Antelude

This is just what's available in the global scope. It is intended this way to encourage qualified or named-exposure imports, to give clarity to everyone reading your code where something came from.

For everything else you require, you are encouraged to:

• See if there's an Antelude module containing what you're looking for (ex.: Antelude.List: List)
• See if there's a base package containing what you're looking for (ex.: Data.Char: Char, Control.Applicative: Applicative)
• See if there's an external package containing what you're looking for (ex.: Data.Text.Lazy.IO: IO from the "text" package)

Symbols and Functions

Symbols

Function Piping and Composition

(.>) :: (a -> b) -> (b -> c) -> a -> c infixr 9

Equivalent to 'flip (.)', but in an arrowhead format.

Since (>>) is already a typeclass-locked Haskell symbol for Monad, (.>) was decided as was decided as it's (.) but with a direction.

(<.) :: (b -> c) -> (a -> b) -> a -> c infixl 9

Equivalent to (.) from Function, but in an arrowhead format.

Since (<<) would be confused with 'flip (>>)', (<.) was decided as it's (.) but with a direction.

(<|) :: (a -> b) -> a -> b infixr 0

Equivalent to ($) from Function, but like Elm. Can be slightly clearer for unfamiliar developers.

(|>) :: a -> (a -> b) -> b infixl 0

Equivalent to (&) from Function, but like Elm. Can be slightly clearer for unfamiliar developers.

Monadic Stuff

Reexport from Monad

(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1

Same as >>=, but with the arguments interchanged.

Reexport from Monad

(<<) :: Monad m => m b -> m a -> m b

Just a flipped version of (>>)

(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c infixr 1

Left-to-right composition of Kleisli arrows.

'(bs >=> cs) a' can be understood as the do expression

do b <- bs a
   cs b

Reexport from Monad

(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c infixr 1

Right-to-left composition of Kleisli arrows. (>=>), with the arguments flipped.

Note how this operator resembles function composition (.):

(.)   ::            (b ->   c) -> (a ->   b) -> a ->   c
(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c

Boolean

Reexport from Bool

(&&) :: Bool -> Bool -> Bool infixr 3

Boolean "and", lazy in the second argument

Reexport from Bool

(||) :: Bool -> Bool -> Bool infixr 2

Boolean "or", lazy in the second argument

Functors

Reexport from Functor

($>) :: Functor f => f a -> b -> f b infixl 4

Flipped version of <$.

Examples

Replace the contents of a Maybe Int with a constant String:

>>> Nothing $> "foo"
Nothing
>>> Just 90210 $> "foo"
Just "foo"

Replace the contents of an Either Int Int with a constant String, resulting in an Either Int String:

>>> Left 8675309 $> "foo"
Left 8675309
>>> Right 8675309 $> "foo"
Right "foo"

Replace each element of a list with a constant String:

>>> [1,2,3] $> "foo"
["foo","foo","foo"]

Replace the second element of a pair with a constant String:

>>> (1,2) $> "foo"
(1,"foo")

Since: base-4.7.0.0

Reexport from Functor

(<$>) :: 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 Int to a Maybe String using show:

>>> show <$> Nothing
Nothing
>>> show <$> Just 3
Just "3"

Convert from an Either Int Int to an Either Int String using show:

>>> show <$> Left 17
Left 17
>>> show <$> Right 17
Right "17"

Double each element of a list:

>>> (*2) <$> [1,2,3]
[2,4,6]

Apply even to the second element of a pair:

>>> even <$> (2,2)
(2,True)

Reexport from Functor

(<&>) :: Functor f => f a -> (a -> b) -> f b infixl 1

Flipped version of <$>.

(<&>) = flip fmap

Examples

Apply (+1) to a list, a Just and a Right:

>>> Just 2 <&> (+1)
Just 3

>>> [1,2,3] <&> (+1)
[2,3,4]

>>> Right 3 <&> (+1)
Right 4

Since: base-4.11.0.0

Numeric Non-Class

Reexport from Prelude

(^) :: (Num a, Integral b) => a -> b -> a infixr 8

raise a number to a non-negative integral power

Reexport from Prelude

(^^) :: (Fractional a, Integral b) => a -> b -> a infixr 8

raise a number to an integral power

Strictly Apply

Reexport from Prelude

($!) :: 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.

Functions

Often used as a catch-all case for multi-way-ifs and guards. Is always True.

otherwise :: Bool

otherwise is defined as the value True. It helps to make guards more readable. eg.

 f x | x < 0     = ...
     | otherwise = ...

Show/print something to stdout.

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]])

Types and Classes

Types

Basics

Reexport from Bool

data Bool

Constructors

False

True

Instances

Bounded Bool

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Bool

maxBound :: Bool

Enum Bool

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Bool -> Bool

pred :: Bool -> Bool

toEnum :: Int -> Bool

fromEnum :: Bool -> Int

enumFrom :: Bool -> [Bool]

enumFromThen :: Bool -> Bool -> [Bool]

enumFromTo :: Bool -> Bool -> [Bool]

enumFromThenTo :: Bool -> Bool -> Bool -> [Bool]

Ix Bool

Since: base-2.1

Defined in GHC.Ix

Methods

range :: (Bool, Bool) -> [Bool]

index :: (Bool, Bool) -> Bool -> Int

unsafeIndex :: (Bool, Bool) -> Bool -> Int

inRange :: (Bool, Bool) -> Bool -> Bool

rangeSize :: (Bool, Bool) -> Int

unsafeRangeSize :: (Bool, Bool) -> Int

Read Bool

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Bool

readList :: ReadS [Bool]

readPrec :: ReadPrec Bool

readListPrec :: ReadPrec [Bool]

Show Bool

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Bool -> ShowS

show :: Bool -> String

showList :: [Bool] -> ShowS

Eq Bool

Defined in GHC.Classes

Methods

(==) :: Bool -> Bool -> Bool

(/=) :: Bool -> Bool -> Bool

Ord Bool

Defined in GHC.Classes

Methods

compare :: Bool -> Bool -> Ordering

(<) :: Bool -> Bool -> Bool

(<=) :: Bool -> Bool -> Bool

(>) :: Bool -> Bool -> Bool

(>=) :: Bool -> Bool -> Bool

max :: Bool -> Bool -> Bool

min :: Bool -> Bool -> Bool

Reexport from Char

data Char

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

Bounded Char

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Char

maxBound :: Char

Enum Char

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Char -> Char

pred :: Char -> Char

toEnum :: Int -> Char

fromEnum :: Char -> Int

enumFrom :: Char -> [Char]

enumFromThen :: Char -> Char -> [Char]

enumFromTo :: Char -> Char -> [Char]

enumFromThenTo :: Char -> Char -> Char -> [Char]

Ix Char

Since: base-2.1

Defined in GHC.Ix

Methods

range :: (Char, Char) -> [Char]

index :: (Char, Char) -> Char -> Int

unsafeIndex :: (Char, Char) -> Char -> Int

inRange :: (Char, Char) -> Char -> Bool

rangeSize :: (Char, Char) -> Int

unsafeRangeSize :: (Char, Char) -> Int

Read Char

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Char

readList :: ReadS [Char]

readPrec :: ReadPrec Char

readListPrec :: ReadPrec [Char]

Show Char

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Char -> ShowS

show :: Char -> String

showList :: [Char] -> ShowS

Eq Char

Defined in GHC.Classes

Methods

(==) :: Char -> Char -> Bool

(/=) :: Char -> Char -> Bool

Ord Char

Defined in GHC.Classes

Methods

compare :: Char -> Char -> Ordering

(<) :: Char -> Char -> Bool

(<=) :: Char -> Char -> Bool

(>) :: Char -> Char -> Bool

(>=) :: Char -> Char -> Bool

max :: Char -> Char -> Char

min :: Char -> Char -> Char

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

toList :: UChar a -> [a]

null :: UChar a -> Bool

length :: UChar a -> Int

elem :: Eq a => a -> UChar a -> Bool

maximum :: Ord a => UChar a -> a

minimum :: Ord a => UChar a -> a

sum :: Num a => UChar a -> a

product :: Num a => UChar a -> a

Traversable (UChar :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UChar a -> f (UChar b)

sequenceA :: Applicative f => UChar (f a) -> f (UChar a)

mapM :: Monad m => (a -> m b) -> UChar a -> m (UChar b)

sequence :: Monad m => UChar (m a) -> m (UChar a)

Reexport from String

type String = [Char]

String is an alias for a list of characters.

String constants in Haskell are values of type String. That means if you write a string literal like "hello world", it will have the type [Char], which is the same as String.

Note: You can ask the compiler to automatically infer different types with the -XOverloadedStrings language extension, for example "hello world" :: Text. See IsString for more information.

Because String is just a list of characters, you can use normal list functions to do basic string manipulation. See Data.List for operations on lists.

Performance considerations

[Char] is a relatively memory-inefficient type. It is a linked list of boxed word-size characters, internally it looks something like:

╭─────┬───┬──╮  ╭─────┬───┬──╮  ╭─────┬───┬──╮  ╭────╮
│ (:) │   │ ─┼─>│ (:) │   │ ─┼─>│ (:) │   │ ─┼─>│ [] │
╰─────┴─┼─┴──╯  ╰─────┴─┼─┴──╯  ╰─────┴─┼─┴──╯  ╰────╯
        v               v               v
       'a'             'b'             'c'

The String "abc" will use 5*3+1 = 16 (in general 5n+1) words of space in memory.

Furthermore, operations like (++) (string concatenation) are O(n) (in the left argument).

For historical reasons, the base library uses String in a lot of places for the conceptual simplicity, but library code dealing with user-data should use the text package for Unicode text, or the the bytestring package for binary data.

Reexport from Int

data Int

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

Defined in GHC.Enum

Methods

minBound :: Int

maxBound :: Int

Enum Int

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Int -> Int

pred :: Int -> Int

toEnum :: Int -> Int

fromEnum :: Int -> Int

enumFrom :: Int -> [Int]

enumFromThen :: Int -> Int -> [Int]

enumFromTo :: Int -> Int -> [Int]

enumFromThenTo :: Int -> Int -> Int -> [Int]

Ix Int

Since: base-2.1

Defined in GHC.Ix

Methods

range :: (Int, Int) -> [Int]

index :: (Int, Int) -> Int -> Int

unsafeIndex :: (Int, Int) -> Int -> Int

inRange :: (Int, Int) -> Int -> Bool

rangeSize :: (Int, Int) -> Int

unsafeRangeSize :: (Int, Int) -> Int

Num Int

Since: base-2.1

Defined in GHC.Num

Methods

(+) :: Int -> Int -> Int

(-) :: Int -> Int -> Int

(*) :: Int -> Int -> Int

negate :: Int -> Int

abs :: Int -> Int

signum :: Int -> Int

fromInteger :: Integer -> Int

Read Int

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Int

readList :: ReadS [Int]

readPrec :: ReadPrec Int

readListPrec :: ReadPrec [Int]

Integral Int

Since: base-2.0.1

Defined in GHC.Real

Methods

quot :: Int -> Int -> Int

rem :: Int -> Int -> Int

div :: Int -> Int -> Int

mod :: Int -> Int -> Int

quotRem :: Int -> Int -> (Int, Int)

divMod :: Int -> Int -> (Int, Int)

toInteger :: Int -> Integer

Real Int

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Int -> Rational

Show Int

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Int -> ShowS

show :: Int -> String

showList :: [Int] -> ShowS

Eq Int

Defined in GHC.Classes

Methods

(==) :: Int -> Int -> Bool

(/=) :: Int -> Int -> Bool

Ord Int

Defined in GHC.Classes

Methods

compare :: Int -> Int -> Ordering

(<) :: Int -> Int -> Bool

(<=) :: Int -> Int -> Bool

(>) :: Int -> Int -> Bool

(>=) :: Int -> Int -> Bool

max :: Int -> Int -> Int

min :: Int -> Int -> Int

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

toList :: UInt a -> [a]

null :: UInt a -> Bool

length :: UInt a -> Int

elem :: Eq a => a -> UInt a -> Bool

maximum :: Ord a => UInt a -> a

minimum :: Ord a => UInt a -> a

sum :: Num a => UInt a -> a

product :: Num a => UInt a -> a

Traversable (UInt :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UInt a -> f (UInt b)

sequenceA :: Applicative f => UInt (f a) -> f (UInt a)

mapM :: Monad m => (a -> m b) -> UInt a -> m (UInt b)

sequence :: Monad m => UInt (m a) -> m (UInt a)

Reexport from Prelude

data Integer

Arbitrary precision integers. In contrast with fixed-size integral types such as Int, the Integer type represents the entire infinite range of integers.

Integers are stored in a kind of sign-magnitude form, hence do not expect two's complement form when using bit operations.

If the value is small (fit into an Int), IS constructor is used. Otherwise Integer and IN constructors are used to store a BigNat representing respectively the positive or the negative value magnitude.

Invariant: Integer and IN are used iff value doesn't fit in IS

Instances

Enum Integer

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Integer -> Integer

pred :: Integer -> Integer

toEnum :: Int -> Integer

fromEnum :: Integer -> Int

enumFrom :: Integer -> [Integer]

enumFromThen :: Integer -> Integer -> [Integer]

enumFromTo :: Integer -> Integer -> [Integer]

enumFromThenTo :: Integer -> Integer -> Integer -> [Integer]

Ix Integer

Since: base-2.1

Defined in GHC.Ix

Methods

range :: (Integer, Integer) -> [Integer]

index :: (Integer, Integer) -> Integer -> Int

unsafeIndex :: (Integer, Integer) -> Integer -> Int

inRange :: (Integer, Integer) -> Integer -> Bool

rangeSize :: (Integer, Integer) -> Int

unsafeRangeSize :: (Integer, Integer) -> Int

Num Integer

Since: base-2.1

Defined in GHC.Num

Methods

(+) :: Integer -> Integer -> Integer

(-) :: Integer -> Integer -> Integer

(*) :: Integer -> Integer -> Integer

negate :: Integer -> Integer

abs :: Integer -> Integer

signum :: Integer -> Integer

fromInteger :: Integer -> Integer

Read Integer

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Integer

readList :: ReadS [Integer]

readPrec :: ReadPrec Integer

readListPrec :: ReadPrec [Integer]

Integral Integer

Since: base-2.0.1

Defined in GHC.Real

Methods

quot :: Integer -> Integer -> Integer

rem :: Integer -> Integer -> Integer

div :: Integer -> Integer -> Integer

mod :: Integer -> Integer -> Integer

quotRem :: Integer -> Integer -> (Integer, Integer)

divMod :: Integer -> Integer -> (Integer, Integer)

toInteger :: Integer -> Integer

Real Integer

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Integer -> Rational

Show Integer

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Integer -> ShowS

show :: Integer -> String

showList :: [Integer] -> ShowS

Eq Integer

Defined in GHC.Num.Integer

Methods

(==) :: Integer -> Integer -> Bool

(/=) :: Integer -> Integer -> Bool

Ord Integer

Defined in GHC.Num.Integer

Methods

compare :: Integer -> Integer -> Ordering

(<) :: Integer -> Integer -> Bool

(<=) :: Integer -> Integer -> Bool

(>) :: Integer -> Integer -> Bool

(>=) :: Integer -> Integer -> Bool

max :: Integer -> Integer -> Integer

min :: Integer -> Integer -> Integer

Reexport from Prelude

data Float

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

Floating Float

Since: base-2.1

Defined in GHC.Float

Methods

pi :: Float

exp :: Float -> Float

log :: Float -> Float

sqrt :: Float -> Float

(**) :: Float -> Float -> Float

logBase :: Float -> Float -> Float

sin :: Float -> Float

cos :: Float -> Float

tan :: Float -> Float

asin :: Float -> Float

acos :: Float -> Float

atan :: Float -> Float

sinh :: Float -> Float

cosh :: Float -> Float

tanh :: Float -> Float

asinh :: Float -> Float

acosh :: Float -> Float

atanh :: Float -> Float

log1p :: Float -> Float

expm1 :: Float -> Float

log1pexp :: Float -> Float

log1mexp :: Float -> Float

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

exponent :: Float -> Int

significand :: Float -> Float

scaleFloat :: Int -> Float -> Float

isNaN :: Float -> Bool

isInfinite :: Float -> Bool

isDenormalized :: Float -> Bool

isNegativeZero :: Float -> Bool

isIEEE :: Float -> Bool

atan2 :: Float -> Float -> Float

Read Float

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Float

readList :: ReadS [Float]

readPrec :: ReadPrec Float

readListPrec :: ReadPrec [Float]

Eq Float

Note that due to the presence of NaN, Float's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Float)
False

Also note that Float's Eq instance does not satisfy extensionality:

>>> 0 == (-0 :: Float)
True
>>> recip 0 == recip (-0 :: Float)
False

Defined in GHC.Classes

Methods

(==) :: Float -> Float -> Bool

(/=) :: Float -> Float -> Bool

Ord Float

Note that due to the presence of NaN, Float's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Float)
False

Also note that, due to the same, Ord's operator interactions are not respected by Float's instance:

>>> (0/0 :: Float) > 1
False
>>> compare (0/0 :: Float) 1
GT

Defined in GHC.Classes

Methods

compare :: Float -> Float -> Ordering

(<) :: Float -> Float -> Bool

(<=) :: Float -> Float -> Bool

(>) :: Float -> Float -> Bool

(>=) :: Float -> Float -> Bool

max :: Float -> Float -> Float

min :: Float -> Float -> Float

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

toList :: UFloat a -> [a]

null :: UFloat a -> Bool

length :: UFloat a -> Int

elem :: Eq a => a -> UFloat a -> Bool

maximum :: Ord a => UFloat a -> a

minimum :: Ord a => UFloat a -> a

sum :: Num a => UFloat a -> a

product :: Num a => UFloat a -> a

Traversable (UFloat :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UFloat a -> f (UFloat b)

sequenceA :: Applicative f => UFloat (f a) -> f (UFloat a)

mapM :: Monad m => (a -> m b) -> UFloat a -> m (UFloat b)

sequence :: Monad m => UFloat (m a) -> m (UFloat a)

Reexport from Prelude

data Double

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

Floating Double

Since: base-2.1

Defined in GHC.Float

Methods

pi :: Double

exp :: Double -> Double

log :: Double -> Double

sqrt :: Double -> Double

(**) :: Double -> Double -> Double

logBase :: Double -> Double -> Double

sin :: Double -> Double

cos :: Double -> Double

tan :: Double -> Double

asin :: Double -> Double

acos :: Double -> Double

atan :: Double -> Double

sinh :: Double -> Double

cosh :: Double -> Double

tanh :: Double -> Double

asinh :: Double -> Double

acosh :: Double -> Double

atanh :: Double -> Double

log1p :: Double -> Double

expm1 :: Double -> Double

log1pexp :: Double -> Double

log1mexp :: Double -> Double

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

exponent :: Double -> Int

significand :: Double -> Double

scaleFloat :: Int -> Double -> Double

isNaN :: Double -> Bool

isInfinite :: Double -> Bool

isDenormalized :: Double -> Bool

isNegativeZero :: Double -> Bool

isIEEE :: Double -> Bool

atan2 :: Double -> Double -> Double

Read Double

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Double

readList :: ReadS [Double]

readPrec :: ReadPrec Double

readListPrec :: ReadPrec [Double]

Eq Double

Note that due to the presence of NaN, Double's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Double)
False

Also note that Double's Eq instance does not satisfy substitutivity:

>>> 0 == (-0 :: Double)
True
>>> recip 0 == recip (-0 :: Double)
False

Defined in GHC.Classes

Methods

(==) :: Double -> Double -> Bool

(/=) :: Double -> Double -> Bool

Ord Double

Note that due to the presence of NaN, Double's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Double)
False

Also note that, due to the same, Ord's operator interactions are not respected by Double's instance:

>>> (0/0 :: Double) > 1
False
>>> compare (0/0 :: Double) 1
GT

Defined in GHC.Classes

Methods

compare :: Double -> Double -> Ordering

(<) :: Double -> Double -> Bool

(<=) :: Double -> Double -> Bool

(>) :: Double -> Double -> Bool

(>=) :: Double -> Double -> Bool

max :: Double -> Double -> Double

min :: Double -> Double -> Double

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

toList :: UDouble a -> [a]

null :: UDouble a -> Bool

length :: UDouble a -> Int

elem :: Eq a => a -> UDouble a -> Bool

maximum :: Ord a => UDouble a -> a

minimum :: Ord a => UDouble a -> a

sum :: Num a => UDouble a -> a

product :: Num a => UDouble a -> a

Traversable (UDouble :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UDouble a -> f (UDouble b)

sequenceA :: Applicative f => UDouble (f a) -> f (UDouble a)

mapM :: Monad m => (a -> m b) -> UDouble a -> m (UDouble b)

sequence :: Monad m => UDouble (m a) -> m (UDouble a)

Reexport from Ratio

type Rational = Ratio Integer

Arbitrary-precision rational numbers, represented as a ratio of two Integer values. A rational number may be constructed using the % operator.

Reexport from Word

data Word

A Word is an unsigned integral type, with the same size as Int.

Instances

Bounded Word

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Word

maxBound :: Word

Enum Word

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Word -> Word

pred :: Word -> Word

toEnum :: Int -> Word

fromEnum :: Word -> Int

enumFrom :: Word -> [Word]

enumFromThen :: Word -> Word -> [Word]

enumFromTo :: Word -> Word -> [Word]

enumFromThenTo :: Word -> Word -> Word -> [Word]

Ix Word

Since: base-4.6.0.0

Defined in GHC.Ix

Methods

range :: (Word, Word) -> [Word]

index :: (Word, Word) -> Word -> Int

unsafeIndex :: (Word, Word) -> Word -> Int

inRange :: (Word, Word) -> Word -> Bool

rangeSize :: (Word, Word) -> Int

unsafeRangeSize :: (Word, Word) -> Int

Num Word

Since: base-2.1

Defined in GHC.Num

Methods

(+) :: Word -> Word -> Word

(-) :: Word -> Word -> Word

(*) :: Word -> Word -> Word

negate :: Word -> Word

abs :: Word -> Word

signum :: Word -> Word

fromInteger :: Integer -> Word

Read Word

Since: base-4.5.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word

readList :: ReadS [Word]

readPrec :: ReadPrec Word

readListPrec :: ReadPrec [Word]

Integral Word

Since: base-2.1

Defined in GHC.Real

Methods

quot :: Word -> Word -> Word

rem :: Word -> Word -> Word

div :: Word -> Word -> Word

mod :: Word -> Word -> Word

quotRem :: Word -> Word -> (Word, Word)

divMod :: Word -> Word -> (Word, Word)

toInteger :: Word -> Integer

Real Word

Since: base-2.1

Defined in GHC.Real

Methods

toRational :: Word -> Rational

Show Word

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Word -> ShowS

show :: Word -> String

showList :: [Word] -> ShowS

Eq Word

Defined in GHC.Classes

Methods

(==) :: Word -> Word -> Bool

(/=) :: Word -> Word -> Bool

Ord Word

Defined in GHC.Classes

Methods

compare :: Word -> Word -> Ordering

(<) :: Word -> Word -> Bool

(<=) :: Word -> Word -> Bool

(>) :: Word -> Word -> Bool

(>=) :: Word -> Word -> Bool

max :: Word -> Word -> Word

min :: Word -> Word -> Word

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

toList :: UWord a -> [a]

null :: UWord a -> Bool

length :: UWord a -> Int

elem :: Eq a => a -> UWord a -> Bool

maximum :: Ord a => UWord a -> a

minimum :: Ord a => UWord a -> a

sum :: Num a => UWord a -> a

product :: Num a => UWord a -> a

Traversable (UWord :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UWord a -> f (UWord b)

sequenceA :: Applicative f => UWord (f a) -> f (UWord a)

mapM :: Monad m => (a -> m b) -> UWord a -> m (UWord b)

sequence :: Monad m => UWord (m a) -> m (UWord a)

Container-Types

List and List-ish

Reexport from List

type List a = [a]

Explicit naming of the List brackets.

Reexport from NonEmpty

data NonEmpty a

Non-empty (and non-strict) list type.

Since: base-4.9.0.0

Constructors

a :| [a] infixr 5

Instances

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

toList :: NonEmpty a -> [a]

null :: NonEmpty a -> Bool

length :: NonEmpty a -> Int

elem :: Eq a => a -> NonEmpty a -> Bool

maximum :: Ord a => NonEmpty a -> a

minimum :: Ord a => NonEmpty a -> a

sum :: Num a => NonEmpty a -> a

product :: Num a => NonEmpty a -> a

Traversable NonEmpty

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> NonEmpty a -> f (NonEmpty b)

sequenceA :: Applicative f => NonEmpty (f a) -> f (NonEmpty a)

mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b)

sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a)

Applicative NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

pure :: a -> NonEmpty a

(<*>) :: NonEmpty (a -> b) -> NonEmpty a -> NonEmpty b

liftA2 :: (a -> b -> c) -> NonEmpty a -> NonEmpty b -> NonEmpty c

(*>) :: NonEmpty a -> NonEmpty b -> NonEmpty b

(<*) :: NonEmpty a -> NonEmpty b -> NonEmpty a

Functor NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

fmap :: (a -> b) -> NonEmpty a -> NonEmpty b

(<$) :: a -> NonEmpty b -> NonEmpty a

Monad NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b

(>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b

return :: a -> NonEmpty a

Semigroup (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: NonEmpty a -> NonEmpty a -> NonEmpty a

sconcat :: NonEmpty (NonEmpty a) -> NonEmpty a

stimes :: Integral b => b -> NonEmpty a -> NonEmpty a

IsList (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.IsList

Associated Types

type Item (NonEmpty a)

Methods

fromList :: [Item (NonEmpty a)] -> NonEmpty a

fromListN :: Int -> [Item (NonEmpty a)] -> NonEmpty a

toList :: NonEmpty a -> [Item (NonEmpty a)]

Read a => Read (NonEmpty a)

Since: base-4.11.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (NonEmpty a)

readList :: ReadS [NonEmpty a]

readPrec :: ReadPrec (NonEmpty a)

readListPrec :: ReadPrec [NonEmpty a]

Show a => Show (NonEmpty a)

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> NonEmpty a -> ShowS

show :: NonEmpty a -> String

showList :: [NonEmpty a] -> ShowS

Eq a => Eq (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(==) :: NonEmpty a -> NonEmpty a -> Bool

(/=) :: NonEmpty a -> NonEmpty a -> Bool

Ord a => Ord (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

compare :: NonEmpty a -> NonEmpty a -> Ordering

(<) :: NonEmpty a -> NonEmpty a -> Bool

(<=) :: NonEmpty a -> NonEmpty a -> Bool

(>) :: NonEmpty a -> NonEmpty a -> Bool

(>=) :: NonEmpty a -> NonEmpty a -> Bool

max :: NonEmpty a -> NonEmpty a -> NonEmpty a

min :: NonEmpty a -> NonEmpty a -> NonEmpty a

type Item (NonEmpty a)

Defined in GHC.IsList

type Item (NonEmpty a) = a

Reexport from Array of the "array" package

data Array i e

The type of immutable non-strict (boxed) arrays with indices in i and elements in e.

Instances

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

toList :: Array i a -> [a]

null :: Array i a -> Bool

length :: Array i a -> Int

elem :: Eq a => a -> Array i a -> Bool

maximum :: Ord a => Array i a -> a

minimum :: Ord a => Array i a -> a

sum :: Num a => Array i a -> a

product :: Num a => Array i a -> a

Ix i => Traversable (Array i)

Since: base-2.1

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Array i a -> f (Array i b)

sequenceA :: Applicative f => Array i (f a) -> f (Array i a)

mapM :: Monad m => (a -> m b) -> Array i a -> m (Array i b)

sequence :: Monad m => Array i (m a) -> m (Array i a)

Functor (Array i)

Since: base-2.1

Defined in GHC.Arr

Methods

fmap :: (a -> b) -> Array i a -> Array i b

(<$) :: a -> Array i b -> Array i a

(Ix a, Read a, Read b) => Read (Array a b)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (Array a b)

readList :: ReadS [Array a b]

readPrec :: ReadPrec (Array a b)

readListPrec :: ReadPrec [Array a b]

(Ix a, Show a, Show b) => Show (Array a b)

Since: base-2.1

Defined in GHC.Arr

Methods

showsPrec :: Int -> Array a b -> ShowS

show :: Array a b -> String

showList :: [Array a b] -> ShowS

(Ix i, Eq e) => Eq (Array i e)

Since: base-2.1

Defined in GHC.Arr

Methods

(==) :: Array i e -> Array i e -> Bool

(/=) :: Array i e -> Array i e -> Bool

(Ix i, Ord e) => Ord (Array i e)

Since: base-2.1

Defined in GHC.Arr

Methods

compare :: Array i e -> Array i e -> Ordering

(<) :: Array i e -> Array i e -> Bool

(<=) :: Array i e -> Array i e -> Bool

(>) :: Array i e -> Array i e -> Bool

(>=) :: Array i e -> Array i e -> Bool

max :: Array i e -> Array i e -> Array i e

min :: Array i e -> Array i e -> Array i e

Formally-Named Tuples

type Pair a b = (a, b)

A two-element Tuple

type Trio a b c = (a, b, c)

A three-element Tuple

External-Package-Types

type ByteString = ByteString

Aliased reexport from ByteString of the "bytestring" package

type ByteStringLazy = ByteString

Aliased reexport from Lazy of the "bytestring" package

type Map key val = Map key val

Aliased reexport from Strict of the "containers" package

type MapLazy key val = Map key val

Aliased reexport from Lazy of the "containers" package

type Text = Text

Aliased reexport from Text of the "text" package

type TextLazy = Text

Aliased reexport from Lazy of the "text" package

Reexport from Set of the "containers" package

data Set a

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

toList :: Set a -> [a]

null :: Set a -> Bool

length :: Set a -> Int

elem :: Eq a => a -> Set a -> Bool

maximum :: Ord a => Set a -> a

minimum :: Ord a => Set a -> a

sum :: Num a => Set a -> a

product :: Num a => Set a -> a

Eq1 Set

Since: containers-0.5.9

Defined in Data.Set.Internal

Methods

liftEq :: (a -> b -> Bool) -> Set a -> Set b -> Bool

Ord1 Set

Since: containers-0.5.9

Defined in Data.Set.Internal

Methods

liftCompare :: (a -> b -> Ordering) -> Set a -> Set b -> Ordering

Show1 Set

Since: containers-0.5.9

Defined in Data.Set.Internal

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Set a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Set a] -> ShowS

Lift a => Lift (Set a :: Type)

Since: containers-0.6.6

Defined in Data.Set.Internal

Methods

lift :: Quote m => Set a -> m Exp

liftTyped :: forall (m :: Type -> Type). Quote m => Set a -> Code m (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)

toConstr :: Set a -> Constr

dataTypeOf :: Set a -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Set a))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Set a))

gmapT :: (forall b. Data b => b -> b) -> Set a -> Set a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r

gmapQ :: (forall d. Data d => d -> u) -> Set a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Set a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Set a -> m (Set a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a)

Ord a => Monoid (Set a)

Defined in Data.Set.Internal

Methods

mempty :: Set a

mappend :: Set a -> Set a -> Set a

mconcat :: [Set a] -> Set a

Ord a => Semigroup (Set a)

Since: containers-0.5.7

Defined in Data.Set.Internal

Methods

(<>) :: Set a -> Set a -> Set a

sconcat :: NonEmpty (Set a) -> Set a

stimes :: Integral b => b -> Set a -> Set a

Ord a => IsList (Set a)

Since: containers-0.5.6.2

Defined in Data.Set.Internal

Associated Types

type Item (Set a)

Methods

fromList :: [Item (Set a)] -> Set a

fromListN :: Int -> [Item (Set a)] -> Set a

toList :: Set a -> [Item (Set a)]

(Read a, Ord a) => Read (Set a)

Defined in Data.Set.Internal

Methods

readsPrec :: Int -> ReadS (Set a)

readList :: ReadS [Set a]

readPrec :: ReadPrec (Set a)

readListPrec :: ReadPrec [Set a]

Show a => Show (Set a)

Defined in Data.Set.Internal

Methods

showsPrec :: Int -> Set a -> ShowS

show :: Set a -> String

showList :: [Set a] -> ShowS

NFData a => NFData (Set a)

Defined in Data.Set.Internal

Methods

rnf :: Set a -> ()

Eq a => Eq (Set a)

Defined in Data.Set.Internal

Methods

(==) :: Set a -> Set a -> Bool

(/=) :: Set a -> Set a -> Bool

Ord a => Ord (Set a)

Defined in Data.Set.Internal

Methods

compare :: Set a -> Set a -> Ordering

(<) :: Set a -> Set a -> Bool

(<=) :: Set a -> Set a -> Bool

(>) :: Set a -> Set a -> Bool

(>=) :: Set a -> Set a -> Bool

max :: Set a -> Set a -> Set a

min :: Set a -> Set a -> Set a

type Item (Set a)

Defined in Data.Set.Internal

type Item (Set a) = a

Reexport from Sequence of the "containers" package

data Seq a

General-purpose finite sequences.

Instances

MonadFix Seq

Since: containers-0.5.11

Defined in Data.Sequence.Internal

Methods

mfix :: (a -> Seq a) -> Seq a

MonadZip Seq

 mzipWith = zipWith

 munzip = unzip

Defined in Data.Sequence.Internal

Methods

mzip :: Seq a -> Seq b -> Seq (a, b)

mzipWith :: (a -> b -> c) -> Seq a -> Seq b -> Seq c

munzip :: Seq (a, b) -> (Seq a, Seq b)

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

toList :: Seq a -> [a]

null :: Seq a -> Bool

length :: Seq a -> Int

elem :: Eq a => a -> Seq a -> Bool

maximum :: Ord a => Seq a -> a

minimum :: Ord a => Seq a -> a

sum :: Num a => Seq a -> a

product :: Num a => Seq a -> a

Eq1 Seq

Since: containers-0.5.9

Defined in Data.Sequence.Internal

Methods

liftEq :: (a -> b -> Bool) -> Seq a -> Seq b -> Bool

Ord1 Seq

Since: containers-0.5.9

Defined in Data.Sequence.Internal

Methods

liftCompare :: (a -> b -> Ordering) -> Seq a -> Seq b -> Ordering

Read1 Seq

Since: containers-0.5.9

Defined in Data.Sequence.Internal

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Seq a)

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Seq a]

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Seq a)

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Seq a]

Show1 Seq

Since: containers-0.5.9

Defined in Data.Sequence.Internal

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Seq a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Seq a] -> ShowS

Traversable Seq

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Seq a -> f (Seq b)

sequenceA :: Applicative f => Seq (f a) -> f (Seq a)

mapM :: Monad m => (a -> m b) -> Seq a -> m (Seq b)

sequence :: Monad m => Seq (m a) -> m (Seq a)

Alternative Seq

Since: containers-0.5.4

Defined in Data.Sequence.Internal

Methods

empty :: Seq a

(<|>) :: Seq a -> Seq a -> Seq a

some :: Seq a -> Seq [a]

many :: Seq a -> Seq [a]

Applicative Seq

Since: containers-0.5.4

Defined in Data.Sequence.Internal

Methods

pure :: a -> Seq a

(<*>) :: Seq (a -> b) -> Seq a -> Seq b

liftA2 :: (a -> b -> c) -> Seq a -> Seq b -> Seq c

(*>) :: Seq a -> Seq b -> Seq b

(<*) :: Seq a -> Seq b -> Seq a

Functor Seq

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Seq a -> Seq b

(<$) :: a -> Seq b -> Seq a

Monad Seq

Defined in Data.Sequence.Internal

Methods

(>>=) :: Seq a -> (a -> Seq b) -> Seq b

(>>) :: Seq a -> Seq b -> Seq b

return :: a -> Seq a

MonadPlus Seq

Defined in Data.Sequence.Internal

Methods

mzero :: Seq a

mplus :: Seq a -> Seq a -> Seq a

UnzipWith Seq

Defined in Data.Sequence.Internal

Methods

unzipWith' :: (x -> (a, b)) -> Seq x -> (Seq a, Seq b)

Lift a => Lift (Seq a :: Type)

Since: containers-0.6.6

Defined in Data.Sequence.Internal

Methods

lift :: Quote m => Seq a -> m Exp

liftTyped :: forall (m :: Type -> Type). Quote m => Seq a -> Code m (Seq a)

Data a => Data (Seq a)

Defined in Data.Sequence.Internal

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Seq a -> c (Seq a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Seq a)

toConstr :: Seq a -> Constr

dataTypeOf :: Seq a -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Seq a))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Seq a))

gmapT :: (forall b. Data b => b -> b) -> Seq a -> Seq a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Seq a -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Seq a -> r

gmapQ :: (forall d. Data d => d -> u) -> Seq a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Seq a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a)

a ~ Char => IsString (Seq a)

Since: containers-0.5.7

Defined in Data.Sequence.Internal

Methods

fromString :: String -> Seq a

Monoid (Seq a)

Defined in Data.Sequence.Internal

Methods

mempty :: Seq a

mappend :: Seq a -> Seq a -> Seq a

mconcat :: [Seq a] -> Seq a

Semigroup (Seq a)

Since: containers-0.5.7

Defined in Data.Sequence.Internal

Methods

(<>) :: Seq a -> Seq a -> Seq a

sconcat :: NonEmpty (Seq a) -> Seq a

stimes :: Integral b => b -> Seq a -> Seq a

IsList (Seq a)

Defined in Data.Sequence.Internal

Associated Types

type Item (Seq a)

Methods

fromList :: [Item (Seq a)] -> Seq a

fromListN :: Int -> [Item (Seq a)] -> Seq a

toList :: Seq a -> [Item (Seq a)]

Read a => Read (Seq a)

Defined in Data.Sequence.Internal

Methods

readsPrec :: Int -> ReadS (Seq a)

readList :: ReadS [Seq a]

readPrec :: ReadPrec (Seq a)

readListPrec :: ReadPrec [Seq a]

Show a => Show (Seq a)

Defined in Data.Sequence.Internal

Methods

showsPrec :: Int -> Seq a -> ShowS

show :: Seq a -> String

showList :: [Seq a] -> ShowS

NFData a => NFData (Seq a)

Defined in Data.Sequence.Internal

Methods

rnf :: Seq a -> ()

Eq a => Eq (Seq a)

Defined in Data.Sequence.Internal

Methods

(==) :: Seq a -> Seq a -> Bool

(/=) :: Seq a -> Seq a -> Bool

Ord a => Ord (Seq a)

Defined in Data.Sequence.Internal

Methods

compare :: Seq a -> Seq a -> Ordering

(<) :: Seq a -> Seq a -> Bool

(<=) :: Seq a -> Seq a -> Bool

(>) :: Seq a -> Seq a -> Bool

(>=) :: Seq a -> Seq a -> Bool

max :: Seq a -> Seq a -> Seq a

min :: Seq a -> Seq a -> Seq a

type Item (Seq a)

Defined in Data.Sequence.Internal

type Item (Seq a) = a

Other Important Things

Reexport from Maybe

data Maybe a

The Maybe type encapsulates an optional value. A value of type Maybe a either contains a value of type a (represented as Just a), or it is empty (represented as Nothing). 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.

Constructors

Nothing

Just a

Instances

MonadFail Maybe

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> Maybe 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

toList :: Maybe a -> [a]

null :: Maybe a -> Bool

length :: Maybe a -> Int

elem :: Eq a => a -> Maybe a -> Bool

maximum :: Ord a => Maybe a -> a

minimum :: Ord a => Maybe a -> a

sum :: Num a => Maybe a -> a

product :: Num a => Maybe a -> a

Traversable Maybe

Since: base-2.1

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Maybe a -> f (Maybe b)

sequenceA :: Applicative f => Maybe (f a) -> f (Maybe a)

mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b)

sequence :: Monad m => Maybe (m a) -> m (Maybe a)

Alternative Maybe

Picks the leftmost Just value, or, alternatively, Nothing.

Since: base-2.1

Defined in GHC.Base

Methods

empty :: Maybe a

(<|>) :: Maybe a -> Maybe a -> Maybe a

some :: Maybe a -> Maybe [a]

many :: Maybe a -> Maybe [a]

Applicative Maybe

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a -> Maybe a

(<*>) :: Maybe (a -> b) -> Maybe a -> Maybe b

liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c

(*>) :: Maybe a -> Maybe b -> Maybe b

(<*) :: Maybe a -> Maybe b -> Maybe a

Functor Maybe

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Maybe a -> Maybe b

(<$) :: a -> Maybe b -> Maybe a

Monad Maybe

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b

(>>) :: Maybe a -> Maybe b -> Maybe b

return :: a -> Maybe a

MonadPlus Maybe

Picks the leftmost Just value, or, alternatively, Nothing.

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: Maybe a

mplus :: Maybe a -> Maybe a -> Maybe a

Semigroup a => Monoid (Maybe a)

Lift a semigroup into Maybe forming a Monoid according to http://en.wikipedia.org/wiki/Monoid: "Any semigroup S may be turned into a monoid simply by adjoining an element e not in S and defining e*e = e and e*s = s = s*e for all s ∈ S."

Since 4.11.0: constraint on inner a value generalised from Monoid to Semigroup.

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: Maybe a

mappend :: Maybe a -> Maybe a -> Maybe a

mconcat :: [Maybe a] -> Maybe a

Semigroup a => Semigroup (Maybe a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: Maybe a -> Maybe a -> Maybe a

sconcat :: NonEmpty (Maybe a) -> Maybe a

stimes :: Integral b => b -> Maybe a -> Maybe a

Read a => Read (Maybe a)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (Maybe a)

readList :: ReadS [Maybe a]

readPrec :: ReadPrec (Maybe a)

readListPrec :: ReadPrec [Maybe a]

Show a => Show (Maybe a)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Maybe a -> ShowS

show :: Maybe a -> String

showList :: [Maybe a] -> ShowS

Eq a => Eq (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

(==) :: Maybe a -> Maybe a -> Bool

(/=) :: Maybe a -> Maybe a -> Bool

Ord a => Ord (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

compare :: Maybe a -> Maybe a -> Ordering

(<) :: Maybe a -> Maybe a -> Bool

(<=) :: Maybe a -> Maybe a -> Bool

(>) :: Maybe a -> Maybe a -> Bool

(>=) :: Maybe a -> Maybe a -> Bool

max :: Maybe a -> Maybe a -> Maybe a

min :: Maybe a -> Maybe a -> Maybe a

Reexport from Either

data Either a b

The Either type represents values with two possibilities: a value of type Either a b is either Left a or Right b.

The Either type is sometimes used to represent a value which is either correct or an error; by convention, the Left constructor is used to hold an error value and the Right constructor is used to hold a correct value (mnemonic: "right" also means "correct").

Examples

The type Either String Int is the type of values which can be either a String 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
>>> s
Left "foo"
>>> let n = Right 3 :: Either String Int
>>> n
Right 3
>>> :type s
s :: Either String Int
>>> :type n
n :: Either String Int

The fmap from our Functor instance will ignore Left values, but will apply the supplied function to values contained in a Right:

>>> let s = Left "foo" :: Either String Int
>>> let n = Right 3 :: Either String Int
>>> fmap (*2) s
Left "foo"
>>> fmap (*2) n
Right 6

The Monad instance for Either allows us to chain together multiple actions which may fail, and fail overall if any of the individual steps failed. First we'll write a function that can either parse an Int from a Char, or fail.

>>> import Data.Char ( digitToInt, isDigit )
>>> :{
    let parseEither :: Char -> Either String Int
        parseEither c
          | isDigit c = Right (digitToInt c)
          | otherwise = Left "parse error"
>>> :}

The following should work, since both '1' and '2' can be parsed as Ints.

>>> :{
    let parseMultiple :: Either String Int
        parseMultiple = do
          x <- parseEither '1'
          y <- parseEither '2'
          return (x + y)
>>> :}

>>> parseMultiple
Right 3

But the following should fail overall, since the first operation where we attempt to parse 'm' as an Int will fail:

>>> :{
    let parseMultiple :: Either String Int
        parseMultiple = do
          x <- parseEither 'm'
          y <- parseEither '2'
          return (x + y)
>>> :}

>>> parseMultiple
Left "parse error"

Constructors

Left a

Right b

Instances

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]

null :: Either a a0 -> Bool

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

sum :: Num a0 => Either a a0 -> a0

product :: Num a0 => Either a a0 -> a0

Traversable (Either a)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a0 -> f b) -> Either a a0 -> f (Either a b)

sequenceA :: Applicative f => Either a (f a0) -> f (Either a a0)

mapM :: Monad m => (a0 -> m b) -> Either a a0 -> m (Either a b)

sequence :: Monad m => Either a (m a0) -> m (Either a a0)

Applicative (Either e)

Since: base-3.0

Defined in Data.Either

Methods

pure :: a -> Either e a

(<*>) :: Either e (a -> b) -> Either e a -> Either e b

liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c

(*>) :: Either e a -> Either e b -> Either e b

(<*) :: Either e a -> Either e b -> Either e a

Functor (Either a)

Since: base-3.0

Defined in Data.Either

Methods

fmap :: (a0 -> b) -> Either a a0 -> Either a b

(<$) :: a0 -> Either a b -> Either a a0

Monad (Either e)

Since: base-4.4.0.0

Defined in Data.Either

Methods

(>>=) :: Either e a -> (a -> Either e b) -> Either e b

(>>) :: Either e a -> Either e b -> Either e b

return :: a -> Either e a

Semigroup (Either a b)

Since: base-4.9.0.0

Defined in Data.Either

Methods

(<>) :: Either a b -> Either a b -> Either a b

sconcat :: NonEmpty (Either a b) -> Either a b

stimes :: Integral b0 => b0 -> Either a b -> Either a b

(Read a, Read b) => Read (Either a b)

Since: base-3.0

Defined in Data.Either

Methods

readsPrec :: Int -> ReadS (Either a b)

readList :: ReadS [Either a b]

readPrec :: ReadPrec (Either a b)

readListPrec :: ReadPrec [Either a b]

(Show a, Show b) => Show (Either a b)

Since: base-3.0

Defined in Data.Either

Methods

showsPrec :: Int -> Either a b -> ShowS

show :: Either a b -> String

showList :: [Either a b] -> ShowS

(Eq a, Eq b) => Eq (Either a b)

Since: base-2.1

Defined in Data.Either

Methods

(==) :: Either a b -> Either a b -> Bool

(/=) :: Either a b -> Either a b -> Bool

(Ord a, Ord b) => Ord (Either a b)

Since: base-2.1

Defined in Data.Either

Methods

compare :: Either a b -> Either a b -> Ordering

(<) :: Either a b -> Either a b -> Bool

(<=) :: Either a b -> Either a b -> Bool

(>) :: Either a b -> Either a b -> Bool

(>=) :: Either a b -> Either a b -> Bool

max :: Either a b -> Either a b -> Either a b

min :: Either a b -> Either a b -> Either a b

data Result err ok

The 'Result err ok' type, with variants `Err err` and 'Ok ok'. Similar to the Either type, but with better naming, and disambiguates the purposes.

Constructors

Err err

Ok ok

Instances

Applicative (Result err)

Defined in Antelude.Internal.TypesClasses

Methods

pure :: a -> Result err a

(<*>) :: Result err (a -> b) -> Result err a -> Result err b

liftA2 :: (a -> b -> c) -> Result err a -> Result err b -> Result err c

(*>) :: Result err a -> Result err b -> Result err b

(<*) :: Result err a -> Result err b -> Result err a

Functor (Result err)

Defined in Antelude.Internal.TypesClasses

Methods

fmap :: (a -> b) -> Result err a -> Result err b

(<$) :: a -> Result err b -> Result err a

Monad (Result err)

Defined in Antelude.Internal.TypesClasses

Methods

(>>=) :: Result err a -> (a -> Result err b) -> Result err b

(>>) :: Result err a -> Result err b -> Result err b

return :: a -> Result err a

(Read err, Read ok) => Read (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

readsPrec :: Int -> ReadS (Result err ok)

readList :: ReadS [Result err ok]

readPrec :: ReadPrec (Result err ok)

readListPrec :: ReadPrec [Result err ok]

(Show err, Show ok) => Show (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

showsPrec :: Int -> Result err ok -> ShowS

show :: Result err ok -> String

showList :: [Result err ok] -> ShowS

(Eq err, Eq ok) => Eq (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

(==) :: Result err ok -> Result err ok -> Bool

(/=) :: Result err ok -> Result err ok -> Bool

(Ord err, Ord ok) => Ord (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

compare :: Result err ok -> Result err ok -> Ordering

(<) :: Result err ok -> Result err ok -> Bool

(<=) :: Result err ok -> Result err ok -> Bool

(>) :: Result err ok -> Result err ok -> Bool

(>=) :: Result err ok -> Result err ok -> Bool

max :: Result err ok -> Result err ok -> Result err ok

min :: Result err ok -> Result err ok -> Result err ok

Reexport from Ord

data Ordering

Constructors

LT

EQ

GT

Instances

Monoid Ordering

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: Ordering

mappend :: Ordering -> Ordering -> Ordering

mconcat :: [Ordering] -> Ordering

Semigroup Ordering

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: Ordering -> Ordering -> Ordering

sconcat :: NonEmpty Ordering -> Ordering

stimes :: Integral b => b -> Ordering -> Ordering

Bounded Ordering

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Ordering

maxBound :: Ordering

Enum Ordering

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Ordering -> Ordering

pred :: Ordering -> Ordering

toEnum :: Int -> Ordering

fromEnum :: Ordering -> Int

enumFrom :: Ordering -> [Ordering]

enumFromThen :: Ordering -> Ordering -> [Ordering]

enumFromTo :: Ordering -> Ordering -> [Ordering]

enumFromThenTo :: Ordering -> Ordering -> Ordering -> [Ordering]

Ix Ordering

Since: base-2.1

Defined in GHC.Ix

Methods

range :: (Ordering, Ordering) -> [Ordering]

index :: (Ordering, Ordering) -> Ordering -> Int

unsafeIndex :: (Ordering, Ordering) -> Ordering -> Int

inRange :: (Ordering, Ordering) -> Ordering -> Bool

rangeSize :: (Ordering, Ordering) -> Int

unsafeRangeSize :: (Ordering, Ordering) -> Int

Read Ordering

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Ordering

readList :: ReadS [Ordering]

readPrec :: ReadPrec Ordering

readListPrec :: ReadPrec [Ordering]

Show Ordering

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Ordering -> ShowS

show :: Ordering -> String

showList :: [Ordering] -> ShowS

Eq Ordering

Defined in GHC.Classes

Methods

(==) :: Ordering -> Ordering -> Bool

(/=) :: Ordering -> Ordering -> Bool

Ord Ordering

Defined in GHC.Classes

Methods

compare :: Ordering -> Ordering -> Ordering

(<) :: Ordering -> Ordering -> Bool

(<=) :: Ordering -> Ordering -> Bool

(>) :: Ordering -> Ordering -> Bool

(>=) :: Ordering -> Ordering -> Bool

max :: Ordering -> Ordering -> Ordering

min :: Ordering -> Ordering -> Ordering

Reexport from Show

type ShowS = String -> String

The shows functions return a function that prepends the output String to an existing String. This allows constant-time concatenation of results using function composition.

Reexport from Read

type ReadS a = String -> [(a, String)]

A parser for a type a, represented as a function that takes a String and returns a list of possible parses as (a,String) pairs.

Note that this kind of backtracking parser is very inefficient; reading a large structure may be quite slow (cf ReadP).

Reexport from IO

data IO a

A value of type IO a is a computation which, when performed, does some I/O before returning a value of type a.

There is really only one way to "perform" an I/O action: bind it to Main.main in your program. When your program is run, the I/O will be performed. It isn't possible to perform I/O from an arbitrary function, unless that function is itself in the IO monad and called at some point, directly or indirectly, from Main.main.

IO is a monad, so IO actions can be combined using either the do-notation or the >> and >>= operations from the Monad class.

Instances

MonadFail IO

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> IO a

MonadIO IO

Since: base-4.9.0.0

Defined in Control.Monad.IO.Class

Methods

liftIO :: IO a -> IO a

Alternative IO

Takes the first non-throwing IO action's result. empty throws an exception.

Since: base-4.9.0.0

Defined in GHC.Base

Methods

empty :: IO a

(<|>) :: IO a -> IO a -> IO a

some :: IO a -> IO [a]

many :: IO a -> IO [a]

Applicative IO

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a -> IO a

(<*>) :: IO (a -> b) -> IO a -> IO b

liftA2 :: (a -> b -> c) -> IO a -> IO b -> IO c

(*>) :: IO a -> IO b -> IO b

(<*) :: IO a -> IO b -> IO a

Functor IO

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> IO a -> IO b

(<$) :: a -> IO b -> IO a

Monad IO

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: IO a -> (a -> IO b) -> IO b

(>>) :: IO a -> IO b -> IO b

return :: a -> IO a

MonadPlus IO

Takes the first non-throwing IO action's result. mzero throws an exception.

Since: base-4.9.0.0

Defined in GHC.Base

Methods

mzero :: IO a

mplus :: IO a -> IO a -> IO a

Monoid a => Monoid (IO a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

mempty :: IO a

mappend :: IO a -> IO a -> IO a

mconcat :: [IO a] -> IO a

Semigroup a => Semigroup (IO a)

Since: base-4.10.0.0

Defined in GHC.Base

Methods

(<>) :: IO a -> IO a -> IO a

sconcat :: NonEmpty (IO a) -> IO a

stimes :: Integral b => b -> IO a -> IO a

Reexport from IO

type FilePath = String

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.

Reexport from Error

type IOError = IOException

The Haskell 2010 type for exceptions in the IO monad. Any I/O operation may raise an IOException instead of returning a result. For a more general type of exception, including also those that arise in pure code, see Exception.

In Haskell 2010, this is an opaque type.

Reexport from Void

data Void

Uninhabited data type

Since: base-4.8.0.0

Instances

Semigroup Void

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: Void -> Void -> Void

sconcat :: NonEmpty Void -> Void

stimes :: Integral b => b -> Void -> Void

Exception Void

Since: base-4.8.0.0

Defined in GHC.Exception.Type

Methods

toException :: Void -> SomeException

fromException :: SomeException -> Maybe Void

displayException :: Void -> String

Ix Void

Since: base-4.8.0.0

Defined in GHC.Ix

Methods

range :: (Void, Void) -> [Void]

index :: (Void, Void) -> Void -> Int

unsafeIndex :: (Void, Void) -> Void -> Int

inRange :: (Void, Void) -> Void -> Bool

rangeSize :: (Void, Void) -> Int

unsafeRangeSize :: (Void, Void) -> Int

Read Void

Reading a Void value is always a parse error, considering Void as a data type with no constructors.

Since: base-4.8.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Void

readList :: ReadS [Void]

readPrec :: ReadPrec Void

readListPrec :: ReadPrec [Void]

Show Void

Since: base-4.8.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Void -> ShowS

show :: Void -> String

showList :: [Void] -> ShowS

Eq Void

Since: base-4.8.0.0

Defined in GHC.Base

Methods

(==) :: Void -> Void -> Bool

(/=) :: Void -> Void -> Bool

Ord Void

Since: base-4.8.0.0

Defined in GHC.Base

Methods

compare :: Void -> Void -> Ordering

(<) :: Void -> Void -> Bool

(<=) :: Void -> Void -> Bool

(>) :: Void -> Void -> Bool

(>=) :: Void -> Void -> Bool

max :: Void -> Void -> Void

min :: Void -> Void -> Void

Classes

Numeric Classes

Reexport from Prelude

class Num a where

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 + x

fromInteger 0 is the additive identity

x + fromInteger 0 = x

negate gives the additive inverse

x + negate x = fromInteger 0

Associativity of (*)

(x * y) * z = x * (y * z)

fromInteger 1 is the multiplicative identity

x * fromInteger 1 = x and fromInteger 1 * x = x

Distributivity of (*) with respect to (+)

a * (b + c) = (a * b) + (a * c) and (b + c) * a = (b * a) + (c * a)

Coherence with toInteger

if the type also implements Integral, then fromInteger is a left inverse for toInteger, i.e. fromInteger (toInteger i) == i

Note that it isn't customarily expected that a type instance of both Num and Ord implement an ordered ring. Indeed, in base only Integer and Rational do.

Minimal complete definition

(+), (*), abs, signum, fromInteger, (negate | (-))

Methods

(+) :: a -> a -> a infixl 6

(-) :: a -> a -> a infixl 6

(*) :: a -> a -> a infixl 7

Instances

Num Word16

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word16 -> Word16 -> Word16

(-) :: Word16 -> Word16 -> Word16

(*) :: Word16 -> Word16 -> Word16

negate :: Word16 -> Word16

abs :: Word16 -> Word16

signum :: Word16 -> Word16

fromInteger :: Integer -> Word16

Num Word32

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word32 -> Word32 -> Word32

(-) :: Word32 -> Word32 -> Word32

(*) :: Word32 -> Word32 -> Word32

negate :: Word32 -> Word32

abs :: Word32 -> Word32

signum :: Word32 -> Word32

fromInteger :: Integer -> Word32

Num Word64

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word64 -> Word64 -> Word64

(-) :: Word64 -> Word64 -> Word64

(*) :: Word64 -> Word64 -> Word64

negate :: Word64 -> Word64

abs :: Word64 -> Word64

signum :: Word64 -> Word64

fromInteger :: Integer -> Word64

Num Word8

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word8 -> Word8 -> Word8

(-) :: Word8 -> Word8 -> Word8

(*) :: Word8 -> Word8 -> Word8

negate :: Word8 -> Word8

abs :: Word8 -> Word8

signum :: Word8 -> Word8

fromInteger :: Integer -> Word8

Num Integer

Since: base-2.1

Defined in GHC.Num

Methods

(+) :: Integer -> Integer -> Integer

(-) :: Integer -> Integer -> Integer

(*) :: Integer -> Integer -> Integer

negate :: Integer -> Integer

abs :: Integer -> Integer

signum :: Integer -> Integer

fromInteger :: Integer -> Integer

Num Natural

Note that Natural's Num instance isn't a ring: no element but 0 has an additive inverse. It is a semiring though.

Since: base-4.8.0.0

Defined in GHC.Num

Methods

(+) :: Natural -> Natural -> Natural

(-) :: Natural -> Natural -> Natural

(*) :: Natural -> Natural -> Natural

negate :: Natural -> Natural

abs :: Natural -> Natural

signum :: Natural -> Natural

fromInteger :: Integer -> Natural

Num Int

Since: base-2.1

Defined in GHC.Num

Methods

(+) :: Int -> Int -> Int

(-) :: Int -> Int -> Int

(*) :: Int -> Int -> Int

negate :: Int -> Int

abs :: Int -> Int

signum :: Int -> Int

fromInteger :: Integer -> Int

Num Word

Since: base-2.1

Defined in GHC.Num

Methods

(+) :: Word -> Word -> Word

(-) :: Word -> Word -> Word

(*) :: Word -> Word -> Word

negate :: Word -> Word

abs :: Word -> Word

signum :: Word -> Word

fromInteger :: Integer -> Word

Integral a => Num (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

(+) :: Ratio a -> Ratio a -> Ratio a

(-) :: Ratio a -> Ratio a -> Ratio a

(*) :: Ratio a -> Ratio a -> Ratio a

negate :: Ratio a -> Ratio a

abs :: Ratio a -> Ratio a

signum :: Ratio a -> Ratio a

fromInteger :: Integer -> Ratio a

Reexport from Prelude

class (Num a, Ord a) => Real a

Real numbers.

The Haskell report defines no laws for Real, however Real instances are customarily expected to adhere to the following law:

Coherence with fromRational

if the type also implements Fractional, then fromRational is a left inverse for toRational, i.e. fromRational (toRational i) = i

Minimal complete definition

toRational

Instances

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 Word8

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word8 -> Rational

Real Integer

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Integer -> Rational

Real Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

toRational :: Natural -> Rational

Real Int

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Int -> Rational

Real Word

Since: base-2.1

Defined in GHC.Real

Methods

toRational :: Word -> Rational

Integral a => Real (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Ratio a -> Rational

Reexport from Prelude

class (Real a, Enum a) => Integral a

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 y with rem x y = fromInteger 0 or g (rem x y) < g y
• x = y * div x y + mod x y with mod x y = fromInteger 0 or f (mod x y) < f y

An example of a suitable Euclidean function, for Integer's instance, is abs.

In addition, toInteger should be total, and fromInteger should be a left inverse for it, i.e. fromInteger (toInteger i) = i.

Minimal complete definition

quotRem, toInteger

Instances

Integral Word16

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word16 -> Word16 -> Word16

rem :: Word16 -> Word16 -> Word16

div :: Word16 -> Word16 -> Word16

mod :: Word16 -> Word16 -> Word16

quotRem :: Word16 -> Word16 -> (Word16, Word16)

divMod :: Word16 -> Word16 -> (Word16, Word16)

toInteger :: Word16 -> Integer

Integral Word32

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word32 -> Word32 -> Word32

rem :: Word32 -> Word32 -> Word32

div :: Word32 -> Word32 -> Word32

mod :: Word32 -> Word32 -> Word32

quotRem :: Word32 -> Word32 -> (Word32, Word32)

divMod :: Word32 -> Word32 -> (Word32, Word32)

toInteger :: Word32 -> Integer

Integral Word64

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word64 -> Word64 -> Word64

rem :: Word64 -> Word64 -> Word64

div :: Word64 -> Word64 -> Word64

mod :: Word64 -> Word64 -> Word64

quotRem :: Word64 -> Word64 -> (Word64, Word64)

divMod :: Word64 -> Word64 -> (Word64, Word64)

toInteger :: Word64 -> Integer

Integral Word8

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word8 -> Word8 -> Word8

rem :: Word8 -> Word8 -> Word8

div :: Word8 -> Word8 -> Word8

mod :: Word8 -> Word8 -> Word8

quotRem :: Word8 -> Word8 -> (Word8, Word8)

divMod :: Word8 -> Word8 -> (Word8, Word8)

toInteger :: Word8 -> Integer

Integral Integer

Since: base-2.0.1

Defined in GHC.Real

Methods

quot :: Integer -> Integer -> Integer

rem :: Integer -> Integer -> Integer

div :: Integer -> Integer -> Integer

mod :: Integer -> Integer -> Integer

quotRem :: Integer -> Integer -> (Integer, Integer)

divMod :: Integer -> Integer -> (Integer, Integer)

toInteger :: Integer -> Integer

Integral Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

quot :: Natural -> Natural -> Natural

rem :: Natural -> Natural -> Natural

div :: Natural -> Natural -> Natural

mod :: Natural -> Natural -> Natural

quotRem :: Natural -> Natural -> (Natural, Natural)

divMod :: Natural -> Natural -> (Natural, Natural)

toInteger :: Natural -> Integer

Integral Int

Since: base-2.0.1

Defined in GHC.Real

Methods

quot :: Int -> Int -> Int

rem :: Int -> Int -> Int

div :: Int -> Int -> Int

mod :: Int -> Int -> Int

quotRem :: Int -> Int -> (Int, Int)

divMod :: Int -> Int -> (Int, Int)

toInteger :: Int -> Integer

Integral Word

Since: base-2.1

Defined in GHC.Real

Methods

quot :: Word -> Word -> Word

rem :: Word -> Word -> Word

div :: Word -> Word -> Word

mod :: Word -> Word -> Word

quotRem :: Word -> Word -> (Word, Word)

divMod :: Word -> Word -> (Word, Word)

toInteger :: Word -> Integer

Reexport from Prelude

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:

recip gives the multiplicative inverse

x * recip x = recip x * x = fromInteger 1

Totality of toRational

toRational is total

Coherence with toRational

if the type also implements Real, then fromRational is a left inverse for toRational, i.e. fromRational (toRational i) = i

Note that it isn't customarily expected that a type instance of Fractional implement a field. However, all instances in base do.

Minimal complete definition

fromRational, (recip | (/))

Methods

(/) :: a -> a -> a infixl 7

Fractional division.

Instances

Integral a => Fractional (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

(/) :: Ratio a -> Ratio a -> Ratio a

recip :: Ratio a -> Ratio a

fromRational :: Rational -> Ratio a

Reexport from Prelude

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 b
• exp (fromInteger 0) = fromInteger 1

Minimal complete definition

pi, exp, log, sin, cos, asin, acos, atan, sinh, cosh, asinh, acosh, atanh

Methods

(**) :: a -> a -> a infixr 8

Instances

Floating Double

Since: base-2.1

Defined in GHC.Float

Methods

pi :: Double

exp :: Double -> Double

log :: Double -> Double

sqrt :: Double -> Double

(**) :: Double -> Double -> Double

logBase :: Double -> Double -> Double

sin :: Double -> Double

cos :: Double -> Double

tan :: Double -> Double

asin :: Double -> Double

acos :: Double -> Double

atan :: Double -> Double

sinh :: Double -> Double

cosh :: Double -> Double

tanh :: Double -> Double

asinh :: Double -> Double

acosh :: Double -> Double

atanh :: Double -> Double

log1p :: Double -> Double

expm1 :: Double -> Double

log1pexp :: Double -> Double

log1mexp :: Double -> Double

Floating Float

Since: base-2.1

Defined in GHC.Float

Methods

pi :: Float

exp :: Float -> Float

log :: Float -> Float

sqrt :: Float -> Float

(**) :: Float -> Float -> Float

logBase :: Float -> Float -> Float

sin :: Float -> Float

cos :: Float -> Float

tan :: Float -> Float

asin :: Float -> Float

acos :: Float -> Float

atan :: Float -> Float

sinh :: Float -> Float

cosh :: Float -> Float

tanh :: Float -> Float

asinh :: Float -> Float

acosh :: Float -> Float

atanh :: Float -> Float

log1p :: Float -> Float

expm1 :: Float -> Float

log1pexp :: Float -> Float

log1mexp :: Float -> Float

Reexport from Prelude

class (Real a, Fractional a) => RealFrac a

Extracting components of fractions.

Minimal complete definition

properFraction

Instances

Integral a => RealFrac (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

properFraction :: Integral b => Ratio a -> (b, Ratio a)

truncate :: Integral b => Ratio a -> b

round :: Integral b => Ratio a -> b

ceiling :: Integral b => Ratio a -> b

floor :: Integral b => Ratio a -> b

Reexport from Prelude

class (RealFrac a, Floating a) => RealFloat a

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

Instances

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

exponent :: Double -> Int

significand :: Double -> Double

scaleFloat :: Int -> Double -> Double

isNaN :: Double -> Bool

isInfinite :: Double -> Bool

isDenormalized :: Double -> Bool

isNegativeZero :: Double -> Bool

isIEEE :: Double -> Bool

atan2 :: Double -> Double -> Double

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

exponent :: Float -> Int

significand :: Float -> Float

scaleFloat :: Int -> Float -> Float

isNaN :: Float -> Bool

isInfinite :: Float -> Bool

isDenormalized :: Float -> Bool

isNegativeZero :: Float -> Bool

isIEEE :: Float -> Bool

atan2 :: Float -> Float -> Float

The "Theorum-Based" Classes

Reexport from Semigroup

class Semigroup a where

The class of semigroups (types with an associative binary operation).

Instances should satisfy the following:

Associativity

x <> (y <> z) = (x <> y) <> z

You can alternatively define sconcat instead of (<>), in which case the laws are:

Unit

sconcat (pure x) = x

Multiplication

sconcat (join xss) = sconcat (fmap sconcat xss)

Since: base-4.9.0.0

Minimal complete definition

(<>) | sconcat

Methods

(<>) :: a -> a -> a infixr 6

An associative operation.

>>> [1,2,3] <> [4,5,6]
[1,2,3,4,5,6]

Instances

Semigroup Void

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: Void -> Void -> Void

sconcat :: NonEmpty Void -> Void

stimes :: Integral b => b -> Void -> Void

Semigroup ByteString

Defined in Data.ByteString.Internal.Type

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 Ordering

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: Ordering -> Ordering -> Ordering

sconcat :: NonEmpty Ordering -> Ordering

stimes :: Integral b => b -> Ordering -> Ordering

Semigroup Doc

Defined in Text.PrettyPrint.HughesPJ

Methods

(<>) :: Doc -> Doc -> Doc

sconcat :: NonEmpty Doc -> Doc

stimes :: Integral b => b -> Doc -> Doc

Semigroup ()

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: () -> () -> ()

sconcat :: NonEmpty () -> ()

stimes :: Integral b => b -> () -> ()

Semigroup (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: NonEmpty a -> NonEmpty a -> NonEmpty a

sconcat :: NonEmpty (NonEmpty a) -> NonEmpty a

stimes :: Integral b => b -> NonEmpty a -> NonEmpty a

Semigroup (Seq a)

Since: containers-0.5.7

Defined in Data.Sequence.Internal

Methods

(<>) :: Seq a -> Seq a -> Seq a

sconcat :: NonEmpty (Seq a) -> Seq a

stimes :: Integral b => b -> Seq a -> Seq a

Ord a => Semigroup (Intersection a)

Defined in Data.Set.Internal

Methods

(<>) :: Intersection a -> Intersection a -> Intersection a

sconcat :: NonEmpty (Intersection a) -> Intersection a

stimes :: Integral b => b -> Intersection a -> Intersection a

Semigroup (MergeSet a)

Defined in Data.Set.Internal

Methods

(<>) :: MergeSet a -> MergeSet a -> MergeSet a

sconcat :: NonEmpty (MergeSet a) -> MergeSet a

stimes :: Integral b => b -> MergeSet a -> MergeSet a

Ord a => Semigroup (Set a)

Since: containers-0.5.7

Defined in Data.Set.Internal

Methods

(<>) :: Set a -> Set a -> Set a

sconcat :: NonEmpty (Set a) -> Set a

stimes :: Integral b => b -> Set a -> Set a

Semigroup a => Semigroup (IO a)

Since: base-4.10.0.0

Defined in GHC.Base

Methods

(<>) :: IO a -> IO a -> IO a

sconcat :: NonEmpty (IO a) -> IO a

stimes :: Integral b => b -> IO a -> IO a

Semigroup (Doc a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

(<>) :: Doc a -> Doc a -> Doc a

sconcat :: NonEmpty (Doc a) -> Doc a

stimes :: Integral b => b -> Doc a -> Doc a

Semigroup a => Semigroup (Maybe a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: Maybe a -> Maybe a -> Maybe a

sconcat :: NonEmpty (Maybe a) -> Maybe a

stimes :: Integral b => b -> Maybe a -> Maybe a

Semigroup a => Semigroup (a)

Since: base-4.15

Defined in GHC.Base

Methods

(<>) :: (a) -> (a) -> (a)

sconcat :: NonEmpty (a) -> (a)

stimes :: Integral b => b -> (a) -> (a)

Semigroup [a]

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: [a] -> [a] -> [a]

sconcat :: NonEmpty [a] -> [a]

stimes :: Integral b => b -> [a] -> [a]

Semigroup (Either a b)

Since: base-4.9.0.0

Defined in Data.Either

Methods

(<>) :: Either a b -> Either a b -> Either a b

sconcat :: NonEmpty (Either a b) -> Either a b

stimes :: Integral b0 => b0 -> Either a b -> Either a b

Ord k => Semigroup (Map k v)

Defined in Data.Map.Internal

Methods

(<>) :: Map k v -> Map k v -> Map k v

sconcat :: NonEmpty (Map k v) -> Map k v

stimes :: Integral b => b -> Map k v -> Map k v

(Semigroup a, Semigroup b) => Semigroup (a, b)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: (a, b) -> (a, b) -> (a, b)

sconcat :: NonEmpty (a, b) -> (a, b)

stimes :: Integral b0 => b0 -> (a, b) -> (a, b)

Semigroup b => Semigroup (a -> b)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: (a -> b) -> (a -> b) -> a -> b

sconcat :: NonEmpty (a -> b) -> a -> b

stimes :: Integral b0 => b0 -> (a -> b) -> a -> b

(Semigroup a, Semigroup b, Semigroup c) => Semigroup (a, b, c)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: (a, b, c) -> (a, b, c) -> (a, b, c)

sconcat :: NonEmpty (a, b, c) -> (a, b, c)

stimes :: Integral b0 => b0 -> (a, b, c) -> (a, b, c)

(Semigroup a, Semigroup b, Semigroup c, Semigroup d) => Semigroup (a, b, c, d)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d)

sconcat :: NonEmpty (a, b, c, d) -> (a, b, c, d)

stimes :: Integral b0 => b0 -> (a, b, c, d) -> (a, b, c, d)

(Semigroup a, Semigroup b, Semigroup c, Semigroup d, Semigroup e) => Semigroup (a, b, c, d, e)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e)

sconcat :: NonEmpty (a, b, c, d, e) -> (a, b, c, d, e)

stimes :: Integral b0 => b0 -> (a, b, c, d, e) -> (a, b, c, d, e)

Reexport from Monoid

class Semigroup a => Monoid a

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) <> z (Semigroup law)

Concatenation

mconcat = foldr (<>) mempty

You can alternatively define mconcat instead of mempty, in which case the laws are:

Unit

mconcat (pure x) = x

Multiplication

mconcat (join xss) = mconcat (fmap mconcat xss)

Subclass

mconcat (toList xs) = sconcat xs

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

mempty | mconcat

Instances

Monoid ByteString

Defined in Data.ByteString.Internal.Type

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 Ordering

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: Ordering

mappend :: Ordering -> Ordering -> Ordering

mconcat :: [Ordering] -> Ordering

Monoid Doc

Defined in Text.PrettyPrint.HughesPJ

Methods

mempty :: Doc

mappend :: Doc -> Doc -> Doc

mconcat :: [Doc] -> Doc

Monoid ()

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: ()

mappend :: () -> () -> ()

mconcat :: [()] -> ()

Monoid (Seq a)

Defined in Data.Sequence.Internal

Methods

mempty :: Seq a

mappend :: Seq a -> Seq a -> Seq a

mconcat :: [Seq a] -> Seq a

Monoid (MergeSet a)

Defined in Data.Set.Internal

Methods

mempty :: MergeSet a

mappend :: MergeSet a -> MergeSet a -> MergeSet a

mconcat :: [MergeSet a] -> MergeSet a

Ord a => Monoid (Set a)

Defined in Data.Set.Internal

Methods

mempty :: Set a

mappend :: Set a -> Set a -> Set a

mconcat :: [Set a] -> Set a

Monoid a => Monoid (IO a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

mempty :: IO a

mappend :: IO a -> IO a -> IO a

mconcat :: [IO a] -> IO a

Monoid (Doc a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

mempty :: Doc a

mappend :: Doc a -> Doc a -> Doc a

mconcat :: [Doc a] -> Doc a

Semigroup a => Monoid (Maybe a)

Lift a semigroup into Maybe forming a Monoid according to http://en.wikipedia.org/wiki/Monoid: "Any semigroup S may be turned into a monoid simply by adjoining an element e not in S and defining e*e = e and e*s = s = s*e for all s ∈ S."

Since 4.11.0: constraint on inner a value generalised from Monoid to Semigroup.

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: Maybe a

mappend :: Maybe a -> Maybe a -> Maybe a

mconcat :: [Maybe a] -> Maybe a

Monoid a => Monoid (a)

Since: base-4.15

Defined in GHC.Base

Methods

mempty :: (a)

mappend :: (a) -> (a) -> (a)

mconcat :: [(a)] -> (a)

Monoid [a]

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: [a]

mappend :: [a] -> [a] -> [a]

mconcat :: [[a]] -> [a]

Ord k => Monoid (Map k v)

Defined in Data.Map.Internal

Methods

mempty :: Map k v

mappend :: Map k v -> Map k v -> Map k v

mconcat :: [Map k v] -> Map k v

(Monoid a, Monoid b) => Monoid (a, b)

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: (a, b)

mappend :: (a, b) -> (a, b) -> (a, b)

mconcat :: [(a, b)] -> (a, b)

Monoid b => Monoid (a -> b)

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: a -> b

mappend :: (a -> b) -> (a -> b) -> a -> b

mconcat :: [a -> b] -> a -> b

(Monoid a, Monoid b, Monoid c) => Monoid (a, b, c)

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: (a, b, c)

mappend :: (a, b, c) -> (a, b, c) -> (a, b, c)

mconcat :: [(a, b, c)] -> (a, b, c)

(Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d)

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: (a, b, c, d)

mappend :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d)

mconcat :: [(a, b, c, d)] -> (a, b, c, d)

(Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e)

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: (a, b, c, d, e)

mappend :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e)

mconcat :: [(a, b, c, d, e)] -> (a, b, c, d, e)

Reexport from Monad

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:

Identity

fmap id == id

Composition

fmap (f . g) == fmap f . fmap g

Note, that the second law follows from the free theorem of the type fmap and the first law, so you need only check that the former condition holds. See https://www.schoolofhaskell.com/user/edwardk/snippets/fmap or https://github.com/quchen/articles/blob/master/second_functor_law.md for an explanation.

Minimal complete definition

fmap

Methods

fmap :: (a -> b) -> f a -> f b

fmap is used to apply a function of type (a -> b) to a value of type f a, where f is a functor, to produce a value of type f b. Note that for any type constructor with more than one parameter (e.g., Either), only the last type parameter can be modified with fmap (e.g., b in `Either a b`).

Some type constructors with two parameters or more have a Bifunctor instance that allows both the last and the penultimate parameters to be mapped over.

Examples

Convert from a Maybe Int to a Maybe String using show:

>>> fmap show Nothing
Nothing
>>> fmap show (Just 3)
Just "3"

Convert from an Either Int Int to an Either Int String using show:

>>> fmap show (Left 17)
Left 17
>>> fmap show (Right 17)
Right "17"

Double each element of a list:

>>> fmap (*2) [1,2,3]
[2,4,6]

Apply even to the second element of a pair:

>>> fmap even (2,2)
(2,True)

It may seem surprising that the function is only applied to the last element of the tuple compared to the list example above which applies it to every element in the list. To understand, remember that tuples are type constructors with multiple type parameters: a tuple of 3 elements (a,b,c) can also be written (,,) a b c and its Functor instance is defined for Functor ((,,) a b) (i.e., only the third parameter is free to be mapped over with fmap).

It explains why fmap can be used with tuples containing values of different types as in the following example:

>>> fmap even ("hello", 1.0, 4)
("hello",1.0,True)

(<$) :: a -> f b -> f a infixl 4

Replace all locations in the input with the same value. The default definition is fmap . const, but this may be overridden with a more efficient version.

Examples

Perform a computation with Maybe and replace the result with a constant value if it is Just:

>>> 'a' <$ Just 2
Just 'a'
>>> 'a' <$ Nothing
Nothing

Instances

Functor ZipList

Since: base-2.1

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> ZipList a -> ZipList b

(<$) :: a -> ZipList b -> ZipList a

Functor Handler

Since: base-4.6.0.0

Defined in Control.Exception

Methods

fmap :: (a -> b) -> Handler a -> Handler b

(<$) :: a -> Handler b -> Handler a

Functor NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

fmap :: (a -> b) -> NonEmpty a -> NonEmpty b

(<$) :: a -> NonEmpty b -> NonEmpty a

Functor P

Since: base-4.8.0.0

Defined in Text.ParserCombinators.ReadP

Methods

fmap :: (a -> b) -> P a -> P b

(<$) :: a -> P b -> P a

Functor ReadP

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

fmap :: (a -> b) -> ReadP a -> ReadP b

(<$) :: a -> ReadP b -> ReadP a

Functor ReadPrec

Since: base-2.1

Defined in Text.ParserCombinators.ReadPrec

Methods

fmap :: (a -> b) -> ReadPrec a -> ReadPrec b

(<$) :: a -> ReadPrec b -> ReadPrec a

Functor Digit

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Digit a -> Digit b

(<$) :: a -> Digit b -> Digit a

Functor Elem

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Elem a -> Elem b

(<$) :: a -> Elem b -> Elem a

Functor FingerTree

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> FingerTree a -> FingerTree b

(<$) :: a -> FingerTree b -> FingerTree a

Functor Node

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Node a -> Node b

(<$) :: a -> Node b -> Node a

Functor Seq

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Seq a -> Seq b

(<$) :: a -> Seq b -> Seq a

Functor ViewL

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> ViewL a -> ViewL b

(<$) :: a -> ViewL b -> ViewL a

Functor ViewR

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> ViewR a -> ViewR b

(<$) :: a -> ViewR b -> ViewR a

Functor IO

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> IO a -> IO b

(<$) :: a -> IO b -> IO a

Functor AnnotDetails

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

fmap :: (a -> b) -> AnnotDetails a -> AnnotDetails b

(<$) :: a -> AnnotDetails b -> AnnotDetails a

Functor Doc

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

fmap :: (a -> b) -> Doc a -> Doc b

(<$) :: a -> Doc b -> Doc a

Functor Span

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

fmap :: (a -> b) -> Span a -> Span b

(<$) :: a -> Span b -> Span a

Functor Maybe

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Maybe a -> Maybe b

(<$) :: a -> Maybe b -> Maybe a

Functor Solo

Since: base-4.15

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Solo a -> Solo b

(<$) :: a -> Solo b -> Solo a

Functor List

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> [a] -> [b]

(<$) :: a -> [b] -> [a]

Functor (Result err)

Defined in Antelude.Internal.TypesClasses

Methods

fmap :: (a -> b) -> Result err a -> Result err b

(<$) :: a -> Result err b -> Result err a

Monad m => Functor (WrappedMonad m)

Since: base-2.1

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b

(<$) :: a -> WrappedMonad m b -> WrappedMonad m a

Functor (Either a)

Since: base-3.0

Defined in Data.Either

Methods

fmap :: (a0 -> b) -> Either a a0 -> Either a b

(<$) :: a0 -> Either a b -> Either a a0

Functor (Array i)

Since: base-2.1

Defined in GHC.Arr

Methods

fmap :: (a -> b) -> Array i a -> Array i b

(<$) :: a -> Array i b -> Array i a

Functor (Map k)

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> Map k a -> Map k b

(<$) :: a -> Map k b -> Map k a

Functor ((,) a)

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a0 -> b) -> (a, a0) -> (a, b)

(<$) :: a0 -> (a, b) -> (a, a0)

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 ((,,) a b)

Since: base-4.14.0.0

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, a0) -> (a, b, b0)

(<$) :: a0 -> (a, b, b0) -> (a, b, a0)

(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 ((,,,) a b c)

Since: base-4.14.0.0

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0)

(<$) :: a0 -> (a, b, c, b0) -> (a, b, c, a0)

Functor ((->) r)

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> (r -> a) -> r -> b

(<$) :: a -> (r -> b) -> r -> a

Functor f => Functor (WhenMatched f k x y)

Since: containers-0.5.9

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b

(<$) :: a -> WhenMatched f k x y b -> WhenMatched f k x y a

Functor ((,,,,) a b c d)

Since: base-4.18.0.0

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, d, a0) -> (a, b, c, d, b0)

(<$) :: a0 -> (a, b, c, d, b0) -> (a, b, c, d, a0)

Functor ((,,,,,) a b c d e)

Since: base-4.18.0.0

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, d, e, a0) -> (a, b, c, d, e, b0)

(<$) :: a0 -> (a, b, c, d, e, b0) -> (a, b, c, d, e, a0)

Functor ((,,,,,,) a b c d e f)

Since: base-4.18.0.0

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, d, e, f, a0) -> (a, b, c, d, e, f, b0)

(<$) :: a0 -> (a, b, c, d, e, f, b0) -> (a, b, c, d, e, f, a0)

Reexport from Applicative

class Applicative f => Alternative (f :: Type -> Type) where

A monoid on applicative functors.

If defined, some and many should be the least solutions of the equations:

• some v = (:) <$> v <*> many v

• many v = some v <|> pure []

Methods

empty :: f a

The identity of <|>

(<|>) :: f a -> f a -> f a infixl 3

An associative binary operation

Instances

Alternative ZipList

Since: base-4.11.0.0

Defined in Control.Applicative

Methods

empty :: ZipList a

(<|>) :: ZipList a -> ZipList a -> ZipList a

some :: ZipList a -> ZipList [a]

many :: ZipList a -> ZipList [a]

Alternative P

Since: base-4.5.0.0

Defined in Text.ParserCombinators.ReadP

Methods

empty :: P a

(<|>) :: P a -> P a -> P a

some :: P a -> P [a]

many :: P a -> P [a]

Alternative ReadP

Since: base-4.6.0.0

Defined in Text.ParserCombinators.ReadP

Methods

empty :: ReadP a

(<|>) :: ReadP a -> ReadP a -> ReadP a

some :: ReadP a -> ReadP [a]

many :: ReadP a -> ReadP [a]

Alternative ReadPrec

Since: base-4.6.0.0

Defined in Text.ParserCombinators.ReadPrec

Methods

empty :: ReadPrec a

(<|>) :: ReadPrec a -> ReadPrec a -> ReadPrec a

some :: ReadPrec a -> ReadPrec [a]

many :: ReadPrec a -> ReadPrec [a]

Alternative Seq

Since: containers-0.5.4

Defined in Data.Sequence.Internal

Methods

empty :: Seq a

(<|>) :: Seq a -> Seq a -> Seq a

some :: Seq a -> Seq [a]

many :: Seq a -> Seq [a]

Alternative IO

Takes the first non-throwing IO action's result. empty throws an exception.

Since: base-4.9.0.0

Defined in GHC.Base

Methods

empty :: IO a

(<|>) :: IO a -> IO a -> IO a

some :: IO a -> IO [a]

many :: IO a -> IO [a]

Alternative Maybe

Picks the leftmost Just value, or, alternatively, Nothing.

Since: base-2.1

Defined in GHC.Base

Methods

empty :: Maybe a

(<|>) :: Maybe a -> Maybe a -> Maybe a

some :: Maybe a -> Maybe [a]

many :: Maybe a -> Maybe [a]

Alternative List

Combines lists by concatenation, starting from the empty list.

Since: base-2.1

Defined in GHC.Base

Methods

empty :: [a]

(<|>) :: [a] -> [a] -> [a]

some :: [a] -> [[a]]

many :: [a] -> [[a]]

MonadPlus m => Alternative (WrappedMonad m)

Since: base-2.1

Defined in Control.Applicative

Methods

empty :: WrappedMonad m a

(<|>) :: WrappedMonad m a -> WrappedMonad m a -> WrappedMonad m a

some :: WrappedMonad m a -> WrappedMonad m [a]

many :: WrappedMonad m a -> WrappedMonad m [a]

(ArrowZero a, ArrowPlus a) => Alternative (WrappedArrow a b)

Since: base-2.1

Defined in Control.Applicative

Methods

empty :: WrappedArrow a b a0

(<|>) :: WrappedArrow a b a0 -> WrappedArrow a b a0 -> WrappedArrow a b a0

some :: WrappedArrow a b a0 -> WrappedArrow a b [a0]

many :: WrappedArrow a b a0 -> WrappedArrow a b [a0]

class Functor f => Applicative (f :: Type -> Type) where

A functor with application, providing operations to

• embed pure expressions (pure), and
• sequence computations and combine their results (<*> and liftA2).

A minimal complete definition must include implementations of pure and of either <*> or liftA2. If it defines both, then they must behave the same as their default definitions:

(<*>) = liftA2 id

liftA2 f x y = f <$> x <*> y

Further, any definition must satisfy the following:

Identity

pure id <*> v = v

Composition

pure (.) <*> u <*> v <*> w = u <*> (v <*> w)

Homomorphism

pure f <*> pure x = pure (f x)

Interchange

u <*> pure y = pure ($ y) <*> u

The other methods have the following default definitions, which may be overridden with equivalent specialized implementations:

• u *> v = (id <$ u) <*> v

• u <* v = liftA2 const u v

As a consequence of these laws, the Functor instance for f will satisfy

• fmap f x = pure f <*> x

It may be useful to note that supposing

forall x y. p (q x y) = f x . g y

it follows from the above that

liftA2 p (liftA2 q u v) = liftA2 f u . liftA2 g v

If f is also a Monad, it should satisfy

• pure = return

• m1 <*> m2 = m1 >>= (\x1 -> m2 >>= (\x2 -> return (x1 x2)))

• (*>) = (>>)

(which implies that pure and <*> satisfy the applicative functor laws).

Minimal complete definition

pure, ((<*>) | liftA2)

Methods

pure :: a -> f a

Lift a value.

(<*>) :: f (a -> b) -> f a -> f b infixl 4

Sequential application.

A few functors support an implementation of <*> that is more efficient than the default one.

Example

Used in combination with (<$>), (<*>) can be used to build a record.

>>> data MyState = MyState {arg1 :: Foo, arg2 :: Bar, arg3 :: Baz}

>>> produceFoo :: Applicative f => f Foo

>>> produceBar :: Applicative f => f Bar
>>> produceBaz :: Applicative f => f Baz

>>> mkState :: Applicative f => f MyState
>>> mkState = MyState <$> produceFoo <*> produceBar <*> produceBaz

liftA2 :: (a -> b -> c) -> f a -> f b -> f c

Lift a binary function to actions.

Some functors support an implementation of liftA2 that is more efficient than the default one. In particular, if fmap is an expensive operation, it is likely better to use liftA2 than to fmap over the structure and then use <*>.

This became a typeclass method in 4.10.0.0. Prior to that, it was a function defined in terms of <*> and fmap.

Example

>>> liftA2 (,) (Just 3) (Just 5)
Just (3,5)

(*>) :: f a -> f b -> f b infixl 4

Sequence actions, discarding the value of the first argument.

Examples

If used in conjunction with the Applicative instance for Maybe, you can chain Maybe computations, with a possible "early return" in case of Nothing.

>>> Just 2 *> Just 3
Just 3

>>> Nothing *> Just 3
Nothing

Of course a more interesting use case would be to have effectful computations instead of just returning pure values.

>>> import Data.Char
>>> import Text.ParserCombinators.ReadP
>>> let p = string "my name is " *> munch1 isAlpha <* eof
>>> readP_to_S p "my name is Simon"
[("Simon","")]

(<*) :: f a -> f b -> f a infixl 4

Sequence actions, discarding the value of the second argument.

Instances

Applicative ZipList

f <$> ZipList xs1 <*> ... <*> ZipList xsN
    = ZipList (zipWithN f xs1 ... xsN)

where zipWithN refers to the zipWith function of the appropriate arity (zipWith, zipWith3, zipWith4, ...). For example:

(\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

Defined in Control.Applicative

Methods

pure :: a -> ZipList a

(<*>) :: ZipList (a -> b) -> ZipList a -> ZipList b

liftA2 :: (a -> b -> c) -> ZipList a -> ZipList b -> ZipList c

(*>) :: ZipList a -> ZipList b -> ZipList b

(<*) :: ZipList a -> ZipList b -> ZipList a

Applicative NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

pure :: a -> NonEmpty a

(<*>) :: NonEmpty (a -> b) -> NonEmpty a -> NonEmpty b

liftA2 :: (a -> b -> c) -> NonEmpty a -> NonEmpty b -> NonEmpty c

(*>) :: NonEmpty a -> NonEmpty b -> NonEmpty b

(<*) :: NonEmpty a -> NonEmpty b -> NonEmpty a

Applicative P

Since: base-4.5.0.0

Defined in Text.ParserCombinators.ReadP

Methods

pure :: a -> P a

(<*>) :: P (a -> b) -> P a -> P b

liftA2 :: (a -> b -> c) -> P a -> P b -> P c

(*>) :: P a -> P b -> P b

(<*) :: P a -> P b -> P a

Applicative ReadP

Since: base-4.6.0.0

Defined in Text.ParserCombinators.ReadP

Methods

pure :: a -> ReadP a

(<*>) :: ReadP (a -> b) -> ReadP a -> ReadP b

liftA2 :: (a -> b -> c) -> ReadP a -> ReadP b -> ReadP c

(*>) :: ReadP a -> ReadP b -> ReadP b

(<*) :: ReadP a -> ReadP b -> ReadP a

Applicative ReadPrec

Since: base-4.6.0.0

Defined in Text.ParserCombinators.ReadPrec

Methods

pure :: a -> ReadPrec a

(<*>) :: ReadPrec (a -> b) -> ReadPrec a -> ReadPrec b

liftA2 :: (a -> b -> c) -> ReadPrec a -> ReadPrec b -> ReadPrec c

(*>) :: ReadPrec a -> ReadPrec b -> ReadPrec b

(<*) :: ReadPrec a -> ReadPrec b -> ReadPrec a

Applicative Seq

Since: containers-0.5.4

Defined in Data.Sequence.Internal

Methods

pure :: a -> Seq a

(<*>) :: Seq (a -> b) -> Seq a -> Seq b

liftA2 :: (a -> b -> c) -> Seq a -> Seq b -> Seq c

(*>) :: Seq a -> Seq b -> Seq b

(<*) :: Seq a -> Seq b -> Seq a

Applicative IO

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a -> IO a

(<*>) :: IO (a -> b) -> IO a -> IO b

liftA2 :: (a -> b -> c) -> IO a -> IO b -> IO c

(*>) :: IO a -> IO b -> IO b

(<*) :: IO a -> IO b -> IO a

Applicative Maybe

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a -> Maybe a

(<*>) :: Maybe (a -> b) -> Maybe a -> Maybe b

liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c

(*>) :: Maybe a -> Maybe b -> Maybe b

(<*) :: Maybe a -> Maybe b -> Maybe a

Applicative Solo

Since: base-4.15

Defined in GHC.Base

Methods

pure :: a -> Solo a

(<*>) :: Solo (a -> b) -> Solo a -> Solo b

liftA2 :: (a -> b -> c) -> Solo a -> Solo b -> Solo c

(*>) :: Solo a -> Solo b -> Solo b

(<*) :: Solo a -> Solo b -> Solo a

Applicative List

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a -> [a]

(<*>) :: [a -> b] -> [a] -> [b]

liftA2 :: (a -> b -> c) -> [a] -> [b] -> [c]

(*>) :: [a] -> [b] -> [b]

(<*) :: [a] -> [b] -> [a]

Applicative (Result err)

Defined in Antelude.Internal.TypesClasses

Methods

pure :: a -> Result err a

(<*>) :: Result err (a -> b) -> Result err a -> Result err b

liftA2 :: (a -> b -> c) -> Result err a -> Result err b -> Result err c

(*>) :: Result err a -> Result err b -> Result err b

(<*) :: Result err a -> Result err b -> Result err a

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

Applicative (Either e)

Since: base-3.0

Defined in Data.Either

Methods

pure :: a -> Either e a

(<*>) :: Either e (a -> b) -> Either e a -> Either e b

liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c

(*>) :: Either e a -> Either e b -> Either e b

(<*) :: Either e a -> Either e b -> Either e a

Monoid a => Applicative ((,) a)

For tuples, the Monoid constraint on a determines how the first values merge. For example, Strings concatenate:

("hello ", (+15)) <*> ("world!", 2002)
("hello world!",2017)

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a0 -> (a, a0)

(<*>) :: (a, a0 -> b) -> (a, a0) -> (a, b)

liftA2 :: (a0 -> b -> c) -> (a, a0) -> (a, b) -> (a, c)

(*>) :: (a, a0) -> (a, b) -> (a, b)

(<*) :: (a, a0) -> (a, b) -> (a, a0)

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

(Monoid a, Monoid b) => Applicative ((,,) a b)

Since: base-4.14.0.0

Defined in GHC.Base

Methods

pure :: a0 -> (a, b, a0)

(<*>) :: (a, b, a0 -> b0) -> (a, b, a0) -> (a, b, b0)

liftA2 :: (a0 -> b0 -> c) -> (a, b, a0) -> (a, b, b0) -> (a, b, c)

(*>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0)

(<*) :: (a, b, a0) -> (a, b, b0) -> (a, b, a0)

(Applicative f, Monad f) => Applicative (WhenMissing f k x)

Equivalent to ReaderT k (ReaderT x (MaybeT f)) .

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

(Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c)

Since: base-4.14.0.0

Defined in GHC.Base

Methods

pure :: a0 -> (a, b, c, a0)

(<*>) :: (a, b, c, a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0)

liftA2 :: (a0 -> b0 -> c0) -> (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, c0)

(*>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0)

(<*) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, a0)

Applicative ((->) r)

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a -> r -> a

(<*>) :: (r -> (a -> b)) -> (r -> a) -> r -> b

liftA2 :: (a -> b -> c) -> (r -> a) -> (r -> b) -> r -> c

(*>) :: (r -> a) -> (r -> b) -> r -> b

(<*) :: (r -> a) -> (r -> b) -> r -> a

(Monad f, Applicative f) => Applicative (WhenMatched f k x y)

Equivalent to ReaderT k (ReaderT x (ReaderT y (MaybeT f)))

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

Reexport from Monad

class Applicative m => Monad (m :: Type -> Type) where

The Monad class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory. From the perspective of a Haskell programmer, however, it is best to think of a monad as an abstract datatype of actions. Haskell's do expressions provide a convenient syntax for writing monadic expressions.

Instances of Monad should satisfy the following:

Left identity

return a >>= k = k a

Right identity

m >>= return = m

Associativity

m >>= (\x -> k x >>= h) = (m >>= k) >>= h

Furthermore, the Monad and Applicative operations should relate as follows:

• pure = return

• m1 <*> m2 = m1 >>= (\x1 -> m2 >>= (\x2 -> return (x1 x2)))

The above laws imply:

• fmap f xs  =  xs >>= return . f

• (>>) = (*>)

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 >>= bs' can be understood as the do 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 >> bs' can be understood as the do expression

do as
   bs

return :: a -> m a

Inject a value into the monadic type.

Instances

Monad NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b

(>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b

return :: a -> NonEmpty a

Monad P

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

(>>=) :: P a -> (a -> P b) -> P b

(>>) :: P a -> P b -> P b

return :: a -> P a

Monad ReadP

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

(>>=) :: ReadP a -> (a -> ReadP b) -> ReadP b

(>>) :: ReadP a -> ReadP b -> ReadP b

return :: a -> ReadP a

Monad ReadPrec

Since: base-2.1

Defined in Text.ParserCombinators.ReadPrec

Methods

(>>=) :: ReadPrec a -> (a -> ReadPrec b) -> ReadPrec b

(>>) :: ReadPrec a -> ReadPrec b -> ReadPrec b

return :: a -> ReadPrec a

Monad Seq

Defined in Data.Sequence.Internal

Methods

(>>=) :: Seq a -> (a -> Seq b) -> Seq b

(>>) :: Seq a -> Seq b -> Seq b

return :: a -> Seq a

Monad IO

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: IO a -> (a -> IO b) -> IO b

(>>) :: IO a -> IO b -> IO b

return :: a -> IO a

Monad Maybe

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b

(>>) :: Maybe a -> Maybe b -> Maybe b

return :: a -> Maybe a

Monad Solo

Since: base-4.15

Defined in GHC.Base

Methods

(>>=) :: Solo a -> (a -> Solo b) -> Solo b

(>>) :: Solo a -> Solo b -> Solo b

return :: a -> Solo a

Monad List

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: [a] -> (a -> [b]) -> [b]

(>>) :: [a] -> [b] -> [b]

return :: a -> [a]

Monad (Result err)

Defined in Antelude.Internal.TypesClasses

Methods

(>>=) :: Result err a -> (a -> Result err b) -> Result err b

(>>) :: Result err a -> Result err b -> Result err b

return :: a -> Result err a

Monad m => Monad (WrappedMonad m)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

(>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b

(>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b

return :: a -> WrappedMonad m a

Monad (Either e)

Since: base-4.4.0.0

Defined in Data.Either

Methods

(>>=) :: Either e a -> (a -> Either e b) -> Either e b

(>>) :: Either e a -> Either e b -> Either e b

return :: a -> Either e a

Monoid a => Monad ((,) a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(>>=) :: (a, a0) -> (a0 -> (a, b)) -> (a, b)

(>>) :: (a, a0) -> (a, b) -> (a, b)

return :: a0 -> (a, a0)

(Monoid a, Monoid b) => Monad ((,,) a b)

Since: base-4.14.0.0

Defined in GHC.Base

Methods

(>>=) :: (a, b, a0) -> (a0 -> (a, b, b0)) -> (a, b, b0)

(>>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0)

return :: a0 -> (a, b, a0)

(Applicative f, Monad f) => Monad (WhenMissing f k x)

Equivalent to ReaderT k (ReaderT x (MaybeT f)) .

Since: containers-0.5.9

Defined in Data.Map.Internal

Methods

(>>=) :: WhenMissing f k x a -> (a -> WhenMissing f k x b) -> WhenMissing f k x b

(>>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b

return :: a -> WhenMissing f k x a

(Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c)

Since: base-4.14.0.0

Defined in GHC.Base

Methods

(>>=) :: (a, b, c, a0) -> (a0 -> (a, b, c, b0)) -> (a, b, c, b0)

(>>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0)

return :: a0 -> (a, b, c, a0)

Monad ((->) r)

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: (r -> a) -> (a -> r -> b) -> r -> b

(>>) :: (r -> a) -> (r -> b) -> r -> b

return :: a -> r -> a

(Monad f, Applicative f) => Monad (WhenMatched f k x y)

Equivalent to ReaderT k (ReaderT x (ReaderT y (MaybeT f)))

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

Reexport from Class

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:

• liftIO . return = return

• liftIO (m >>= f) = liftIO m >>= (liftIO . f)

Methods

liftIO :: IO a -> m a

Lift a computation from the IO monad. This allows us to run IO computations in any monadic stack, so long as it supports these kinds of operations (i.e. IO is the base monad for the stack).

Example

import Control.Monad.Trans.State -- from the "transformers" library

printState :: Show s => StateT s IO ()
printState = do
  state <- get
  liftIO $ print state

Had we omitted liftIO, we would have ended up with this error:

• Couldn't match type ‘IO’ with ‘StateT s IO’
 Expected type: StateT s IO ()
   Actual type: IO ()

The important part here is the mismatch between StateT s IO () and IO ().

Luckily, we know of a function that takes an IO a and returns an (m a): liftIO, enabling us to run the program and see the expected results:

> evalStateT printState "hello"
"hello"

> evalStateT printState 3
3

Instances

MonadIO IO

Since: base-4.9.0.0

Defined in Control.Monad.IO.Class

Methods

liftIO :: IO a -> IO a

Reexport from Monad

class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type)

Monads that also support choice and failure.

Instances

MonadPlus P

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

mzero :: P a

mplus :: P a -> P a -> P a

MonadPlus ReadP

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

mzero :: ReadP a

mplus :: ReadP a -> ReadP a -> ReadP a

MonadPlus ReadPrec

Since: base-2.1

Defined in Text.ParserCombinators.ReadPrec

Methods

mzero :: ReadPrec a

mplus :: ReadPrec a -> ReadPrec a -> ReadPrec a

MonadPlus Seq

Defined in Data.Sequence.Internal

Methods

mzero :: Seq a

mplus :: Seq a -> Seq a -> Seq a

MonadPlus IO

Takes the first non-throwing IO action's result. mzero throws an exception.

Since: base-4.9.0.0

Defined in GHC.Base

Methods

mzero :: IO a

mplus :: IO a -> IO a -> IO a

MonadPlus Maybe

Picks the leftmost Just value, or, alternatively, Nothing.

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: Maybe a

mplus :: Maybe a -> Maybe a -> Maybe a

MonadPlus List

Combines lists by concatenation, starting from the empty list.

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: [a]

mplus :: [a] -> [a] -> [a]

Reexport from Fail

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

fail s should be an action that runs in the monad itself, not an exception (except in instances of MonadIO). In particular, fail should not be implemented in terms of error.

Since: base-4.9.0.0

Minimal complete definition

fail

Instances

MonadFail P

Since: base-4.9.0.0

Defined in Text.ParserCombinators.ReadP

Methods

fail :: String -> P a

MonadFail ReadP

Since: base-4.9.0.0

Defined in Text.ParserCombinators.ReadP

Methods

fail :: String -> ReadP a

MonadFail ReadPrec

Since: base-4.9.0.0

Defined in Text.ParserCombinators.ReadPrec

Methods

fail :: String -> ReadPrec a

MonadFail IO

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> IO a

MonadFail Maybe

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> Maybe a

MonadFail List

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> [a]

The Rest of the Classes

Reexport from Eq

class Eq a where

The Eq class defines equality (==) and inequality (/=). All the basic datatypes exported by the Prelude are instances of Eq, and Eq may be derived for any datatype whose constituents are also instances of Eq.

The Haskell Report defines no laws for Eq. However, instances are encouraged to follow these properties:

Reflexivity

x == x = True

Symmetry

x == y = y == x

Transitivity

if x == y && y == z = True, then x == z = True

Extensionality

if x == y = True and f is a function whose return type is an instance of Eq, then f x == f y = True

Negation

x /= y = not (x == y)

Minimal complete definition: either == or /=.

Minimal complete definition

(==) | (/=)

Methods

(==) :: a -> a -> Bool infix 4

(/=) :: a -> a -> Bool infix 4

Instances

Eq Case

Defined in Antelude.String.Case

Methods

(==) :: Case -> Case -> Bool

(/=) :: Case -> Case -> Bool

Eq Void

Since: base-4.8.0.0

Defined in GHC.Base

Methods

(==) :: Void -> Void -> Bool

(/=) :: Void -> Void -> Bool

Eq ArithException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

(==) :: ArithException -> ArithException -> Bool

(/=) :: ArithException -> ArithException -> Bool

Eq MaskingState

Since: base-4.3.0.0

Defined in GHC.IO

Methods

(==) :: MaskingState -> MaskingState -> Bool

(/=) :: MaskingState -> MaskingState -> Bool

Eq ArrayException

Since: base-4.2.0.0

Defined in GHC.IO.Exception

Methods

(==) :: ArrayException -> ArrayException -> Bool

(/=) :: ArrayException -> ArrayException -> Bool

Eq AsyncException

Since: base-4.2.0.0

Defined in GHC.IO.Exception

Methods

(==) :: AsyncException -> AsyncException -> Bool

(/=) :: AsyncException -> AsyncException -> Bool

Eq ExitCode

Defined in GHC.IO.Exception

Methods

(==) :: ExitCode -> ExitCode -> Bool

(/=) :: ExitCode -> ExitCode -> Bool

Eq IOErrorType

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

(==) :: IOErrorType -> IOErrorType -> Bool

(/=) :: IOErrorType -> IOErrorType -> Bool

Eq IOException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

(==) :: IOException -> IOException -> Bool

(/=) :: IOException -> IOException -> Bool

Eq SrcLoc

Since: base-4.9.0.0

Defined in GHC.Stack.Types

Methods

(==) :: SrcLoc -> SrcLoc -> Bool

(/=) :: SrcLoc -> SrcLoc -> Bool

Eq GeneralCategory

Since: base-2.1

Defined in GHC.Unicode

Methods

(==) :: GeneralCategory -> GeneralCategory -> Bool

(/=) :: GeneralCategory -> GeneralCategory -> Bool

Eq Word16

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word16 -> Word16 -> Bool

(/=) :: Word16 -> Word16 -> Bool

Eq Word32

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word32 -> Word32 -> Bool

(/=) :: Word32 -> Word32 -> Bool

Eq Word64

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word64 -> Word64 -> Bool

(/=) :: Word64 -> Word64 -> Bool

Eq Word8

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word8 -> Word8 -> Bool

(/=) :: Word8 -> Word8 -> Bool

Eq Lexeme

Since: base-2.1

Defined in Text.Read.Lex

Methods

(==) :: Lexeme -> Lexeme -> Bool

(/=) :: Lexeme -> Lexeme -> Bool

Eq Number

Since: base-4.6.0.0

Defined in Text.Read.Lex

Methods

(==) :: Number -> Number -> Bool

(/=) :: Number -> Number -> Bool

Eq ByteString

Defined in Data.ByteString.Internal.Type

Methods

(==) :: ByteString -> ByteString -> Bool

(/=) :: ByteString -> ByteString -> Bool

Eq ByteString

Defined in Data.ByteString.Lazy.Internal

Methods

(==) :: ByteString -> ByteString -> Bool

(/=) :: ByteString -> ByteString -> Bool

Eq Module

Defined in GHC.Classes

Methods

(==) :: Module -> Module -> Bool

(/=) :: Module -> Module -> Bool

Eq Ordering

Defined in GHC.Classes

Methods

(==) :: Ordering -> Ordering -> Bool

(/=) :: Ordering -> Ordering -> Bool

Eq TrName

Defined in GHC.Classes

Methods

(==) :: TrName -> TrName -> Bool

(/=) :: TrName -> TrName -> Bool

Eq TyCon

Defined in GHC.Classes

Methods

(==) :: TyCon -> TyCon -> Bool

(/=) :: TyCon -> TyCon -> Bool

Eq Mode

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

(==) :: Mode -> Mode -> Bool

(/=) :: Mode -> Mode -> Bool

Eq Style

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

(==) :: Style -> Style -> Bool

(/=) :: Style -> Style -> Bool

Eq TextDetails

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

(==) :: TextDetails -> TextDetails -> Bool

(/=) :: TextDetails -> TextDetails -> Bool

Eq Doc

Defined in Text.PrettyPrint.HughesPJ

Methods

(==) :: Doc -> Doc -> Bool

(/=) :: Doc -> Doc -> Bool

Eq Integer

Defined in GHC.Num.Integer

Methods

(==) :: Integer -> Integer -> Bool

(/=) :: Integer -> Integer -> Bool

Eq ()

Defined in GHC.Classes

Methods

(==) :: () -> () -> Bool

(/=) :: () -> () -> Bool

Eq Bool

Defined in GHC.Classes

Methods

(==) :: Bool -> Bool -> Bool

(/=) :: Bool -> Bool -> Bool

Eq Char

Defined in GHC.Classes

Methods

(==) :: Char -> Char -> Bool

(/=) :: Char -> Char -> Bool

Eq Double

Note that due to the presence of NaN, Double's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Double)
False

Also note that Double's Eq instance does not satisfy substitutivity:

>>> 0 == (-0 :: Double)
True
>>> recip 0 == recip (-0 :: Double)
False

Defined in GHC.Classes

Methods

(==) :: Double -> Double -> Bool

(/=) :: Double -> Double -> Bool

Eq Float

Note that due to the presence of NaN, Float's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Float)
False

Also note that Float's Eq instance does not satisfy extensionality:

>>> 0 == (-0 :: Float)
True
>>> recip 0 == recip (-0 :: Float)
False

Defined in GHC.Classes

Methods

(==) :: Float -> Float -> Bool

(/=) :: Float -> Float -> Bool

Eq Int

Defined in GHC.Classes

Methods

(==) :: Int -> Int -> Bool

(/=) :: Int -> Int -> Bool

Eq Word

Defined in GHC.Classes

Methods

(==) :: Word -> Word -> Bool

(/=) :: Word -> Word -> Bool

Eq a => Eq (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

(==) :: ZipList a -> ZipList a -> Bool

(/=) :: ZipList a -> ZipList a -> Bool

Eq a => Eq (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(==) :: NonEmpty a -> NonEmpty a -> Bool

(/=) :: NonEmpty a -> NonEmpty a -> Bool

Eq (ForeignPtr a)

Since: base-2.1

Defined in GHC.ForeignPtr

Methods

(==) :: ForeignPtr a -> ForeignPtr a -> Bool

(/=) :: ForeignPtr a -> ForeignPtr a -> Bool

Eq a => Eq (Ratio a)

Since: base-2.1

Defined in GHC.Real

Methods

(==) :: Ratio a -> Ratio a -> Bool

(/=) :: Ratio a -> Ratio a -> Bool

Eq a => Eq (Seq a)

Defined in Data.Sequence.Internal

Methods

(==) :: Seq a -> Seq a -> Bool

(/=) :: Seq a -> Seq a -> Bool

Eq a => Eq (ViewL a)

Defined in Data.Sequence.Internal

Methods

(==) :: ViewL a -> ViewL a -> Bool

(/=) :: ViewL a -> ViewL a -> Bool

Eq a => Eq (ViewR a)

Defined in Data.Sequence.Internal

Methods

(==) :: ViewR a -> ViewR a -> Bool

(/=) :: ViewR a -> ViewR a -> Bool

Eq a => Eq (Intersection a)

Defined in Data.Set.Internal

Methods

(==) :: Intersection a -> Intersection a -> Bool

(/=) :: Intersection a -> Intersection a -> Bool

Eq a => Eq (Set a)

Defined in Data.Set.Internal

Methods

(==) :: Set a -> Set a -> Bool

(/=) :: Set a -> Set a -> Bool

Eq a => Eq (AnnotDetails a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

(==) :: AnnotDetails a -> AnnotDetails a -> Bool

(/=) :: AnnotDetails a -> AnnotDetails a -> Bool

Eq (Doc a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

(==) :: Doc a -> Doc a -> Bool

(/=) :: Doc a -> Doc a -> Bool

Eq a => Eq (Span a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

(==) :: Span a -> Span a -> Bool

(/=) :: Span a -> Span a -> Bool

Eq a => Eq (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

(==) :: Maybe a -> Maybe a -> Bool

(/=) :: Maybe a -> Maybe a -> Bool

Eq a => Eq (a)

Defined in GHC.Classes

Methods

(==) :: (a) -> (a) -> Bool

(/=) :: (a) -> (a) -> Bool

Eq a => Eq [a]

Defined in GHC.Classes

Methods

(==) :: [a] -> [a] -> Bool

(/=) :: [a] -> [a] -> Bool

(Eq err, Eq ok) => Eq (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

(==) :: Result err ok -> Result err ok -> Bool

(/=) :: Result err ok -> Result err ok -> Bool

(Eq a, Eq b) => Eq (Either a b)

Since: base-2.1

Defined in Data.Either

Methods

(==) :: Either a b -> Either a b -> Bool

(/=) :: Either a b -> Either a b -> Bool

(Ix i, Eq e) => Eq (Array i e)

Since: base-2.1

Defined in GHC.Arr

Methods

(==) :: Array i e -> Array i e -> Bool

(/=) :: Array i e -> Array i e -> Bool

(Eq k, Eq a) => Eq (Map k a)

Defined in Data.Map.Internal

Methods

(==) :: Map k a -> Map k a -> Bool

(/=) :: Map k a -> Map k a -> Bool

(Eq a, Eq b) => Eq (a, b)

Defined in GHC.Classes

Methods

(==) :: (a, b) -> (a, b) -> Bool

(/=) :: (a, b) -> (a, b) -> Bool

Eq (STArray s i e)

Since: base-2.1

Defined in GHC.Arr

Methods

(==) :: STArray s i e -> STArray s i e -> Bool

(/=) :: STArray s i e -> STArray s i e -> Bool

(Eq a, Eq b, Eq c) => Eq (a, b, c)

Defined in GHC.Classes

Methods

(==) :: (a, b, c) -> (a, b, c) -> Bool

(/=) :: (a, b, c) -> (a, b, c) -> Bool

(Eq a, Eq b, Eq c, Eq d) => Eq (a, b, c, d)

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d) -> (a, b, c, d) -> Bool

(/=) :: (a, b, c, d) -> (a, b, c, d) -> Bool

(Eq a, Eq b, Eq c, Eq d, Eq e) => Eq (a, b, c, d, e)

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool

(/=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f)

Defined in GHC.Classes

Methods

(==) :: (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

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g) => Eq (a, b, c, d, e, f, g)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

(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)

Defined in GHC.Classes

Methods

(==) :: (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

Reexport from Ord

class Eq a => Ord a where

The Ord class is used for totally ordered datatypes.

Instances of Ord can be derived for any user-defined datatype whose constituent types are in Ord. The declared order of the constructors in the data declaration determines the ordering in derived Ord instances. The Ordering datatype allows a single comparison to determine the precise ordering of two objects.

Ord, as defined by the Haskell report, implements a total order and has the following properties:

Comparability

x <= y || y <= x = True

Transitivity

if x <= y && y <= z = True, then x <= z = True

Reflexivity

x <= x = True

Antisymmetry

if x <= y && y <= x = True, then x == y = True

The following operator interactions are expected to hold:

1. x >= y = y <= x
2. x < y = x <= y && x /= y
3. x > y = y < x
4. x < y = compare x y == LT
5. x > y = compare x y == GT
6. x == y = compare x y == EQ
7. min x y == if x <= y then x else y = True
8. max x y == if x >= y then x else y = True

Note that (7.) and (8.) do not require min and max to return either of their arguments. The result is merely required to equal one of the arguments in terms of (==).

Minimal complete definition: either compare or <=. Using compare can be more efficient for complex types.

Minimal complete definition

compare | (<=)

Methods

(<) :: a -> a -> Bool infix 4

(<=) :: a -> a -> Bool infix 4

(>) :: a -> a -> Bool infix 4

(>=) :: a -> a -> Bool infix 4

Instances

Ord Void

Since: base-4.8.0.0

Defined in GHC.Base

Methods

compare :: Void -> Void -> Ordering

(<) :: Void -> Void -> Bool

(<=) :: Void -> Void -> Bool

(>) :: Void -> Void -> Bool

(>=) :: Void -> Void -> Bool

max :: Void -> Void -> Void

min :: Void -> Void -> Void

Ord ArithException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

compare :: ArithException -> ArithException -> Ordering

(<) :: ArithException -> ArithException -> Bool

(<=) :: ArithException -> ArithException -> Bool

(>) :: ArithException -> ArithException -> Bool

(>=) :: ArithException -> ArithException -> Bool

max :: ArithException -> ArithException -> ArithException

min :: ArithException -> ArithException -> ArithException

Ord ArrayException

Since: base-4.2.0.0

Defined in GHC.IO.Exception

Methods

compare :: ArrayException -> ArrayException -> Ordering

(<) :: ArrayException -> ArrayException -> Bool

(<=) :: ArrayException -> ArrayException -> Bool

(>) :: ArrayException -> ArrayException -> Bool

(>=) :: ArrayException -> ArrayException -> Bool

max :: ArrayException -> ArrayException -> ArrayException

min :: ArrayException -> ArrayException -> ArrayException

Ord AsyncException

Since: base-4.2.0.0

Defined in GHC.IO.Exception

Methods

compare :: AsyncException -> AsyncException -> Ordering

(<) :: AsyncException -> AsyncException -> Bool

(<=) :: AsyncException -> AsyncException -> Bool

(>) :: AsyncException -> AsyncException -> Bool

(>=) :: AsyncException -> AsyncException -> Bool

max :: AsyncException -> AsyncException -> AsyncException

min :: AsyncException -> AsyncException -> AsyncException

Ord ExitCode

Defined in GHC.IO.Exception

Methods

compare :: ExitCode -> ExitCode -> Ordering

(<) :: ExitCode -> ExitCode -> Bool

(<=) :: ExitCode -> ExitCode -> Bool

(>) :: ExitCode -> ExitCode -> Bool

(>=) :: ExitCode -> ExitCode -> Bool

max :: ExitCode -> ExitCode -> ExitCode

min :: ExitCode -> ExitCode -> ExitCode

Ord GeneralCategory

Since: base-2.1

Defined in GHC.Unicode

Methods

compare :: GeneralCategory -> GeneralCategory -> Ordering

(<) :: GeneralCategory -> GeneralCategory -> Bool

(<=) :: GeneralCategory -> GeneralCategory -> Bool

(>) :: GeneralCategory -> GeneralCategory -> Bool

(>=) :: GeneralCategory -> GeneralCategory -> Bool

max :: GeneralCategory -> GeneralCategory -> GeneralCategory

min :: GeneralCategory -> GeneralCategory -> GeneralCategory

Ord Word16

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word16 -> Word16 -> Ordering

(<) :: Word16 -> Word16 -> Bool

(<=) :: Word16 -> Word16 -> Bool

(>) :: Word16 -> Word16 -> Bool

(>=) :: Word16 -> Word16 -> Bool

max :: Word16 -> Word16 -> Word16

min :: Word16 -> Word16 -> Word16

Ord Word32

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word32 -> Word32 -> Ordering

(<) :: Word32 -> Word32 -> Bool

(<=) :: Word32 -> Word32 -> Bool

(>) :: Word32 -> Word32 -> Bool

(>=) :: Word32 -> Word32 -> Bool

max :: Word32 -> Word32 -> Word32

min :: Word32 -> Word32 -> Word32

Ord Word64

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word64 -> Word64 -> Ordering

(<) :: Word64 -> Word64 -> Bool

(<=) :: Word64 -> Word64 -> Bool

(>) :: Word64 -> Word64 -> Bool

(>=) :: Word64 -> Word64 -> Bool

max :: Word64 -> Word64 -> Word64

min :: Word64 -> Word64 -> Word64

Ord Word8

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word8 -> Word8 -> Ordering

(<) :: Word8 -> Word8 -> Bool

(<=) :: Word8 -> Word8 -> Bool

(>) :: Word8 -> Word8 -> Bool

(>=) :: Word8 -> Word8 -> Bool

max :: Word8 -> Word8 -> Word8

min :: Word8 -> Word8 -> Word8

Ord ByteString

Defined in Data.ByteString.Internal.Type

Methods

compare :: ByteString -> ByteString -> Ordering

(<) :: ByteString -> ByteString -> Bool

(<=) :: ByteString -> ByteString -> Bool

(>) :: ByteString -> ByteString -> Bool

(>=) :: ByteString -> ByteString -> Bool

max :: ByteString -> ByteString -> ByteString

min :: ByteString -> ByteString -> ByteString

Ord 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 Ordering

Defined in GHC.Classes

Methods

compare :: Ordering -> Ordering -> Ordering

(<) :: Ordering -> Ordering -> Bool

(<=) :: Ordering -> Ordering -> Bool

(>) :: Ordering -> Ordering -> Bool

(>=) :: Ordering -> Ordering -> Bool

max :: Ordering -> Ordering -> Ordering

min :: Ordering -> Ordering -> Ordering

Ord TyCon

Defined in GHC.Classes

Methods

compare :: TyCon -> TyCon -> Ordering

(<) :: TyCon -> TyCon -> Bool

(<=) :: TyCon -> TyCon -> Bool

(>) :: TyCon -> TyCon -> Bool

(>=) :: TyCon -> TyCon -> Bool

max :: TyCon -> TyCon -> TyCon

min :: TyCon -> TyCon -> TyCon

Ord Integer

Defined in GHC.Num.Integer

Methods

compare :: Integer -> Integer -> Ordering

(<) :: Integer -> Integer -> Bool

(<=) :: Integer -> Integer -> Bool

(>) :: Integer -> Integer -> Bool

(>=) :: Integer -> Integer -> Bool

max :: Integer -> Integer -> Integer

min :: Integer -> Integer -> Integer

Ord ()

Defined in GHC.Classes

Methods

compare :: () -> () -> Ordering

(<) :: () -> () -> Bool

(<=) :: () -> () -> Bool

(>) :: () -> () -> Bool

(>=) :: () -> () -> Bool

max :: () -> () -> ()

min :: () -> () -> ()

Ord Bool

Defined in GHC.Classes

Methods

compare :: Bool -> Bool -> Ordering

(<) :: Bool -> Bool -> Bool

(<=) :: Bool -> Bool -> Bool

(>) :: Bool -> Bool -> Bool

(>=) :: Bool -> Bool -> Bool

max :: Bool -> Bool -> Bool

min :: Bool -> Bool -> Bool

Ord Char

Defined in GHC.Classes

Methods

compare :: Char -> Char -> Ordering

(<) :: Char -> Char -> Bool

(<=) :: Char -> Char -> Bool

(>) :: Char -> Char -> Bool

(>=) :: Char -> Char -> Bool

max :: Char -> Char -> Char

min :: Char -> Char -> Char

Ord Double

Note that due to the presence of NaN, Double's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Double)
False

Also note that, due to the same, Ord's operator interactions are not respected by Double's instance:

>>> (0/0 :: Double) > 1
False
>>> compare (0/0 :: Double) 1
GT

Defined in GHC.Classes

Methods

compare :: Double -> Double -> Ordering

(<) :: Double -> Double -> Bool

(<=) :: Double -> Double -> Bool

(>) :: Double -> Double -> Bool

(>=) :: Double -> Double -> Bool

max :: Double -> Double -> Double

min :: Double -> Double -> Double

Ord Float

Note that due to the presence of NaN, Float's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Float)
False

Also note that, due to the same, Ord's operator interactions are not respected by Float's instance:

>>> (0/0 :: Float) > 1
False
>>> compare (0/0 :: Float) 1
GT

Defined in GHC.Classes

Methods

compare :: Float -> Float -> Ordering

(<) :: Float -> Float -> Bool

(<=) :: Float -> Float -> Bool

(>) :: Float -> Float -> Bool

(>=) :: Float -> Float -> Bool

max :: Float -> Float -> Float

min :: Float -> Float -> Float

Ord Int

Defined in GHC.Classes

Methods

compare :: Int -> Int -> Ordering

(<) :: Int -> Int -> Bool

(<=) :: Int -> Int -> Bool

(>) :: Int -> Int -> Bool

(>=) :: Int -> Int -> Bool

max :: Int -> Int -> Int

min :: Int -> Int -> Int

Ord Word

Defined in GHC.Classes

Methods

compare :: Word -> Word -> Ordering

(<) :: Word -> Word -> Bool

(<=) :: Word -> Word -> Bool

(>) :: Word -> Word -> Bool

(>=) :: Word -> Word -> Bool

max :: Word -> Word -> Word

min :: Word -> Word -> Word

Ord a => Ord (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

compare :: ZipList a -> ZipList a -> Ordering

(<) :: ZipList a -> ZipList a -> Bool

(<=) :: ZipList a -> ZipList a -> Bool

(>) :: ZipList a -> ZipList a -> Bool

(>=) :: ZipList a -> ZipList a -> Bool

max :: ZipList a -> ZipList a -> ZipList a

min :: ZipList a -> ZipList a -> ZipList a

Ord a => Ord (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

compare :: NonEmpty a -> NonEmpty a -> Ordering

(<) :: NonEmpty a -> NonEmpty a -> Bool

(<=) :: NonEmpty a -> NonEmpty a -> Bool

(>) :: NonEmpty a -> NonEmpty a -> Bool

(>=) :: NonEmpty a -> NonEmpty a -> Bool

max :: NonEmpty a -> NonEmpty a -> NonEmpty a

min :: NonEmpty a -> NonEmpty a -> NonEmpty a

Ord (ForeignPtr a)

Since: base-2.1

Defined in GHC.ForeignPtr

Methods

compare :: ForeignPtr a -> ForeignPtr a -> Ordering

(<) :: ForeignPtr a -> ForeignPtr a -> Bool

(<=) :: ForeignPtr a -> ForeignPtr a -> Bool

(>) :: ForeignPtr a -> ForeignPtr a -> Bool

(>=) :: ForeignPtr a -> ForeignPtr a -> Bool

max :: ForeignPtr a -> ForeignPtr a -> ForeignPtr a

min :: ForeignPtr a -> ForeignPtr a -> ForeignPtr a

Integral a => Ord (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

compare :: Ratio a -> Ratio a -> Ordering

(<) :: Ratio a -> Ratio a -> Bool

(<=) :: Ratio a -> Ratio a -> Bool

(>) :: Ratio a -> Ratio a -> Bool

(>=) :: Ratio a -> Ratio a -> Bool

max :: Ratio a -> Ratio a -> Ratio a

min :: Ratio a -> Ratio a -> Ratio a

Ord a => Ord (Seq a)

Defined in Data.Sequence.Internal

Methods

compare :: Seq a -> Seq a -> Ordering

(<) :: Seq a -> Seq a -> Bool

(<=) :: Seq a -> Seq a -> Bool

(>) :: Seq a -> Seq a -> Bool

(>=) :: Seq a -> Seq a -> Bool

max :: Seq a -> Seq a -> Seq a

min :: Seq a -> Seq a -> Seq a

Ord a => Ord (ViewL a)

Defined in Data.Sequence.Internal

Methods

compare :: ViewL a -> ViewL a -> Ordering

(<) :: ViewL a -> ViewL a -> Bool

(<=) :: ViewL a -> ViewL a -> Bool

(>) :: ViewL a -> ViewL a -> Bool

(>=) :: ViewL a -> ViewL a -> Bool

max :: ViewL a -> ViewL a -> ViewL a

min :: ViewL a -> ViewL a -> ViewL a

Ord a => Ord (ViewR a)

Defined in Data.Sequence.Internal

Methods

compare :: ViewR a -> ViewR a -> Ordering

(<) :: ViewR a -> ViewR a -> Bool

(<=) :: ViewR a -> ViewR a -> Bool

(>) :: ViewR a -> ViewR a -> Bool

(>=) :: ViewR a -> ViewR a -> Bool

max :: ViewR a -> ViewR a -> ViewR a

min :: ViewR a -> ViewR a -> ViewR a

Ord a => Ord (Intersection a)

Defined in Data.Set.Internal

Methods

compare :: Intersection a -> Intersection a -> Ordering

(<) :: Intersection a -> Intersection a -> Bool

(<=) :: Intersection a -> Intersection a -> Bool

(>) :: Intersection a -> Intersection a -> Bool

(>=) :: Intersection a -> Intersection a -> Bool

max :: Intersection a -> Intersection a -> Intersection a

min :: Intersection a -> Intersection a -> Intersection a

Ord a => Ord (Set a)

Defined in Data.Set.Internal

Methods

compare :: Set a -> Set a -> Ordering

(<) :: Set a -> Set a -> Bool

(<=) :: Set a -> Set a -> Bool

(>) :: Set a -> Set a -> Bool

(>=) :: Set a -> Set a -> Bool

max :: Set a -> Set a -> Set a

min :: Set a -> Set a -> Set a

Ord a => Ord (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

compare :: Maybe a -> Maybe a -> Ordering

(<) :: Maybe a -> Maybe a -> Bool

(<=) :: Maybe a -> Maybe a -> Bool

(>) :: Maybe a -> Maybe a -> Bool

(>=) :: Maybe a -> Maybe a -> Bool

max :: Maybe a -> Maybe a -> Maybe a

min :: Maybe a -> Maybe a -> Maybe a

Ord a => Ord (a)

Defined in GHC.Classes

Methods

compare :: (a) -> (a) -> Ordering

(<) :: (a) -> (a) -> Bool

(<=) :: (a) -> (a) -> Bool

(>) :: (a) -> (a) -> Bool

(>=) :: (a) -> (a) -> Bool

max :: (a) -> (a) -> (a)

min :: (a) -> (a) -> (a)

Ord a => Ord [a]

Defined in GHC.Classes

Methods

compare :: [a] -> [a] -> Ordering

(<) :: [a] -> [a] -> Bool

(<=) :: [a] -> [a] -> Bool

(>) :: [a] -> [a] -> Bool

(>=) :: [a] -> [a] -> Bool

max :: [a] -> [a] -> [a]

min :: [a] -> [a] -> [a]

(Ord err, Ord ok) => Ord (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

compare :: Result err ok -> Result err ok -> Ordering

(<) :: Result err ok -> Result err ok -> Bool

(<=) :: Result err ok -> Result err ok -> Bool

(>) :: Result err ok -> Result err ok -> Bool

(>=) :: Result err ok -> Result err ok -> Bool

max :: Result err ok -> Result err ok -> Result err ok

min :: Result err ok -> Result err ok -> Result err ok

(Ord a, Ord b) => Ord (Either a b)

Since: base-2.1

Defined in Data.Either

Methods

compare :: Either a b -> Either a b -> Ordering

(<) :: Either a b -> Either a b -> Bool

(<=) :: Either a b -> Either a b -> Bool

(>) :: Either a b -> Either a b -> Bool

(>=) :: Either a b -> Either a b -> Bool

max :: Either a b -> Either a b -> Either a b

min :: Either a b -> Either a b -> Either a b

(Ix i, Ord e) => Ord (Array i e)

Since: base-2.1

Defined in GHC.Arr

Methods

compare :: Array i e -> Array i e -> Ordering

(<) :: Array i e -> Array i e -> Bool

(<=) :: Array i e -> Array i e -> Bool

(>) :: Array i e -> Array i e -> Bool

(>=) :: Array i e -> Array i e -> Bool

max :: Array i e -> Array i e -> Array i e

min :: Array i e -> Array i e -> Array i e

(Ord k, Ord v) => Ord (Map k v)

Defined in Data.Map.Internal

Methods

compare :: Map k v -> Map k v -> Ordering

(<) :: Map k v -> Map k v -> Bool

(<=) :: Map k v -> Map k v -> Bool

(>) :: Map k v -> Map k v -> Bool

(>=) :: Map k v -> Map k v -> Bool

max :: Map k v -> Map k v -> Map k v

min :: Map k v -> Map k v -> Map k v

(Ord a, Ord b) => Ord (a, b)

Defined in GHC.Classes

Methods

compare :: (a, b) -> (a, b) -> Ordering

(<) :: (a, b) -> (a, b) -> Bool

(<=) :: (a, b) -> (a, b) -> Bool

(>) :: (a, b) -> (a, b) -> Bool

(>=) :: (a, b) -> (a, b) -> Bool

max :: (a, b) -> (a, b) -> (a, b)

min :: (a, b) -> (a, b) -> (a, b)

(Ord a, Ord b, Ord c) => Ord (a, b, c)

Defined in GHC.Classes

Methods

compare :: (a, b, c) -> (a, b, c) -> Ordering

(<) :: (a, b, c) -> (a, b, c) -> Bool

(<=) :: (a, b, c) -> (a, b, c) -> Bool

(>) :: (a, b, c) -> (a, b, c) -> Bool

(>=) :: (a, b, c) -> (a, b, c) -> Bool

max :: (a, b, c) -> (a, b, c) -> (a, b, c)

min :: (a, b, c) -> (a, b, c) -> (a, b, c)

(Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d) -> (a, b, c, d) -> Ordering

(<) :: (a, b, c, d) -> (a, b, c, d) -> Bool

(<=) :: (a, b, c, d) -> (a, b, c, d) -> Bool

(>) :: (a, b, c, d) -> (a, b, c, d) -> Bool

(>=) :: (a, b, c, d) -> (a, b, c, d) -> Bool

max :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d)

min :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d)

(Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e) -> (a, b, c, d, e) -> Ordering

(<) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool

(<=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool

(>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool

(>=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool

max :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e)

min :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f) => Ord (a, b, c, d, e, f)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Ordering

(<) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool

(<=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool

(>) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool

(>=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool

max :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f)

min :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g) => Ord (a, b, c, d, e, f, g)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Ordering

(<) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool

(<=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool

(>) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool

(>=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool

max :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g)

min :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h) => Ord (a, b, c, d, e, f, g, h)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Ordering

(<) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool

(<=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool

(>) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool

(>=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool

max :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h)

min :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i) => Ord (a, b, c, d, e, f, g, h, i)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Ordering

(<) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool

(<=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool

(>) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool

(>=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool

max :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i)

min :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j) => Ord (a, b, c, d, e, f, g, h, i, j)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Ordering

(<) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool

(<=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool

(>) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool

(>=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool

max :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j)

min :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k) => Ord (a, b, c, d, e, f, g, h, i, j, k)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Ordering

(<) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool

(<=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool

(>) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool

(>=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool

max :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k)

min :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l) => Ord (a, b, c, d, e, f, g, h, i, j, k, l)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Ordering

(<) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool

(<=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool

(>) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool

(>=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool

max :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l)

min :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Ordering

(<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool

(<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool

(>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool

(>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool

max :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m)

min :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Ordering

(<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool

(<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool

(>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool

(>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool

max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n, Ord o) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Defined in GHC.Classes

Methods

compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Ordering

(<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool

(<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool

(>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool

(>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool

max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Reexport from Prelude

class Enum a

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 succ maxBound and pred minBound should result in a runtime error.
• fromEnum and toEnum should give a runtime error if the result value is not representable in the result type. For example, toEnum 7 :: Bool is an error.
• enumFrom and enumFromThen should be defined with an implicit bound, thus:

   enumFrom     x   = enumFromTo     x maxBound
   enumFromThen x y = enumFromThenTo x y bound
     where
       bound | fromEnum y >= fromEnum x = maxBound
             | otherwise                = minBound

Minimal complete definition

toEnum, fromEnum

Instances

Enum GeneralCategory

Since: base-2.1

Defined in GHC.Unicode

Methods

succ :: GeneralCategory -> GeneralCategory

pred :: GeneralCategory -> GeneralCategory

toEnum :: Int -> GeneralCategory

fromEnum :: GeneralCategory -> Int

enumFrom :: GeneralCategory -> [GeneralCategory]

enumFromThen :: GeneralCategory -> GeneralCategory -> [GeneralCategory]

enumFromTo :: GeneralCategory -> GeneralCategory -> [GeneralCategory]

enumFromThenTo :: GeneralCategory -> GeneralCategory -> GeneralCategory -> [GeneralCategory]

Enum Word16

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word16 -> Word16

pred :: Word16 -> Word16

toEnum :: Int -> Word16

fromEnum :: Word16 -> Int

enumFrom :: Word16 -> [Word16]

enumFromThen :: Word16 -> Word16 -> [Word16]

enumFromTo :: Word16 -> Word16 -> [Word16]

enumFromThenTo :: Word16 -> Word16 -> Word16 -> [Word16]

Enum Word32

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word32 -> Word32

pred :: Word32 -> Word32

toEnum :: Int -> Word32

fromEnum :: Word32 -> Int

enumFrom :: Word32 -> [Word32]

enumFromThen :: Word32 -> Word32 -> [Word32]

enumFromTo :: Word32 -> Word32 -> [Word32]

enumFromThenTo :: Word32 -> Word32 -> Word32 -> [Word32]

Enum Word64

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word64 -> Word64

pred :: Word64 -> Word64

toEnum :: Int -> Word64

fromEnum :: Word64 -> Int

enumFrom :: Word64 -> [Word64]

enumFromThen :: Word64 -> Word64 -> [Word64]

enumFromTo :: Word64 -> Word64 -> [Word64]

enumFromThenTo :: Word64 -> Word64 -> Word64 -> [Word64]

Enum Word8

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word8 -> Word8

pred :: Word8 -> Word8

toEnum :: Int -> Word8

fromEnum :: Word8 -> Int

enumFrom :: Word8 -> [Word8]

enumFromThen :: Word8 -> Word8 -> [Word8]

enumFromTo :: Word8 -> Word8 -> [Word8]

enumFromThenTo :: Word8 -> Word8 -> Word8 -> [Word8]

Enum Ordering

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Ordering -> Ordering

pred :: Ordering -> Ordering

toEnum :: Int -> Ordering

fromEnum :: Ordering -> Int

enumFrom :: Ordering -> [Ordering]

enumFromThen :: Ordering -> Ordering -> [Ordering]

enumFromTo :: Ordering -> Ordering -> [Ordering]

enumFromThenTo :: Ordering -> Ordering -> Ordering -> [Ordering]

Enum Integer

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Integer -> Integer

pred :: Integer -> Integer

toEnum :: Int -> Integer

fromEnum :: Integer -> Int

enumFrom :: Integer -> [Integer]

enumFromThen :: Integer -> Integer -> [Integer]

enumFromTo :: Integer -> Integer -> [Integer]

enumFromThenTo :: Integer -> Integer -> Integer -> [Integer]

Enum Natural

Since: base-4.8.0.0

Defined in GHC.Enum

Methods

succ :: Natural -> Natural

pred :: Natural -> Natural

toEnum :: Int -> Natural

fromEnum :: Natural -> Int

enumFrom :: Natural -> [Natural]

enumFromThen :: Natural -> Natural -> [Natural]

enumFromTo :: Natural -> Natural -> [Natural]

enumFromThenTo :: Natural -> Natural -> Natural -> [Natural]

Enum ()

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: () -> ()

pred :: () -> ()

toEnum :: Int -> ()

fromEnum :: () -> Int

enumFrom :: () -> [()]

enumFromThen :: () -> () -> [()]

enumFromTo :: () -> () -> [()]

enumFromThenTo :: () -> () -> () -> [()]

Enum Bool

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Bool -> Bool

pred :: Bool -> Bool

toEnum :: Int -> Bool

fromEnum :: Bool -> Int

enumFrom :: Bool -> [Bool]

enumFromThen :: Bool -> Bool -> [Bool]

enumFromTo :: Bool -> Bool -> [Bool]

enumFromThenTo :: Bool -> Bool -> Bool -> [Bool]

Enum Char

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Char -> Char

pred :: Char -> Char

toEnum :: Int -> Char

fromEnum :: Char -> Int

enumFrom :: Char -> [Char]

enumFromThen :: Char -> Char -> [Char]

enumFromTo :: Char -> Char -> [Char]

enumFromThenTo :: Char -> Char -> Char -> [Char]

Enum Int

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Int -> Int

pred :: Int -> Int

toEnum :: Int -> Int

fromEnum :: Int -> Int

enumFrom :: Int -> [Int]

enumFromThen :: Int -> Int -> [Int]

enumFromTo :: Int -> Int -> [Int]

enumFromThenTo :: Int -> Int -> Int -> [Int]

Enum Levity

Since: base-4.16.0.0

Defined in GHC.Enum

Methods

succ :: Levity -> Levity

pred :: Levity -> Levity

toEnum :: Int -> Levity

fromEnum :: Levity -> Int

enumFrom :: Levity -> [Levity]

enumFromThen :: Levity -> Levity -> [Levity]

enumFromTo :: Levity -> Levity -> [Levity]

enumFromThenTo :: Levity -> Levity -> Levity -> [Levity]

Enum VecCount

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

succ :: VecCount -> VecCount

pred :: VecCount -> VecCount

toEnum :: Int -> VecCount

fromEnum :: VecCount -> Int

enumFrom :: VecCount -> [VecCount]

enumFromThen :: VecCount -> VecCount -> [VecCount]

enumFromTo :: VecCount -> VecCount -> [VecCount]

enumFromThenTo :: VecCount -> VecCount -> VecCount -> [VecCount]

Enum VecElem

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

succ :: VecElem -> VecElem

pred :: VecElem -> VecElem

toEnum :: Int -> VecElem

fromEnum :: VecElem -> Int

enumFrom :: VecElem -> [VecElem]

enumFromThen :: VecElem -> VecElem -> [VecElem]

enumFromTo :: VecElem -> VecElem -> [VecElem]

enumFromThenTo :: VecElem -> VecElem -> VecElem -> [VecElem]

Enum Word

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Word -> Word

pred :: Word -> Word

toEnum :: Int -> Word

fromEnum :: Word -> Int

enumFrom :: Word -> [Word]

enumFromThen :: Word -> Word -> [Word]

enumFromTo :: Word -> Word -> [Word]

enumFromThenTo :: Word -> Word -> Word -> [Word]

Integral a => Enum (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

succ :: Ratio a -> Ratio a

pred :: Ratio a -> Ratio a

toEnum :: Int -> Ratio a

fromEnum :: Ratio a -> Int

enumFrom :: Ratio a -> [Ratio a]

enumFromThen :: Ratio a -> Ratio a -> [Ratio a]

enumFromTo :: Ratio a -> Ratio a -> [Ratio a]

enumFromThenTo :: Ratio a -> Ratio a -> Ratio a -> [Ratio a]

Enum a => Enum (a)

Defined in GHC.Enum

Methods

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)]

Reexport from Prelude

class Bounded a

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.

Minimal complete definition

minBound, maxBound

Instances

Bounded GeneralCategory

Since: base-2.1

Defined in GHC.Unicode

Methods

minBound :: GeneralCategory

maxBound :: GeneralCategory

Bounded Word16

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word16

maxBound :: Word16

Bounded Word32

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word32

maxBound :: Word32

Bounded Word64

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word64

maxBound :: Word64

Bounded Word8

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word8

maxBound :: Word8

Bounded Ordering

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Ordering

maxBound :: Ordering

Bounded ()

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: ()

maxBound :: ()

Bounded Bool

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Bool

maxBound :: Bool

Bounded Char

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Char

maxBound :: Char

Bounded Int

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Int

maxBound :: Int

Bounded Levity

Since: base-4.16.0.0

Defined in GHC.Enum

Methods

minBound :: Levity

maxBound :: Levity

Bounded VecCount

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

minBound :: VecCount

maxBound :: VecCount

Bounded VecElem

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

minBound :: VecElem

maxBound :: VecElem

Bounded Word

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Word

maxBound :: Word

Bounded a => Bounded (a)

Defined in GHC.Enum

Methods

minBound :: (a)

maxBound :: (a)

(Bounded a, Bounded b) => Bounded (a, b)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b)

maxBound :: (a, b)

(Bounded a, Bounded b, Bounded c) => Bounded (a, b, c)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c)

maxBound :: (a, b, c)

(Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d)

maxBound :: (a, b, c, d)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e)

maxBound :: (a, b, c, d, e)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f)

maxBound :: (a, b, c, d, e, f)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g) => Bounded (a, b, c, d, e, f, g)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g)

maxBound :: (a, b, c, d, e, f, g)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h) => Bounded (a, b, c, d, e, f, g, h)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h)

maxBound :: (a, b, c, d, e, f, g, h)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i) => Bounded (a, b, c, d, e, f, g, h, i)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i)

maxBound :: (a, b, c, d, e, f, g, h, i)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j) => Bounded (a, b, c, d, e, f, g, h, i, j)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j)

maxBound :: (a, b, c, d, e, f, g, h, i, j)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k) => Bounded (a, b, c, d, e, f, g, h, i, j, k)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Reexport from Foldable

class Foldable (t :: Type -> Type)

The Foldable class represents data structures that can be reduced to a summary value one element at a time. Strict left-associative folds are a good fit for space-efficient reduction, while lazy right-associative folds are a good fit for corecursive iteration, or for folds that short-circuit after processing an initial subsequence of the structure's elements.

Instances can be derived automatically by enabling the DeriveFoldable extension. For example, a derived instance for a binary tree might be:

{-# LANGUAGE DeriveFoldable #-}
data Tree a = Empty
            | Leaf a
            | Node (Tree a) a (Tree a)
    deriving Foldable

A more detailed description can be found in the Overview section of Data.Foldable.

For the class laws see the Laws section of Data.Foldable.

Minimal complete definition

foldMap | foldr

Instances

Foldable ZipList

Since: base-4.9.0.0

Defined in Control.Applicative

Methods

fold :: Monoid m => ZipList m -> m

foldMap :: Monoid m => (a -> m) -> ZipList a -> m

foldMap' :: Monoid m => (a -> m) -> ZipList a -> m

foldr :: (a -> b -> b) -> b -> ZipList a -> b

foldr' :: (a -> b -> b) -> b -> ZipList a -> b

foldl :: (b -> a -> b) -> b -> ZipList a -> b

foldl' :: (b -> a -> b) -> b -> ZipList a -> b

foldr1 :: (a -> a -> a) -> ZipList a -> a

foldl1 :: (a -> a -> a) -> ZipList a -> a

toList :: ZipList a -> [a]

null :: ZipList a -> Bool

length :: ZipList a -> Int

elem :: Eq a => a -> ZipList a -> Bool

maximum :: Ord a => ZipList a -> a

minimum :: Ord a => ZipList a -> a

sum :: Num a => ZipList a -> a

product :: Num a => ZipList 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

toList :: First a -> [a]

null :: First a -> Bool

length :: First a -> Int

elem :: Eq a => a -> First a -> Bool

maximum :: Ord a => First a -> a

minimum :: Ord a => First a -> a

sum :: Num a => First a -> a

product :: Num 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

toList :: Last a -> [a]

null :: Last a -> Bool

length :: Last a -> Int

elem :: Eq a => a -> Last a -> Bool

maximum :: Ord a => Last a -> a

minimum :: Ord a => Last a -> a

sum :: Num a => Last a -> a

product :: Num a => Last a -> a

Foldable Down

Since: base-4.12.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Down m -> m

foldMap :: Monoid m => (a -> m) -> Down a -> m

foldMap' :: Monoid m => (a -> m) -> Down a -> m

foldr :: (a -> b -> b) -> b -> Down a -> b

foldr' :: (a -> b -> b) -> b -> Down a -> b

foldl :: (b -> a -> b) -> b -> Down a -> b

foldl' :: (b -> a -> b) -> b -> Down a -> b

foldr1 :: (a -> a -> a) -> Down a -> a

foldl1 :: (a -> a -> a) -> Down a -> a

toList :: Down a -> [a]

null :: Down a -> Bool

length :: Down a -> Int

elem :: Eq a => a -> Down a -> Bool

maximum :: Ord a => Down a -> a

minimum :: Ord a => Down a -> a

sum :: Num a => Down a -> a

product :: Num a => Down 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

toList :: Dual a -> [a]

null :: Dual a -> Bool

length :: Dual a -> Int

elem :: Eq a => a -> Dual a -> Bool

maximum :: Ord a => Dual a -> a

minimum :: Ord a => Dual a -> a

sum :: Num a => Dual a -> a

product :: Num a => Dual a -> a

Foldable Product

Since: base-4.8.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Product m -> m

foldMap :: Monoid m => (a -> m) -> Product a -> m

foldMap' :: Monoid m => (a -> m) -> Product a -> m

foldr :: (a -> b -> b) -> b -> Product a -> b

foldr' :: (a -> b -> b) -> b -> Product a -> b

foldl :: (b -> a -> b) -> b -> Product a -> b

foldl' :: (b -> a -> b) -> b -> Product a -> b

foldr1 :: (a -> a -> a) -> Product a -> a

foldl1 :: (a -> a -> a) -> Product a -> a

toList :: Product a -> [a]

null :: Product a -> Bool

length :: Product a -> Int

elem :: Eq a => a -> Product a -> Bool

maximum :: Ord a => Product a -> a

minimum :: Ord a => Product a -> a

sum :: Num a => Product a -> a

product :: Num a => Product a -> a

Foldable Sum

Since: base-4.8.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Sum m -> m

foldMap :: Monoid m => (a -> m) -> Sum a -> m

foldMap' :: Monoid m => (a -> m) -> Sum a -> m

foldr :: (a -> b -> b) -> b -> Sum a -> b

foldr' :: (a -> b -> b) -> b -> Sum a -> b

foldl :: (b -> a -> b) -> b -> Sum a -> b

foldl' :: (b -> a -> b) -> b -> Sum a -> b

foldr1 :: (a -> a -> a) -> Sum a -> a

foldl1 :: (a -> a -> a) -> Sum a -> a

toList :: Sum a -> [a]

null :: Sum a -> Bool

length :: Sum a -> Int

elem :: Eq a => a -> Sum a -> Bool

maximum :: Ord a => Sum a -> a

minimum :: Ord a => Sum a -> a

sum :: Num a => Sum a -> a

product :: Num a => Sum a -> a

Foldable NonEmpty

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => NonEmpty m -> m

foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m

foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m

foldr :: (a -> b -> b) -> b -> NonEmpty a -> b

foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b

foldl :: (b -> a -> b) -> b -> NonEmpty a -> b

foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b

foldr1 :: (a -> a -> a) -> NonEmpty a -> a

foldl1 :: (a -> a -> a) -> NonEmpty a -> a

toList :: NonEmpty a -> [a]

null :: NonEmpty a -> Bool

length :: NonEmpty a -> Int

elem :: Eq a => a -> NonEmpty a -> Bool

maximum :: Ord a => NonEmpty a -> a

minimum :: Ord a => NonEmpty a -> a

sum :: Num a => NonEmpty a -> a

product :: Num a => NonEmpty a -> a

Foldable Par1

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Par1 m -> m

foldMap :: Monoid m => (a -> m) -> Par1 a -> m

foldMap' :: Monoid m => (a -> m) -> Par1 a -> m

foldr :: (a -> b -> b) -> b -> Par1 a -> b

foldr' :: (a -> b -> b) -> b -> Par1 a -> b

foldl :: (b -> a -> b) -> b -> Par1 a -> b

foldl' :: (b -> a -> b) -> b -> Par1 a -> b

foldr1 :: (a -> a -> a) -> Par1 a -> a

foldl1 :: (a -> a -> a) -> Par1 a -> a

toList :: Par1 a -> [a]

null :: Par1 a -> Bool

length :: Par1 a -> Int

elem :: Eq a => a -> Par1 a -> Bool

maximum :: Ord a => Par1 a -> a

minimum :: Ord a => Par1 a -> a

sum :: Num a => Par1 a -> a

product :: Num a => Par1 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

toList :: Digit a -> [a]

null :: Digit a -> Bool

length :: Digit a -> Int

elem :: Eq a => a -> Digit a -> Bool

maximum :: Ord a => Digit a -> a

minimum :: Ord a => Digit a -> a

sum :: Num a => Digit a -> a

product :: Num a => Digit a -> a

Foldable Elem

Defined in Data.Sequence.Internal

Methods

fold :: Monoid m => Elem m -> m

foldMap :: Monoid m => (a -> m) -> Elem a -> m

foldMap' :: Monoid m => (a -> m) -> Elem a -> m

foldr :: (a -> b -> b) -> b -> Elem a -> b

foldr' :: (a -> b -> b) -> b -> Elem a -> b

foldl :: (b -> a -> b) -> b -> Elem a -> b

foldl' :: (b -> a -> b) -> b -> Elem a -> b

foldr1 :: (a -> a -> a) -> Elem a -> a

foldl1 :: (a -> a -> a) -> Elem a -> a

toList :: Elem a -> [a]

null :: Elem a -> Bool

length :: Elem a -> Int

elem :: Eq a => a -> Elem a -> Bool

maximum :: Ord a => Elem a -> a

minimum :: Ord a => Elem a -> a

sum :: Num a => Elem a -> a

product :: Num a => Elem a -> a

Foldable FingerTree

Defined in Data.Sequence.Internal

Methods

fold :: Monoid m => FingerTree m -> m

foldMap :: Monoid m => (a -> m) -> FingerTree a -> m

foldMap' :: Monoid m => (a -> m) -> FingerTree a -> m

foldr :: (a -> b -> b) -> b -> FingerTree a -> b

foldr' :: (a -> b -> b) -> b -> FingerTree a -> b

foldl :: (b -> a -> b) -> b -> FingerTree a -> b

foldl' :: (b -> a -> b) -> b -> FingerTree a -> b

foldr1 :: (a -> a -> a) -> FingerTree a -> a

foldl1 :: (a -> a -> a) -> FingerTree a -> a

toList :: FingerTree a -> [a]

null :: FingerTree a -> Bool

length :: FingerTree a -> Int

elem :: Eq a => a -> FingerTree a -> Bool

maximum :: Ord a => FingerTree a -> a

minimum :: Ord a => FingerTree a -> a

sum :: Num a => FingerTree a -> a

product :: Num a => FingerTree a -> a

Foldable Node

Defined in Data.Sequence.Internal

Methods

fold :: Monoid m => Node m -> m

foldMap :: Monoid m => (a -> m) -> Node a -> m

foldMap' :: Monoid m => (a -> m) -> Node a -> m

foldr :: (a -> b -> b) -> b -> Node a -> b

foldr' :: (a -> b -> b) -> b -> Node a -> b

foldl :: (b -> a -> b) -> b -> Node a -> b

foldl' :: (b -> a -> b) -> b -> Node a -> b

foldr1 :: (a -> a -> a) -> Node a -> a

foldl1 :: (a -> a -> a) -> Node a -> a

toList :: Node a -> [a]

null :: Node a -> Bool

length :: Node a -> Int

elem :: Eq a => a -> Node a -> Bool

maximum :: Ord a => Node a -> a

minimum :: Ord a => Node a -> a

sum :: Num a => Node a -> a

product :: Num a => Node a -> a

Foldable Seq

Defined in Data.Sequence.Internal

Methods

fold :: Monoid m => Seq m -> m

foldMap :: Monoid m => (a -> m) -> Seq a -> m

foldMap' :: Monoid m => (a -> m) -> Seq a -> m

foldr :: (a -> b -> b) -> b -> Seq a -> b

foldr' :: (a -> b -> b) -> b -> Seq a -> b

foldl :: (b -> a -> b) -> b -> Seq a -> b

foldl' :: (b -> a -> b) -> b -> Seq a -> b

foldr1 :: (a -> a -> a) -> Seq a -> a

foldl1 :: (a -> a -> a) -> Seq a -> a

toList :: Seq a -> [a]

null :: Seq a -> Bool

length :: Seq a -> Int

elem :: Eq a => a -> Seq a -> Bool

maximum :: Ord a => Seq a -> a

minimum :: Ord a => Seq a -> a

sum :: Num a => Seq a -> a

product :: Num a => Seq a -> a

Foldable ViewL

Defined in Data.Sequence.Internal

Methods

fold :: Monoid m => ViewL m -> m

foldMap :: Monoid m => (a -> m) -> ViewL a -> m

foldMap' :: Monoid m => (a -> m) -> ViewL a -> m

foldr :: (a -> b -> b) -> b -> ViewL a -> b

foldr' :: (a -> b -> b) -> b -> ViewL a -> b

foldl :: (b -> a -> b) -> b -> ViewL a -> b

foldl' :: (b -> a -> b) -> b -> ViewL a -> b

foldr1 :: (a -> a -> a) -> ViewL a -> a

foldl1 :: (a -> a -> a) -> ViewL a -> a

toList :: ViewL a -> [a]

null :: ViewL a -> Bool

length :: ViewL a -> Int

elem :: Eq a => a -> ViewL a -> Bool

maximum :: Ord a => ViewL a -> a

minimum :: Ord a => ViewL a -> a

sum :: Num a => ViewL a -> a

product :: Num 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

toList :: ViewR a -> [a]

null :: ViewR a -> Bool

length :: ViewR a -> Int

elem :: Eq a => a -> ViewR a -> Bool

maximum :: Ord a => ViewR a -> a

minimum :: Ord a => ViewR a -> a

sum :: Num a => ViewR a -> a

product :: Num 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

toList :: Set a -> [a]

null :: Set a -> Bool

length :: Set a -> Int

elem :: Eq a => a -> Set a -> Bool

maximum :: Ord a => Set a -> a

minimum :: Ord a => Set a -> a

sum :: Num a => Set a -> a

product :: Num a => Set 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

toList :: Maybe a -> [a]

null :: Maybe a -> Bool

length :: Maybe a -> Int

elem :: Eq a => a -> Maybe a -> Bool

maximum :: Ord a => Maybe a -> a

minimum :: Ord a => Maybe a -> a

sum :: Num a => Maybe a -> a

product :: Num a => Maybe a -> a

Foldable Solo

Since: base-4.15

Defined in Data.Foldable

Methods

fold :: Monoid m => Solo m -> m

foldMap :: Monoid m => (a -> m) -> Solo a -> m

foldMap' :: Monoid m => (a -> m) -> Solo a -> m

foldr :: (a -> b -> b) -> b -> Solo a -> b

foldr' :: (a -> b -> b) -> b -> Solo a -> b

foldl :: (b -> a -> b) -> b -> Solo a -> b

foldl' :: (b -> a -> b) -> b -> Solo a -> b

foldr1 :: (a -> a -> a) -> Solo a -> a

foldl1 :: (a -> a -> a) -> Solo a -> a

toList :: Solo a -> [a]

null :: Solo a -> Bool

length :: Solo a -> Int

elem :: Eq a => a -> Solo a -> Bool

maximum :: Ord a => Solo a -> a

minimum :: Ord a => Solo a -> a

sum :: Num a => Solo a -> a

product :: Num a => Solo a -> a

Foldable List

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

toList :: [a] -> [a]

null :: [a] -> Bool

length :: [a] -> Int

elem :: Eq a => a -> [a] -> Bool

maximum :: Ord a => [a] -> a

minimum :: Ord a => [a] -> a

sum :: Num a => [a] -> a

product :: Num a => [a] -> a

Foldable (Either a)

Since: base-4.7.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Either a m -> m

foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m

foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m

foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b

foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b

foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b

foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b

foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0

foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0

toList :: Either a a0 -> [a0]

null :: Either a a0 -> Bool

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

sum :: Num a0 => Either a a0 -> a0

product :: Num a0 => Either a a0 -> a0

Foldable (Proxy :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Proxy m -> m

foldMap :: Monoid m => (a -> m) -> Proxy a -> m

foldMap' :: Monoid m => (a -> m) -> Proxy a -> m

foldr :: (a -> b -> b) -> b -> Proxy a -> b

foldr' :: (a -> b -> b) -> b -> Proxy a -> b

foldl :: (b -> a -> b) -> b -> Proxy a -> b

foldl' :: (b -> a -> b) -> b -> Proxy a -> b

foldr1 :: (a -> a -> a) -> Proxy a -> a

foldl1 :: (a -> a -> a) -> Proxy a -> a

toList :: Proxy a -> [a]

null :: Proxy a -> Bool

length :: Proxy a -> Int

elem :: Eq a => a -> Proxy a -> Bool

maximum :: Ord a => Proxy a -> a

minimum :: Ord a => Proxy a -> a

sum :: Num a => Proxy a -> a

product :: Num a => Proxy 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

toList :: Array i a -> [a]

null :: Array i a -> Bool

length :: Array i a -> Int

elem :: Eq a => a -> Array i a -> Bool

maximum :: Ord a => Array i a -> a

minimum :: Ord a => Array i a -> a

sum :: Num a => Array i a -> a

product :: Num a => Array i a -> a

Foldable (U1 :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => U1 m -> m

foldMap :: Monoid m => (a -> m) -> U1 a -> m

foldMap' :: Monoid m => (a -> m) -> U1 a -> m

foldr :: (a -> b -> b) -> b -> U1 a -> b

foldr' :: (a -> b -> b) -> b -> U1 a -> b

foldl :: (b -> a -> b) -> b -> U1 a -> b

foldl' :: (b -> a -> b) -> b -> U1 a -> b

foldr1 :: (a -> a -> a) -> U1 a -> a

foldl1 :: (a -> a -> a) -> U1 a -> a

toList :: U1 a -> [a]

null :: U1 a -> Bool

length :: U1 a -> Int

elem :: Eq a => a -> U1 a -> Bool

maximum :: Ord a => U1 a -> a

minimum :: Ord a => U1 a -> a

sum :: Num a => U1 a -> a

product :: Num 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

toList :: UAddr a -> [a]

null :: UAddr a -> Bool

length :: UAddr a -> Int

elem :: Eq a => a -> UAddr a -> Bool

maximum :: Ord a => UAddr a -> a

minimum :: Ord a => UAddr a -> a

sum :: Num a => UAddr a -> a

product :: Num 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

toList :: UChar a -> [a]

null :: UChar a -> Bool

length :: UChar a -> Int

elem :: Eq a => a -> UChar a -> Bool

maximum :: Ord a => UChar a -> a

minimum :: Ord a => UChar a -> a

sum :: Num a => UChar a -> a

product :: Num 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

toList :: UDouble a -> [a]

null :: UDouble a -> Bool

length :: UDouble a -> Int

elem :: Eq a => a -> UDouble a -> Bool

maximum :: Ord a => UDouble a -> a

minimum :: Ord a => UDouble a -> a

sum :: Num a => UDouble a -> a

product :: Num 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

toList :: UFloat a -> [a]

null :: UFloat a -> Bool

length :: UFloat a -> Int

elem :: Eq a => a -> UFloat a -> Bool

maximum :: Ord a => UFloat a -> a

minimum :: Ord a => UFloat a -> a

sum :: Num a => UFloat a -> a

product :: Num 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

toList :: UInt a -> [a]

null :: UInt a -> Bool

length :: UInt a -> Int

elem :: Eq a => a -> UInt a -> Bool

maximum :: Ord a => UInt a -> a

minimum :: Ord a => UInt a -> a

sum :: Num a => UInt a -> a

product :: Num 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

toList :: UWord a -> [a]

null :: UWord a -> Bool

length :: UWord a -> Int

elem :: Eq a => a -> UWord a -> Bool

maximum :: Ord a => UWord a -> a

minimum :: Ord a => UWord a -> a

sum :: Num a => UWord a -> a

product :: Num a => UWord a -> a

Foldable (V1 :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => V1 m -> m

foldMap :: Monoid m => (a -> m) -> V1 a -> m

foldMap' :: Monoid m => (a -> m) -> V1 a -> m

foldr :: (a -> b -> b) -> b -> V1 a -> b

foldr' :: (a -> b -> b) -> b -> V1 a -> b

foldl :: (b -> a -> b) -> b -> V1 a -> b

foldl' :: (b -> a -> b) -> b -> V1 a -> b

foldr1 :: (a -> a -> a) -> V1 a -> a

foldl1 :: (a -> a -> a) -> V1 a -> a

toList :: V1 a -> [a]

null :: V1 a -> Bool

length :: V1 a -> Int

elem :: Eq a => a -> V1 a -> Bool

maximum :: Ord a => V1 a -> a

minimum :: Ord a => V1 a -> a

sum :: Num a => V1 a -> a

product :: Num a => V1 a -> a

Foldable (Map k)

Folds in order of increasing key.

Defined in Data.Map.Internal

Methods

fold :: Monoid m => Map k m -> m

foldMap :: Monoid m => (a -> m) -> Map k a -> m

foldMap' :: Monoid m => (a -> m) -> Map k a -> m

foldr :: (a -> b -> b) -> b -> Map k a -> b

foldr' :: (a -> b -> b) -> b -> Map k a -> b

foldl :: (b -> a -> b) -> b -> Map k a -> b

foldl' :: (b -> a -> b) -> b -> Map k a -> b

foldr1 :: (a -> a -> a) -> Map k a -> a

foldl1 :: (a -> a -> a) -> Map k a -> a

toList :: Map k a -> [a]

null :: Map k a -> Bool

length :: Map k a -> Int

elem :: Eq a => a -> Map k a -> Bool

maximum :: Ord a => Map k a -> a

minimum :: Ord a => Map k a -> a

sum :: Num a => Map k a -> a

product :: Num a => Map k a -> a

Foldable ((,) a)

Since: base-4.7.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => (a, m) -> m

foldMap :: Monoid m => (a0 -> m) -> (a, a0) -> m

foldMap' :: Monoid m => (a0 -> m) -> (a, a0) -> m

foldr :: (a0 -> b -> b) -> b -> (a, a0) -> b

foldr' :: (a0 -> b -> b) -> b -> (a, a0) -> b

foldl :: (b -> a0 -> b) -> b -> (a, a0) -> b

foldl' :: (b -> a0 -> b) -> b -> (a, a0) -> b

foldr1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0

foldl1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0

toList :: (a, a0) -> [a0]

null :: (a, a0) -> Bool

length :: (a, a0) -> Int

elem :: Eq a0 => a0 -> (a, a0) -> Bool

maximum :: Ord a0 => (a, a0) -> a0

minimum :: Ord a0 => (a, a0) -> a0

sum :: Num a0 => (a, a0) -> a0

product :: Num a0 => (a, a0) -> a0

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

toList :: Ap f a -> [a]

null :: Ap f a -> Bool

length :: Ap f a -> Int

elem :: Eq a => a -> Ap f a -> Bool

maximum :: Ord a => Ap f a -> a

minimum :: Ord a => Ap f a -> a

sum :: Num a => Ap f a -> a

product :: Num 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

toList :: Alt f a -> [a]

null :: Alt f a -> Bool

length :: Alt f a -> Int

elem :: Eq a => a -> Alt f a -> Bool

maximum :: Ord a => Alt f a -> a

minimum :: Ord a => Alt f a -> a

sum :: Num a => Alt f a -> a

product :: Num a => Alt f a -> a

Foldable f => Foldable (Rec1 f)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Rec1 f m -> m

foldMap :: Monoid m => (a -> m) -> Rec1 f a -> m

foldMap' :: Monoid m => (a -> m) -> Rec1 f a -> m

foldr :: (a -> b -> b) -> b -> Rec1 f a -> b

foldr' :: (a -> b -> b) -> b -> Rec1 f a -> b

foldl :: (b -> a -> b) -> b -> Rec1 f a -> b

foldl' :: (b -> a -> b) -> b -> Rec1 f a -> b

foldr1 :: (a -> a -> a) -> Rec1 f a -> a

foldl1 :: (a -> a -> a) -> Rec1 f a -> a

toList :: Rec1 f a -> [a]

null :: Rec1 f a -> Bool

length :: Rec1 f a -> Int

elem :: Eq a => a -> Rec1 f a -> Bool

maximum :: Ord a => Rec1 f a -> a

minimum :: Ord a => Rec1 f a -> a

sum :: Num a => Rec1 f a -> a

product :: Num a => Rec1 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]

null :: (f :*: g) a -> Bool

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

sum :: Num a => (f :*: g) a -> a

product :: Num 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]

null :: (f :+: g) a -> Bool

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

sum :: Num a => (f :+: g) a -> a

product :: Num a => (f :+: g) a -> a

Foldable (K1 i c :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => K1 i c m -> m

foldMap :: Monoid m => (a -> m) -> K1 i c a -> m

foldMap' :: Monoid m => (a -> m) -> K1 i c a -> m

foldr :: (a -> b -> b) -> b -> K1 i c a -> b

foldr' :: (a -> b -> b) -> b -> K1 i c a -> b

foldl :: (b -> a -> b) -> b -> K1 i c a -> b

foldl' :: (b -> a -> b) -> b -> K1 i c a -> b

foldr1 :: (a -> a -> a) -> K1 i c a -> a

foldl1 :: (a -> a -> a) -> K1 i c a -> a

toList :: K1 i c a -> [a]

null :: K1 i c a -> Bool

length :: K1 i c a -> Int

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

sum :: Num a => K1 i c a -> a

product :: Num 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]

null :: (f :.: g) a -> Bool

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

sum :: Num a => (f :.: g) a -> a

product :: Num a => (f :.: g) a -> a

Foldable f => Foldable (M1 i c f)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => M1 i c f m -> m

foldMap :: Monoid m => (a -> m) -> M1 i c f a -> m

foldMap' :: Monoid m => (a -> m) -> M1 i c f a -> m

foldr :: (a -> b -> b) -> b -> M1 i c f a -> b

foldr' :: (a -> b -> b) -> b -> M1 i c f a -> b

foldl :: (b -> a -> b) -> b -> M1 i c f a -> b

foldl' :: (b -> a -> b) -> b -> M1 i c f a -> b

foldr1 :: (a -> a -> a) -> M1 i c f a -> a

foldl1 :: (a -> a -> a) -> M1 i c f a -> a

toList :: M1 i c f a -> [a]

null :: M1 i c f a -> Bool

length :: M1 i c f a -> Int

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

sum :: Num a => M1 i c f a -> a

product :: Num a => M1 i c f a -> a

Reexport from Traversable

class (Functor t, Foldable t) => Traversable (t :: Type -> Type)

Functors representing data structures that can be transformed to structures of the same shape by performing an Applicative (or, therefore, Monad) action on each element from left to right.

A more detailed description of what same shape means, the various methods, how traversals are constructed, and example advanced use-cases can be found in the Overview section of Data.Traversable.

For the class laws see the Laws section of Data.Traversable.

Minimal complete definition

traverse | sequenceA

Instances

Traversable ZipList

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b)

sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a)

mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b)

sequence :: Monad m => ZipList (m a) -> m (ZipList a)

Traversable Identity

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Identity a -> f (Identity b)

sequenceA :: Applicative f => Identity (f a) -> f (Identity a)

mapM :: Monad m => (a -> m b) -> Identity a -> m (Identity b)

sequence :: Monad m => Identity (m a) -> m (Identity a)

Traversable First

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> First a -> f (First b)

sequenceA :: Applicative f => First (f a) -> f (First a)

mapM :: Monad m => (a -> m b) -> First a -> m (First b)

sequence :: Monad m => First (m a) -> m (First a)

Traversable Last

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Last a -> f (Last b)

sequenceA :: Applicative f => Last (f a) -> f (Last a)

mapM :: Monad m => (a -> m b) -> Last a -> m (Last b)

sequence :: Monad m => Last (m a) -> m (Last a)

Traversable Down

Since: base-4.12.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Down a -> f (Down b)

sequenceA :: Applicative f => Down (f a) -> f (Down a)

mapM :: Monad m => (a -> m b) -> Down a -> m (Down b)

sequence :: Monad m => Down (m a) -> m (Down a)

Traversable Dual

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Dual a -> f (Dual b)

sequenceA :: Applicative f => Dual (f a) -> f (Dual a)

mapM :: Monad m => (a -> m b) -> Dual a -> m (Dual b)

sequence :: Monad m => Dual (m a) -> m (Dual a)

Traversable Product

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Product a -> f (Product b)

sequenceA :: Applicative f => Product (f a) -> f (Product a)

mapM :: Monad m => (a -> m b) -> Product a -> m (Product b)

sequence :: Monad m => Product (m a) -> m (Product a)

Traversable Sum

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Sum a -> f (Sum b)

sequenceA :: Applicative f => Sum (f a) -> f (Sum a)

mapM :: Monad m => (a -> m b) -> Sum a -> m (Sum b)

sequence :: Monad m => Sum (m a) -> m (Sum a)

Traversable NonEmpty

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> NonEmpty a -> f (NonEmpty b)

sequenceA :: Applicative f => NonEmpty (f a) -> f (NonEmpty a)

mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b)

sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a)

Traversable Par1

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Par1 a -> f (Par1 b)

sequenceA :: Applicative f => Par1 (f a) -> f (Par1 a)

mapM :: Monad m => (a -> m b) -> Par1 a -> m (Par1 b)

sequence :: Monad m => Par1 (m a) -> m (Par1 a)

Traversable Digit

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Digit a -> f (Digit b)

sequenceA :: Applicative f => Digit (f a) -> f (Digit a)

mapM :: Monad m => (a -> m b) -> Digit a -> m (Digit b)

sequence :: Monad m => Digit (m a) -> m (Digit a)

Traversable Elem

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Elem a -> f (Elem b)

sequenceA :: Applicative f => Elem (f a) -> f (Elem a)

mapM :: Monad m => (a -> m b) -> Elem a -> m (Elem b)

sequence :: Monad m => Elem (m a) -> m (Elem a)

Traversable FingerTree

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> FingerTree a -> f (FingerTree b)

sequenceA :: Applicative f => FingerTree (f a) -> f (FingerTree a)

mapM :: Monad m => (a -> m b) -> FingerTree a -> m (FingerTree b)

sequence :: Monad m => FingerTree (m a) -> m (FingerTree a)

Traversable Node

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Node a -> f (Node b)

sequenceA :: Applicative f => Node (f a) -> f (Node a)

mapM :: Monad m => (a -> m b) -> Node a -> m (Node b)

sequence :: Monad m => Node (m a) -> m (Node a)

Traversable Seq

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Seq a -> f (Seq b)

sequenceA :: Applicative f => Seq (f a) -> f (Seq a)

mapM :: Monad m => (a -> m b) -> Seq a -> m (Seq b)

sequence :: Monad m => Seq (m a) -> m (Seq a)

Traversable ViewL

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> ViewL a -> f (ViewL b)

sequenceA :: Applicative f => ViewL (f a) -> f (ViewL a)

mapM :: Monad m => (a -> m b) -> ViewL a -> m (ViewL b)

sequence :: Monad m => ViewL (m a) -> m (ViewL a)

Traversable ViewR

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> ViewR a -> f (ViewR b)

sequenceA :: Applicative f => ViewR (f a) -> f (ViewR a)

mapM :: Monad m => (a -> m b) -> ViewR a -> m (ViewR b)

sequence :: Monad m => ViewR (m a) -> m (ViewR a)

Traversable Maybe

Since: base-2.1

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Maybe a -> f (Maybe b)

sequenceA :: Applicative f => Maybe (f a) -> f (Maybe a)

mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b)

sequence :: Monad m => Maybe (m a) -> m (Maybe a)

Traversable Solo

Since: base-4.15

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Solo a -> f (Solo b)

sequenceA :: Applicative f => Solo (f a) -> f (Solo a)

mapM :: Monad m => (a -> m b) -> Solo a -> m (Solo b)

sequence :: Monad m => Solo (m a) -> m (Solo a)

Traversable List

Since: base-2.1

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> [a] -> f [b]

sequenceA :: Applicative f => [f a] -> f [a]

mapM :: Monad m => (a -> m b) -> [a] -> m [b]

sequence :: Monad m => [m a] -> m [a]

Traversable (Either a)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a0 -> f b) -> Either a a0 -> f (Either a b)

sequenceA :: Applicative f => Either a (f a0) -> f (Either a a0)

mapM :: Monad m => (a0 -> m b) -> Either a a0 -> m (Either a b)

sequence :: Monad m => Either a (m a0) -> m (Either a a0)

Traversable (Proxy :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b)

sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a)

mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b)

sequence :: Monad m => Proxy (m a) -> m (Proxy a)

Ix i => Traversable (Array i)

Since: base-2.1

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Array i a -> f (Array i b)

sequenceA :: Applicative f => Array i (f a) -> f (Array i a)

mapM :: Monad m => (a -> m b) -> Array i a -> m (Array i b)

sequence :: Monad m => Array i (m a) -> m (Array i a)

Traversable (U1 :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> U1 a -> f (U1 b)

sequenceA :: Applicative f => U1 (f a) -> f (U1 a)

mapM :: Monad m => (a -> m b) -> U1 a -> m (U1 b)

sequence :: Monad m => U1 (m a) -> m (U1 a)

Traversable (UAddr :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UAddr a -> f (UAddr b)

sequenceA :: Applicative f => UAddr (f a) -> f (UAddr a)

mapM :: Monad m => (a -> m b) -> UAddr a -> m (UAddr b)

sequence :: Monad m => UAddr (m a) -> m (UAddr a)

Traversable (UChar :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UChar a -> f (UChar b)

sequenceA :: Applicative f => UChar (f a) -> f (UChar a)

mapM :: Monad m => (a -> m b) -> UChar a -> m (UChar b)

sequence :: Monad m => UChar (m a) -> m (UChar a)

Traversable (UDouble :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UDouble a -> f (UDouble b)

sequenceA :: Applicative f => UDouble (f a) -> f (UDouble a)

mapM :: Monad m => (a -> m b) -> UDouble a -> m (UDouble b)

sequence :: Monad m => UDouble (m a) -> m (UDouble a)

Traversable (UFloat :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UFloat a -> f (UFloat b)

sequenceA :: Applicative f => UFloat (f a) -> f (UFloat a)

mapM :: Monad m => (a -> m b) -> UFloat a -> m (UFloat b)

sequence :: Monad m => UFloat (m a) -> m (UFloat a)

Traversable (UInt :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UInt a -> f (UInt b)

sequenceA :: Applicative f => UInt (f a) -> f (UInt a)

mapM :: Monad m => (a -> m b) -> UInt a -> m (UInt b)

sequence :: Monad m => UInt (m a) -> m (UInt a)

Traversable (UWord :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UWord a -> f (UWord b)

sequenceA :: Applicative f => UWord (f a) -> f (UWord a)

mapM :: Monad m => (a -> m b) -> UWord a -> m (UWord b)

sequence :: Monad m => UWord (m a) -> m (UWord a)

Traversable (V1 :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> V1 a -> f (V1 b)

sequenceA :: Applicative f => V1 (f a) -> f (V1 a)

mapM :: Monad m => (a -> m b) -> V1 a -> m (V1 b)

sequence :: Monad m => V1 (m a) -> m (V1 a)

Traversable (Map k)

Traverses in order of increasing key.

Defined in Data.Map.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Map k a -> f (Map k b)

sequenceA :: Applicative f => Map k (f a) -> f (Map k a)

mapM :: Monad m => (a -> m b) -> Map k a -> m (Map k b)

sequence :: Monad m => Map k (m a) -> m (Map k a)

Traversable ((,) a)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a0 -> f b) -> (a, a0) -> f (a, b)

sequenceA :: Applicative f => (a, f a0) -> f (a, a0)

mapM :: Monad m => (a0 -> m b) -> (a, a0) -> m (a, b)

sequence :: Monad m => (a, m a0) -> m (a, a0)

Traversable (Const m :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Const m a -> f (Const m b)

sequenceA :: Applicative f => Const m (f a) -> f (Const m a)

mapM :: Monad m0 => (a -> m0 b) -> Const m a -> m0 (Const m b)

sequence :: Monad m0 => Const m (m0 a) -> m0 (Const m a)

Traversable f => Traversable (Ap f)

Since: base-4.12.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Ap f a -> f0 (Ap f b)

sequenceA :: Applicative f0 => Ap f (f0 a) -> f0 (Ap f a)

mapM :: Monad m => (a -> m b) -> Ap f a -> m (Ap f b)

sequence :: Monad m => Ap f (m a) -> m (Ap f a)

Traversable f => Traversable (Alt f)

Since: base-4.12.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Alt f a -> f0 (Alt f b)

sequenceA :: Applicative f0 => Alt f (f0 a) -> f0 (Alt f a)

mapM :: Monad m => (a -> m b) -> Alt f a -> m (Alt f b)

sequence :: Monad m => Alt f (m a) -> m (Alt f a)

Traversable f => Traversable (Rec1 f)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Rec1 f a -> f0 (Rec1 f b)

sequenceA :: Applicative f0 => Rec1 f (f0 a) -> f0 (Rec1 f a)

mapM :: Monad m => (a -> m b) -> Rec1 f a -> m (Rec1 f b)

sequence :: Monad m => Rec1 f (m a) -> m (Rec1 f a)

(Traversable f, Traversable g) => Traversable (f :*: g)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> (f :*: g) a -> f0 ((f :*: g) b)

sequenceA :: Applicative f0 => (f :*: g) (f0 a) -> f0 ((f :*: g) a)

mapM :: Monad m => (a -> m b) -> (f :*: g) a -> m ((f :*: g) b)

sequence :: Monad m => (f :*: g) (m a) -> m ((f :*: g) a)

(Traversable f, Traversable g) => Traversable (f :+: g)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> (f :+: g) a -> f0 ((f :+: g) b)

sequenceA :: Applicative f0 => (f :+: g) (f0 a) -> f0 ((f :+: g) a)

mapM :: Monad m => (a -> m b) -> (f :+: g) a -> m ((f :+: g) b)

sequence :: Monad m => (f :+: g) (m a) -> m ((f :+: g) a)

Traversable (K1 i c :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> K1 i c a -> f (K1 i c b)

sequenceA :: Applicative f => K1 i c (f a) -> f (K1 i c a)

mapM :: Monad m => (a -> m b) -> K1 i c a -> m (K1 i c b)

sequence :: Monad m => K1 i c (m a) -> m (K1 i c a)

(Traversable f, Traversable g) => Traversable (f :.: g)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> (f :.: g) a -> f0 ((f :.: g) b)

sequenceA :: Applicative f0 => (f :.: g) (f0 a) -> f0 ((f :.: g) a)

mapM :: Monad m => (a -> m b) -> (f :.: g) a -> m ((f :.: g) b)

sequence :: Monad m => (f :.: g) (m a) -> m ((f :.: g) a)

Traversable f => Traversable (M1 i c f)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> M1 i c f a -> f0 (M1 i c f b)

sequenceA :: Applicative f0 => M1 i c f (f0 a) -> f0 (M1 i c f a)

mapM :: Monad m => (a -> m b) -> M1 i c f a -> m (M1 i c f b)

sequence :: Monad m => M1 i c f (m a) -> m (M1 i c f a)

Reexport from Show

class Show a where

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 show is a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used.
• If the constructor is defined to be an infix operator, then showsPrec will produce infix applications of the constructor.
• the representation will be enclosed in parentheses if the precedence of the top-level constructor in x is less than d (associativity is ignored). Thus, if d is 0 then the result is never surrounded in parentheses; if d is 11 it is always surrounded in parentheses, unless it is an atomic expression.
• If the constructor is defined using record syntax, then show will produce the record-syntax form, with the fields given in the same order as the original declaration.

For example, given the declarations

infixr 5 :^:
data Tree a =  Leaf a  |  Tree a :^: Tree a

the derived instance of Show is equivalent to

instance (Show a) => Show (Tree a) where

       showsPrec d (Leaf m) = showParen (d > app_prec) $
            showString "Leaf " . showsPrec (app_prec+1) m
         where app_prec = 10

       showsPrec d (u :^: v) = showParen (d > up_prec) $
            showsPrec (up_prec+1) u .
            showString " :^: "      .
            showsPrec (up_prec+1) v
         where up_prec = 5

Note that right-associativity of :^: is ignored. For example,

• show (Leaf 1 :^: Leaf 2 :^: Leaf 3) produces the string "Leaf 1 :^: (Leaf 2 :^: Leaf 3)".

Minimal complete definition

showsPrec | show

Methods

show :: a -> String

A specialised variant of showsPrec, using precedence context zero, and returning an ordinary String.

showList :: [a] -> ShowS

The method showList is provided to allow the programmer to give a specialised way of showing lists of values. For example, this is used by the predefined Show instance of the Char type, where values of type String should be shown in double quotes, rather than between square brackets.

Instances

Show Case

Defined in Antelude.String.Case

Methods

showsPrec :: Int -> Case -> ShowS

show :: Case -> String

showList :: [Case] -> ShowS

Show NestedAtomically

Since: base-4.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> NestedAtomically -> ShowS

show :: NestedAtomically -> String

showList :: [NestedAtomically] -> ShowS

Show NoMatchingContinuationPrompt

Since: base-4.18

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> NoMatchingContinuationPrompt -> ShowS

show :: NoMatchingContinuationPrompt -> String

showList :: [NoMatchingContinuationPrompt] -> ShowS

Show NoMethodError

Since: base-4.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> NoMethodError -> ShowS

show :: NoMethodError -> String

showList :: [NoMethodError] -> ShowS

Show NonTermination

Since: base-4.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> NonTermination -> ShowS

show :: NonTermination -> String

showList :: [NonTermination] -> ShowS

Show PatternMatchFail

Since: base-4.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> PatternMatchFail -> ShowS

show :: PatternMatchFail -> String

showList :: [PatternMatchFail] -> ShowS

Show RecConError

Since: base-4.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> RecConError -> ShowS

show :: RecConError -> String

showList :: [RecConError] -> ShowS

Show RecSelError

Since: base-4.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> RecSelError -> ShowS

show :: RecSelError -> String

showList :: [RecSelError] -> ShowS

Show RecUpdError

Since: base-4.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> RecUpdError -> ShowS

show :: RecUpdError -> String

showList :: [RecUpdError] -> ShowS

Show TypeError

Since: base-4.9.0.0

Defined in Control.Exception.Base

Methods

showsPrec :: Int -> TypeError -> ShowS

show :: TypeError -> String

showList :: [TypeError] -> ShowS

Show Void

Since: base-4.8.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Void -> ShowS

show :: Void -> String

showList :: [Void] -> ShowS

Show ArithException

Since: base-4.0.0.0

Defined in GHC.Exception.Type

Methods

showsPrec :: Int -> ArithException -> ShowS

show :: ArithException -> String

showList :: [ArithException] -> ShowS

Show SomeException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

showsPrec :: Int -> SomeException -> ShowS

show :: SomeException -> String

showList :: [SomeException] -> ShowS

Show MaskingState

Since: base-4.3.0.0

Defined in GHC.IO

Methods

showsPrec :: Int -> MaskingState -> ShowS

show :: MaskingState -> String

showList :: [MaskingState] -> ShowS

Show AllocationLimitExceeded

Since: base-4.7.1.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AllocationLimitExceeded -> ShowS

show :: AllocationLimitExceeded -> String

showList :: [AllocationLimitExceeded] -> ShowS

Show ArrayException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> ArrayException -> ShowS

show :: ArrayException -> String

showList :: [ArrayException] -> ShowS

Show AssertionFailed

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AssertionFailed -> ShowS

show :: AssertionFailed -> String

showList :: [AssertionFailed] -> ShowS

Show AsyncException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AsyncException -> ShowS

show :: AsyncException -> String

showList :: [AsyncException] -> ShowS

Show BlockedIndefinitelyOnMVar

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS

show :: BlockedIndefinitelyOnMVar -> String

showList :: [BlockedIndefinitelyOnMVar] -> ShowS

Show BlockedIndefinitelyOnSTM

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS

show :: BlockedIndefinitelyOnSTM -> String

showList :: [BlockedIndefinitelyOnSTM] -> ShowS

Show CompactionFailed

Since: base-4.10.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> CompactionFailed -> ShowS

show :: CompactionFailed -> String

showList :: [CompactionFailed] -> ShowS

Show Deadlock

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> Deadlock -> ShowS

show :: Deadlock -> String

showList :: [Deadlock] -> ShowS

Show ExitCode

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> ExitCode -> ShowS

show :: ExitCode -> String

showList :: [ExitCode] -> ShowS

Show FixIOException

Since: base-4.11.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> FixIOException -> ShowS

show :: FixIOException -> String

showList :: [FixIOException] -> ShowS

Show IOErrorType

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> IOErrorType -> ShowS

show :: IOErrorType -> String

showList :: [IOErrorType] -> ShowS

Show IOException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> IOException -> ShowS

show :: IOException -> String

showList :: [IOException] -> ShowS

Show SomeAsyncException

Since: base-4.7.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> SomeAsyncException -> ShowS

show :: SomeAsyncException -> String

showList :: [SomeAsyncException] -> ShowS

Show FractionalExponentBase

Defined in GHC.Real

Methods

showsPrec :: Int -> FractionalExponentBase -> ShowS

show :: FractionalExponentBase -> String

showList :: [FractionalExponentBase] -> ShowS

Show CallStack

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> CallStack -> ShowS

show :: CallStack -> String

showList :: [CallStack] -> ShowS

Show SrcLoc

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> SrcLoc -> ShowS

show :: SrcLoc -> String

showList :: [SrcLoc] -> ShowS

Show GeneralCategory

Since: base-2.1

Defined in GHC.Unicode

Methods

showsPrec :: Int -> GeneralCategory -> ShowS

show :: GeneralCategory -> String

showList :: [GeneralCategory] -> ShowS

Show Word16

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word16 -> ShowS

show :: Word16 -> String

showList :: [Word16] -> ShowS

Show Word32

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word32 -> ShowS

show :: Word32 -> String

showList :: [Word32] -> ShowS

Show Word64

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word64 -> ShowS

show :: Word64 -> String

showList :: [Word64] -> ShowS

Show Word8

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word8 -> ShowS

show :: Word8 -> String

showList :: [Word8] -> ShowS

Show Lexeme

Since: base-2.1

Defined in Text.Read.Lex

Methods

showsPrec :: Int -> Lexeme -> ShowS

show :: Lexeme -> String

showList :: [Lexeme] -> ShowS

Show Number

Since: base-4.6.0.0

Defined in Text.Read.Lex

Methods

showsPrec :: Int -> Number -> ShowS

show :: Number -> String

showList :: [Number] -> ShowS

Show ByteString

Defined in Data.ByteString.Internal.Type

Methods

showsPrec :: Int -> ByteString -> ShowS

show :: ByteString -> String

showList :: [ByteString] -> ShowS

Show ByteString

Defined in Data.ByteString.Lazy.Internal

Methods

showsPrec :: Int -> ByteString -> ShowS

show :: ByteString -> String

showList :: [ByteString] -> ShowS

Show KindRep

Defined in GHC.Show

Methods

showsPrec :: Int -> KindRep -> ShowS

show :: KindRep -> String

showList :: [KindRep] -> ShowS

Show Module

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Module -> ShowS

show :: Module -> String

showList :: [Module] -> ShowS

Show Ordering

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Ordering -> ShowS

show :: Ordering -> String

showList :: [Ordering] -> ShowS

Show TrName

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> TrName -> ShowS

show :: TrName -> String

showList :: [TrName] -> ShowS

Show TyCon

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> TyCon -> ShowS

show :: TyCon -> String

showList :: [TyCon] -> ShowS

Show TypeLitSort

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> TypeLitSort -> ShowS

show :: TypeLitSort -> String

showList :: [TypeLitSort] -> ShowS

Show Mode

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

showsPrec :: Int -> Mode -> ShowS

show :: Mode -> String

showList :: [Mode] -> ShowS

Show Style

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

showsPrec :: Int -> Style -> ShowS

show :: Style -> String

showList :: [Style] -> ShowS

Show TextDetails

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

showsPrec :: Int -> TextDetails -> ShowS

show :: TextDetails -> String

showList :: [TextDetails] -> ShowS

Show Doc

Defined in Text.PrettyPrint.HughesPJ

Methods

showsPrec :: Int -> Doc -> ShowS

show :: Doc -> String

showList :: [Doc] -> ShowS

Show Integer

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Integer -> ShowS

show :: Integer -> String

showList :: [Integer] -> ShowS

Show Natural

Since: base-4.8.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Natural -> ShowS

show :: Natural -> String

showList :: [Natural] -> ShowS

Show ()

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> () -> ShowS

show :: () -> String

showList :: [()] -> ShowS

Show Bool

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Bool -> ShowS

show :: Bool -> String

showList :: [Bool] -> ShowS

Show Char

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Char -> ShowS

show :: Char -> String

showList :: [Char] -> ShowS

Show Int

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Int -> ShowS

show :: Int -> String

showList :: [Int] -> ShowS

Show Levity

Since: base-4.15.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Levity -> ShowS

show :: Levity -> String

showList :: [Levity] -> ShowS

Show RuntimeRep

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> RuntimeRep -> ShowS

show :: RuntimeRep -> String

showList :: [RuntimeRep] -> ShowS

Show VecCount

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> VecCount -> ShowS

show :: VecCount -> String

showList :: [VecCount] -> ShowS

Show VecElem

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> VecElem -> ShowS

show :: VecElem -> String

showList :: [VecElem] -> ShowS

Show Word

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Word -> ShowS

show :: Word -> String

showList :: [Word] -> ShowS

Show a => Show (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

showsPrec :: Int -> ZipList a -> ShowS

show :: ZipList a -> String

showList :: [ZipList a] -> ShowS

Show a => Show (NonEmpty a)

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> NonEmpty a -> ShowS

show :: NonEmpty a -> String

showList :: [NonEmpty a] -> ShowS

Show (ForeignPtr a)

Since: base-2.1

Defined in GHC.ForeignPtr

Methods

showsPrec :: Int -> ForeignPtr a -> ShowS

show :: ForeignPtr a -> String

showList :: [ForeignPtr a] -> ShowS

Show a => Show (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

showsPrec :: Int -> Ratio a -> ShowS

show :: Ratio a -> String

showList :: [Ratio a] -> ShowS

Show a => Show (Seq a)

Defined in Data.Sequence.Internal

Methods

showsPrec :: Int -> Seq a -> ShowS

show :: Seq a -> String

showList :: [Seq a] -> ShowS

Show a => Show (ViewL a)

Defined in Data.Sequence.Internal

Methods

showsPrec :: Int -> ViewL a -> ShowS

show :: ViewL a -> String

showList :: [ViewL a] -> ShowS

Show a => Show (ViewR a)

Defined in Data.Sequence.Internal

Methods

showsPrec :: Int -> ViewR a -> ShowS

show :: ViewR a -> String

showList :: [ViewR a] -> ShowS

Show a => Show (Intersection a)

Defined in Data.Set.Internal

Methods

showsPrec :: Int -> Intersection a -> ShowS

show :: Intersection a -> String

showList :: [Intersection a] -> ShowS

Show a => Show (Set a)

Defined in Data.Set.Internal

Methods

showsPrec :: Int -> Set a -> ShowS

show :: Set a -> String

showList :: [Set a] -> ShowS

Show a => Show (AnnotDetails a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

showsPrec :: Int -> AnnotDetails a -> ShowS

show :: AnnotDetails a -> String

showList :: [AnnotDetails a] -> ShowS

Show (Doc a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

showsPrec :: Int -> Doc a -> ShowS

show :: Doc a -> String

showList :: [Doc a] -> ShowS

Show a => Show (Span a)

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

showsPrec :: Int -> Span a -> ShowS

show :: Span a -> String

showList :: [Span a] -> ShowS

Show a => Show (Maybe a)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Maybe a -> ShowS

show :: Maybe a -> String

showList :: [Maybe a] -> ShowS

Show a => Show (a)

Since: base-4.15

Defined in GHC.Show

Methods

showsPrec :: Int -> (a) -> ShowS

show :: (a) -> String

showList :: [(a)] -> ShowS

Show a => Show [a]

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> [a] -> ShowS

show :: [a] -> String

showList :: [[a]] -> ShowS

(Show err, Show ok) => Show (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

showsPrec :: Int -> Result err ok -> ShowS

show :: Result err ok -> String

showList :: [Result err ok] -> ShowS

(Show a, Show b) => Show (Either a b)

Since: base-3.0

Defined in Data.Either

Methods

showsPrec :: Int -> Either a b -> ShowS

show :: Either a b -> String

showList :: [Either a b] -> ShowS

(Ix a, Show a, Show b) => Show (Array a b)

Since: base-2.1

Defined in GHC.Arr

Methods

showsPrec :: Int -> Array a b -> ShowS

show :: Array a b -> String

showList :: [Array a b] -> ShowS

(Show k, Show a) => Show (Map k a)

Defined in Data.Map.Internal

Methods

showsPrec :: Int -> Map k a -> ShowS

show :: Map k a -> String

showList :: [Map k a] -> ShowS

(Show a, Show b) => Show (a, b)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b) -> ShowS

show :: (a, b) -> String

showList :: [(a, b)] -> ShowS

(Show a, Show b, Show c) => Show (a, b, c)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c) -> ShowS

show :: (a, b, c) -> String

showList :: [(a, b, c)] -> ShowS

(Show a, Show b, Show c, Show d) => Show (a, b, c, d)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d) -> ShowS

show :: (a, b, c, d) -> String

showList :: [(a, b, c, d)] -> ShowS

(Show a, Show b, Show c, Show d, Show e) => Show (a, b, c, d, e)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e) -> ShowS

show :: (a, b, c, d, e) -> String

showList :: [(a, b, c, d, e)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f) => Show (a, b, c, d, e, f)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f) -> ShowS

show :: (a, b, c, d, e, f) -> String

showList :: [(a, b, c, d, e, f)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g) => Show (a, b, c, d, e, f, g)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g) -> ShowS

show :: (a, b, c, d, e, f, g) -> String

showList :: [(a, b, c, d, e, f, g)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h) => Show (a, b, c, d, e, f, g, h)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h) -> ShowS

show :: (a, b, c, d, e, f, g, h) -> String

showList :: [(a, b, c, d, e, f, g, h)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i) => Show (a, b, c, d, e, f, g, h, i)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i) -> ShowS

show :: (a, b, c, d, e, f, g, h, i) -> String

showList :: [(a, b, c, d, e, f, g, h, i)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j) => Show (a, b, c, d, e, f, g, h, i, j)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k) => Show (a, b, c, d, e, f, g, h, i, j, k)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l) => Show (a, b, c, d, e, f, g, h, i, j, k, l)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n, Show o) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] -> ShowS

Reexport from Read

class Read a

Parsing of Strings, producing values.

Derived instances of Read make the following assumptions, which derived instances of Show obey:

• If the constructor is defined to be an infix operator, then the derived Read instance 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 Read will parse only the record-syntax form, and furthermore, the fields must be given in the same order as the original declaration.
• The derived Read instance 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 = 5

Note 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 = readListPrecDefault

Why 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:

instance Read T where
  readPrec     = ...
  readListPrec = readListPrecDefault

Minimal complete definition

readsPrec | readPrec

Instances

Read Void

Reading a Void value is always a parse error, considering Void as a data type with no constructors.

Since: base-4.8.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Void

readList :: ReadS [Void]

readPrec :: ReadPrec Void

readListPrec :: ReadPrec [Void]

Read ExitCode

Defined in GHC.IO.Exception

Methods

readsPrec :: Int -> ReadS ExitCode

readList :: ReadS [ExitCode]

readPrec :: ReadPrec ExitCode

readListPrec :: ReadPrec [ExitCode]

Read GeneralCategory

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS GeneralCategory

readList :: ReadS [GeneralCategory]

readPrec :: ReadPrec GeneralCategory

readListPrec :: ReadPrec [GeneralCategory]

Read Word16

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word16

readList :: ReadS [Word16]

readPrec :: ReadPrec Word16

readListPrec :: ReadPrec [Word16]

Read Word32

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word32

readList :: ReadS [Word32]

readPrec :: ReadPrec Word32

readListPrec :: ReadPrec [Word32]

Read Word64

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word64

readList :: ReadS [Word64]

readPrec :: ReadPrec Word64

readListPrec :: ReadPrec [Word64]

Read Word8

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word8

readList :: ReadS [Word8]

readPrec :: ReadPrec Word8

readListPrec :: ReadPrec [Word8]

Read Lexeme

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Lexeme

readList :: ReadS [Lexeme]

readPrec :: ReadPrec Lexeme

readListPrec :: ReadPrec [Lexeme]

Read ByteString

Defined in Data.ByteString.Internal.Type

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 Ordering

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Ordering

readList :: ReadS [Ordering]

readPrec :: ReadPrec Ordering

readListPrec :: ReadPrec [Ordering]

Read Integer

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Integer

readList :: ReadS [Integer]

readPrec :: ReadPrec Integer

readListPrec :: ReadPrec [Integer]

Read Natural

Since: base-4.8.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Natural

readList :: ReadS [Natural]

readPrec :: ReadPrec Natural

readListPrec :: ReadPrec [Natural]

Read ()

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS ()

readList :: ReadS [()]

readPrec :: ReadPrec ()

readListPrec :: ReadPrec [()]

Read Bool

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Bool

readList :: ReadS [Bool]

readPrec :: ReadPrec Bool

readListPrec :: ReadPrec [Bool]

Read Char

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Char

readList :: ReadS [Char]

readPrec :: ReadPrec Char

readListPrec :: ReadPrec [Char]

Read Double

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Double

readList :: ReadS [Double]

readPrec :: ReadPrec Double

readListPrec :: ReadPrec [Double]

Read Float

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Float

readList :: ReadS [Float]

readPrec :: ReadPrec Float

readListPrec :: ReadPrec [Float]

Read Int

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Int

readList :: ReadS [Int]

readPrec :: ReadPrec Int

readListPrec :: ReadPrec [Int]

Read Word

Since: base-4.5.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word

readList :: ReadS [Word]

readPrec :: ReadPrec Word

readListPrec :: ReadPrec [Word]

Read a => Read (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

readsPrec :: Int -> ReadS (ZipList a)

readList :: ReadS [ZipList a]

readPrec :: ReadPrec (ZipList a)

readListPrec :: ReadPrec [ZipList a]

Read a => Read (NonEmpty a)

Since: base-4.11.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (NonEmpty a)

readList :: ReadS [NonEmpty a]

readPrec :: ReadPrec (NonEmpty a)

readListPrec :: ReadPrec [NonEmpty a]

(Integral a, Read a) => Read (Ratio a)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (Ratio a)

readList :: ReadS [Ratio a]

readPrec :: ReadPrec (Ratio a)

readListPrec :: ReadPrec [Ratio a]

Read a => Read (Seq a)

Defined in Data.Sequence.Internal

Methods

readsPrec :: Int -> ReadS (Seq a)

readList :: ReadS [Seq a]

readPrec :: ReadPrec (Seq a)

readListPrec :: ReadPrec [Seq a]

Read a => Read (ViewL a)

Defined in Data.Sequence.Internal

Methods

readsPrec :: Int -> ReadS (ViewL a)

readList :: ReadS [ViewL a]

readPrec :: ReadPrec (ViewL a)

readListPrec :: ReadPrec [ViewL a]

Read a => Read (ViewR a)

Defined in Data.Sequence.Internal

Methods

readsPrec :: Int -> ReadS (ViewR a)

readList :: ReadS [ViewR a]

readPrec :: ReadPrec (ViewR a)

readListPrec :: ReadPrec [ViewR a]

(Read a, Ord a) => Read (Set a)

Defined in Data.Set.Internal

Methods

readsPrec :: Int -> ReadS (Set a)

readList :: ReadS [Set a]

readPrec :: ReadPrec (Set a)

readListPrec :: ReadPrec [Set a]

Read a => Read (Maybe a)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (Maybe a)

readList :: ReadS [Maybe a]

readPrec :: ReadPrec (Maybe a)

readListPrec :: ReadPrec [Maybe a]

Read a => Read (a)

Since: base-4.15

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a)

readList :: ReadS [(a)]

readPrec :: ReadPrec (a)

readListPrec :: ReadPrec [(a)]

Read a => Read [a]

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS [a]

readList :: ReadS [[a]]

readPrec :: ReadPrec [a]

readListPrec :: ReadPrec [[a]]

(Read err, Read ok) => Read (Result err ok)

Defined in Antelude.Internal.TypesClasses

Methods

readsPrec :: Int -> ReadS (Result err ok)

readList :: ReadS [Result err ok]

readPrec :: ReadPrec (Result err ok)

readListPrec :: ReadPrec [Result err ok]

(Read a, Read b) => Read (Either a b)

Since: base-3.0

Defined in Data.Either

Methods

readsPrec :: Int -> ReadS (Either a b)

readList :: ReadS [Either a b]

readPrec :: ReadPrec (Either a b)

readListPrec :: ReadPrec [Either a b]

(Ix a, Read a, Read b) => Read (Array a b)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (Array a b)

readList :: ReadS [Array a b]

readPrec :: ReadPrec (Array a b)

readListPrec :: ReadPrec [Array a b]

(Ord k, Read k, Read e) => Read (Map k e)

Defined in Data.Map.Internal

Methods

readsPrec :: Int -> ReadS (Map k e)

readList :: ReadS [Map k e]

readPrec :: ReadPrec (Map k e)

readListPrec :: ReadPrec [Map k e]

(Read a, Read b) => Read (a, b)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b)

readList :: ReadS [(a, b)]

readPrec :: ReadPrec (a, b)

readListPrec :: ReadPrec [(a, b)]

(Read a, Read b, Read c) => Read (a, b, c)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c)

readList :: ReadS [(a, b, c)]

readPrec :: ReadPrec (a, b, c)

readListPrec :: ReadPrec [(a, b, c)]

(Read a, Read b, Read c, Read d) => Read (a, b, c, d)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d)

readList :: ReadS [(a, b, c, d)]

readPrec :: ReadPrec (a, b, c, d)

readListPrec :: ReadPrec [(a, b, c, d)]

(Read a, Read b, Read c, Read d, Read e) => Read (a, b, c, d, e)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e)

readList :: ReadS [(a, b, c, d, e)]

readPrec :: ReadPrec (a, b, c, d, e)

readListPrec :: ReadPrec [(a, b, c, d, e)]

(Read a, Read b, Read c, Read d, Read e, Read f) => Read (a, b, c, d, e, f)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f)

readList :: ReadS [(a, b, c, d, e, f)]

readPrec :: ReadPrec (a, b, c, d, e, f)

readListPrec :: ReadPrec [(a, b, c, d, e, f)]

(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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g)

readList :: ReadS [(a, b, c, d, e, f, g)]

readPrec :: ReadPrec (a, b, c, d, e, f, g)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g)]

(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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h)

readList :: ReadS [(a, b, c, d, e, f, g, h)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h)]

(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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i)

readList :: ReadS [(a, b, c, d, e, f, g, h, i)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i)]

(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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j)

readList :: ReadS [(a, b, c, d, e, f, g, h, i, j)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j)]

(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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k)

readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k)]

(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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l)

readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l)]

(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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m)

readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m)]

(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m, Read n) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)]

(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

Methods

readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)]

readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)]