a # elem :: Eq a => a -> Elem a -> Bool # maximum :: Ord a => Elem a -> a # | |
| Foldable ViewL | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => ViewL m -> m # foldMap :: Monoid m => (a -> m) -> ViewL a -> m # foldMap' :: Monoid m => (a -> m) -> ViewL a -> m # foldr :: (a -> b -> b) -> b -> ViewL a -> b # foldr' :: (a -> b -> b) -> b -> ViewL a -> b # foldl :: (b -> a -> b) -> b -> ViewL a -> b # foldl' :: (b -> a -> b) -> b -> ViewL a -> b # foldr1 :: (a -> a -> a) -> ViewL a -> a # foldl1 :: (a -> a -> a) -> ViewL a -> a # elem :: Eq a => a -> ViewL a -> Bool # maximum :: Ord a => ViewL a -> a # minimum :: Ord a => ViewL a -> a # | |
| Foldable ViewR | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => ViewR m -> m # foldMap :: Monoid m => (a -> m) -> ViewR a -> m # foldMap' :: Monoid m => (a -> m) -> ViewR a -> m # foldr :: (a -> b -> b) -> b -> ViewR a -> b # foldr' :: (a -> b -> b) -> b -> ViewR a -> b # foldl :: (b -> a -> b) -> b -> ViewR a -> b # foldl' :: (b -> a -> b) -> b -> ViewR a -> b # foldr1 :: (a -> a -> a) -> ViewR a -> a # foldl1 :: (a -> a -> a) -> ViewR a -> a # elem :: Eq a => a -> ViewR a -> Bool # maximum :: Ord a => ViewR a -> a # minimum :: Ord a => ViewR a -> a # | |
| Foldable Set | Folds in order of increasing key. |
Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # | |
| Foldable DNonEmpty | |
Defined in Data.DList.DNonEmpty.Internal Methods fold :: Monoid m => DNonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> DNonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> DNonEmpty a -> m # foldr :: (a -> b -> b) -> b -> DNonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> DNonEmpty a -> b # foldl :: (b -> a -> b) -> b -> DNonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> DNonEmpty a -> b # foldr1 :: (a -> a -> a) -> DNonEmpty a -> a # foldl1 :: (a -> a -> a) -> DNonEmpty a -> a # toList :: DNonEmpty a -> [a] # length :: DNonEmpty a -> Int # elem :: Eq a => a -> DNonEmpty a -> Bool # maximum :: Ord a => DNonEmpty a -> a # minimum :: Ord a => DNonEmpty a -> a # | |
| Foldable DList | |
Defined in Data.DList.Internal Methods fold :: Monoid m => DList m -> m # foldMap :: Monoid m => (a -> m) -> DList a -> m # foldMap' :: Monoid m => (a -> m) -> DList a -> m # foldr :: (a -> b -> b) -> b -> DList a -> b # foldr' :: (a -> b -> b) -> b -> DList a -> b # foldl :: (b -> a -> b) -> b -> DList a -> b # foldl' :: (b -> a -> b) -> b -> DList a -> b # foldr1 :: (a -> a -> a) -> DList a -> a # foldl1 :: (a -> a -> a) -> DList a -> a # elem :: Eq a => a -> DList a -> Bool # maximum :: Ord a => DList a -> a # minimum :: Ord a => DList a -> a # | |
| Foldable Hashed | |
Defined in Data.Hashable.Class Methods fold :: Monoid m => Hashed m -> m # foldMap :: Monoid m => (a -> m) -> Hashed a -> m # foldMap' :: Monoid m => (a -> m) -> Hashed a -> m # foldr :: (a -> b -> b) -> b -> Hashed a -> b # foldr' :: (a -> b -> b) -> b -> Hashed a -> b # foldl :: (b -> a -> b) -> b -> Hashed a -> b # foldl' :: (b -> a -> b) -> b -> Hashed a -> b # foldr1 :: (a -> a -> a) -> Hashed a -> a # foldl1 :: (a -> a -> a) -> Hashed a -> a # elem :: Eq a => a -> Hashed a -> Bool # maximum :: Ord a => Hashed a -> a # minimum :: Ord a => Hashed a -> a # | |
| Foldable SimpleDocStream | Collect all annotations from a document. |
Defined in Prettyprinter.Internal Methods fold :: Monoid m => SimpleDocStream m -> m # foldMap :: Monoid m => (a -> m) -> SimpleDocStream a -> m # foldMap' :: Monoid m => (a -> m) -> SimpleDocStream a -> m # foldr :: (a -> b -> b) -> b -> SimpleDocStream a -> b # foldr' :: (a -> b -> b) -> b -> SimpleDocStream a -> b # foldl :: (b -> a -> b) -> b -> SimpleDocStream a -> b # foldl' :: (b -> a -> b) -> b -> SimpleDocStream a -> b # foldr1 :: (a -> a -> a) -> SimpleDocStream a -> a # foldl1 :: (a -> a -> a) -> SimpleDocStream a -> a # toList :: SimpleDocStream a -> [a] # null :: SimpleDocStream a -> Bool # length :: SimpleDocStream a -> Int # elem :: Eq a => a -> SimpleDocStream a -> Bool # maximum :: Ord a => SimpleDocStream a -> a # minimum :: Ord a => SimpleDocStream a -> a # sum :: Num a => SimpleDocStream a -> a # product :: Num a => SimpleDocStream a -> a # | |
| Foldable SmallArray | |
Defined in Data.Primitive.SmallArray Methods fold :: Monoid m => SmallArray m -> m # foldMap :: Monoid m => (a -> m) -> SmallArray a -> m # foldMap' :: Monoid m => (a -> m) -> SmallArray a -> m # foldr :: (a -> b -> b) -> b -> SmallArray a -> b # foldr' :: (a -> b -> b) -> b -> SmallArray a -> b # foldl :: (b -> a -> b) -> b -> SmallArray a -> b # foldl' :: (b -> a -> b) -> b -> SmallArray a -> b # foldr1 :: (a -> a -> a) -> SmallArray a -> a # foldl1 :: (a -> a -> a) -> SmallArray a -> a # toList :: SmallArray a -> [a] # null :: SmallArray a -> Bool # length :: SmallArray a -> Int # elem :: Eq a => a -> SmallArray a -> Bool # maximum :: Ord a => SmallArray a -> a # minimum :: Ord a => SmallArray a -> a # sum :: Num a => SmallArray a -> a # product :: Num a => SmallArray a -> a # | |
| Foldable Array | |
Defined in Data.Primitive.Array Methods fold :: Monoid m => Array m -> m # foldMap :: Monoid m => (a -> m) -> Array a -> m # foldMap' :: Monoid m => (a -> m) -> Array a -> m # foldr :: (a -> b -> b) -> b -> Array a -> b # foldr' :: (a -> b -> b) -> b -> Array a -> b # foldl :: (b -> a -> b) -> b -> Array a -> b # foldl' :: (b -> a -> b) -> b -> Array a -> b # foldr1 :: (a -> a -> a) -> Array a -> a # foldl1 :: (a -> a -> a) -> Array a -> a # elem :: Eq a => a -> Array a -> Bool # maximum :: Ord a => Array a -> a # minimum :: Ord a => Array a -> a # | |
| Foldable Maybe | |
Defined in Data.Strict.Maybe Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Foldable HashSet | |
Defined in Data.HashSet.Internal Methods fold :: Monoid m => HashSet m -> m # foldMap :: Monoid m => (a -> m) -> HashSet a -> m # foldMap' :: Monoid m => (a -> m) -> HashSet a -> m # foldr :: (a -> b -> b) -> b -> HashSet a -> b # foldr' :: (a -> b -> b) -> b -> HashSet a -> b # foldl :: (b -> a -> b) -> b -> HashSet a -> b # foldl' :: (b -> a -> b) -> b -> HashSet a -> b # foldr1 :: (a -> a -> a) -> HashSet a -> a # foldl1 :: (a -> a -> a) -> HashSet a -> a # elem :: Eq a => a -> HashSet a -> Bool # maximum :: Ord a => HashSet a -> a # minimum :: Ord a => HashSet a -> a # | |
| Foldable Vector | |
Defined in Data.Vector Methods fold :: Monoid m => Vector m -> m # foldMap :: Monoid m => (a -> m) -> Vector a -> m # foldMap' :: Monoid m => (a -> m) -> Vector a -> m # foldr :: (a -> b -> b) -> b -> Vector a -> b # foldr' :: (a -> b -> b) -> b -> Vector a -> b # foldl :: (b -> a -> b) -> b -> Vector a -> b # foldl' :: (b -> a -> b) -> b -> Vector a -> b # foldr1 :: (a -> a -> a) -> Vector a -> a # foldl1 :: (a -> a -> a) -> Vector a -> a # elem :: Eq a => a -> Vector a -> Bool # maximum :: Ord a => Vector a -> a # minimum :: Ord a => Vector a -> a # | |
| Foldable (Either a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # toList :: Either a a0 -> [a0] # length :: Either a a0 -> Int # elem :: Eq a0 => a0 -> Either a a0 -> Bool # maximum :: Ord a0 => Either a a0 -> a0 # minimum :: Ord a0 => Either a a0 -> a0 # | |
| Foldable (V1 :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => V1 m -> m # foldMap :: Monoid m => (a -> m) -> V1 a -> m # foldMap' :: Monoid m => (a -> m) -> V1 a -> m # foldr :: (a -> b -> b) -> b -> V1 a -> b # foldr' :: (a -> b -> b) -> b -> V1 a -> b # foldl :: (b -> a -> b) -> b -> V1 a -> b # foldl' :: (b -> a -> b) -> b -> V1 a -> b # foldr1 :: (a -> a -> a) -> V1 a -> a # foldl1 :: (a -> a -> a) -> V1 a -> a # elem :: Eq a => a -> V1 a -> Bool # maximum :: Ord a => V1 a -> a # | |
| Foldable (U1 :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => U1 m -> m # foldMap :: Monoid m => (a -> m) -> U1 a -> m # foldMap' :: Monoid m => (a -> m) -> U1 a -> m # foldr :: (a -> b -> b) -> b -> U1 a -> b # foldr' :: (a -> b -> b) -> b -> U1 a -> b # foldl :: (b -> a -> b) -> b -> U1 a -> b # foldl' :: (b -> a -> b) -> b -> U1 a -> b # foldr1 :: (a -> a -> a) -> U1 a -> a # foldl1 :: (a -> a -> a) -> U1 a -> a # elem :: Eq a => a -> U1 a -> Bool # maximum :: Ord a => U1 a -> a # | |
| Foldable (UAddr :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UAddr m -> m # foldMap :: Monoid m => (a -> m) -> UAddr a -> m # foldMap' :: Monoid m => (a -> m) -> UAddr a -> m # foldr :: (a -> b -> b) -> b -> UAddr a -> b # foldr' :: (a -> b -> b) -> b -> UAddr a -> b # foldl :: (b -> a -> b) -> b -> UAddr a -> b # foldl' :: (b -> a -> b) -> b -> UAddr a -> b # foldr1 :: (a -> a -> a) -> UAddr a -> a # foldl1 :: (a -> a -> a) -> UAddr a -> a # elem :: Eq a => a -> UAddr a -> Bool # maximum :: Ord a => UAddr a -> a # minimum :: Ord a => UAddr a -> a # | |
| Foldable (UChar :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UChar m -> m # foldMap :: Monoid m => (a -> m) -> UChar a -> m # foldMap' :: Monoid m => (a -> m) -> UChar a -> m # foldr :: (a -> b -> b) -> b -> UChar a -> b # foldr' :: (a -> b -> b) -> b -> UChar a -> b # foldl :: (b -> a -> b) -> b -> UChar a -> b # foldl' :: (b -> a -> b) -> b -> UChar a -> b # foldr1 :: (a -> a -> a) -> UChar a -> a # foldl1 :: (a -> a -> a) -> UChar a -> a # elem :: Eq a => a -> UChar a -> Bool # maximum :: Ord a => UChar a -> a # minimum :: Ord a => UChar a -> a # | |
| Foldable (UDouble :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UDouble m -> m # foldMap :: Monoid m => (a -> m) -> UDouble a -> m # foldMap' :: Monoid m => (a -> m) -> UDouble a -> m # foldr :: (a -> b -> b) -> b -> UDouble a -> b # foldr' :: (a -> b -> b) -> b -> UDouble a -> b # foldl :: (b -> a -> b) -> b -> UDouble a -> b # foldl' :: (b -> a -> b) -> b -> UDouble a -> b # foldr1 :: (a -> a -> a) -> UDouble a -> a # foldl1 :: (a -> a -> a) -> UDouble a -> a # elem :: Eq a => a -> UDouble a -> Bool # maximum :: Ord a => UDouble a -> a # minimum :: Ord a => UDouble a -> a # | |
| Foldable (UFloat :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # | |
| Foldable (UInt :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UInt m -> m # foldMap :: Monoid m => (a -> m) -> UInt a -> m # foldMap' :: Monoid m => (a -> m) -> UInt a -> m # foldr :: (a -> b -> b) -> b -> UInt a -> b # foldr' :: (a -> b -> b) -> b -> UInt a -> b # foldl :: (b -> a -> b) -> b -> UInt a -> b # foldl' :: (b -> a -> b) -> b -> UInt a -> b # foldr1 :: (a -> a -> a) -> UInt a -> a # foldl1 :: (a -> a -> a) -> UInt a -> a # elem :: Eq a => a -> UInt a -> Bool # maximum :: Ord a => UInt a -> a # | |
| Foldable (UWord :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UWord m -> m # foldMap :: Monoid m => (a -> m) -> UWord a -> m # foldMap' :: Monoid m => (a -> m) -> UWord a -> m # foldr :: (a -> b -> b) -> b -> UWord a -> b # foldr' :: (a -> b -> b) -> b -> UWord a -> b # foldl :: (b -> a -> b) -> b -> UWord a -> b # foldl' :: (b -> a -> b) -> b -> UWord a -> b # foldr1 :: (a -> a -> a) -> UWord a -> a # foldl1 :: (a -> a -> a) -> UWord a -> a # elem :: Eq a => a -> UWord a -> Bool # maximum :: Ord a => UWord a -> a # minimum :: Ord a => UWord a -> a # | |
| Foldable ((,) a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (a, m) -> m # foldMap :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldMap' :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldr :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldr' :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldl :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldl' :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldr1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # foldl1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # elem :: Eq a0 => a0 -> (a, a0) -> Bool # maximum :: Ord a0 => (a, a0) -> a0 # minimum :: Ord a0 => (a, a0) -> a0 # | |
| Foldable (Map k) | Folds in order of increasing key. |
Defined in Data.Map.Internal Methods fold :: Monoid m => Map k m -> m # foldMap :: Monoid m => (a -> m) -> Map k a -> m # foldMap' :: Monoid m => (a -> m) -> Map k a -> m # foldr :: (a -> b -> b) -> b -> Map k a -> b # foldr' :: (a -> b -> b) -> b -> Map k a -> b # foldl :: (b -> a -> b) -> b -> Map k a -> b # foldl' :: (b -> a -> b) -> b -> Map k a -> b # foldr1 :: (a -> a -> a) -> Map k a -> a # foldl1 :: (a -> a -> a) -> Map k a -> a # elem :: Eq a => a -> Map k a -> Bool # maximum :: Ord a => Map k a -> a # minimum :: Ord a => Map k a -> a # | |
| Foldable (HashMap k) | |
Defined in Data.HashMap.Internal Methods fold :: Monoid m => HashMap k m -> m # foldMap :: Monoid m => (a -> m) -> HashMap k a -> m # foldMap' :: Monoid m => (a -> m) -> HashMap k a -> m # foldr :: (a -> b -> b) -> b -> HashMap k a -> b # foldr' :: (a -> b -> b) -> b -> HashMap k a -> b # foldl :: (b -> a -> b) -> b -> HashMap k a -> b # foldl' :: (b -> a -> b) -> b -> HashMap k a -> b # foldr1 :: (a -> a -> a) -> HashMap k a -> a # foldl1 :: (a -> a -> a) -> HashMap k a -> a # toList :: HashMap k a -> [a] # length :: HashMap k a -> Int # elem :: Eq a => a -> HashMap k a -> Bool # maximum :: Ord a => HashMap k a -> a # minimum :: Ord a => HashMap k a -> a # | |
| Foldable (Array i) | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Array i m -> m # foldMap :: Monoid m => (a -> m) -> Array i a -> m # foldMap' :: Monoid m => (a -> m) -> Array i a -> m # foldr :: (a -> b -> b) -> b -> Array i a -> b # foldr' :: (a -> b -> b) -> b -> Array i a -> b # foldl :: (b -> a -> b) -> b -> Array i a -> b # foldl' :: (b -> a -> b) -> b -> Array i a -> b # foldr1 :: (a -> a -> a) -> Array i a -> a # foldl1 :: (a -> a -> a) -> Array i a -> a # elem :: Eq a => a -> Array i a -> Bool # maximum :: Ord a => Array i a -> a # minimum :: Ord a => Array i a -> a # | |
| Foldable (Arg a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Arg a m -> m # foldMap :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # elem :: Eq a0 => a0 -> Arg a a0 -> Bool # maximum :: Ord a0 => Arg a a0 -> a0 # minimum :: Ord a0 => Arg a a0 -> a0 # | |
| Foldable (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # | |
| Foldable (These a) | |
Defined in Data.These Methods fold :: Monoid m => These a m -> m # foldMap :: Monoid m => (a0 -> m) -> These a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> These a a0 -> m # foldr :: (a0 -> b -> b) -> b -> These a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> These a a0 -> b # foldl :: (b -> a0 -> b) -> b -> These a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> These a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # toList :: These a a0 -> [a0] # elem :: Eq a0 => a0 -> These a a0 -> Bool # maximum :: Ord a0 => These a a0 -> a0 # minimum :: Ord a0 => These a a0 -> a0 # | |
| Foldable (Pair e) | |
Defined in Data.Strict.Tuple Methods fold :: Monoid m => Pair e m -> m # foldMap :: Monoid m => (a -> m) -> Pair e a -> m # foldMap' :: Monoid m => (a -> m) -> Pair e a -> m # foldr :: (a -> b -> b) -> b -> Pair e a -> b # foldr' :: (a -> b -> b) -> b -> Pair e a -> b # foldl :: (b -> a -> b) -> b -> Pair e a -> b # foldl' :: (b -> a -> b) -> b -> Pair e a -> b # foldr1 :: (a -> a -> a) -> Pair e a -> a # foldl1 :: (a -> a -> a) -> Pair e a -> a # elem :: Eq a => a -> Pair e a -> Bool # maximum :: Ord a => Pair e a -> a # minimum :: Ord a => Pair e a -> a # | |
| Foldable (These a) | |
Defined in Data.Strict.These Methods fold :: Monoid m => These a m -> m # foldMap :: Monoid m => (a0 -> m) -> These a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> These a a0 -> m # foldr :: (a0 -> b -> b) -> b -> These a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> These a a0 -> b # foldl :: (b -> a0 -> b) -> b -> These a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> These a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # toList :: These a a0 -> [a0] # elem :: Eq a0 => a0 -> These a a0 -> Bool # maximum :: Ord a0 => These a a0 -> a0 # minimum :: Ord a0 => These a a0 -> a0 # | |
| Foldable (Either e) | |
Defined in Data.Strict.Either Methods fold :: Monoid m => Either e m -> m # foldMap :: Monoid m => (a -> m) -> Either e a -> m # foldMap' :: Monoid m => (a -> m) -> Either e a -> m # foldr :: (a -> b -> b) -> b -> Either e a -> b # foldr' :: (a -> b -> b) -> b -> Either e a -> b # foldl :: (b -> a -> b) -> b -> Either e a -> b # foldl' :: (b -> a -> b) -> b -> Either e a -> b # foldr1 :: (a -> a -> a) -> Either e a -> a # foldl1 :: (a -> a -> a) -> Either e a -> a # elem :: Eq a => a -> Either e a -> Bool # maximum :: Ord a => Either e a -> a # minimum :: Ord a => Either e a -> a # | |
| Foldable f => Foldable (Rec1 f) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Rec1 f m -> m # foldMap :: Monoid m => (a -> m) -> Rec1 f a -> m # foldMap' :: Monoid m => (a -> m) -> Rec1 f a -> m # foldr :: (a -> b -> b) -> b -> Rec1 f a -> b # foldr' :: (a -> b -> b) -> b -> Rec1 f a -> b # foldl :: (b -> a -> b) -> b -> Rec1 f a -> b # foldl' :: (b -> a -> b) -> b -> Rec1 f a -> b # foldr1 :: (a -> a -> a) -> Rec1 f a -> a # foldl1 :: (a -> a -> a) -> Rec1 f a -> a # elem :: Eq a => a -> Rec1 f a -> Bool # maximum :: Ord a => Rec1 f a -> a # minimum :: Ord a => Rec1 f a -> a # | |
| Foldable (Const m :: Type -> Type) | Since: base-4.7.0.0 |
Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # | |
| Foldable f => Foldable (Ap f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Ap f m -> m # foldMap :: Monoid m => (a -> m) -> Ap f a -> m # foldMap' :: Monoid m => (a -> m) -> Ap f a -> m # foldr :: (a -> b -> b) -> b -> Ap f a -> b # foldr' :: (a -> b -> b) -> b -> Ap f a -> b # foldl :: (b -> a -> b) -> b -> Ap f a -> b # foldl' :: (b -> a -> b) -> b -> Ap f a -> b # foldr1 :: (a -> a -> a) -> Ap f a -> a # foldl1 :: (a -> a -> a) -> Ap f a -> a # elem :: Eq a => a -> Ap f a -> Bool # maximum :: Ord a => Ap f a -> a # | |
| Foldable f => Foldable (Alt f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m # foldMap :: Monoid m => (a -> m) -> Alt f a -> m # foldMap' :: Monoid m => (a -> m) -> Alt f a -> m # foldr :: (a -> b -> b) -> b -> Alt f a -> b # foldr' :: (a -> b -> b) -> b -> Alt f a -> b # foldl :: (b -> a -> b) -> b -> Alt f a -> b # foldl' :: (b -> a -> b) -> b -> Alt f a -> b # foldr1 :: (a -> a -> a) -> Alt f a -> a # foldl1 :: (a -> a -> a) -> Alt f a -> a # elem :: Eq a => a -> Alt f a -> Bool # maximum :: Ord a => Alt f a -> a # minimum :: Ord a => Alt f a -> a # | |
| Bifoldable p => Foldable (Join p) | |
Defined in Data.Bifunctor.Join Methods fold :: Monoid m => Join p m -> m # foldMap :: Monoid m => (a -> m) -> Join p a -> m # foldMap' :: Monoid m => (a -> m) -> Join p a -> m # foldr :: (a -> b -> b) -> b -> Join p a -> b # foldr' :: (a -> b -> b) -> b -> Join p a -> b # foldl :: (b -> a -> b) -> b -> Join p a -> b # foldl' :: (b -> a -> b) -> b -> Join p a -> b # foldr1 :: (a -> a -> a) -> Join p a -> a # foldl1 :: (a -> a -> a) -> Join p a -> a # elem :: Eq a => a -> Join p a -> Bool # maximum :: Ord a => Join p a -> a # minimum :: Ord a => Join p a -> a # | |
| Foldable f => Foldable (ExceptT e f) | |
Defined in Control.Monad.Trans.Except Methods fold :: Monoid m => ExceptT e f m -> m # foldMap :: Monoid m => (a -> m) -> ExceptT e f a -> m # foldMap' :: Monoid m => (a -> m) -> ExceptT e f a -> m # foldr :: (a -> b -> b) -> b -> ExceptT e f a -> b # foldr' :: (a -> b -> b) -> b -> ExceptT e f a -> b # foldl :: (b -> a -> b) -> b -> ExceptT e f a -> b # foldl' :: (b -> a -> b) -> b -> ExceptT e f a -> b # foldr1 :: (a -> a -> a) -> ExceptT e f a -> a # foldl1 :: (a -> a -> a) -> ExceptT e f a -> a # toList :: ExceptT e f a -> [a] # null :: ExceptT e f a -> Bool # length :: ExceptT e f a -> Int # elem :: Eq a => a -> ExceptT e f a -> Bool # maximum :: Ord a => ExceptT e f a -> a # minimum :: Ord a => ExceptT e f a -> a # | |
| Foldable f => Foldable (ErrorT e f) | |
Defined in Control.Monad.Trans.Error Methods fold :: Monoid m => ErrorT e f m -> m # foldMap :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldMap' :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldr :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldr' :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldl :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldl' :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldr1 :: (a -> a -> a) -> ErrorT e f a -> a # foldl1 :: (a -> a -> a) -> ErrorT e f a -> a # toList :: ErrorT e f a -> [a] # null :: ErrorT e f a -> Bool # length :: ErrorT e f a -> Int # elem :: Eq a => a -> ErrorT e f a -> Bool # maximum :: Ord a => ErrorT e f a -> a # minimum :: Ord a => ErrorT e f a -> a # | |
| Foldable (Tagged s) | |
Defined in Data.Tagged Methods fold :: Monoid m => Tagged s m -> m # foldMap :: Monoid m => (a -> m) -> Tagged s a -> m # foldMap' :: Monoid m => (a -> m) -> Tagged s a -> m # foldr :: (a -> b -> b) -> b -> Tagged s a -> b # foldr' :: (a -> b -> b) -> b -> Tagged s a -> b # foldl :: (b -> a -> b) -> b -> Tagged s a -> b # foldl' :: (b -> a -> b) -> b -> Tagged s a -> b # foldr1 :: (a -> a -> a) -> Tagged s a -> a # foldl1 :: (a -> a -> a) -> Tagged s a -> a # elem :: Eq a => a -> Tagged s a -> Bool # maximum :: Ord a => Tagged s a -> a # minimum :: Ord a => Tagged s a -> a # | |
| (Foldable f, Foldable g) => Foldable (These1 f g) | |
Defined in Data.Functor.These Methods fold :: Monoid m => These1 f g m -> m # foldMap :: Monoid m => (a -> m) -> These1 f g a -> m # foldMap' :: Monoid m => (a -> m) -> These1 f g a -> m # foldr :: (a -> b -> b) -> b -> These1 f g a -> b # foldr' :: (a -> b -> b) -> b -> These1 f g a -> b # foldl :: (b -> a -> b) -> b -> These1 f g a -> b # foldl' :: (b -> a -> b) -> b -> These1 f g a -> b # foldr1 :: (a -> a -> a) -> These1 f g a -> a # foldl1 :: (a -> a -> a) -> These1 f g a -> a # toList :: These1 f g a -> [a] # null :: These1 f g a -> Bool # length :: These1 f g a -> Int # elem :: Eq a => a -> These1 f g a -> Bool # maximum :: Ord a => These1 f g a -> a # minimum :: Ord a => These1 f g a -> a # | |
| Foldable (K1 i c :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => K1 i c m -> m # foldMap :: Monoid m => (a -> m) -> K1 i c a -> m # foldMap' :: Monoid m => (a -> m) -> K1 i c a -> m # foldr :: (a -> b -> b) -> b -> K1 i c a -> b # foldr' :: (a -> b -> b) -> b -> K1 i c a -> b # foldl :: (b -> a -> b) -> b -> K1 i c a -> b # foldl' :: (b -> a -> b) -> b -> K1 i c a -> b # foldr1 :: (a -> a -> a) -> K1 i c a -> a # foldl1 :: (a -> a -> a) -> K1 i c a -> a # elem :: Eq a => a -> K1 i c a -> Bool # maximum :: Ord a => K1 i c a -> a # minimum :: Ord a => K1 i c a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :+: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :+: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldr1 :: (a -> a -> a) -> (f :+: g) a -> a # foldl1 :: (a -> a -> a) -> (f :+: g) a -> a # toList :: (f :+: g) a -> [a] # length :: (f :+: g) a -> Int # elem :: Eq a => a -> (f :+: g) a -> Bool # maximum :: Ord a => (f :+: g) a -> a # minimum :: Ord a => (f :+: g) a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :*: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :*: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :*: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :*: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :*: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :*: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :*: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :*: g) a -> b # foldr1 :: (a -> a -> a) -> (f :*: g) a -> a # foldl1 :: (a -> a -> a) -> (f :*: g) a -> a # toList :: (f :*: g) a -> [a] # length :: (f :*: g) a -> Int # elem :: Eq a => a -> (f :*: g) a -> Bool # maximum :: Ord a => (f :*: g) a -> a # minimum :: Ord a => (f :*: g) a -> a # | |
| (Foldable f, Foldable g) => Foldable (Product f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product Methods fold :: Monoid m => Product f g m -> m # foldMap :: Monoid m => (a -> m) -> Product f g a -> m # foldMap' :: Monoid m => (a -> m) -> Product f g a -> m # foldr :: (a -> b -> b) -> b -> Product f g a -> b # foldr' :: (a -> b -> b) -> b -> Product f g a -> b # foldl :: (b -> a -> b) -> b -> Product f g a -> b # foldl' :: (b -> a -> b) -> b -> Product f g a -> b # foldr1 :: (a -> a -> a) -> Product f g a -> a # foldl1 :: (a -> a -> a) -> Product f g a -> a # toList :: Product f g a -> [a] # null :: Product f g a -> Bool # length :: Product f g a -> Int # elem :: Eq a => a -> Product f g a -> Bool # maximum :: Ord a => Product f g a -> a # minimum :: Ord a => Product f g a -> a # | |
| (Foldable f, Foldable g) => Foldable (Sum f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Sum Methods fold :: Monoid m => Sum f g m -> m # foldMap :: Monoid m => (a -> m) -> Sum f g a -> m # foldMap' :: Monoid m => (a -> m) -> Sum f g a -> m # foldr :: (a -> b -> b) -> b -> Sum f g a -> b # foldr' :: (a -> b -> b) -> b -> Sum f g a -> b # foldl :: (b -> a -> b) -> b -> Sum f g a -> b # foldl' :: (b -> a -> b) -> b -> Sum f g a -> b # foldr1 :: (a -> a -> a) -> Sum f g a -> a # foldl1 :: (a -> a -> a) -> Sum f g a -> a # elem :: Eq a => a -> Sum f g a -> Bool # maximum :: Ord a => Sum f g a -> a # minimum :: Ord a => Sum f g a -> a # | |
| Foldable f => Foldable (M1 i c f) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => M1 i c f m -> m # foldMap :: Monoid m => (a -> m) -> M1 i c f a -> m # foldMap' :: Monoid m => (a -> m) -> M1 i c f a -> m # foldr :: (a -> b -> b) -> b -> M1 i c f a -> b # foldr' :: (a -> b -> b) -> b -> M1 i c f a -> b # foldl :: (b -> a -> b) -> b -> M1 i c f a -> b # foldl' :: (b -> a -> b) -> b -> M1 i c f a -> b # foldr1 :: (a -> a -> a) -> M1 i c f a -> a # foldl1 :: (a -> a -> a) -> M1 i c f a -> a # elem :: Eq a => a -> M1 i c f a -> Bool # maximum :: Ord a => M1 i c f a -> a # minimum :: Ord a => M1 i c f a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :.: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :.: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldr1 :: (a -> a -> a) -> (f :.: g) a -> a # foldl1 :: (a -> a -> a) -> (f :.: g) a -> a # toList :: (f :.: g) a -> [a] # length :: (f :.: g) a -> Int # elem :: Eq a => a -> (f :.: g) a -> Bool # maximum :: Ord a => (f :.: g) a -> a # minimum :: Ord a => (f :.: g) a -> a # | |
| (Foldable f, Foldable g) => Foldable (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods fold :: Monoid m => Compose f g m -> m # foldMap :: Monoid m => (a -> m) -> Compose f g a -> m # foldMap' :: Monoid m => (a -> m) -> Compose f g a -> m # foldr :: (a -> b -> b) -> b -> Compose f g a -> b # foldr' :: (a -> b -> b) -> b -> Compose f g a -> b # foldl :: (b -> a -> b) -> b -> Compose f g a -> b # foldl' :: (b -> a -> b) -> b -> Compose f g a -> b # foldr1 :: (a -> a -> a) -> Compose f g a -> a # foldl1 :: (a -> a -> a) -> Compose f g a -> a # toList :: Compose f g a -> [a] # null :: Compose f g a -> Bool # length :: Compose f g a -> Int # elem :: Eq a => a -> Compose f g a -> Bool # maximum :: Ord a => Compose f g a -> a # minimum :: Ord a => Compose f g a -> a # | |
| Bifoldable p => Foldable (WrappedBifunctor p a) | |
Defined in Data.Bifunctor.Wrapped Methods fold :: Monoid m => WrappedBifunctor p a m -> m # foldMap :: Monoid m => (a0 -> m) -> WrappedBifunctor p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> WrappedBifunctor p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> WrappedBifunctor p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> WrappedBifunctor p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> WrappedBifunctor p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> WrappedBifunctor p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> WrappedBifunctor p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> WrappedBifunctor p a a0 -> a0 # toList :: WrappedBifunctor p a a0 -> [a0] # null :: WrappedBifunctor p a a0 -> Bool # length :: WrappedBifunctor p a a0 -> Int # elem :: Eq a0 => a0 -> WrappedBifunctor p a a0 -> Bool # maximum :: Ord a0 => WrappedBifunctor p a a0 -> a0 # minimum :: Ord a0 => WrappedBifunctor p a a0 -> a0 # sum :: Num a0 => WrappedBifunctor p a a0 -> a0 # product :: Num a0 => WrappedBifunctor p a a0 -> a0 # | |
| Foldable g => Foldable (Joker g a) | |
Defined in Data.Bifunctor.Joker Methods fold :: Monoid m => Joker g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Joker g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Joker g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Joker g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Joker g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Joker g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Joker g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Joker g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Joker g a a0 -> a0 # toList :: Joker g a a0 -> [a0] # null :: Joker g a a0 -> Bool # length :: Joker g a a0 -> Int # elem :: Eq a0 => a0 -> Joker g a a0 -> Bool # maximum :: Ord a0 => Joker g a a0 -> a0 # minimum :: Ord a0 => Joker g a a0 -> a0 # | |
| Bifoldable p => Foldable (Flip p a) | |
Defined in Data.Bifunctor.Flip Methods fold :: Monoid m => Flip p a m -> m # foldMap :: Monoid m => (a0 -> m) -> Flip p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Flip p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Flip p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Flip p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Flip p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Flip p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Flip p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Flip p a a0 -> a0 # toList :: Flip p a a0 -> [a0] # length :: Flip p a a0 -> Int # elem :: Eq a0 => a0 -> Flip p a a0 -> Bool # maximum :: Ord a0 => Flip p a a0 -> a0 # minimum :: Ord a0 => Flip p a a0 -> a0 # | |
| Foldable (Clown f a :: Type -> Type) | |
Defined in Data.Bifunctor.Clown Methods fold :: Monoid m => Clown f a m -> m # foldMap :: Monoid m => (a0 -> m) -> Clown f a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Clown f a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Clown f a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Clown f a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Clown f a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Clown f a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Clown f a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Clown f a a0 -> a0 # toList :: Clown f a a0 -> [a0] # null :: Clown f a a0 -> Bool # length :: Clown f a a0 -> Int # elem :: Eq a0 => a0 -> Clown f a a0 -> Bool # maximum :: Ord a0 => Clown f a a0 -> a0 # minimum :: Ord a0 => Clown f a a0 -> a0 # | |
| (Foldable (f a), Foldable (g a)) => Foldable (Sum f g a) | |
Defined in Data.Bifunctor.Sum Methods fold :: Monoid m => Sum f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Sum f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Sum f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Sum f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Sum f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Sum f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Sum f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Sum f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Sum f g a a0 -> a0 # toList :: Sum f g a a0 -> [a0] # null :: Sum f g a a0 -> Bool # length :: Sum f g a a0 -> Int # elem :: Eq a0 => a0 -> Sum f g a a0 -> Bool # maximum :: Ord a0 => Sum f g a a0 -> a0 # minimum :: Ord a0 => Sum f g a a0 -> a0 # | |
| (Foldable (f a), Foldable (g a)) => Foldable (Product f g a) | |
Defined in Data.Bifunctor.Product Methods fold :: Monoid m => Product f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Product f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Product f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Product f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Product f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Product f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Product f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Product f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Product f g a a0 -> a0 # toList :: Product f g a a0 -> [a0] # null :: Product f g a a0 -> Bool # length :: Product f g a a0 -> Int # elem :: Eq a0 => a0 -> Product f g a a0 -> Bool # maximum :: Ord a0 => Product f g a a0 -> a0 # minimum :: Ord a0 => Product f g a a0 -> a0 # | |
| (Foldable f, Bifoldable p) => Foldable (Tannen f p a) | |
Defined in Data.Bifunctor.Tannen Methods fold :: Monoid m => Tannen f p a m -> m # foldMap :: Monoid m => (a0 -> m) -> Tannen f p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Tannen f p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Tannen f p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Tannen f p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Tannen f p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Tannen f p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Tannen f p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Tannen f p a a0 -> a0 # toList :: Tannen f p a a0 -> [a0] # null :: Tannen f p a a0 -> Bool # length :: Tannen f p a a0 -> Int # elem :: Eq a0 => a0 -> Tannen f p a a0 -> Bool # maximum :: Ord a0 => Tannen f p a a0 -> a0 # minimum :: Ord a0 => Tannen f p a a0 -> a0 # | |
| (Bifoldable p, Foldable g) => Foldable (Biff p f g a) | |
Defined in Data.Bifunctor.Biff Methods fold :: Monoid m => Biff p f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Biff p f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Biff p f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Biff p f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Biff p f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Biff p f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Biff p f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Biff p f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Biff p f g a a0 -> a0 # toList :: Biff p f g a a0 -> [a0] # null :: Biff p f g a a0 -> Bool # length :: Biff p f g a a0 -> Int # elem :: Eq a0 => a0 -> Biff p f g a a0 -> Bool # maximum :: Ord a0 => Biff p f g a a0 -> a0 # minimum :: Ord a0 => Biff p f g a a0 -> a0 # | |
class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where #
Functors representing data structures that can be traversed from left to right.
A definition of traverse must satisfy the following laws:
- Naturality
t .for every applicative transformationtraversef =traverse(t . f)t- Identity
traverseIdentity=Identity- Composition
traverse(Compose.fmapg . f) =Compose.fmap(traverseg) .traversef
A definition of sequenceA must satisfy the following laws:
- Naturality
t .for every applicative transformationsequenceA=sequenceA.fmaptt- Identity
sequenceA.fmapIdentity=Identity- Composition
sequenceA.fmapCompose=Compose.fmapsequenceA.sequenceA
where an applicative transformation is a function
t :: (Applicative f, Applicative g) => f a -> g a
preserving the Applicative operations, i.e.
t (purex) =purex t (f<*>x) = t f<*>t x
and the identity functor Identity and composition functors
Compose are from Data.Functor.Identity and
Data.Functor.Compose.
A result of the naturality law is a purity law for traverse
traversepure=pure
(The naturality law is implied by parametricity and thus so is the purity law [1, p15].)
Instances are similar to Functor, e.g. given a data type
data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)
a suitable instance would be
instance Traversable Tree where traverse f Empty = pure Empty traverse f (Leaf x) = Leaf <$> f x traverse f (Node l k r) = Node <$> traverse f l <*> f k <*> traverse f r
This is suitable even for abstract types, as the laws for <*>
imply a form of associativity.
The superclass instances should satisfy the following:
- In the
Functorinstance,fmapshould be equivalent to traversal with the identity applicative functor (fmapDefault). - In the
Foldableinstance,foldMapshould be equivalent to traversal with a constant applicative functor (foldMapDefault).
References: [1] The Essence of the Iterator Pattern, Jeremy Gibbons and Bruno C. d. S. Oliveira
Methods
traverse :: Applicative f => (a -> f b) -> t a -> f (t b) #
Map each element of a structure to an action, evaluate these actions
from left to right, and collect the results. For a version that ignores
the results see traverse_.
sequenceA :: Applicative f => t (f a) -> f (t a) #
Evaluate each action in the structure from left to right, and
collect the results. For a version that ignores the results
see sequenceA_.
mapM :: Monad m => (a -> m b) -> t a -> m (t b) #
Map each element of a structure to a monadic action, evaluate
these actions from left to right, and collect the results. For
a version that ignores the results see mapM_.
sequence :: Monad m => t (m a) -> m (t a) #
Evaluate each monadic action in the structure from left to
right, and collect the results. For a version that ignores the
results see sequence_.
Instances
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 Ordering | Since: base-4.9.0.0 |
| Semigroup () | Since: base-4.9.0.0 |
| Semigroup ByteString | |
Defined in Data.ByteString.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString # | |
| Semigroup ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString # | |
| Semigroup Series | |
| Semigroup Key | |
| Semigroup Void | Since: base-4.9.0.0 |
| Semigroup All | Since: base-4.9.0.0 |
| Semigroup Any | Since: base-4.9.0.0 |
| Semigroup ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods (<>) :: ShortByteString -> ShortByteString -> ShortByteString # sconcat :: NonEmpty ShortByteString -> ShortByteString # stimes :: Integral b => b -> ShortByteString -> ShortByteString # | |
| Semigroup IntSet | Since: containers-0.5.7 |
| Semigroup ByteArray | |
| Semigroup ParseError | |
Defined in Options.Applicative.Types Methods (<>) :: ParseError -> ParseError -> ParseError # sconcat :: NonEmpty ParseError -> ParseError # stimes :: Integral b => b -> ParseError -> ParseError # | |
| Semigroup Completer | |
| Semigroup Doc | |
| Semigroup ShortText | |
| Semigroup Line | |
| Semigroup More | |
| Semigroup ChangeLog Source # | |
| Semigroup ProjectId Source # | |
| Semigroup [a] | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (IO a) | Since: base-4.10.0.0 |
| Semigroup p => Semigroup (Par1 p) | Since: base-4.12.0.0 |
| Semigroup a => Semigroup (Solo a) | |
| Semigroup (IResult a) | |
| Semigroup (Result a) | |
| Semigroup (Parser a) | |
| Semigroup (KeyMap v) | |
| Ord a => Semigroup (Min a) | Since: base-4.9.0.0 |
| Ord a => Semigroup (Max 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 |
| 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 (Option a) | Since: base-4.9.0.0 |
| 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 (Dual a) | Since: base-4.9.0.0 |
| Semigroup (Endo a) | Since: base-4.9.0.0 |
| Num a => Semigroup (Sum a) | Since: base-4.9.0.0 |
| Num a => Semigroup (Product a) | Since: base-4.9.0.0 |
| Semigroup (NonEmpty a) | Since: base-4.9.0.0 |
| Semigroup (PutM ()) | |
| Semigroup (IntMap a) | Since: containers-0.5.7 |
| Semigroup (Seq a) | Since: containers-0.5.7 |
| Ord a => Semigroup (Set a) | Since: containers-0.5.7 |
| Semigroup (DNonEmpty a) | |
| Semigroup (DList a) | |
| Semigroup a => Semigroup (Managed a) | |
| Semigroup (Doc a) | |
| Semigroup (Doc ann) | x
|
| Semigroup (PrimArray a) | Since: primitive-0.6.4.0 |
| Semigroup (SmallArray a) | Since: primitive-0.6.3.0 |
Defined in Data.Primitive.SmallArray Methods (<>) :: SmallArray a -> SmallArray a -> SmallArray a # sconcat :: NonEmpty (SmallArray a) -> SmallArray a # stimes :: Integral b => b -> SmallArray a -> SmallArray a # | |
| Semigroup (Array a) | Since: primitive-0.6.3.0 |
| Semigroup a => Semigroup (Maybe a) | |
| Monoid a => Semigroup (Shell a) | |
| Monoid a => Semigroup (Pattern a) | |
| (Hashable a, Eq a) => Semigroup (HashSet a) | \(O(n+m)\) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| Storable a => Semigroup (Vector a) | |
| Prim a => Semigroup (Vector a) | |
| Semigroup (Vector a) | |
| Semigroup (MergeSet a) | |
| Semigroup b => Semigroup (a -> b) | Since: base-4.9.0.0 |
| Semigroup (Either a b) | Since: base-4.9.0.0 |
| Semigroup (V1 p) | Since: base-4.12.0.0 |
| Semigroup (U1 p) | Since: base-4.12.0.0 |
| (Semigroup a, Semigroup b) => Semigroup (a, b) | Since: base-4.9.0.0 |
| Ord k => Semigroup (Map k v) | |
| (Eq k, Hashable k) => Semigroup (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| Semigroup b => Semigroup (Fold a b) | |
| Monad m => Semigroup (EndoM m a) | |
| (Semigroup a, Semigroup b) => Semigroup (These a b) | |
| (Semigroup a, Semigroup b) => Semigroup (Pair a b) | |
| (Semigroup a, Semigroup b) => Semigroup (These a b) | |
| Semigroup (Either a b) | |
| Semigroup (Parser i a) | |
| 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 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 b, Monad m) => Semigroup (FoldM m a b) | |
| Semigroup a => Semigroup (Tagged s a) | |
| Semigroup c => Semigroup (K1 i c p) | Since: base-4.12.0.0 |
| (Semigroup (f p), Semigroup (g p)) => Semigroup ((f :*: g) 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 a => Semigroup (ParsecT s u m a) | The (many $ char The above will parse a string like (many $ char Since: parsec-3.1.12 |
| Semigroup (f p) => Semigroup (M1 i c f p) | Since: base-4.12.0.0 |
| Semigroup (f (g p)) => Semigroup ((f :.: g) 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)<>zSemigrouplaw)- Concatenation
mconcat=foldr(<>)mempty
The method names refer to the monoid of lists under concatenation, but there are many other instances.
Some types can be viewed as a monoid in more than one way,
e.g. both addition and multiplication on numbers.
In such cases we often define newtypes and make those instances
of Monoid, e.g. Sum and Product.
NOTE: Semigroup is a superclass of Monoid since base-4.11.0.0.
Minimal complete definition
Methods
Identity of mappend
>>>"Hello world" <> mempty"Hello world"
An associative operation
NOTE: This method is redundant and has the default
implementation mappend = (<>)mappend is a synonym for
(<>), it is expected that the two functions are defined the same
way. In a future GHC release mappend will be removed from Monoid.
Fold a list using the monoid.
For most types, the default definition for mconcat will be
used, but the function is included in the class definition so
that an optimized version can be provided for specific types.
>>>mconcat ["Hello", " ", "Haskell", "!"]"Hello Haskell!"
Instances
| Monoid Ordering | Since: base-2.1 |
| Monoid () | Since: base-2.1 |
| Monoid ByteString | |
Defined in Data.ByteString.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid Series | |
| Monoid Key | |
| Monoid All | Since: base-2.1 |
| Monoid Any | Since: base-2.1 |
| Monoid ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods mappend :: ShortByteString -> ShortByteString -> ShortByteString # mconcat :: [ShortByteString] -> ShortByteString # | |
| Monoid IntSet | |
| Monoid ByteArray | |
| Monoid ParseError | |
Defined in Options.Applicative.Types Methods mempty :: ParseError # mappend :: ParseError -> ParseError -> ParseError # mconcat :: [ParseError] -> ParseError # | |
| Monoid Completer | |
| Monoid Doc | |
| Monoid ShortText | |
| Monoid Line | |
| Monoid More | |
| Monoid ChangeLog Source # | |
| Monoid ProjectId Source # | |
| Monoid [a] | Since: base-2.1 |
| Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
| Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
| Monoid p => Monoid (Par1 p) | Since: base-4.12.0.0 |
| Monoid a => Monoid (Solo a) | |
| Monoid (IResult a) | |
| Monoid (Result a) | |
| Monoid (Parser a) | |
| Monoid (KeyMap v) | |
| (Ord a, Bounded a) => Monoid (Min a) | Since: base-4.9.0.0 |
| (Ord a, Bounded a) => Monoid (Max 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 # | |
| Semigroup a => Monoid (Option a) | Since: base-4.9.0.0 |
| 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 (Dual a) | Since: base-2.1 |
| Monoid (Endo a) | Since: base-2.1 |
| Num a => Monoid (Sum a) | Since: base-2.1 |
| Num a => Monoid (Product a) | Since: base-2.1 |
| Monoid (PutM ()) | |
| Monoid (IntMap a) | |
| Monoid (Seq a) | |
| Ord a => Monoid (Set a) | |
| Monoid (DList a) | |
| Monoid a => Monoid (Managed a) | |
| Monoid (Doc a) | |
| Monoid (Doc ann) |
|
| Monoid (PrimArray a) | Since: primitive-0.6.4.0 |
| Monoid (SmallArray a) | |
Defined in Data.Primitive.SmallArray Methods mempty :: SmallArray a # mappend :: SmallArray a -> SmallArray a -> SmallArray a # mconcat :: [SmallArray a] -> SmallArray a # | |
| Monoid (Array a) | |
| Semigroup a => Monoid (Maybe a) | |
| Monoid a => Monoid (Shell a) | |
| Monoid a => Monoid (Pattern a) | |
| (Hashable a, Eq a) => Monoid (HashSet a) | \(O(n+m)\) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| Storable a => Monoid (Vector a) | |
| Prim a => Monoid (Vector a) | |
| Monoid (Vector a) | |
| Monoid (MergeSet a) | |
| Monoid b => Monoid (a -> b) | Since: base-2.1 |
| Monoid (U1 p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b) => Monoid (a, b) | Since: base-2.1 |
| Ord k => Monoid (Map k v) | |
| (Eq k, Hashable k) => Monoid (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| Monoid b => Monoid (Fold a b) | |
| Monad m => Monoid (EndoM m a) | |
| (Monoid a, Monoid b) => Monoid (Pair a b) | |
| Monoid (Parser i a) | |
| 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 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 b, Monad m) => Monoid (FoldM m a b) | |
| (Semigroup a, Monoid a) => Monoid (Tagged s a) | |
| Monoid c => Monoid (K1 i c p) | Since: base-4.12.0.0 |
| (Monoid (f p), Monoid (g p)) => Monoid ((f :*: g) 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 a, Semigroup (ParsecT s u m a)) => Monoid (ParsecT s u m a) | The Since: parsec-3.1.12 |
| Monoid (f p) => Monoid (M1 i c f p) | Since: base-4.12.0.0 |
| Monoid (f (g p)) => Monoid ((f :.: g) 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 |
Instances
The character type Char is an enumeration whose values represent
Unicode (or equivalently ISO/IEC 10646) code points (i.e. characters, see
http://www.unicode.org/ for details). This set extends the ISO 8859-1
(Latin-1) character set (the first 256 characters), which is itself an extension
of the ASCII character set (the first 128 characters). A character literal in
Haskell has type Char.
To convert a Char to or from the corresponding Int value defined
by Unicode, use toEnum and fromEnum from the
Enum class respectively (or equivalently ord and
chr).
Instances
Double-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE double-precision type.
Instances
| Eq Double | Note that due to the presence of
Also note that
|
| Floating Double | Since: base-2.1 |
| 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 # | |
| Ord Double | Note that due to the presence of
Also note that, due to the same,
|
| Read 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 # | |
| Hashable Double | Note: prior to The Since: hashable-1.3.0.0 |
| ToJSON Double | |
| ToJSONKey Double | |
Defined in Data.Aeson.Types.ToJSON Methods | |
| FromJSON Double | |
| FromJSONKey Double | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| Pretty Double |
|
| Storable Double | Since: base-2.1 |
| Binary Double | |
| NFData Double | |
Defined in Control.DeepSeq | |
| Pretty Double | |
Defined in Text.PrettyPrint.HughesPJClass Methods pPrintPrec :: PrettyLevel -> Rational -> Double -> Doc # pPrintList :: PrettyLevel -> [Double] -> Doc # | |
| Prim Double | |
Defined in Data.Primitive.Types Methods sizeOf# :: Double -> Int# Source # alignment# :: Double -> Int# Source # indexByteArray# :: ByteArray# -> Int# -> Double Source # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Double #) Source # writeByteArray# :: MutableByteArray# s -> Int# -> Double -> State# s -> State# s Source # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Double -> State# s -> State# s Source # indexOffAddr# :: Addr# -> Int# -> Double Source # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Double #) Source # writeOffAddr# :: Addr# -> Int# -> Double -> State# s -> State# s Source # setOffAddr# :: Addr# -> Int# -> Int# -> Double -> State# s -> State# s Source # | |
| UniformRange Double | |
Defined in System.Random.Internal | |
| Unbox Double | |
Defined in Data.Vector.Unboxed.Base | |
| Lift Double | |
| Vector Vector Double | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Double -> ST s (Vector Double) Source # basicUnsafeThaw :: Vector Double -> ST s (Mutable Vector s Double) Source # basicLength :: Vector Double -> Int Source # basicUnsafeSlice :: Int -> Int -> Vector Double -> Vector Double Source # basicUnsafeIndexM :: Vector Double -> Int -> Box Double Source # basicUnsafeCopy :: Mutable Vector s Double -> Vector Double -> ST s () Source # | |
| MVector MVector Double | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Double -> Int Source # basicUnsafeSlice :: Int -> Int -> MVector s Double -> MVector s Double Source # basicOverlaps :: MVector s Double -> MVector s Double -> Bool Source # basicUnsafeNew :: Int -> ST s (MVector s Double) Source # basicInitialize :: MVector s Double -> ST s () Source # basicUnsafeReplicate :: Int -> Double -> ST s (MVector s Double) Source # basicUnsafeRead :: MVector s Double -> Int -> ST s Double Source # basicUnsafeWrite :: MVector s Double -> Int -> Double -> ST s () Source # basicClear :: MVector s Double -> ST s () Source # basicSet :: MVector s Double -> Double -> ST s () Source # basicUnsafeCopy :: MVector s Double -> MVector s Double -> ST s () Source # basicUnsafeMove :: MVector s Double -> MVector s Double -> ST s () Source # basicUnsafeGrow :: MVector s Double -> Int -> ST s (MVector s Double) Source # | |
| Generic1 (URec Double :: k -> Type) | Since: base-4.9.0.0 |
| Foldable (UDouble :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UDouble m -> m # foldMap :: Monoid m => (a -> m) -> UDouble a -> m # foldMap' :: Monoid m => (a -> m) -> UDouble a -> m # foldr :: (a -> b -> b) -> b -> UDouble a -> b # foldr' :: (a -> b -> b) -> b -> UDouble a -> b # foldl :: (b -> a -> b) -> b -> UDouble a -> b # foldl' :: (b -> a -> b) -> b -> UDouble a -> b # foldr1 :: (a -> a -> a) -> UDouble a -> a # foldl1 :: (a -> a -> a) -> UDouble a -> a # elem :: Eq a => a -> UDouble a -> Bool # maximum :: Ord a => UDouble a -> a # minimum :: Ord a => UDouble a -> a # | |
| Traversable (UDouble :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Double :: Type -> Type) | 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 # | |
| Show (URec Double p) | Since: base-4.9.0.0 |
| Generic (URec Double p) | Since: base-4.9.0.0 |
| newtype Vector Double | |
| data URec Double (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
| newtype MVector s Double | |
| type Rep1 (URec Double :: k -> Type) | |
Defined in GHC.Generics | |
| type Rep (URec Double p) | |
Defined in GHC.Generics | |
Single-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE single-precision type.
Instances
| Eq Float | Note that due to the presence of
Also note that
|
| Floating Float | Since: base-2.1 |
| 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 # | |
| Ord Float | Note that due to the presence of
Also note that, due to the same,
|
| Read 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 # | |
| Hashable Float | Note: prior to The Since: hashable-1.3.0.0 |
| ToJSON Float | |
| ToJSONKey Float | |
Defined in Data.Aeson.Types.ToJSON Methods | |
| FromJSON Float | |
| FromJSONKey Float | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| Pretty Float |
|
| Storable Float | Since: base-2.1 |
| Binary Float | |
| NFData Float | |
Defined in Control.DeepSeq | |
| Pretty Float | |
Defined in Text.PrettyPrint.HughesPJClass Methods pPrintPrec :: PrettyLevel -> Rational -> Float -> Doc # pPrintList :: PrettyLevel -> [Float] -> Doc # | |
| Prim Float | |
Defined in Data.Primitive.Types Methods sizeOf# :: Float -> Int# Source # alignment# :: Float -> Int# Source # indexByteArray# :: ByteArray# -> Int# -> Float Source # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Float #) Source # writeByteArray# :: MutableByteArray# s -> Int# -> Float -> State# s -> State# s Source # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Float -> State# s -> State# s Source # indexOffAddr# :: Addr# -> Int# -> Float Source # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Float #) Source # writeOffAddr# :: Addr# -> Int# -> Float -> State# s -> State# s Source # setOffAddr# :: Addr# -> Int# -> Int# -> Float -> State# s -> State# s Source # | |
| UniformRange Float | |
Defined in System.Random.Internal | |
| Unbox Float | |
Defined in Data.Vector.Unboxed.Base | |
| Lift Float | |
| Vector Vector Float | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Float -> ST s (Vector Float) Source # basicUnsafeThaw :: Vector Float -> ST s (Mutable Vector s Float) Source # basicLength :: Vector Float -> Int Source # basicUnsafeSlice :: Int -> Int -> Vector Float -> Vector Float Source # basicUnsafeIndexM :: Vector Float -> Int -> Box Float Source # basicUnsafeCopy :: Mutable Vector s Float -> Vector Float -> ST s () Source # | |
| MVector MVector Float | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Float -> Int Source # basicUnsafeSlice :: Int -> Int -> MVector s Float -> MVector s Float Source # basicOverlaps :: MVector s Float -> MVector s Float -> Bool Source # basicUnsafeNew :: Int -> ST s (MVector s Float) Source # basicInitialize :: MVector s Float -> ST s () Source # basicUnsafeReplicate :: Int -> Float -> ST s (MVector s Float) Source # basicUnsafeRead :: MVector s Float -> Int -> ST s Float Source # basicUnsafeWrite :: MVector s Float -> Int -> Float -> ST s () Source # basicClear :: MVector s Float -> ST s () Source # basicSet :: MVector s Float -> Float -> ST s () Source # basicUnsafeCopy :: MVector s Float -> MVector s Float -> ST s () Source # basicUnsafeMove :: MVector s Float -> MVector s Float -> ST s () Source # basicUnsafeGrow :: MVector s Float -> Int -> ST s (MVector s Float) Source # | |
| Generic1 (URec Float :: k -> Type) | Since: base-4.9.0.0 |
| Foldable (UFloat :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # | |
| Traversable (UFloat :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Float :: Type -> Type) | Since: base-4.9.0.0 |
| Eq (URec Float p) | |
| Ord (URec Float p) | |
Defined in GHC.Generics | |
| Show (URec Float p) | |
| Generic (URec Float p) | |
| newtype Vector Float | |
| data URec Float (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
| newtype MVector s Float | |
| type Rep1 (URec Float :: k -> Type) | |
Defined in GHC.Generics | |
| type Rep (URec Float p) | |
Defined in GHC.Generics | |
A fixed-precision integer type with at least the range [-2^29 .. 2^29-1].
The exact range for a given implementation can be determined by using
minBound and maxBound from the Bounded class.
Instances
| Bounded Int | Since: base-2.1 |
| Enum Int | Since: base-2.1 |
| Eq Int | |
| Integral Int | Since: base-2.0.1 |
| Data Int | 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) -> Int -> c Int # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Int # dataTypeOf :: Int -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Int) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Int) # gmapT :: (forall b. Data b => b -> b) -> Int -> Int # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Int -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Int -> r # gmapQ :: (forall d. Data d => d -> u) -> Int -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Int -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Int -> m Int # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Int -> m Int # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Int -> m Int # | |
| Num Int | Since: base-2.1 |
| Ord Int | |
| Read Int | Since: base-2.1 |
| Real Int | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Int -> Rational # | |
| Show Int | Since: base-2.1 |
| Ix Int | Since: base-2.1 |
| Hashable Int | |
| ToJSON Int | |
| ToJSONKey Int | |
Defined in Data.Aeson.Types.ToJSON | |
| FromJSON Int | |
| FromJSONKey Int | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| Pretty Int |
|
| Storable Int | Since: base-2.1 |
Defined in Foreign.Storable | |
| Binary Int | |
| NFData Int | |
Defined in Control.DeepSeq | |
| Pretty Int | |
Defined in Text.PrettyPrint.HughesPJClass Methods pPrintPrec :: PrettyLevel -> Rational -> Int -> Doc # pPrintList :: PrettyLevel -> [Int] -> Doc # | |
| Prim Int | |
Defined in Data.Primitive.Types Methods sizeOf# :: Int -> Int# Source # alignment# :: Int -> Int# Source # indexByteArray# :: ByteArray# -> Int# -> Int Source # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Int #) Source # writeByteArray# :: MutableByteArray# s -> Int# -> Int -> State# s -> State# s Source # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Int -> State# s -> State# s Source # indexOffAddr# :: Addr# -> Int# -> Int Source # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Int #) Source # writeOffAddr# :: Addr# -> Int# -> Int -> State# s -> State# s Source # setOffAddr# :: Addr# -> Int# -> Int# -> Int -> State# s -> State# s Source # | |
| Uniform Int | |
Defined in System.Random.Internal Methods uniformM :: StatefulGen g m => g -> m Int Source # | |
| UniformRange Int | |
Defined in System.Random.Internal | |
| ByteSource Int | |
Defined in Data.UUID.Types.Internal.Builder | |
| Unbox Int | |
Defined in Data.Vector.Unboxed.Base | |
| Lift Int | |
| Vector Vector Int | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Int -> ST s (Vector Int) Source # basicUnsafeThaw :: Vector Int -> ST s (Mutable Vector s Int) Source # basicLength :: Vector Int -> Int Source # basicUnsafeSlice :: Int -> Int -> Vector Int -> Vector Int Source # basicUnsafeIndexM :: Vector Int -> Int -> Box Int Source # basicUnsafeCopy :: Mutable Vector s Int -> Vector Int -> ST s () Source # | |
| MVector MVector Int | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Int -> Int Source # basicUnsafeSlice :: Int -> Int -> MVector s Int -> MVector s Int Source # basicOverlaps :: MVector s Int -> MVector s Int -> Bool Source # basicUnsafeNew :: Int -> ST s (MVector s Int) Source # basicInitialize :: MVector s Int -> ST s () Source # basicUnsafeReplicate :: Int -> Int -> ST s (MVector s Int) Source # basicUnsafeRead :: MVector s Int -> Int -> ST s Int Source # basicUnsafeWrite :: MVector s Int -> Int -> Int -> ST s () Source # basicClear :: MVector s Int -> ST s () Source # basicSet :: MVector s Int -> Int -> ST s () Source # basicUnsafeCopy :: MVector s Int -> MVector s Int -> ST s () Source # basicUnsafeMove :: MVector s Int -> MVector s Int -> ST s () Source # basicUnsafeGrow :: MVector s Int -> Int -> ST s (MVector s Int) Source # | |
| Generic1 (URec Int :: k -> Type) | Since: base-4.9.0.0 |
| Foldable (UInt :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UInt m -> m # foldMap :: Monoid m => (a -> m) -> UInt a -> m # foldMap' :: Monoid m => (a -> m) -> UInt a -> m # foldr :: (a -> b -> b) -> b -> UInt a -> b # foldr' :: (a -> b -> b) -> b -> UInt a -> b # foldl :: (b -> a -> b) -> b -> UInt a -> b # foldl' :: (b -> a -> b) -> b -> UInt a -> b # foldr1 :: (a -> a -> a) -> UInt a -> a # foldl1 :: (a -> a -> a) -> UInt a -> a # elem :: Eq a => a -> UInt a -> Bool # maximum :: Ord a => UInt a -> a # | |
| Traversable (UInt :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Int :: Type -> Type) | Since: base-4.9.0.0 |
| Eq (URec Int p) | Since: base-4.9.0.0 |
| Ord (URec Int p) | Since: base-4.9.0.0 |
| Show (URec Int p) | Since: base-4.9.0.0 |
| Generic (URec Int p) | Since: base-4.9.0.0 |
| newtype Vector Int | |
| data URec Int (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
| type ByteSink Int g | |
Defined in Data.UUID.Types.Internal.Builder type ByteSink Int g = Takes4Bytes g | |
| newtype MVector s Int | |
| type Rep1 (URec Int :: k -> Type) | |
Defined in GHC.Generics | |
| type Rep (URec Int p) | |
Defined in GHC.Generics | |
Arbitrary precision integers. In contrast with fixed-size integral types
such as Int, the Integer type represents the entire infinite range of
integers.
For more information about this type's representation, see the comments in its implementation.
Instances
| Enum Integer | Since: base-2.1 |
| Eq Integer | |
| Integral Integer | Since: base-2.0.1 |
Defined in GHC.Real | |
| Data Integer | 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) -> Integer -> c Integer # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Integer # toConstr :: Integer -> Constr # dataTypeOf :: Integer -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Integer) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Integer) # gmapT :: (forall b. Data b => b -> b) -> Integer -> Integer # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Integer -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Integer -> r # gmapQ :: (forall d. Data d => d -> u) -> Integer -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Integer -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Integer -> m Integer # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Integer -> m Integer # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Integer -> m Integer # | |
| Num Integer | Since: base-2.1 |
| Ord Integer | |
| Read Integer | Since: base-2.1 |
| Real Integer | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Integer -> Rational # | |
| Show Integer | Since: base-2.1 |
| Ix Integer | Since: base-2.1 |
Defined in GHC.Ix | |
| Hashable Integer | |
| ToJSON Integer | |
| ToJSONKey Integer | |
Defined in Data.Aeson.Types.ToJSON Methods | |
| FromJSON Integer | This instance includes a bounds check to prevent maliciously
large inputs to fill up the memory of the target system. You can
newtype |
| FromJSONKey Integer | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| Pretty Integer |
|
| Binary Integer | |
| NFData Integer | |
Defined in Control.DeepSeq | |
| Pretty Integer | |
Defined in Text.PrettyPrint.HughesPJClass Methods pPrintPrec :: PrettyLevel -> Rational -> Integer -> Doc # pPrintList :: PrettyLevel -> [Integer] -> Doc # | |
| UniformRange Integer | |
Defined in System.Random.Internal | |
| Lift Integer | |
The Maybe type encapsulates an optional value. A value of type
Maybe aa (represented as Just aNothing). Using Maybe is a good way to
deal with errors or exceptional cases without resorting to drastic
measures such as error.
The Maybe type is also a monad. It is a simple kind of error
monad, where all errors are represented by Nothing. A richer
error monad can be built using the Either type.
Instances
| Monad Maybe | Since: base-2.1 |
| Functor Maybe | Since: base-2.1 |
| MonadFix Maybe | Since: base-2.1 |
Defined in Control.Monad.Fix | |
| MonadFail Maybe | Since: base-4.9.0.0 |
Defined in Control.Monad.Fail | |
| Applicative Maybe | Since: base-2.1 |
| 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 |
| ToJSON1 Maybe | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Maybe a -> Value Source # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Maybe a] -> Value Source # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Maybe a -> Encoding Source # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Maybe a] -> Encoding Source # | |
| FromJSON1 Maybe | |
| Eq1 Maybe | Since: base-4.9.0.0 |
| Ord1 Maybe | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read1 Maybe | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Show1 Maybe | Since: base-4.9.0.0 |
| Alternative Maybe | Since: base-2.1 |
| MonadPlus Maybe | Since: base-2.1 |
| NFData1 Maybe | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable1 Maybe | |
Defined in Data.Hashable.Class | |
| MonadError () Maybe | Since: mtl-2.2.2 |
Defined in Control.Monad.Error.Class | |
| (Selector s, GToJSON' enc arity (K1 i (Maybe a) :: Type -> Type), KeyValuePair enc pairs, Monoid pairs) => RecordToPairs enc pairs arity (S1 s (K1 i (Maybe a) :: Type -> Type)) | |
Defined in Data.Aeson.Types.ToJSON | |
| Lift a => Lift (Maybe a :: Type) | |
| (Selector s, FromJSON a) => RecordFromJSON' arity (S1 s (K1 i (Maybe a) :: Type -> Type)) | |
Defined in Data.Aeson.Types.FromJSON | |
| Eq a => Eq (Maybe a) | Since: base-2.1 |
| 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) # | |
| Ord a => Ord (Maybe a) | Since: base-2.1 |
| Read a => Read (Maybe a) | Since: base-2.1 |
| Show a => Show (Maybe a) | Since: base-2.1 |
| Generic (Maybe a) | Since: base-4.6.0.0 |
| Semigroup a => Semigroup (Maybe 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 |
| Hashable a => Hashable (Maybe a) | |
| ToJSON a => ToJSON (Maybe a) | |
| FromJSON a => FromJSON (Maybe a) | |
| Pretty a => Pretty (Maybe a) | Ignore
|
| Binary a => Binary (Maybe a) | |
| NFData a => NFData (Maybe a) | |
Defined in Control.DeepSeq | |
| Pretty a => Pretty (Maybe a) | |
Defined in Text.PrettyPrint.HughesPJClass Methods pPrintPrec :: PrettyLevel -> Rational -> Maybe a -> Doc # pPrintList :: PrettyLevel -> [Maybe a] -> Doc # | |
| SingKind a => SingKind (Maybe a) | Since: base-4.9.0.0 |
Defined in GHC.Generics Associated Types type DemoteRep (Maybe a) | |
| Generic1 Maybe | Since: base-4.6.0.0 |
| 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 | |
| type Rep (Maybe a) | |
Defined in GHC.Generics | |
| type DemoteRep (Maybe a) | |
Defined in GHC.Generics | |
| data Sing (b :: Maybe a) | |
| type Rep1 Maybe | |
Instances
| Bounded Ordering | Since: base-2.1 |
| Enum Ordering | Since: base-2.1 |
| Eq Ordering | |
| 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 # | |
| Ord Ordering | |
Defined in GHC.Classes | |
| Read Ordering | Since: base-2.1 |
| Show Ordering | Since: base-2.1 |
| 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 # | |
| Generic Ordering | Since: base-4.6.0.0 |
| Semigroup Ordering | Since: base-4.9.0.0 |
| Monoid Ordering | Since: base-2.1 |
| Hashable Ordering | |
| ToJSON Ordering | |
| FromJSON Ordering | |
| Binary Ordering | |
| NFData Ordering | |
Defined in Control.DeepSeq | |
| Pretty Ordering | |
Defined in Text.PrettyPrint.HughesPJClass Methods pPrintPrec :: PrettyLevel -> Rational -> Ordering -> Doc # pPrintList :: PrettyLevel -> [Ordering] -> Doc # | |
| type Rep Ordering | |
A value of type IO aa.
There is really only one way to "perform" an I/O action: bind it to
Main.main in your program. When your program is run, the I/O will
be performed. It isn't possible to perform I/O from an arbitrary
function, unless that function is itself in the IO monad and called
at some point, directly or indirectly, from Main.main.
IO is a monad, so IO actions can be combined using either the do-notation
or the >> and >>= operations from the Monad
class.
Instances
Instances
The Either type represents values with two possibilities: a value of
type Either a bLeft aRight b
The Either type is sometimes used to represent a value which is
either correct or an error; by convention, the Left constructor is
used to hold an error value and the Right constructor is used to
hold a correct value (mnemonic: "right" also means "correct").
Examples
The type Either String IntString or an Int. The Left constructor can be used only on
Strings, and the Right constructor can be used only on Ints:
>>>let s = Left "foo" :: Either String Int>>>sLeft "foo">>>let n = Right 3 :: Either String Int>>>nRight 3>>>:type ss :: Either String Int>>>:type nn :: Either String Int
The fmap from our Functor instance will ignore Left values, but
will apply the supplied function to values contained in a Right:
>>>let s = Left "foo" :: Either String Int>>>let n = Right 3 :: Either String Int>>>fmap (*2) sLeft "foo">>>fmap (*2) nRight 6
The Monad instance for Either allows us to chain together multiple
actions which may fail, and fail overall if any of the individual
steps failed. First we'll write a function that can either parse an
Int from a Char, or fail.
>>>import Data.Char ( digitToInt, isDigit )>>>:{let parseEither :: Char -> Either String Int parseEither c | isDigit c = Right (digitToInt c) | otherwise = Left "parse error">>>:}
The following should work, since both '1' and '2' can be
parsed as Ints.
>>>:{let parseMultiple :: Either String Int parseMultiple = do x <- parseEither '1' y <- parseEither '2' return (x + y)>>>:}
>>>parseMultipleRight 3
But the following should fail overall, since the first operation where
we attempt to parse 'm' as an Int will fail:
>>>:{let parseMultiple :: Either String Int parseMultiple = do x <- parseEither 'm' y <- parseEither '2' return (x + y)>>>:}
>>>parseMultipleLeft "parse error"
Instances
| ToJSON2 Either | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> Either a b -> Value Source # liftToJSONList2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> [Either a b] -> Value Source # liftToEncoding2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> Either a b -> Encoding Source # liftToEncodingList2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> [Either a b] -> Encoding Source # | |
| FromJSON2 Either | |
Defined in Data.Aeson.Types.FromJSON Methods liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (Either a b) Source # liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [Either a b] Source # | |
| Eq2 Either | Since: base-4.9.0.0 |
| Ord2 Either | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read2 Either | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Either a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Either a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Either a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Either a b] # | |
| Show2 Either | Since: base-4.9.0.0 |
| NFData2 Either | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable2 Either | |
| MonadError e (Either e) | |
Defined in Control.Monad.Error.Class | |
| (Lift a, Lift b) => Lift (Either a b :: Type) | |
| Monad (Either e) | Since: base-4.4.0.0 |
| Functor (Either a) | Since: base-3.0 |
| MonadFix (Either e) | Since: base-4.3.0.0 |
Defined in Control.Monad.Fix | |
| Applicative (Either e) | Since: base-3.0 |
| 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 | |
| ToJSON a => ToJSON1 (Either a) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a0 -> Value) -> ([a0] -> Value) -> Either a a0 -> Value Source # liftToJSONList :: (a0 -> Value) -> ([a0] -> Value) -> [Either a a0] -> Value Source # liftToEncoding :: (a0 -> Encoding) -> ([a0] -> Encoding) -> Either a a0 -> Encoding Source # liftToEncodingList :: (a0 -> Encoding) -> ([a0] -> Encoding) -> [Either a a0] -> Encoding Source # | |
| FromJSON a => FromJSON1 (Either a) | |
| Eq a => Eq1 (Either a) | Since: base-4.9.0.0 |
| Ord a => Ord1 (Either a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read a => Read1 (Either a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Either a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Either a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Either a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Either a a0] # | |
| Show a => Show1 (Either a) | Since: base-4.9.0.0 |
| NFData a => NFData1 (Either a) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable a => Hashable1 (Either a) | |
Defined in Data.Hashable.Class | |
| Generic1 (Either a :: Type -> Type) | Since: base-4.6.0.0 |
| (Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 |
| (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) # | |
| (Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 |
| (Read a, Read b) => Read (Either a b) | Since: base-3.0 |
| (Show a, Show b) => Show (Either a b) | Since: base-3.0 |
| Generic (Either a b) | Since: base-4.6.0.0 |
| Semigroup (Either a b) | Since: base-4.9.0.0 |
| (Hashable a, Hashable b) => Hashable (Either a b) | |
| (ToJSON a, ToJSON b) => ToJSON (Either a b) | |
| (FromJSON a, FromJSON b) => FromJSON (Either a b) | |
| (Binary a, Binary b) => Binary (Either a b) | |
| (NFData a, NFData b) => NFData (Either a b) | |
Defined in Control.DeepSeq | |
| (Pretty a, Pretty b) => Pretty (Either a b) | |
Defined in Text.PrettyPrint.HughesPJClass Methods pPrintPrec :: PrettyLevel -> Rational -> Either a b -> Doc # pPrintList :: PrettyLevel -> [Either a b] -> Doc # | |
| type Rep1 (Either a :: Type -> Type) | |
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 Rep (Either a b) | |
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))) | |
(<$>) :: Functor f => (a -> b) -> f a -> f b infixl 4 #
An infix synonym for fmap.
The name of this operator is an allusion to $.
Note the similarities between their types:
($) :: (a -> b) -> a -> b (<$>) :: Functor f => (a -> b) -> f a -> f b
Whereas $ is function application, <$> is function
application lifted over a Functor.
Examples
Convert from a Maybe IntMaybe
Stringshow:
>>>show <$> NothingNothing>>>show <$> Just 3Just "3"
Convert from an Either Int IntEither IntString using show:
>>>show <$> Left 17Left 17>>>show <$> Right 17Right "17"
Double each element of a list:
>>>(*2) <$> [1,2,3][2,4,6]
Apply even to the second element of a pair:
>>>even <$> (2,2)(2,True)
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]
appendFile :: FilePath -> String -> IO () #
The computation appendFile file str function appends the string str,
to the file file.
Note that writeFile and appendFile write a literal string
to a file. To write a value of any printable type, as with print,
use the show function to convert the value to a string first.
main = appendFile "squares" (show [(x,x*x) | x <- [0,0.1..2]])
writeFile :: FilePath -> String -> IO () #
The computation writeFile file str function writes the string str,
to the file file.
readFile :: FilePath -> IO String #
The readFile function reads a file and
returns the contents of the file as a string.
The file is read lazily, on demand, as with getContents.
interact :: (String -> String) -> IO () #
The interact function takes a function of type String->String
as its argument. The entire input from the standard input device is
passed to this function as its argument, and the resulting string is
output on the standard output device.
getContents :: IO String #
The getContents operation returns all user input as a single string,
which is read lazily as it is needed
(same as hGetContents stdin).
File and directory names are values of type String, whose precise
meaning is operating system dependent. Files can be opened, yielding a
handle which can then be used to operate on the contents of that file.
type IOError = IOException #
all :: Foldable t => (a -> Bool) -> t a -> Bool #
Determines whether all elements of the structure satisfy the predicate.
any :: Foldable t => (a -> Bool) -> t a -> Bool #
Determines whether any element of the structure satisfies the predicate.
concatMap :: Foldable t => (a -> [b]) -> t a -> [b] #
Map a function over all the elements of a container and concatenate the resulting lists.
concat :: Foldable t => t [a] -> [a] #
The concatenation of all the elements of a container of lists.
sequence_ :: (Foldable t, Monad m) => t (m a) -> m () #
Evaluate each monadic action in the structure from left to right,
and ignore the results. For a version that doesn't ignore the
results see sequence.
As of base 4.8.0.0, sequence_ is just sequenceA_, specialized
to Monad.
words breaks a string up into a list of words, which were delimited
by white space.
>>>words "Lorem ipsum\ndolor"["Lorem","ipsum","dolor"]
lines breaks a string up into a list of strings at newline
characters. The resulting strings do not contain newlines.
Note that after splitting the string at newline characters, the last part of the string is considered a line even if it doesn't end with a newline. For example,
>>>lines ""[]
>>>lines "\n"[""]
>>>lines "one"["one"]
>>>lines "one\n"["one"]
>>>lines "one\n\n"["one",""]
>>>lines "one\ntwo"["one","two"]
>>>lines "one\ntwo\n"["one","two"]
Thus lines ss.
read :: Read a => String -> a #
The read function reads input from a string, which must be
completely consumed by the input process. read fails with an error if the
parse is unsuccessful, and it is therefore discouraged from being used in
real applications. Use readMaybe or readEither for safe alternatives.
>>>read "123" :: Int123
>>>read "hello" :: Int*** Exception: Prelude.read: no parse
either :: (a -> c) -> (b -> c) -> Either a b -> c #
Case analysis for the Either type.
If the value is Left aa;
if it is Right bb.
Examples
We create two values of type Either String IntLeft constructor and another using the Right constructor. Then
we apply "either" the length function (if we have a String)
or the "times-two" function (if we have an Int):
>>>let s = Left "foo" :: Either String Int>>>let n = Right 3 :: Either String Int>>>either length (*2) s3>>>either length (*2) n6
The lex function reads a single lexeme from the input, discarding
initial white space, and returning the characters that constitute the
lexeme. If the input string contains only white space, lex returns a
single successful `lexeme' consisting of the empty string. (Thus
lex "" = [("","")]lex fails (i.e. returns []).
This lexer is not completely faithful to the Haskell lexical syntax in the following respects:
- Qualified names are not handled properly
- Octal and hexadecimal numerics are not recognized as a single token
- Comments are not treated properly
lcm :: Integral a => a -> a -> a #
lcm x yx and y divide.
gcd :: Integral a => a -> a -> a #
gcd x yx and y of which
every common factor of x and y is also a factor; for example
gcd 4 2 = 2gcd (-4) 6 = 2gcd 0 44. gcd 0 00.
(That is, the common divisor that is "greatest" in the divisibility
preordering.)
Note: Since for signed fixed-width integer types, abs minBound < 0minBound0 or minBound
(^^) :: (Fractional a, Integral b) => a -> b -> a infixr 8 #
raise a number to an integral power
showString :: String -> ShowS #
utility function converting a String to a show function that
simply prepends the string unchanged.
utility function converting a Char to a show function that
simply prepends the character unchanged.
unzip :: [(a, b)] -> ([a], [b]) #
unzip transforms a list of pairs into a list of first components
and a list of second components.
zipWith :: (a -> b -> c) -> [a] -> [b] -> [c] #
\(\mathcal{O}(\min(m,n))\). zipWith generalises zip by zipping with the
function given as the first argument, instead of a tupling function. For
example, zipWith (+)
>>>zipWith (+) [1, 2, 3] [4, 5, 6][5,7,9]
zipWith is right-lazy:
zipWith f [] _|_ = []
zipWith is capable of list fusion, but it is restricted to its
first list argument and its resulting list.
(!!) :: [a] -> Int -> a infixl 9 #
List index (subscript) operator, starting from 0.
It is an instance of the more general genericIndex,
which takes an index of any integral type.
lookup :: Eq a => a -> [(a, b)] -> Maybe b #
\(\mathcal{O}(n)\). lookup key assocs looks up a key in an association
list.
>>>lookup 2 [(1, "first"), (2, "second"), (3, "third")]Just "second"
break :: (a -> Bool) -> [a] -> ([a], [a]) #
break, applied to a predicate p and a list xs, returns a tuple where
first element is longest prefix (possibly empty) of xs of elements that
do not satisfy p and second element is the remainder of the list:
break (> 3) [1,2,3,4,1,2,3,4] == ([1,2,3],[4,1,2,3,4]) break (< 9) [1,2,3] == ([],[1,2,3]) break (> 9) [1,2,3] == ([1,2,3],[])
span :: (a -> Bool) -> [a] -> ([a], [a]) #
span, applied to a predicate p and a list xs, returns a tuple where
first element is longest prefix (possibly empty) of xs of elements that
satisfy p and second element is the remainder of the list:
span (< 3) [1,2,3,4,1,2,3,4] == ([1,2],[3,4,1,2,3,4]) span (< 9) [1,2,3] == ([1,2,3],[]) span (< 0) [1,2,3] == ([],[1,2,3])
splitAt :: Int -> [a] -> ([a], [a]) #
splitAt n xs returns a tuple where first element is xs prefix of
length n and second element is the remainder of the list:
splitAt 6 "Hello World!" == ("Hello ","World!")
splitAt 3 [1,2,3,4,5] == ([1,2,3],[4,5])
splitAt 1 [1,2,3] == ([1],[2,3])
splitAt 3 [1,2,3] == ([1,2,3],[])
splitAt 4 [1,2,3] == ([1,2,3],[])
splitAt 0 [1,2,3] == ([],[1,2,3])
splitAt (-1) [1,2,3] == ([],[1,2,3])It is equivalent to ( when take n xs, drop n xs)n is not _|_
(splitAt _|_ xs = _|_).
splitAt is an instance of the more general genericSplitAt,
in which n may be of any integral type.
drop n xs returns the suffix of xs
after the first n elements, or [] if n > :length xs
drop 6 "Hello World!" == "World!" drop 3 [1,2,3,4,5] == [4,5] drop 3 [1,2] == [] drop 3 [] == [] drop (-1) [1,2] == [1,2] drop 0 [1,2] == [1,2]
It is an instance of the more general genericDrop,
in which n may be of any integral type.
take n, applied to a list xs, returns the prefix of xs
of length n, or xs itself if n > :length xs
take 5 "Hello World!" == "Hello" take 3 [1,2,3,4,5] == [1,2,3] take 3 [1,2] == [1,2] take 3 [] == [] take (-1) [1,2] == [] take 0 [1,2] == []
It is an instance of the more general genericTake,
in which n may be of any integral type.
takeWhile :: (a -> Bool) -> [a] -> [a] #
takeWhile, applied to a predicate p and a list xs, returns the
longest prefix (possibly empty) of xs of elements that satisfy p:
takeWhile (< 3) [1,2,3,4,1,2,3,4] == [1,2] takeWhile (< 9) [1,2,3] == [1,2,3] takeWhile (< 0) [1,2,3] == []
cycle ties a finite list into a circular one, or equivalently,
the infinite repetition of the original list. It is the identity
on infinite lists.
replicate :: Int -> a -> [a] #
replicate n x is a list of length n with x the value of
every element.
It is an instance of the more general genericReplicate,
in which n may be of any integral type.
\(\mathcal{O}(n)\). Return all the elements of a list except the last one. The list must be non-empty.
\(\mathcal{O}(n)\). Extract the last element of a list, which must be finite and non-empty.
\(\mathcal{O}(1)\). Extract the elements after the head of a list, which must be non-empty.
maybe :: b -> (a -> b) -> Maybe a -> b #
The maybe function takes a default value, a function, and a Maybe
value. If the Maybe value is Nothing, the function returns the
default value. Otherwise, it applies the function to the value inside
the Just and returns the result.
Examples
Basic usage:
>>>maybe False odd (Just 3)True
>>>maybe False odd NothingFalse
Read an integer from a string using readMaybe. If we succeed,
return twice the integer; that is, apply (*2) to it. If instead
we fail to parse an integer, return 0 by default:
>>>import Text.Read ( readMaybe )>>>maybe 0 (*2) (readMaybe "5")10>>>maybe 0 (*2) (readMaybe "")0
Apply show to a Maybe Int. If we have Just n, we want to show
the underlying Int n. But if we have Nothing, we return the
empty string instead of (for example) "Nothing":
>>>maybe "" show (Just 5)"5">>>maybe "" show Nothing""
uncurry :: (a -> b -> c) -> (a, b) -> c #
uncurry converts a curried function to a function on pairs.
Examples
>>>uncurry (+) (1,2)3
>>>uncurry ($) (show, 1)"1"
>>>map (uncurry max) [(1,2), (3,4), (6,8)][2,4,8]
until :: (a -> Bool) -> (a -> a) -> a -> a #
until p ff until p holds.
($!) :: 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.
flip :: (a -> b -> c) -> b -> a -> c #
flip ff.
>>>flip (++) "hello" "world""worldhello"
(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1 #
Same as >>=, but with the arguments interchanged.
undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a #
errorWithoutStackTrace :: forall (r :: RuntimeRep) (a :: TYPE r). [Char] -> a #
A variant of error that does not produce a stack trace.
Since: base-4.9.0.0
error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => [Char] -> a #
error stops execution and displays an error message.
guard :: Alternative f => Bool -> f () #
Conditional failure of Alternative computations. Defined by
guard True =pure() guard False =empty
Examples
Common uses of guard include conditionally signaling an error in
an error monad and conditionally rejecting the current choice in an
Alternative-based parser.
As an example of signaling an error in the error monad Maybe,
consider a safe division function safeDiv x y that returns
Nothing when the denominator y is zero and Just (x `div`
y)
>>> safeDiv 4 0 Nothing >>> safeDiv 4 2 Just 2
A definition of safeDiv using guards, but not guard:
safeDiv :: Int -> Int -> Maybe Int
safeDiv x y | y /= 0 = Just (x `div` y)
| otherwise = Nothing
A definition of safeDiv using guard and Monad do-notation:
safeDiv :: Int -> Int -> Maybe Int safeDiv x y = do guard (y /= 0) return (x `div` y)
join :: Monad m => m (m a) -> m a #
The join function is the conventional monad join operator. It
is used to remove one level of monadic structure, projecting its
bound argument into the outer level.
'join bssdo expression
do bs <- bss bs
Examples
A common use of join is to run an IO computation returned from
an STM transaction, since STM transactions
can't perform IO directly. Recall that
atomically :: STM a -> IO a
is used to run STM transactions atomically. So, by
specializing the types of atomically and join to
atomically:: STM (IO b) -> IO (IO b)join:: IO (IO b) -> IO b
we can compose them as
join.atomically:: STM (IO b) -> IO b
class Applicative m => Monad (m :: Type -> Type) where #
The Monad class defines the basic operations over a monad,
a concept from a branch of mathematics known as category theory.
From the perspective of a Haskell programmer, however, it is best to
think of a monad as an abstract datatype of actions.
Haskell's do expressions provide a convenient syntax for writing
monadic expressions.
Instances of Monad should satisfy the following:
- Left identity
returna>>=k = k a- Right identity
m>>=return= m- Associativity
m>>=(\x -> k x>>=h) = (m>>=k)>>=h
Furthermore, the Monad and Applicative operations should relate as follows:
The above laws imply:
and that pure and (<*>) satisfy the applicative functor laws.
The instances of Monad for lists, Maybe and IO
defined in the Prelude satisfy these laws.
Minimal complete definition
Methods
(>>=) :: m a -> (a -> m b) -> m b infixl 1 #
Sequentially compose two actions, passing any value produced by the first as an argument to the second.
'as ' can be understood as the >>= bsdo expression
do a <- as bs a
(>>) :: m a -> m b -> m b infixl 1 #
Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.
'as ' can be understood as the >> bsdo expression
do as bs
Inject a value into the monadic type.
Instances
| Monad [] | Since: base-2.1 |
| Monad Maybe | Since: base-2.1 |
| Monad IO | Since: base-2.1 |
| Monad Par1 | Since: base-4.9.0.0 |
| Monad Q | |
| Monad Solo | |
| Monad IResult | |
| Monad Result | |
| Monad Parser | |
| Monad Complex | Since: base-4.9.0.0 |
| Monad Min | Since: base-4.9.0.0 |
| Monad Max | Since: base-4.9.0.0 |
| Monad First | Since: base-4.9.0.0 |
| Monad Last | Since: base-4.9.0.0 |
| Monad Option | Since: base-4.9.0.0 |
| Monad Identity | Since: base-4.8.0.0 |
| Monad First | Since: base-4.8.0.0 |
| Monad Last | Since: base-4.8.0.0 |
| Monad Dual | Since: base-4.8.0.0 |
| Monad Sum | Since: base-4.8.0.0 |
| Monad Product | Since: base-4.8.0.0 |
| Monad ReadPrec | Since: base-2.1 |
| Monad ReadP | Since: base-2.1 |
| Monad NonEmpty | Since: base-4.9.0.0 |
| Monad PutM | |
| Monad Get | |
| Monad Tree | |
| Monad Seq | |
| Monad DNonEmpty | |
| Monad DList | |
| Monad Managed | |
| Monad ReadM | |
| Monad ParserM | |
| Monad ParserResult | |
Defined in Options.Applicative.Types Methods (>>=) :: ParserResult a -> (a -> ParserResult b) -> ParserResult b # (>>) :: ParserResult a -> ParserResult b -> ParserResult b # return :: a -> ParserResult a # | |
| Monad SmallArray | |
Defined in Data.Primitive.SmallArray Methods (>>=) :: SmallArray a -> (a -> SmallArray b) -> SmallArray b # (>>) :: SmallArray a -> SmallArray b -> SmallArray b # return :: a -> SmallArray a # | |
| Monad Array | |
| Monad Shell | |
| Monad Pattern | |
| Monad Vector | |
| Monad P | Since: base-2.1 |
| Monad (Either e) | Since: base-4.4.0.0 |
| Monad (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monoid a => Monad ((,) a) | Since: base-4.9.0.0 |
| 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 # | |
| Semigroup a => Monad (These a) | |
| Semigroup a => Monad (These a) | |
| Monad (Parser i) | |
| Monad f => Monad (Rec1 f) | Since: base-4.9.0.0 |
| (Monoid a, Monoid b) => Monad ((,,) a b) | Since: base-4.14.0.0 |
| 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 |
| (Applicative f, Monad f) => Monad (WhenMissing f x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMissing f x a -> (a -> WhenMissing f x b) -> WhenMissing f x b # (>>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # return :: a -> WhenMissing f x a # | |
| Monad m => Monad (ExceptT e m) | |
| (Monad m, Error e) => Monad (ErrorT e m) | |
| Monad (Tagged s) | |
| Monad ((->) r :: Type -> Type) | Since: base-2.1 |
| (Monad f, Monad g) => Monad (f :*: g) | Since: base-4.9.0.0 |
| (Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c) | Since: base-4.14.0.0 |
| (Monad f, Monad g) => Monad (Product f g) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Monad (WhenMatched f x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMatched f x y a -> (a -> WhenMatched f x y b) -> WhenMatched f x y b # (>>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # return :: a -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Monad (WhenMissing f k x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMissing f k x a -> (a -> WhenMissing f k x b) -> WhenMissing f k x b # (>>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # return :: a -> WhenMissing f k x a # | |
| Monad (ParsecT s u m) | |
| Monad f => Monad (M1 i c f) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Monad (WhenMatched f k x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMatched f k x y a -> (a -> WhenMatched f k x y b) -> WhenMatched f k x y b # (>>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # return :: a -> WhenMatched f k x y a # | |
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 #
Using ApplicativeDo: 'fmap f asdo expression
do a <- as pure (f a)
with an inferred Functor constraint.
Instances
| Functor [] | Since: base-2.1 |
| Functor Maybe | Since: base-2.1 |
| Functor IO | Since: base-2.1 |
| Functor Par1 | Since: base-4.9.0.0 |
| Functor Q | |
| Functor Solo | |
| Functor FromJSONKeyFunction | Only law abiding up to interpretation |
Defined in Data.Aeson.Types.FromJSON Methods fmap :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b # (<$) :: a -> FromJSONKeyFunction b -> FromJSONKeyFunction a # | |
| Functor IResult | |
| Functor Result | |
| Functor Parser | |
| Functor KeyMap | |
| Functor Complex | Since: base-4.9.0.0 |
| Functor Min | Since: base-4.9.0.0 |
| Functor Max | Since: base-4.9.0.0 |
| Functor First | Since: base-4.9.0.0 |
| Functor Last | Since: base-4.9.0.0 |
| Functor Option | Since: base-4.9.0.0 |
| Functor ZipList | Since: base-2.1 |
| Functor Identity | Since: base-4.8.0.0 |
| Functor First | Since: base-4.8.0.0 |
| Functor Last | Since: base-4.8.0.0 |
| Functor Dual | Since: base-4.8.0.0 |
| Functor Sum | Since: base-4.8.0.0 |
| Functor Product | Since: base-4.8.0.0 |
| Functor ReadPrec | Since: base-2.1 |
| Functor ReadP | Since: base-2.1 |
| Functor NonEmpty | Since: base-4.9.0.0 |
| Functor PutM | |
| Functor Decoder | |
| Functor Get | |
| Functor IntMap | |
| Functor Tree | |
| Functor Seq | |
| Functor FingerTree | |
Defined in Data.Sequence.Internal Methods fmap :: (a -> b) -> FingerTree a -> FingerTree b # (<$) :: a -> FingerTree b -> FingerTree a # | |
| Functor Digit | |
| Functor Node | |
| Functor Elem | |
| Functor ViewL | |
| Functor ViewR | |
| Functor DNonEmpty | |
| Functor DList | |
| Functor Managed | |
| Functor ParserInfo | |
Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserInfo a -> ParserInfo b # (<$) :: a -> ParserInfo b -> ParserInfo a # | |
| Functor Option | |
| Functor ReadM | |
| Functor CReader | |
| Functor OptReader | |
| Functor Parser | |
| Functor ParserM | |
| Functor ParserFailure | |
Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserFailure a -> ParserFailure b # (<$) :: a -> ParserFailure b -> ParserFailure a # | |
| Functor ParserResult | |
Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserResult a -> ParserResult b # (<$) :: a -> ParserResult b -> ParserResult a # | |
| Functor SimpleDocStream | Alter the document’s annotations. This instance makes |
Defined in Prettyprinter.Internal Methods fmap :: (a -> b) -> SimpleDocStream a -> SimpleDocStream b # (<$) :: a -> SimpleDocStream b -> SimpleDocStream a # | |
| Functor Consumed | |
| Functor Doc | |
| Functor AnnotDetails | |
Defined in Text.PrettyPrint.Annotated.HughesPJ Methods fmap :: (a -> b) -> AnnotDetails a -> AnnotDetails b # (<$) :: a -> AnnotDetails b -> AnnotDetails a # | |
| Functor Span | |
| Functor Doc | Alter the document’s annotations. This instance makes |
| Functor SmallArray | |
Defined in Data.Primitive.SmallArray Methods fmap :: (a -> b) -> SmallArray a -> SmallArray b # (<$) :: a -> SmallArray b -> SmallArray a # | |
| Functor Array | |
| Functor Maybe | |
| Functor Shell | |
| Functor Pattern | |
| Functor Vector | |
| Functor P | Since: base-4.8.0.0 |
Defined in Text.ParserCombinators.ReadP | |
| Functor FlattenResult | |
Defined in Prettyprinter.Internal | |
| Functor (Either a) | Since: base-3.0 |
| Functor (V1 :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Functor ((,) a) | Since: base-2.1 |
| Functor (Tagged2 s) | |
Defined in Data.Aeson.Types.Generic | |
| Functor (Map k) | |
| Functor (HashMap k) | |
| Functor (Array i) | Since: base-2.1 |
| Functor (Arg a) | Since: base-4.9.0.0 |
| 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 (Fold a) | |
| Functor (These a) | |
| Functor (Pair e) | |
| Functor (These a) | |
| Functor (Either a) | |
| Functor (IResult i) | |
Defined in Data.Attoparsec.Internal.Types | |
| Functor (Parser i) | |
Defined in Data.Attoparsec.Internal.Types | |
| Functor f => Functor (Rec1 f) | Since: base-4.9.0.0 |
| Functor (URec Char :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Double :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Float :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Int :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec Word :: Type -> Type) | Since: base-4.9.0.0 |
| Functor (URec (Ptr ()) :: Type -> Type) | Since: base-4.9.0.0 |
| Functor ((,,) a b) | Since: base-4.14.0.0 |
| 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 # (<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
| Functor m => Functor (Kleisli m a) | Since: base-4.14.0.0 |
| Functor (Const m :: Type -> Type) | Since: base-2.1 |
| Functor f => Functor (Ap f) | Since: base-4.12.0.0 |
| Functor f => Functor (Alt f) | Since: base-4.8.0.0 |
| Bifunctor p => Functor (Join p) | |
| (Applicative f, Monad f) => Functor (WhenMissing f x) | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods fmap :: (a -> b) -> WhenMissing f x a -> WhenMissing f x b # (<$) :: a -> WhenMissing f x b -> WhenMissing f x a # | |
| Functor m => Functor (ExceptT e m) | |
| Functor m => Functor (FoldM m a) | |
| Functor m => Functor (ErrorT e m) | |
| Functor (Reply s u) | |
| Functor (Tagged s) | |
| (Functor f, Functor g) => Functor (These1 f g) | |
| Functor ((->) r :: Type -> Type) | Since: base-2.1 |
| Functor (K1 i c :: Type -> Type) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :+: g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :*: g) | Since: base-4.9.0.0 |
| Functor ((,,,) a b c) | Since: base-4.14.0.0 |
| (Functor f, Functor g) => Functor (Product f g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (Sum f g) | Since: base-4.9.0.0 |
| Functor f => Functor (WhenMatched f x y) | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods fmap :: (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b # (<$) :: a -> WhenMatched f x y b -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Functor (WhenMissing f k x) | Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods fmap :: (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # (<$) :: a -> WhenMissing f k x b -> WhenMissing f k x a # | |
| Functor (ParsecT s u m) | |
| Functor f => Functor (M1 i c f) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (f :.: g) | Since: base-4.9.0.0 |
| (Functor f, Functor g) => Functor (Compose f g) | Since: base-4.9.0.0 |
| Bifunctor p => Functor (WrappedBifunctor p a) | |
Defined in Data.Bifunctor.Wrapped Methods fmap :: (a0 -> b) -> WrappedBifunctor p a a0 -> WrappedBifunctor p a b # (<$) :: a0 -> WrappedBifunctor p a b -> WrappedBifunctor p a a0 # | |
| Functor g => Functor (Joker g a) | |
| Bifunctor p => Functor (Flip p a) | |
| Functor (Clown f a :: Type -> Type) | |
| Functor f => Functor (WhenMatched f k x y) | Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods fmap :: (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # (<$) :: a -> WhenMatched f k x y b -> WhenMatched f k x y a # | |
| (Functor (f a), Functor (g a)) => Functor (Sum f g a) | |
| (Functor (f a), Functor (g a)) => Functor (Product f g a) | |
| (Functor f, Bifunctor p) => Functor (Tannen f p a) | |
| (Bifunctor p, Functor g) => Functor (Biff p f g a) | |
class Monad m => MonadFail (m :: Type -> Type) #
When a value is bound in do-notation, the pattern on the left
hand side of <- might not match. In this case, this class
provides a function to recover.
A Monad without a MonadFail instance may only be used in conjunction
with pattern that always match, such as newtypes, tuples, data types with
only a single data constructor, and irrefutable patterns (~pat).
Instances of MonadFail should satisfy the following law: fail s should
be a left zero for >>=,
fail s >>= f = fail s
If your Monad is also MonadPlus, a popular definition is
fail _ = mzero
Since: base-4.9.0.0
Minimal complete definition
Instances
mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b) #
Map each element of a structure to a monadic action, evaluate
these actions from left to right, and collect the results. For
a version that ignores the results see mapM_.
sequence :: (Traversable t, Monad m) => t (m a) -> m (t a) #
Evaluate each monadic action in the structure from left to
right, and collect the results. For a version that ignores the
results see sequence_.
unless :: Applicative f => Bool -> f () -> f () #
The reverse of when.
replicateM_ :: Applicative m => Int -> m a -> m () #
Like replicateM, but discards the result.
replicateM :: Applicative m => Int -> m a -> m [a] #
replicateM n actn times,
gathering the results.
Using ApplicativeDo: 'replicateM 5 asdo expression
do a1 <- as a2 <- as a3 <- as a4 <- as a5 <- as pure [a1,a2,a3,a4,a5]
Note the Applicative constraint.
foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m () #
Like foldM, but discards the result.
foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b #
The foldM function is analogous to foldl, except that its result is
encapsulated in a monad. Note that foldM works from left-to-right over
the list arguments. This could be an issue where ( and the `folded
function' are not commutative.>>)
foldM f a1 [x1, x2, ..., xm] == do a2 <- f a1 x1 a3 <- f a2 x2 ... f am xm
If right-to-left evaluation is required, the input list should be reversed.
zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m () #
zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c] #
mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c]) #
The mapAndUnzipM function maps its first argument over a list, returning
the result as a pair of lists. This function is mainly used with complicated
data structures or a state monad.
forever :: Applicative f => f a -> f b #
Repeat an action indefinitely.
Using ApplicativeDo: 'forever asdo expression
do as as ..
with as repeating.
Examples
A common use of forever is to process input from network sockets,
Handles, and channels
(e.g. MVar and
Chan).
For example, here is how we might implement an echo
server, using
forever both to listen for client connections on a network socket
and to echo client input on client connection handles:
echoServer :: Socket -> IO () echoServer socket =forever$ do client <- accept socketforkFinally(echo client) (\_ -> hClose client) where echo :: Handle -> IO () echo client =forever$ hGetLine client >>= hPutStrLn client
(>=>) :: 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
filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a] #
This generalizes the list-based filter function.
forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b) #
sequence_ :: (Foldable t, Monad m) => t (m a) -> m () #
Evaluate each monadic action in the structure from left to right,
and ignore the results. For a version that doesn't ignore the
results see sequence.
As of base 4.8.0.0, sequence_ is just sequenceA_, specialized
to Monad.
void :: Functor f => f a -> f () #
void valueIO action.
Using ApplicativeDo: 'void asdo expression
do as pure ()
with an inferred Functor constraint.
Examples
Replace the contents of a Maybe Int
>>>void NothingNothing>>>void (Just 3)Just ()
Replace the contents of an Either Int IntEither Int ()
>>>void (Left 8675309)Left 8675309>>>void (Right 8675309)Right ()
Replace every element of a list with unit:
>>>void [1,2,3][(),(),()]
Replace the second element of a pair with unit:
>>>void (1,2)(1,())
Discard the result of an IO action:
>>>mapM print [1,2]1 2 [(),()]>>>void $ mapM print [1,2]1 2
liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r #
Promote a function to a monad, scanning the monadic arguments from
left to right (cf. liftM2).
liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r #
Promote a function to a monad, scanning the monadic arguments from
left to right (cf. liftM2).
liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r #
Promote a function to a monad, scanning the monadic arguments from
left to right (cf. liftM2).
liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r #
Promote a function to a monad, scanning the monadic arguments from left to right. For example,
liftM2 (+) [0,1] [0,2] = [0,2,1,3] liftM2 (+) (Just 1) Nothing = Nothing
when :: Applicative f => Bool -> f () -> f () #
Conditional execution of Applicative expressions. For example,
when debug (putStrLn "Debugging")
will output the string Debugging if the Boolean value debug
is True, and otherwise do nothing.
(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1 #
Same as >>=, but with the arguments interchanged.
class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type) where #
Monads that also support choice and failure.
Minimal complete definition
Nothing
Methods
The identity of mplus. It should also satisfy the equations
mzero >>= f = mzero v >> mzero = mzero
The default definition is
mzero = empty
An associative operation. The default definition is
mplus = (<|>)
Instances
firstJustM :: Monad m => (a -> m (Maybe b)) -> [a] -> m (Maybe b) Source #
Like findM, but also allows you to compute some additional information in the predicate.
findM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a) Source #
Like find, but where the test can be monadic.
findM (Just . isUpper) "teST" == Just (Just 'S') findM (Just . isUpper) "test" == Just Nothing findM (Just . const True) ["x",undefined] == Just (Just "x")
andM :: Monad m => [m Bool] -> m Bool Source #
A version of and lifted to a monad. Retains the short-circuiting behaviour.
andM [Just True,Just False,undefined] == Just False andM [Just True,Just True ,undefined] == undefined \xs -> Just (and xs) == andM (map Just xs)
orM :: Monad m => [m Bool] -> m Bool Source #
A version of or lifted to a monad. Retains the short-circuiting behaviour.
orM [Just False,Just True ,undefined] == Just True orM [Just False,Just False,undefined] == undefined \xs -> Just (or xs) == orM (map Just xs)
allM :: Monad m => (a -> m Bool) -> [a] -> m Bool Source #
A version of all lifted to a monad. Retains the short-circuiting behaviour.
allM Just [True,False,undefined] == Just False allM Just [True,True ,undefined] == undefined \(f :: Int -> Maybe Bool) xs -> anyM f xs == orM (map f xs)
anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool Source #
A version of any lifted to a monad. Retains the short-circuiting behaviour.
anyM Just [False,True ,undefined] == Just True anyM Just [False,False,undefined] == undefined \(f :: Int -> Maybe Bool) xs -> anyM f xs == orM (map f xs)
unlessM :: Monad m => m Bool -> m () -> m () Source #
Like unless, but where the test can be monadic.
untilJustM :: Monad m => m (Maybe a) -> m a Source #
mapMaybeM :: Monad m => (a -> m (Maybe b)) -> [a] -> m [b] Source #
A version of mapMaybe that works with a monadic predicate.
mconcatMapM :: (Monad m, Monoid b) => (a -> m b) -> [a] -> m b Source #
A version of mconcatMap that works with a monadic predicate.
concatForM :: Monad m => [a] -> (a -> m [b]) -> m [b] Source #
Like concatMapM, but has its arguments flipped, so can be used
instead of the common fmap concat $ forM pattern.
concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b] Source #
A version of concatMap that works with a monadic predicate.
partitionM :: Monad m => (a -> m Bool) -> [a] -> m ([a], [a]) Source #
A version of partition that works with a monadic predicate.
partitionM (Just . even) [1,2,3] == Just ([2], [1,3]) partitionM (const Nothing) [1,2,3] == Nothing
fold1M_ :: (Partial, Monad m) => (a -> a -> m a) -> [a] -> m () Source #
Like fold1M but discards the result.
fold1M :: (Partial, Monad m) => (a -> a -> m a) -> [a] -> m a Source #
A variant of foldM that has no base case, and thus may only be applied to non-empty lists.
fold1M (\x y -> Just x) [] == undefined fold1M (\x y -> Just $ x + y) [1, 2, 3] == Just 6
eitherM :: Monad m => (a -> m c) -> (b -> m c) -> m (Either a b) -> m c Source #
Monadic generalisation of either.
maybeM :: Monad m => m b -> (a -> m b) -> m (Maybe a) -> m b Source #
Monadic generalisation of maybe.
The identity function which requires the inner argument to be (). Useful for functions
with overloaded return types.
\(x :: Maybe ()) -> unit x == x
whenMaybeM :: Monad m => m Bool -> m a -> m (Maybe a) Source #
Like whenMaybe, but where the test can be monadic.
pureIf :: Alternative m => Bool -> a -> m a Source #
whenJustM :: Monad m => m (Maybe a) -> (a -> m ()) -> m () Source #
Like whenJust, but where the test can be monadic.
whenJust :: Applicative m => Maybe a -> (a -> m ()) -> m () Source #
module Control.Monad.Fail
class Monad m => MonadIO (m :: Type -> Type) where #
Monads in which IO computations may be embedded.
Any monad built by applying a sequence of monad transformers to the
IO monad will be an instance of this class.
Instances should satisfy the following laws, which state that liftIO
is a transformer of monads:
Instances
| MonadIO IO | Since: base-4.9.0.0 |
Defined in Control.Monad.IO.Class | |
| MonadIO Q | |
Defined in Language.Haskell.TH.Syntax | |
| MonadIO Managed | |
Defined in Control.Monad.Managed | |
| MonadIO Shell | |
Defined in Turtle.Shell | |
| MonadIO m => MonadIO (ExceptT e m) | |
Defined in Control.Monad.Trans.Except | |
| (Error e, MonadIO m) => MonadIO (ErrorT e m) | |
Defined in Control.Monad.Trans.Error | |
| MonadIO m => MonadIO (ParsecT s u m) | |
Defined in Text.Parsec.Prim | |
class Semigroup a => Monoid a where #
The class of monoids (types with an associative binary operation that has an identity). Instances should satisfy the following:
- Right identity
x<>mempty= x- Left identity
mempty<>x = x- Associativity
x(<>(y<>z) = (x<>y)<>zSemigrouplaw)- Concatenation
mconcat=foldr(<>)mempty
The method names refer to the monoid of lists under concatenation, but there are many other instances.
Some types can be viewed as a monoid in more than one way,
e.g. both addition and multiplication on numbers.
In such cases we often define newtypes and make those instances
of Monoid, e.g. Sum and Product.
NOTE: Semigroup is a superclass of Monoid since base-4.11.0.0.
Minimal complete definition
Methods
Identity of mappend
>>>"Hello world" <> mempty"Hello world"
An associative operation
NOTE: This method is redundant and has the default
implementation mappend = (<>)mappend is a synonym for
(<>), it is expected that the two functions are defined the same
way. In a future GHC release mappend will be removed from Monoid.
Fold a list using the monoid.
For most types, the default definition for mconcat will be
used, but the function is included in the class definition so
that an optimized version can be provided for specific types.
>>>mconcat ["Hello", " ", "Haskell", "!"]"Hello Haskell!"
Instances
| Monoid Ordering | Since: base-2.1 |
| Monoid () | Since: base-2.1 |
| Monoid ByteString | |
Defined in Data.ByteString.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid Series | |
| Monoid Key | |
| Monoid All | Since: base-2.1 |
| Monoid Any | Since: base-2.1 |
| Monoid ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods mappend :: ShortByteString -> ShortByteString -> ShortByteString # mconcat :: [ShortByteString] -> ShortByteString # | |
| Monoid IntSet | |
| Monoid ByteArray | |
| Monoid ParseError | |
Defined in Options.Applicative.Types Methods mempty :: ParseError # mappend :: ParseError -> ParseError -> ParseError # mconcat :: [ParseError] -> ParseError # | |
| Monoid Completer | |
| Monoid Doc | |
| Monoid ShortText | |
| Monoid Line | |
| Monoid More | |
| Monoid ChangeLog Source # | |
| Monoid ProjectId Source # | |
| Monoid [a] | Since: base-2.1 |
| Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
| Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
| Monoid p => Monoid (Par1 p) | Since: base-4.12.0.0 |
| Monoid a => Monoid (Solo a) | |
| Monoid (IResult a) | |
| Monoid (Result a) | |
| Monoid (Parser a) | |
| Monoid (KeyMap v) | |
| (Ord a, Bounded a) => Monoid (Min a) | Since: base-4.9.0.0 |
| (Ord a, Bounded a) => Monoid (Max 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 # | |
| Semigroup a => Monoid (Option a) | Since: base-4.9.0.0 |
| 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 (Dual a) | Since: base-2.1 |
| Monoid (Endo a) | Since: base-2.1 |
| Num a => Monoid (Sum a) | Since: base-2.1 |
| Num a => Monoid (Product a) | Since: base-2.1 |
| Monoid (PutM ()) | |
| Monoid (IntMap a) | |
| Monoid (Seq a) | |
| Ord a => Monoid (Set a) | |
| Monoid (DList a) | |
| Monoid a => Monoid (Managed a) | |
| Monoid (Doc a) | |
| Monoid (Doc ann) |
|
| Monoid (PrimArray a) | Since: primitive-0.6.4.0 |
| Monoid (SmallArray a) | |
Defined in Data.Primitive.SmallArray Methods mempty :: SmallArray a # mappend :: SmallArray a -> SmallArray a -> SmallArray a # mconcat :: [SmallArray a] -> SmallArray a # | |
| Monoid (Array a) | |
| Semigroup a => Monoid (Maybe a) | |
| Monoid a => Monoid (Shell a) | |
| Monoid a => Monoid (Pattern a) | |
| (Hashable a, Eq a) => Monoid (HashSet a) | \(O(n+m)\) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| Storable a => Monoid (Vector a) | |
| Prim a => Monoid (Vector a) | |
| Monoid (Vector a) | |
| Monoid (MergeSet a) | |
| Monoid b => Monoid (a -> b) | Since: base-2.1 |
| Monoid (U1 p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b) => Monoid (a, b) | Since: base-2.1 |
| Ord k => Monoid (Map k v) | |
| (Eq k, Hashable k) => Monoid (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| Monoid b => Monoid (Fold a b) | |
| Monad m => Monoid (EndoM m a) | |
| (Monoid a, Monoid b) => Monoid (Pair a b) | |
| Monoid (Parser i a) | |
| 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 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 b, Monad m) => Monoid (FoldM m a b) | |
| (Semigroup a, Monoid a) => Monoid (Tagged s a) | |
| Monoid c => Monoid (K1 i c p) | Since: base-4.12.0.0 |
| (Monoid (f p), Monoid (g p)) => Monoid ((f :*: g) 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 a, Semigroup (ParsecT s u m a)) => Monoid (ParsecT s u m a) | The Since: parsec-3.1.12 |
| Monoid (f p) => Monoid (M1 i c f p) | Since: base-4.12.0.0 |
| Monoid (f (g p)) => Monoid ((f :.: g) 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 |
The class of semigroups (types with an associative binary operation).
Instances should satisfy the following:
Since: base-4.9.0.0
Minimal complete definition
Methods
(<>) :: a -> a -> a infixr 6 #
An associative operation.
>>>[1,2,3] <> [4,5,6][1,2,3,4,5,6]
Reduce a non-empty list with <>
The default definition should be sufficient, but this can be overridden for efficiency.
>>>import Data.List.NonEmpty>>>sconcat $ "Hello" :| [" ", "Haskell", "!"]"Hello Haskell!"
stimes :: Integral b => b -> a -> a #
Repeat a value n times.
Given that this works on a Semigroup it is allowed to fail if
you request 0 or fewer repetitions, and the default definition
will do so.
By making this a member of the class, idempotent semigroups
and monoids can upgrade this to execute in \(\mathcal{O}(1)\) by
picking stimes = or stimesIdempotentstimes =
respectively.stimesIdempotentMonoid
>>>stimes 4 [1][1,1,1,1]
Instances
| Semigroup Ordering | Since: base-4.9.0.0 |
| Semigroup () | Since: base-4.9.0.0 |
| Semigroup ByteString | |
Defined in Data.ByteString.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString # | |
| Semigroup ByteString | |
Defined in Data.ByteString.Lazy.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString # | |
| Semigroup Series | |
| Semigroup Key | |
| Semigroup Void | Since: base-4.9.0.0 |
| Semigroup All | Since: base-4.9.0.0 |
| Semigroup Any | Since: base-4.9.0.0 |
| Semigroup ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods (<>) :: ShortByteString -> ShortByteString -> ShortByteString # sconcat :: NonEmpty ShortByteString -> ShortByteString # stimes :: Integral b => b -> ShortByteString -> ShortByteString # | |
| Semigroup IntSet | Since: containers-0.5.7 |
| Semigroup ByteArray | |
| Semigroup ParseError | |
Defined in Options.Applicative.Types Methods (<>) :: ParseError -> ParseError -> ParseError # sconcat :: NonEmpty ParseError -> ParseError # stimes :: Integral b => b -> ParseError -> ParseError # | |
| Semigroup Completer | |
| Semigroup Doc | |
| Semigroup ShortText | |
| Semigroup Line | |
| Semigroup More | |
| Semigroup ChangeLog Source # | |
| Semigroup ProjectId Source # | |
| Semigroup [a] | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (IO a) | Since: base-4.10.0.0 |
| Semigroup p => Semigroup (Par1 p) | Since: base-4.12.0.0 |
| Semigroup a => Semigroup (Solo a) | |
| Semigroup (IResult a) | |
| Semigroup (Result a) | |
| Semigroup (Parser a) | |
| Semigroup (KeyMap v) | |
| Ord a => Semigroup (Min a) | Since: base-4.9.0.0 |
| Ord a => Semigroup (Max 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 |
| 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 (Option a) | Since: base-4.9.0.0 |
| 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 (Dual a) | Since: base-4.9.0.0 |
| Semigroup (Endo a) | Since: base-4.9.0.0 |
| Num a => Semigroup (Sum a) | Since: base-4.9.0.0 |
| Num a => Semigroup (Product a) | Since: base-4.9.0.0 |
| Semigroup (NonEmpty a) | Since: base-4.9.0.0 |
| Semigroup (PutM ()) | |
| Semigroup (IntMap a) | Since: containers-0.5.7 |
| Semigroup (Seq a) | Since: containers-0.5.7 |
| Ord a => Semigroup (Set a) | Since: containers-0.5.7 |
| Semigroup (DNonEmpty a) | |
| Semigroup (DList a) | |
| Semigroup a => Semigroup (Managed a) | |
| Semigroup (Doc a) | |
| Semigroup (Doc ann) | x
|
| Semigroup (PrimArray a) | Since: primitive-0.6.4.0 |
| Semigroup (SmallArray a) | Since: primitive-0.6.3.0 |
Defined in Data.Primitive.SmallArray Methods (<>) :: SmallArray a -> SmallArray a -> SmallArray a # sconcat :: NonEmpty (SmallArray a) -> SmallArray a # stimes :: Integral b => b -> SmallArray a -> SmallArray a # | |
| Semigroup (Array a) | Since: primitive-0.6.3.0 |
| Semigroup a => Semigroup (Maybe a) | |
| Monoid a => Semigroup (Shell a) | |
| Monoid a => Semigroup (Pattern a) | |
| (Hashable a, Eq a) => Semigroup (HashSet a) | \(O(n+m)\) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| Storable a => Semigroup (Vector a) | |
| Prim a => Semigroup (Vector a) | |
| Semigroup (Vector a) | |
| Semigroup (MergeSet a) | |
| Semigroup b => Semigroup (a -> b) | Since: base-4.9.0.0 |
| Semigroup (Either a b) | Since: base-4.9.0.0 |
| Semigroup (V1 p) | Since: base-4.12.0.0 |
| Semigroup (U1 p) | Since: base-4.12.0.0 |
| (Semigroup a, Semigroup b) => Semigroup (a, b) | Since: base-4.9.0.0 |
| Ord k => Semigroup (Map k v) | |
| (Eq k, Hashable k) => Semigroup (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| Semigroup b => Semigroup (Fold a b) | |
| Monad m => Semigroup (EndoM m a) | |
| (Semigroup a, Semigroup b) => Semigroup (These a b) | |
| (Semigroup a, Semigroup b) => Semigroup (Pair a b) | |
| (Semigroup a, Semigroup b) => Semigroup (These a b) | |
| Semigroup (Either a b) | |
| Semigroup (Parser i a) | |
| 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 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 b, Monad m) => Semigroup (FoldM m a b) | |
| Semigroup a => Semigroup (Tagged s a) | |
| Semigroup c => Semigroup (K1 i c p) | Since: base-4.12.0.0 |
| (Semigroup (f p), Semigroup (g p)) => Semigroup ((f :*: g) 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 a => Semigroup (ParsecT s u m a) | The (many $ char The above will parse a string like (many $ char Since: parsec-3.1.12 |
| Semigroup (f p) => Semigroup (M1 i c f p) | Since: base-4.12.0.0 |
| Semigroup (f (g p)) => Semigroup ((f :.: g) 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 |
8-bit unsigned integer type
Instances
Representable types of kind *.
This class is derivable in GHC with the DeriveGeneric flag on.
A Generic instance must satisfy the following laws:
from.to≡idto.from≡id
Instances
Type representing arbitrary-precision non-negative integers.
>>>2^100 :: Natural1267650600228229401496703205376
Operations whose result would be negative throw
(Underflow :: ArithException)
>>>-1 :: Natural*** Exception: arithmetic underflow
Since: base-4.8.0.0
Instances
| Enum Natural | Since: base-4.8.0.0 |
| Eq Natural | Since: base-4.8.0.0 |
| Integral Natural | Since: base-4.8.0.0 |
Defined in GHC.Real | |
| Data Natural | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Natural -> c Natural # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Natural # toConstr :: Natural -> Constr # dataTypeOf :: Natural -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Natural) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Natural) # gmapT :: (forall b. Data b => b -> b) -> Natural -> Natural # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Natural -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Natural -> r # gmapQ :: (forall d. Data d => d -> u) -> Natural -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Natural -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Natural -> m Natural # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Natural -> m Natural # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Natural -> m Natural # | |
| Num Natural | Note that Since: base-4.8.0.0 |
| Ord Natural | Since: base-4.8.0.0 |
| Read Natural | Since: base-4.8.0.0 |
| Real Natural | Since: base-4.8.0.0 |
Defined in GHC.Real Methods toRational :: Natural -> Rational # | |
| Show Natural | Since: base-4.8.0.0 |
| Ix Natural | Since: base-4.8.0.0 |
Defined in GHC.Ix | |
| Hashable Natural | |
| ToJSON Natural | |
| ToJSONKey Natural | |
Defined in Data.Aeson.Types.ToJSON Methods | |
| FromJSON Natural | |
| FromJSONKey Natural | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| Pretty Natural | |
| Binary Natural | Since: binary-0.7.3.0 |
| NFData Natural | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| HasParser Natural | |
Defined in Text.Parsec.Class | |
| Pretty Natural Source # | |
Defined in OpenSuse.Prelude.PrettyPrinting.Orphans Methods pPrintPrec :: PrettyLevel -> Rational -> Natural -> Doc # pPrintList :: PrettyLevel -> [Natural] -> Doc # | |
| UniformRange Natural | |
Defined in System.Random.Internal | |
| Lift Natural | |
Parsing & Pretty Printing
A space efficient, packed, unboxed Unicode text type.
Instances
| Hashable Text | |
| ToJSON Text | |
| ToJSONKey Text | |
Defined in Data.Aeson.Types.ToJSON Methods | |
| FromJSON Text | |
| FromJSONKey Text | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| Pretty Text | Automatically converts all newlines to
Note that
Manually use |
| Chunk Text | |
Defined in Data.Attoparsec.Internal.Types Associated Types type ChunkElem Text Methods pappendChunk :: State Text -> Text -> State Text atBufferEnd :: Text -> State Text -> Pos bufferElemAt :: Text -> Pos -> State Text -> Maybe (ChunkElem Text, Int) chunkElemToChar :: Text -> ChunkElem Text -> Char | |
| Monad m => Stream Text m Char | |
| type Item Text | |
| type State Text | |
Defined in Data.Attoparsec.Internal.Types type State Text = Buffer | |
| type ChunkElem Text | |
Defined in Data.Attoparsec.Internal.Types | |
data ByteString #
A space-efficient representation of a Word8 vector, supporting many
efficient operations.
A ByteString contains 8-bit bytes, or by using the operations from
Data.ByteString.Char8 it can be interpreted as containing 8-bit
characters.
Instances
type LazyByteString = ByteString Source #
unpackText :: Text -> String Source #
runParser :: Stream s Identity t => Parsec s u a -> u -> SourceName -> s -> Either ParseError a #
The most general way to run a parser over the Identity monad. runParser p state filePath
input runs parser p on the input list of tokens input,
obtained from source filePath with the initial user state st.
The filePath is only used in error messages and may be the empty
string. Returns either a ParseError (Left) or a
value of type a (Right).
parseFromFile p fname
= do{ input <- readFile fname
; return (runParser p () fname input)
}runParserT :: Stream s m t => ParsecT s u m a -> u -> SourceName -> s -> m (Either ParseError a) #
The most general way to run a parser. runParserT p state filePath
input runs parser p on the input list of tokens input,
obtained from source filePath with the initial user state st.
The filePath is only used in error messages and may be the empty
string. Returns a computation in the underlying monad m that return either a ParseError (Left) or a
value of type a (Right).
parse :: (Stream input Identity Char, HasParser a) => ErrorContext -> input -> a Source #
Convenience wrapper around runParser that uses the HasParser class to
determine the desired parser for the given result type. The function reports
syntax errors by throwing ParseError. This approach is inherently impure
and complicates error handling greatly. Use this function only on occasions
where parser errors are fatal errors that your code cannot recover from. In
almost all cases, parseM is the better choice.
>>>parse "Natural" "12345" :: Natural12345
Like parseM, this function does not skip over any white space. Use
Parsec's primitive runParser or runParserT functions if you don't like
this behavior:
>>>runParser (spaces >> parser) () "Natural" " 1 " :: Either ParseError NaturalRight 1
parseM :: (MonadFail m, Stream input m Char, HasParser a) => ErrorContext -> input -> m a Source #
Convenience wrapper around runParserT that uses the HasParser class to
determine the desired parser for the given result type. The function reports
syntax errors via fail.
>>>parseM "Natural" "987654321" :: IO Natural987654321>>>parseM "Natural" "123456789" :: Maybe NaturalJust 123456789
Please note that parsers run this way do not ignore any white space:
>>>parseM "Natural" " 1" :: Maybe NaturalNothing>>>parseM "Natural" "1 " :: Maybe NaturalNothing
type CharParser st input (m :: Type -> Type) a = Stream st m Char => ParsecT st input m a Source #
A simplified ParsecT parser that consumes some kind of character stream
without requiring any particular state state.
class HasParser a where Source #
Types that are instances of this class can be parsed and constructed from some character based text representation.
Instances
| HasParser Natural | |
Defined in Text.Parsec.Class | |
| HasParser EMailAddress Source # | |
Defined in OpenSuse.Types.EMailAddress Methods parser :: forall st input (m :: Type -> Type). CharParser st input m EMailAddress Source # | |
| HasParser Entry Source # | |
Defined in OpenSuse.Types.ChangeLog | |
| HasParser ChangeLog Source # | |
Defined in OpenSuse.Types.ChangeLog | |
| HasParser ProjectId Source # | |
Defined in OpenSuse.Types.ProjectId | |
| HasParser RequestId Source # | |
Defined in OpenSuse.Types.RequestId | |
type ErrorContext = String Source #
Parsers functions like parse or parseM use this type to provide a
helpful context in case the parser failes. Parsec uses the synonym
SourceName for the same purpose, but in fact this type doesn't necessarily
have to be a file name. It can be any name or identifier. Oftentimes, it
it's useful to pass the name of the type that the parser attempted to parse.
prettyShow :: Pretty a => a -> String #
Pretty print a value with the prettyNormal level.
Pretty printing class. The precedence level is used in a similar way as in
the Show class. Minimal complete definition is either pPrintPrec or
pPrint.
Minimal complete definition
Instances
The abstract type of documents. A Doc represents a set of layouts. A Doc with no occurrences of Union or NoDoc represents just one layout.
A type that can be converted to JSON.
Instances in general must specify toJSON and should (but don't need
to) specify toEncoding.
An example type and instance:
-- Allow ourselves to writeTextliterals. {-# LANGUAGE OverloadedStrings #-} data Coord = Coord { x :: Double, y :: Double } instanceToJSONCoord wheretoJSON(Coord x y) =object["x".=x, "y".=y]toEncoding(Coord x y) =pairs("x".=x<>"y".=y)
Instead of manually writing your ToJSON instance, there are two options
to do it automatically:
- Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
- The compiler can provide a default generic implementation for
toJSON.
To use the second, simply add a deriving clause to your
datatype and declare a GenericToJSON instance. If you require nothing other than
defaultOptions, it is sufficient to write (and this is the only
alternative where the default toJSON implementation is sufficient):
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics
data Coord = Coord { x :: Double, y :: Double } deriving Generic
instance ToJSON Coord where
toEncoding = genericToEncoding defaultOptions
or more conveniently using the DerivingVia extension
deriving viaGenericallyCoord instanceToJSONCoord
If on the other hand you wish to customize the generic decoding, you have to implement both methods:
customOptions =defaultOptions{fieldLabelModifier=maptoUpper} instanceToJSONCoord wheretoJSON=genericToJSONcustomOptionstoEncoding=genericToEncodingcustomOptions
Previous versions of this library only had the toJSON method. Adding
toEncoding had two reasons:
toEncodingis more efficient for the common case that the output oftoJSONis directly serialized to aByteString. Further, expressing either method in terms of the other would be non-optimal.- The choice of defaults allows a smooth transition for existing users:
Existing instances that do not define
toEncodingstill compile and have the correct semantics. This is ensured by making the default implementation oftoEncodingusetoJSON. This produces correct results, but since it performs an intermediate conversion to aValue, it will be less efficient than directly emitting anEncoding. (this also means that specifying nothing more thaninstance ToJSON Coordwould be sufficient as a generically decoding instance, but there probably exists no good reason to not specifytoEncodingin new instances.)
Instances
A type that can be converted from JSON, with the possibility of failure.
In many cases, you can get the compiler to generate parsing code for you (see below). To begin, let's cover writing an instance by hand.
There are various reasons a conversion could fail. For example, an
Object could be missing a required key, an Array could be of
the wrong size, or a value could be of an incompatible type.
The basic ways to signal a failed conversion are as follows:
failyields a custom error message: it is the recommended way of reporting a failure;empty(ormzero) is uninformative: use it when the error is meant to be caught by some(;<|>)typeMismatchcan be used to report a failure when the encountered value is not of the expected JSON type;unexpectedis an appropriate alternative when more than one type may be expected, or to keep the expected type implicit.
prependFailure (or modifyFailure) add more information to a parser's
error messages.
An example type and instance using typeMismatch and prependFailure:
-- Allow ourselves to writeTextliterals. {-# LANGUAGE OverloadedStrings #-} data Coord = Coord { x :: Double, y :: Double } instanceFromJSONCoord whereparseJSON(Objectv) = Coord<$>v.:"x"<*>v.:"y" -- We do not expect a non-Objectvalue here. -- We could useemptyto fail, buttypeMismatch-- gives a much more informative error message.parseJSONinvalid =prependFailure"parsing Coord failed, " (typeMismatch"Object" invalid)
For this common case of only being concerned with a single
type of JSON value, the functions withObject, withScientific, etc.
are provided. Their use is to be preferred when possible, since
they are more terse. Using withObject, we can rewrite the above instance
(assuming the same language extension and data type) as:
instanceFromJSONCoord whereparseJSON=withObject"Coord" $ \v -> Coord<$>v.:"x"<*>v.:"y"
Instead of manually writing your FromJSON instance, there are two options
to do it automatically:
- Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so it will probably be more efficient than the following option.
- The compiler can provide a default generic implementation for
parseJSON.
To use the second, simply add a deriving clause to your
datatype and declare a GenericFromJSON instance for your datatype without giving
a definition for parseJSON.
For example, the previous example can be simplified to just:
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics
data Coord = Coord { x :: Double, y :: Double } deriving Generic
instance FromJSON Coord
or using the DerivingVia extension
deriving viaGenericallyCoord instanceFromJSONCoord
The default implementation will be equivalent to
parseJSON = ; if you need different
options, you can customize the generic decoding by defining:genericParseJSON defaultOptions
customOptions =defaultOptions{fieldLabelModifier=maptoUpper} instanceFromJSONCoord whereparseJSON=genericParseJSONcustomOptions
Instances
Class for string-like datastructures; used by the overloaded string extension (-XOverloadedStrings in GHC).
Methods
fromString :: String -> a #
Instances
Date & Time
This is the simplest representation of UTC. It consists of the day number, and a time offset from midnight. Note that if a day has a leap second added to it, it will have 86401 seconds.
Constructors
| UTCTime | |
Fields
| |
Instances
| Eq UTCTime | |
| Data UTCTime | |
Defined in Data.Time.Clock.Internal.UTCTime Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> UTCTime -> c UTCTime # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c UTCTime # toConstr :: UTCTime -> Constr # dataTypeOf :: UTCTime -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c UTCTime) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c UTCTime) # gmapT :: (forall b. Data b => b -> b) -> UTCTime -> UTCTime # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> UTCTime -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> UTCTime -> r # gmapQ :: (forall d. Data d => d -> u) -> UTCTime -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> UTCTime -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> UTCTime -> m UTCTime # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> UTCTime -> m UTCTime # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> UTCTime -> m UTCTime # | |
| Ord UTCTime | |
Defined in Data.Time.Clock.Internal.UTCTime | |
| ToJSON UTCTime | |
| ToJSONKey UTCTime | |
Defined in Data.Aeson.Types.ToJSON Methods | |
| FromJSON UTCTime | |
| FromJSONKey UTCTime | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| NFData UTCTime | |
Defined in Data.Time.Clock.Internal.UTCTime | |
This is a length of time, as measured by a clock. Conversion functions will treat it as seconds. It has a precision of 10^-12 s.
Instances
| Enum DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Eq DiffTime | |
| Fractional DiffTime | |
| Data DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> DiffTime -> c DiffTime # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c DiffTime # toConstr :: DiffTime -> Constr # dataTypeOf :: DiffTime -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c DiffTime) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c DiffTime) # gmapT :: (forall b. Data b => b -> b) -> DiffTime -> DiffTime # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> DiffTime -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> DiffTime -> r # gmapQ :: (forall d. Data d => d -> u) -> DiffTime -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> DiffTime -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> DiffTime -> m DiffTime # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> DiffTime -> m DiffTime # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> DiffTime -> m DiffTime # | |
| Num DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Ord DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
| Real DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime Methods toRational :: DiffTime -> Rational # | |
| RealFrac DiffTime | |
| Show DiffTime | |
| ToJSON DiffTime | |
| FromJSON DiffTime | This instance includes a bounds check to prevent maliciously
large inputs to fill up the memory of the target system. You can
newtype |
| NFData DiffTime | |
Defined in Data.Time.Clock.Internal.DiffTime | |
Container
A set of values a.
Instances
| Foldable Set | Folds in order of increasing key. |
Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # | |
| ToJSON1 Set | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Set a -> Value Source # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Set a] -> Value Source # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Set a -> Encoding Source # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Set a] -> Encoding Source # | |
| Eq1 Set | Since: containers-0.5.9 |
| Ord1 Set | Since: containers-0.5.9 |
Defined in Data.Set.Internal | |
| Show1 Set | Since: containers-0.5.9 |
| Hashable1 Set | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Ord a => IsList (Set a) | Since: containers-0.5.6.2 |
| Eq a => Eq (Set a) | |
| (Data a, Ord a) => Data (Set a) | |
Defined in Data.Set.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Set a -> c (Set a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Set a) # dataTypeOf :: Set a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Set a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Set a)) # gmapT :: (forall b. Data b => b -> b) -> Set a -> Set a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQ :: (forall d. Data d => d -> u) -> Set a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Set a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # | |
| Ord a => Ord (Set a) | |
| (Read a, Ord a) => Read (Set a) | |
| Show a => Show (Set a) | |
| Ord a => Semigroup (Set a) | Since: containers-0.5.7 |
| Ord a => Monoid (Set a) | |
| Hashable v => Hashable (Set v) | Since: hashable-1.3.4.0 |
| ToJSON a => ToJSON (Set a) | |
| (Ord a, FromJSON a) => FromJSON (Set a) | |
| Binary a => Binary (Set a) | |
| NFData a => NFData (Set a) | |
Defined in Data.Set.Internal | |
| type Item (Set a) | |
Defined in Data.Set.Internal | |
Miscellaneous
A class of types that can be fully evaluated.
Since: deepseq-1.1.0.0
Instances
The Binary class provides put and get, methods to encode and
decode a Haskell value to a lazy ByteString. It mirrors the Read and
Show classes for textual representation of Haskell types, and is
suitable for serialising Haskell values to disk, over the network.
For decoding and generating simple external binary formats (e.g. C
structures), Binary may be used, but in general is not suitable
for complex protocols. Instead use the Put and Get primitives
directly.
Instances of Binary should satisfy the following property:
decode . encode == id
That is, the get and put methods should be the inverse of each
other. A range of instances are provided for basic Haskell types.
Instances
| Binary Bool | |
| Binary Char | |
| Binary Double | |
| Binary Float | |
| Binary Int | |
| Binary Int8 | |
| Binary Int16 | |
| Binary Int32 | |
| Binary Int64 | |
| Binary Integer | |
| Binary Natural | Since: binary-0.7.3.0 |
| Binary Ordering | |
| Binary Word | |
| Binary Word8 | |
| Binary Word16 | |
| Binary Word32 | |
| Binary Word64 | |
| Binary RuntimeRep | Since: binary-0.8.5.0 |
Defined in Data.Binary.Class | |
| Binary VecCount | Since: binary-0.8.5.0 |
| Binary VecElem | Since: binary-0.8.5.0 |
| Binary SomeTypeRep | |
Defined in Data.Binary.Class | |
| Binary () | |
| Binary TyCon | Since: binary-0.8.5.0 |
| Binary KindRep | Since: binary-0.8.5.0 |
| Binary TypeLitSort | Since: binary-0.8.5.0 |
Defined in Data.Binary.Class | |
| Binary Version | Since: binary-0.8.0.0 |
| Binary Scientific | Note that in the future I intend to change the type of the |
Defined in Data.Scientific | |
| Binary ByteString | |
Defined in Data.Binary.Class | |
| Binary ByteString | |
Defined in Data.Binary.Class | |
| Binary Void | Since: binary-0.8.0.0 |
| Binary All | Since: binary-0.8.4.0 |
| Binary Any | Since: binary-0.8.4.0 |
| Binary Fingerprint | Since: binary-0.7.6.0 |
Defined in Data.Binary.Class | |
| Binary ShortByteString | |
Defined in Data.Binary.Class Methods put :: ShortByteString -> Put # get :: Get ShortByteString # putList :: [ShortByteString] -> Put # | |
| Binary IntSet | |
| Binary ShortText | |
| Binary UUID | This |
| Binary EMailAddress Source # | |
Defined in OpenSuse.Types.EMailAddress | |
| Binary Issue Source # | |
| Binary ProjectId Source # | |
| Binary RequestId Source # | |
| Binary a => Binary [a] | |
| Binary a => Binary (Maybe a) | |
| (Binary a, Integral a) => Binary (Ratio a) | |
| Binary a => Binary (Complex a) | |
| Binary a => Binary (Min a) | Since: binary-0.8.4.0 |
| Binary a => Binary (Max a) | Since: binary-0.8.4.0 |
| Binary a => Binary (First a) | Since: binary-0.8.4.0 |
| Binary a => Binary (Last a) | Since: binary-0.8.4.0 |
| Binary m => Binary (WrappedMonoid m) | Since: binary-0.8.4.0 |
Defined in Data.Binary.Class Methods put :: WrappedMonoid m -> Put # get :: Get (WrappedMonoid m) # putList :: [WrappedMonoid m] -> Put # | |
| Binary a => Binary (Option a) | Since: binary-0.8.4.0 |
| Binary a => Binary (Identity a) | |
| Binary a => Binary (First a) | Since: binary-0.8.4.0 |
| Binary a => Binary (Last a) | Since: binary-0.8.4.0 |
| Binary a => Binary (Dual a) | Since: binary-0.8.4.0 |
| Binary a => Binary (Sum a) | Since: binary-0.8.4.0 |
| Binary a => Binary (Product a) | Since: binary-0.8.4.0 |
| Binary a => Binary (NonEmpty a) | Since: binary-0.8.4.0 |
| Binary e => Binary (IntMap e) | |
| Binary e => Binary (Tree e) | |
| Binary e => Binary (Seq e) | |
| Binary a => Binary (Set a) | |
| Binary a => Binary (Maybe a) | |
| (Binary a, Binary b) => Binary (Either a b) | |
| Typeable a => Binary (TypeRep a) | |
| (Binary a, Binary b) => Binary (a, b) | |
| (Binary k, Binary e) => Binary (Map k e) | |
| (Binary i, Ix i, Binary e, IArray UArray e) => Binary (UArray i e) | |
| (Binary i, Ix i, Binary e) => Binary (Array i e) | |
| Binary (Fixed a) | Since: binary-0.8.0.0 |
| (Binary a, Binary b) => Binary (Arg a b) | Since: binary-0.8.4.0 |
| (Binary a, Binary b) => Binary (These a b) | Since: these-0.7.1 |
| (Binary a, Binary b) => Binary (Pair a b) | |
| (Binary a, Binary b) => Binary (These a b) | |
| (Binary a, Binary b) => Binary (Either a b) | |
| (Binary a, Binary b, Binary c) => Binary (a, b, c) | |
| Binary (f a) => Binary (Alt f a) | Since: binary-0.8.4.0 |
| (Binary a, Binary b, Binary c, Binary d) => Binary (a, b, c, d) | |
| (Binary a, Binary b, Binary c, Binary d, Binary e) => Binary (a, b, c, d, e) | |
| (Binary a, Binary b, Binary c, Binary d, Binary e, Binary f) => Binary (a, b, c, d, e, f) | |
| (Binary a, Binary b, Binary c, Binary d, Binary e, Binary f, Binary g) => Binary (a, b, c, d, e, f, g) | |
| (Binary a, Binary b, Binary c, Binary d, Binary e, Binary f, Binary g, Binary h) => Binary (a, b, c, d, e, f, g, h) | |
| (Binary a, Binary b, Binary c, Binary d, Binary e, Binary f, Binary g, Binary h, Binary i) => Binary (a, b, c, d, e, f, g, h, i) | |
| (Binary a, Binary b, Binary c, Binary d, Binary e, Binary f, Binary g, Binary h, Binary i, Binary j) => Binary (a, b, c, d, e, f, g, h, i, j) | |
class Eq a => Hashable a Source #
The class of types that can be converted to a hash value.
Minimal implementation: hashWithSalt.
Note: the hash is not guaranteed to be stable across library versions, operating systems or architectures. For stable hashing use named hashes: SHA256, CRC32 etc.
If you are looking for Hashable instance in time package,
check time-compat
Instances
fromMaybe :: a -> Maybe a -> a #
The fromMaybe function takes a default value and and Maybe
value. If the Maybe is Nothing, it returns the default values;
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