base-4.20.0.0: Core data structures and operations
Copyright(c) The University of Glasgow 2002
Licensesee libraries/base/LICENSE
Maintainerghc-devs@haskell.org
Stabilityinternal
Portabilitynon-portable (GHC Extensions)
Safe HaskellNone
LanguageHaskell2010

GHC.Exts

Description

GHC Extensions: this is the Approved Way to get at GHC-specific extensions.

Note: no other base module should import this module.

Synopsis

Pointer types

data Ptr a Source #

A value of type Ptr a represents a pointer to an object, or an array of objects, which may be marshalled to or from Haskell values of type a.

The type a will often be an instance of class Storable which provides the marshalling operations. However this is not essential, and you can provide your own operations to access the pointer. For example you might write small foreign functions to get or set the fields of a C struct.

Constructors

Ptr Addr# 

Instances

Instances details
Generic1 (URec (Ptr ()) :: k -> Type) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep1 (URec (Ptr ()) :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec (Ptr ()) :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UAddr" 'PrefixI 'True) (S1 ('MetaSel ('Just "uAddr#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UAddr :: k -> Type)))

Methods

from1 :: forall (a :: k). URec (Ptr ()) a -> Rep1 (URec (Ptr ()) :: k -> Type) a Source #

to1 :: forall (a :: k). Rep1 (URec (Ptr ()) :: k -> Type) a -> URec (Ptr ()) a Source #

Data a => Data (Ptr a)

Since: base-4.8.0.0

Instance details

Defined in GHC.Internal.Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Ptr a -> c (Ptr a) Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Ptr a) Source #

toConstr :: Ptr a -> Constr Source #

dataTypeOf :: Ptr a -> DataType Source #

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

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

gmapT :: (forall b. Data b => b -> b) -> Ptr a -> Ptr a Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Ptr a -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Ptr a -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Ptr a -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Ptr a -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Ptr a -> m (Ptr a) Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Ptr a -> m (Ptr a) Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Ptr a -> m (Ptr a) Source #

Foldable (UAddr :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Foldable

Methods

fold :: Monoid m => UAddr m -> m Source #

foldMap :: Monoid m => (a -> m) -> UAddr a -> m Source #

foldMap' :: Monoid m => (a -> m) -> UAddr a -> m Source #

foldr :: (a -> b -> b) -> b -> UAddr a -> b Source #

foldr' :: (a -> b -> b) -> b -> UAddr a -> b Source #

foldl :: (b -> a -> b) -> b -> UAddr a -> b Source #

foldl' :: (b -> a -> b) -> b -> UAddr a -> b Source #

foldr1 :: (a -> a -> a) -> UAddr a -> a Source #

foldl1 :: (a -> a -> a) -> UAddr a -> a Source #

toList :: UAddr a -> [a] Source #

null :: UAddr a -> Bool Source #

length :: UAddr a -> Int Source #

elem :: Eq a => a -> UAddr a -> Bool Source #

maximum :: Ord a => UAddr a -> a Source #

minimum :: Ord a => UAddr a -> a Source #

sum :: Num a => UAddr a -> a Source #

product :: Num a => UAddr a -> a Source #

Traversable (UAddr :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UAddr a -> f (UAddr b) Source #

sequenceA :: Applicative f => UAddr (f a) -> f (UAddr a) Source #

mapM :: Monad m => (a -> m b) -> UAddr a -> m (UAddr b) Source #

sequence :: Monad m => UAddr (m a) -> m (UAddr a) Source #

Storable (Ptr a)

Since: base-2.1

Instance details

Defined in GHC.Internal.Foreign.Storable

Methods

sizeOf :: Ptr a -> Int Source #

alignment :: Ptr a -> Int Source #

peekElemOff :: Ptr (Ptr a) -> Int -> IO (Ptr a) Source #

pokeElemOff :: Ptr (Ptr a) -> Int -> Ptr a -> IO () Source #

peekByteOff :: Ptr b -> Int -> IO (Ptr a) Source #

pokeByteOff :: Ptr b -> Int -> Ptr a -> IO () Source #

peek :: Ptr (Ptr a) -> IO (Ptr a) Source #

poke :: Ptr (Ptr a) -> Ptr a -> IO () Source #

Show (Ptr a)

Since: base-2.1

Instance details

Defined in GHC.Internal.Ptr

Methods

showsPrec :: Int -> Ptr a -> ShowS Source #

show :: Ptr a -> String Source #

showList :: [Ptr a] -> ShowS Source #

Eq (Ptr a)

Since: base-2.1

Instance details

Defined in GHC.Internal.Ptr

Methods

(==) :: Ptr a -> Ptr a -> Bool Source #

(/=) :: Ptr a -> Ptr a -> Bool Source #

Ord (Ptr a)

Since: base-2.1

Instance details

Defined in GHC.Internal.Ptr

Methods

compare :: Ptr a -> Ptr a -> Ordering Source #

(<) :: Ptr a -> Ptr a -> Bool Source #

(<=) :: Ptr a -> Ptr a -> Bool Source #

(>) :: Ptr a -> Ptr a -> Bool Source #

(>=) :: Ptr a -> Ptr a -> Bool Source #

max :: Ptr a -> Ptr a -> Ptr a Source #

min :: Ptr a -> Ptr a -> Ptr a Source #

Functor (URec (Ptr ()) :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

fmap :: (a -> b) -> URec (Ptr ()) a -> URec (Ptr ()) b Source #

(<$) :: a -> URec (Ptr ()) b -> URec (Ptr ()) a Source #

Generic (URec (Ptr ()) p) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep (URec (Ptr ()) p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec (Ptr ()) p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UAddr" 'PrefixI 'True) (S1 ('MetaSel ('Just "uAddr#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UAddr :: Type -> Type)))

Methods

from :: URec (Ptr ()) p -> Rep (URec (Ptr ()) p) x Source #

to :: Rep (URec (Ptr ()) p) x -> URec (Ptr ()) p Source #

Eq (URec (Ptr ()) p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

(==) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

(/=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

Ord (URec (Ptr ()) p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

compare :: URec (Ptr ()) p -> URec (Ptr ()) p -> Ordering Source #

(<) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

(<=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

(>) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

(>=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

max :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p Source #

min :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p Source #

data URec (Ptr ()) (p :: k)

Used for marking occurrences of Addr#

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

data URec (Ptr ()) (p :: k) = UAddr {}
type Rep1 (URec (Ptr ()) :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec (Ptr ()) :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UAddr" 'PrefixI 'True) (S1 ('MetaSel ('Just "uAddr#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UAddr :: k -> Type)))
type Rep (URec (Ptr ()) p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec (Ptr ()) p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UAddr" 'PrefixI 'True) (S1 ('MetaSel ('Just "uAddr#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UAddr :: Type -> Type)))

data FunPtr a Source #

A value of type FunPtr a is a pointer to a function callable from foreign code. The type a will normally be a foreign type, a function type with zero or more arguments where

A value of type FunPtr a may be a pointer to a foreign function, either returned by another foreign function or imported with a a static address import like

foreign import ccall "stdlib.h &free"
  p_free :: FunPtr (Ptr a -> IO ())

or a pointer to a Haskell function created using a wrapper stub declared to produce a FunPtr of the correct type. For example:

type Compare = Int -> Int -> Bool
foreign import ccall "wrapper"
  mkCompare :: Compare -> IO (FunPtr Compare)

Calls to wrapper stubs like mkCompare allocate storage, which should be released with freeHaskellFunPtr when no longer required.

To convert FunPtr values to corresponding Haskell functions, one can define a dynamic stub for the specific foreign type, e.g.

type IntFunction = CInt -> IO ()
foreign import ccall "dynamic"
  mkFun :: FunPtr IntFunction -> IntFunction

Constructors

FunPtr Addr# 

Instances

Instances details
Storable (FunPtr a)

Since: base-2.1

Instance details

Defined in GHC.Internal.Foreign.Storable

Methods

sizeOf :: FunPtr a -> Int Source #

alignment :: FunPtr a -> Int Source #

peekElemOff :: Ptr (FunPtr a) -> Int -> IO (FunPtr a) Source #

pokeElemOff :: Ptr (FunPtr a) -> Int -> FunPtr a -> IO () Source #

peekByteOff :: Ptr b -> Int -> IO (FunPtr a) Source #

pokeByteOff :: Ptr b -> Int -> FunPtr a -> IO () Source #

peek :: Ptr (FunPtr a) -> IO (FunPtr a) Source #

poke :: Ptr (FunPtr a) -> FunPtr a -> IO () Source #

Show (FunPtr a)

Since: base-2.1

Instance details

Defined in GHC.Internal.Ptr

Eq (FunPtr a) 
Instance details

Defined in GHC.Internal.Ptr

Methods

(==) :: FunPtr a -> FunPtr a -> Bool Source #

(/=) :: FunPtr a -> FunPtr a -> Bool Source #

Ord (FunPtr a) 
Instance details

Defined in GHC.Internal.Ptr

Methods

compare :: FunPtr a -> FunPtr a -> Ordering Source #

(<) :: FunPtr a -> FunPtr a -> Bool Source #

(<=) :: FunPtr a -> FunPtr a -> Bool Source #

(>) :: FunPtr a -> FunPtr a -> Bool Source #

(>=) :: FunPtr a -> FunPtr a -> Bool Source #

max :: FunPtr a -> FunPtr a -> FunPtr a Source #

min :: FunPtr a -> FunPtr a -> FunPtr a Source #

Other primitive types

data List a Source #

The builtin linked list type.

In Haskell, lists are one of the most important data types as they are often used analogous to loops in imperative programming languages. These lists are singly linked, which makes them unsuited for operations that require \(\mathcal{O}(1)\) access. Instead, they are intended to be traversed.

You can use List a or [a] in type signatures:

length :: [a] -> Int

or

length :: List a -> Int

They are fully equivalent, and List a will be normalised to [a].

Usage

Lists are constructed recursively using the right-associative constructor operator (or cons) (:) :: a -> [a] -> [a], which prepends an element to a list, and the empty list [].

(1 : 2 : 3 : []) == (1 : (2 : (3 : []))) == [1, 2, 3]

Lists can also be constructed using list literals of the form [x_1, x_2, ..., x_n] which are syntactic sugar and, unless -XOverloadedLists is enabled, are translated into uses of (:) and []

String literals, like "I 💜 hs", are translated into Lists of characters, ['I', ' ', '💜', ' ', 'h', 's'].

Implementation

Expand

Internally and in memory, all the above are represented like this, with arrows being pointers to locations in memory.

╭───┬───┬──╮   ╭───┬───┬──╮   ╭───┬───┬──╮   ╭────╮
│(:)│   │ ─┼──>│(:)│   │ ─┼──>│(:)│   │ ─┼──>│ [] │
╰───┴─┼─┴──╯   ╰───┴─┼─┴──╯   ╰───┴─┼─┴──╯   ╰────╯
      v              v              v
      1              2              3

Examples

Expand
>>> ['H', 'a', 's', 'k', 'e', 'l', 'l']
"Haskell"
>>> 1 : [4, 1, 5, 9]
[1,4,1,5,9]
>>> [] : [] : []
[[],[]]

Since: ghc-prim-0.10.0

Instances

Instances details
MonadZip [] Source #

Since: base-4.3.1.0

Instance details

Defined in Control.Monad.Zip

Methods

mzip :: [a] -> [b] -> [(a, b)] Source #

mzipWith :: (a -> b -> c) -> [a] -> [b] -> [c] Source #

munzip :: [(a, b)] -> ([a], [b]) Source #

Eq1 [] Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftEq :: (a -> b -> Bool) -> [a] -> [b] -> Bool Source #

Ord1 [] Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftCompare :: (a -> b -> Ordering) -> [a] -> [b] -> Ordering Source #

Read1 [] Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS [a] Source #

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [[a]] Source #

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [a] Source #

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [[a]] Source #

Show1 [] Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> [a] -> ShowS Source #

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [[a]] -> ShowS Source #

Alternative []

Combines lists by concatenation, starting from the empty list.

Since: base-2.1

Instance details

Defined in GHC.Internal.Base

Methods

empty :: [a] Source #

(<|>) :: [a] -> [a] -> [a] Source #

some :: [a] -> [[a]] Source #

many :: [a] -> [[a]] Source #

Applicative []

Since: base-2.1

Instance details

Defined in GHC.Internal.Base

Methods

pure :: a -> [a] Source #

(<*>) :: [a -> b] -> [a] -> [b] Source #

liftA2 :: (a -> b -> c) -> [a] -> [b] -> [c] Source #

(*>) :: [a] -> [b] -> [b] Source #

(<*) :: [a] -> [b] -> [a] Source #

Functor []

Since: base-2.1

Instance details

Defined in GHC.Internal.Base

Methods

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

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

Monad []

Since: base-2.1

Instance details

Defined in GHC.Internal.Base

Methods

(>>=) :: [a] -> (a -> [b]) -> [b] Source #

(>>) :: [a] -> [b] -> [b] Source #

return :: a -> [a] Source #

MonadPlus []

Combines lists by concatenation, starting from the empty list.

Since: base-2.1

Instance details

Defined in GHC.Internal.Base

Methods

mzero :: [a] Source #

mplus :: [a] -> [a] -> [a] Source #

MonadFail []

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Control.Monad.Fail

Methods

fail :: String -> [a] Source #

MonadFix []

Since: base-2.1

Instance details

Defined in GHC.Internal.Control.Monad.Fix

Methods

mfix :: (a -> [a]) -> [a] Source #

Foldable []

Since: base-2.1

Instance details

Defined in GHC.Internal.Data.Foldable

Methods

fold :: Monoid m => [m] -> m Source #

foldMap :: Monoid m => (a -> m) -> [a] -> m Source #

foldMap' :: Monoid m => (a -> m) -> [a] -> m Source #

foldr :: (a -> b -> b) -> b -> [a] -> b Source #

foldr' :: (a -> b -> b) -> b -> [a] -> b Source #

foldl :: (b -> a -> b) -> b -> [a] -> b Source #

foldl' :: (b -> a -> b) -> b -> [a] -> b Source #

foldr1 :: (a -> a -> a) -> [a] -> a Source #

foldl1 :: (a -> a -> a) -> [a] -> a Source #

toList :: [a] -> [a] Source #

null :: [a] -> Bool Source #

length :: [a] -> Int Source #

elem :: Eq a => a -> [a] -> Bool Source #

maximum :: Ord a => [a] -> a Source #

minimum :: Ord a => [a] -> a Source #

sum :: Num a => [a] -> a Source #

product :: Num a => [a] -> a Source #

Traversable []

Since: base-2.1

Instance details

Defined in GHC.Internal.Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> [a] -> f [b] Source #

sequenceA :: Applicative f => [f a] -> f [a] Source #

mapM :: Monad m => (a -> m b) -> [a] -> m [b] Source #

sequence :: Monad m => [m a] -> m [a] Source #

Generic1 [] 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep1 []

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

from1 :: [a] -> Rep1 [] a Source #

to1 :: Rep1 [] a -> [a] Source #

IsChar c => PrintfArg [c] Source #

Since: base-2.1

Instance details

Defined in Text.Printf

IsChar c => PrintfType [c] Source #

Since: base-2.1

Instance details

Defined in Text.Printf

Methods

spr :: String -> [UPrintf] -> [c]

Monoid [a]

Since: base-2.1

Instance details

Defined in GHC.Internal.Base

Methods

mempty :: [a] Source #

mappend :: [a] -> [a] -> [a] Source #

mconcat :: [[a]] -> [a] Source #

Semigroup [a]

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Base

Methods

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

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

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

Data a => Data [a]

For historical reasons, the constructor name used for (:) is "(:)". In a derived instance, it would be ":".

Since: base-4.0.0.0

Instance details

Defined in GHC.Internal.Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> [a] -> c [a] Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c [a] Source #

toConstr :: [a] -> Constr Source #

dataTypeOf :: [a] -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c [a]) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c [a]) Source #

gmapT :: (forall b. Data b => b -> b) -> [a] -> [a] Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> [a] -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> [a] -> r Source #

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

gmapQi :: Int -> (forall d. Data d => d -> u) -> [a] -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> [a] -> m [a] Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> [a] -> m [a] Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> [a] -> m [a] Source #

a ~ Char => IsString [a]

(a ~ Char) context was introduced in 4.9.0.0

Since: base-2.1

Instance details

Defined in GHC.Internal.Data.String

Methods

fromString :: String -> [a] Source #

Generic [a] 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep [a]

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

from :: [a] -> Rep [a] x Source #

to :: Rep [a] x -> [a] Source #

IsList [a]

Since: base-4.7.0.0

Instance details

Defined in GHC.Internal.IsList

Associated Types

type Item [a] 
Instance details

Defined in GHC.Internal.IsList

type Item [a] = a

Methods

fromList :: [Item [a]] -> [a] Source #

fromListN :: Int -> [Item [a]] -> [a] Source #

toList :: [a] -> [Item [a]] Source #

Read a => Read [a]

Since: base-2.1

Instance details

Defined in GHC.Internal.Read

Show a => Show [a]

Since: base-2.1

Instance details

Defined in GHC.Internal.Show

Methods

showsPrec :: Int -> [a] -> ShowS Source #

show :: [a] -> String Source #

showList :: [[a]] -> ShowS Source #

Eq a => Eq [a] 
Instance details

Defined in GHC.Classes

Methods

(==) :: [a] -> [a] -> Bool Source #

(/=) :: [a] -> [a] -> Bool Source #

Ord a => Ord [a] 
Instance details

Defined in GHC.Classes

Methods

compare :: [a] -> [a] -> Ordering Source #

(<) :: [a] -> [a] -> Bool Source #

(<=) :: [a] -> [a] -> Bool Source #

(>) :: [a] -> [a] -> Bool Source #

(>=) :: [a] -> [a] -> Bool Source #

max :: [a] -> [a] -> [a] Source #

min :: [a] -> [a] -> [a] Source #

type Rep1 []

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep [a]

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Generics

type Item [a] 
Instance details

Defined in GHC.Internal.IsList

type Item [a] = a

data Char Source #

The character type Char represents Unicode codespace and its elements are code points as in definitions D9 and D10 of the Unicode Standard.

Character literals in Haskell are single-quoted: 'Q', 'Я' or 'Ω'. To represent a single quote itself use '\'', and to represent a backslash use '\\'. The full grammar can be found in the section 2.6 of the Haskell 2010 Language Report.

To specify a character by its code point one can use decimal, hexadecimal or octal notation: '\65', '\x41' and '\o101' are all alternative forms of 'A'. The largest code point is '\x10ffff'.

There is a special escape syntax for ASCII control characters:

EscapeAlternativesMeaning
'\NUL''\0'null character
'\SOH''\1'start of heading
'\STX''\2'start of text
'\ETX''\3'end of text
'\EOT''\4'end of transmission
'\ENQ''\5'enquiry
'\ACK''\6'acknowledge
'\BEL''\7', '\a'bell (alert)
'\BS''\8', '\b'backspace
'\HT''\9', '\t'horizontal tab
'\LF''\10', '\n'line feed (new line)
'\VT''\11', '\v'vertical tab
'\FF''\12', '\f'form feed
'\CR''\13', '\r'carriage return
'\SO''\14'shift out
'\SI''\15'shift in
'\DLE''\16'data link escape
'\DC1''\17'device control 1
'\DC2''\18'device control 2
'\DC3''\19'device control 3
'\DC4''\20'device control 4
'\NAK''\21'negative acknowledge
'\SYN''\22'synchronous idle
'\ETB''\23'end of transmission block
'\CAN''\24'cancel
'\EM''\25'end of medium
'\SUB''\26'substitute
'\ESC''\27'escape
'\FS''\28'file separator
'\GS''\29'group separator
'\RS''\30'record separator
'\US''\31'unit separator
'\SP''\32', ' 'space
'\DEL''\127'delete

Data.Char provides utilities to work with Char.

Constructors

C# Char# 

Instances

Instances details
IsChar Char Source #

Since: base-2.1

Instance details

Defined in Text.Printf

PrintfArg Char Source #

Since: base-2.1

Instance details

Defined in Text.Printf

Data Char

Since: base-4.0.0.0

Instance details

Defined in GHC.Internal.Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Char -> c Char Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Char Source #

toConstr :: Char -> Constr Source #

dataTypeOf :: Char -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Char) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Char) Source #

gmapT :: (forall b. Data b => b -> b) -> Char -> Char Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Char -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Char -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Char -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Char -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Char -> m Char Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Char -> m Char Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Char -> m Char Source #

Bounded Char

Since: base-2.1

Instance details

Defined in GHC.Internal.Enum

Enum Char

Since: base-2.1

Instance details

Defined in GHC.Internal.Enum

Storable Char

Since: base-2.1

Instance details

Defined in GHC.Internal.Foreign.Storable

Ix Char

Since: base-2.1

Instance details

Defined in GHC.Internal.Ix

Read Char

Since: base-2.1

Instance details

Defined in GHC.Internal.Read

Show Char

Since: base-2.1

Instance details

Defined in GHC.Internal.Show

Eq Char 
Instance details

Defined in GHC.Classes

Methods

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

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

Ord Char 
Instance details

Defined in GHC.Classes

TestCoercion SChar

Since: base-4.18.0.0

Instance details

Defined in GHC.Internal.TypeLits

Methods

testCoercion :: forall (a :: Char) (b :: Char). SChar a -> SChar b -> Maybe (Coercion a b) Source #

TestEquality SChar

Since: base-4.18.0.0

Instance details

Defined in GHC.Internal.TypeLits

Methods

testEquality :: forall (a :: Char) (b :: Char). SChar a -> SChar b -> Maybe (a :~: b) Source #

Generic1 (URec Char :: k -> Type) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep1 (URec Char :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Char :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: k -> Type)))

Methods

from1 :: forall (a :: k). URec Char a -> Rep1 (URec Char :: k -> Type) a Source #

to1 :: forall (a :: k). Rep1 (URec Char :: k -> Type) a -> URec Char a Source #

Foldable (UChar :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Foldable

Methods

fold :: Monoid m => UChar m -> m Source #

foldMap :: Monoid m => (a -> m) -> UChar a -> m Source #

foldMap' :: Monoid m => (a -> m) -> UChar a -> m Source #

foldr :: (a -> b -> b) -> b -> UChar a -> b Source #

foldr' :: (a -> b -> b) -> b -> UChar a -> b Source #

foldl :: (b -> a -> b) -> b -> UChar a -> b Source #

foldl' :: (b -> a -> b) -> b -> UChar a -> b Source #

foldr1 :: (a -> a -> a) -> UChar a -> a Source #

foldl1 :: (a -> a -> a) -> UChar a -> a Source #

toList :: UChar a -> [a] Source #

null :: UChar a -> Bool Source #

length :: UChar a -> Int Source #

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

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

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

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

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

Traversable (UChar :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Traversable

Methods

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

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

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

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

Functor (URec Char :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

fmap :: (a -> b) -> URec Char a -> URec Char b Source #

(<$) :: a -> URec Char b -> URec Char a Source #

Generic (URec Char p) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep (URec Char p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec Char p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: Type -> Type)))

Methods

from :: URec Char p -> Rep (URec Char p) x Source #

to :: Rep (URec Char p) x -> URec Char p Source #

Show (URec Char p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Eq (URec Char p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

(==) :: URec Char p -> URec Char p -> Bool Source #

(/=) :: URec Char p -> URec Char p -> Bool Source #

Ord (URec Char p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

compare :: URec Char p -> URec Char p -> Ordering Source #

(<) :: URec Char p -> URec Char p -> Bool Source #

(<=) :: URec Char p -> URec Char p -> Bool Source #

(>) :: URec Char p -> URec Char p -> Bool Source #

(>=) :: URec Char p -> URec Char p -> Bool Source #

max :: URec Char p -> URec Char p -> URec Char p Source #

min :: URec Char p -> URec Char p -> URec Char p Source #

data URec Char (p :: k)

Used for marking occurrences of Char#

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

data URec Char (p :: k) = UChar {}
type Compare (a :: Char) (b :: Char) 
Instance details

Defined in GHC.Internal.Data.Type.Ord

type Compare (a :: Char) (b :: Char) = CmpChar a b
type Rep1 (URec Char :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Char :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: k -> Type)))
type Rep (URec Char p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec Char p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: Type -> Type)))

data Int Source #

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.

Constructors

I# Int# 

Instances

Instances details
PrintfArg Int Source #

Since: base-2.1

Instance details

Defined in Text.Printf

Bits Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Bits

FiniteBits Int

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Bits

Data Int

Since: base-4.0.0.0

Instance details

Defined in GHC.Internal.Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Int -> c Int Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Int Source #

toConstr :: Int -> Constr Source #

dataTypeOf :: Int -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Int) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Int) Source #

gmapT :: (forall b. Data b => b -> b) -> Int -> Int Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Int -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Int -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Int -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Int -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Int -> m Int Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Int -> m Int Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Int -> m Int Source #

Bounded Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Enum

Enum Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Enum

Storable Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Foreign.Storable

Ix Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Ix

Num Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Num

Read Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Read

Integral Int

Since: base-2.0.1

Instance details

Defined in GHC.Internal.Real

Methods

quot :: Int -> Int -> Int Source #

rem :: Int -> Int -> Int Source #

div :: Int -> Int -> Int Source #

mod :: Int -> Int -> Int Source #

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

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

toInteger :: Int -> Integer Source #

Real Int

Since: base-2.0.1

Instance details

Defined in GHC.Internal.Real

Show Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Show

Eq Int 
Instance details

Defined in GHC.Classes

Methods

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

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

Ord Int 
Instance details

Defined in GHC.Classes

Methods

compare :: Int -> Int -> Ordering Source #

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

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

(>) :: Int -> Int -> Bool Source #

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

max :: Int -> Int -> Int Source #

min :: Int -> Int -> Int Source #

Generic1 (URec Int :: k -> Type) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep1 (URec Int :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Int :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UInt" 'PrefixI 'True) (S1 ('MetaSel ('Just "uInt#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UInt :: k -> Type)))

Methods

from1 :: forall (a :: k). URec Int a -> Rep1 (URec Int :: k -> Type) a Source #

to1 :: forall (a :: k). Rep1 (URec Int :: k -> Type) a -> URec Int a Source #

Foldable (UInt :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Foldable

Methods

fold :: Monoid m => UInt m -> m Source #

foldMap :: Monoid m => (a -> m) -> UInt a -> m Source #

foldMap' :: Monoid m => (a -> m) -> UInt a -> m Source #

foldr :: (a -> b -> b) -> b -> UInt a -> b Source #

foldr' :: (a -> b -> b) -> b -> UInt a -> b Source #

foldl :: (b -> a -> b) -> b -> UInt a -> b Source #

foldl' :: (b -> a -> b) -> b -> UInt a -> b Source #

foldr1 :: (a -> a -> a) -> UInt a -> a Source #

foldl1 :: (a -> a -> a) -> UInt a -> a Source #

toList :: UInt a -> [a] Source #

null :: UInt a -> Bool Source #

length :: UInt a -> Int Source #

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

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

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

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

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

Traversable (UInt :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Traversable

Methods

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

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

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

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

Functor (URec Int :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

fmap :: (a -> b) -> URec Int a -> URec Int b Source #

(<$) :: a -> URec Int b -> URec Int a Source #

Generic (URec Int p) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep (URec Int p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec Int p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UInt" 'PrefixI 'True) (S1 ('MetaSel ('Just "uInt#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UInt :: Type -> Type)))

Methods

from :: URec Int p -> Rep (URec Int p) x Source #

to :: Rep (URec Int p) x -> URec Int p Source #

Show (URec Int p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Eq (URec Int p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

(==) :: URec Int p -> URec Int p -> Bool Source #

(/=) :: URec Int p -> URec Int p -> Bool Source #

Ord (URec Int p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

compare :: URec Int p -> URec Int p -> Ordering Source #

(<) :: URec Int p -> URec Int p -> Bool Source #

(<=) :: URec Int p -> URec Int p -> Bool Source #

(>) :: URec Int p -> URec Int p -> Bool Source #

(>=) :: URec Int p -> URec Int p -> Bool Source #

max :: URec Int p -> URec Int p -> URec Int p Source #

min :: URec Int p -> URec Int p -> URec Int p Source #

data URec Int (p :: k)

Used for marking occurrences of Int#

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

data URec Int (p :: k) = UInt {}
type Rep1 (URec Int :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Int :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UInt" 'PrefixI 'True) (S1 ('MetaSel ('Just "uInt#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UInt :: k -> Type)))
type Rep (URec Int p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec Int p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UInt" 'PrefixI 'True) (S1 ('MetaSel ('Just "uInt#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UInt :: Type -> Type)))

data Bool Source #

Constructors

False 
True 

Instances

Instances details
Bits Bool

Interpret Bool as 1-bit bit-field

Since: base-4.7.0.0

Instance details

Defined in GHC.Internal.Bits

FiniteBits Bool

Since: base-4.7.0.0

Instance details

Defined in GHC.Internal.Bits

Data Bool

Since: base-4.0.0.0

Instance details

Defined in GHC.Internal.Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Bool -> c Bool Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Bool Source #

toConstr :: Bool -> Constr Source #

dataTypeOf :: Bool -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Bool) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Bool) Source #

gmapT :: (forall b. Data b => b -> b) -> Bool -> Bool Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Bool -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Bool -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Bool -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Bool -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Bool -> m Bool Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Bool -> m Bool Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Bool -> m Bool Source #

Bounded Bool

Since: base-2.1

Instance details

Defined in GHC.Internal.Enum

Enum Bool

Since: base-2.1

Instance details

Defined in GHC.Internal.Enum

Storable Bool

Since: base-2.1

Instance details

Defined in GHC.Internal.Foreign.Storable

Generic Bool 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep Bool

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep Bool = D1 ('MetaData "Bool" "GHC.Types" "ghc-prim" 'False) (C1 ('MetaCons "False" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "True" 'PrefixI 'False) (U1 :: Type -> Type))

Methods

from :: Bool -> Rep Bool x Source #

to :: Rep Bool x -> Bool Source #

SingKind Bool

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Associated Types

type DemoteRep Bool 
Instance details

Defined in GHC.Internal.Generics

type DemoteRep Bool = Bool

Methods

fromSing :: forall (a :: Bool). Sing a -> DemoteRep Bool

Ix Bool

Since: base-2.1

Instance details

Defined in GHC.Internal.Ix

Read Bool

Since: base-2.1

Instance details

Defined in GHC.Internal.Read

Show Bool

Since: base-2.1

Instance details

Defined in GHC.Internal.Show

Eq Bool 
Instance details

Defined in GHC.Classes

Methods

(==) :: Bool -> Bool -> Bool Source #

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

Ord Bool 
Instance details

Defined in GHC.Classes

SingI 'False

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

sing :: Sing 'False

SingI 'True

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

sing :: Sing 'True

type DemoteRep Bool 
Instance details

Defined in GHC.Internal.Generics

type DemoteRep Bool = Bool
type Rep Bool

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep Bool = D1 ('MetaData "Bool" "GHC.Types" "ghc-prim" 'False) (C1 ('MetaCons "False" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "True" 'PrefixI 'False) (U1 :: Type -> Type))
data Sing (a :: Bool) 
Instance details

Defined in GHC.Internal.Generics

data Sing (a :: Bool) where

data Double Source #

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.

Constructors

D# Double# 

Instances

Instances details
PrintfArg Double Source #

Since: base-2.1

Instance details

Defined in Text.Printf

Data Double

Since: base-4.0.0.0

Instance details

Defined in GHC.Internal.Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Double -> c Double Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Double Source #

toConstr :: Double -> Constr Source #

dataTypeOf :: Double -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Double) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Double) Source #

gmapT :: (forall b. Data b => b -> b) -> Double -> Double Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Double -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Double -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Double -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Double -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Double -> m Double Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Double -> m Double Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Double -> m Double Source #

Floating Double

Since: base-2.1

Instance details

Defined in GHC.Internal.Float

RealFloat Double

Since: base-2.1

Instance details

Defined in GHC.Internal.Float

Storable Double

Since: base-2.1

Instance details

Defined in GHC.Internal.Foreign.Storable

Read Double

Since: base-2.1

Instance details

Defined in GHC.Internal.Read

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
Instance details

Defined in GHC.Classes

Ord Double

IEEE 754 Double-precision type includes not only numbers, but also positive and negative infinities and a special element called NaN (which can be quiet or signal).

IEEE 754-2008, section 5.11 requires that if at least one of arguments of <=, <, >, >= is NaN then the result of the comparison is False, and instance Ord Double complies with this requirement. This violates the reflexivity: both NaN <= NaN and NaN >= NaN are False.

IEEE 754-2008, section 5.10 defines totalOrder predicate. Unfortunately, compare on Doubles violates the IEEE standard and does not define a total order. More specifically, both compare NaN x and compare x NaN always return GT.

Thus, users must be extremely cautious when using instance Ord Double. For instance, one should avoid ordered containers with keys represented by Double, because data loss and corruption may happen. An IEEE-compliant compare is available in fp-ieee package as TotallyOrdered newtype.

Moving further, the behaviour of min and max with regards to NaN is also non-compliant. IEEE 754-2008, section 5.3.1 defines that quiet NaN should be treated as a missing data by minNum and maxNum functions, for example, minNum(NaN, 1) = minNum(1, NaN) = 1. Some languages such as Java deviate from the standard implementing minNum(NaN, 1) = minNum(1, NaN) = NaN. However, min / max in base are even worse: min NaN 1 is 1, but min 1 NaN is NaN.

IEEE 754-2008 compliant min / max can be found in ieee754 package under minNum / maxNum names. Implementations compliant with minimumNumber / maximumNumber from a newer IEEE 754-2019, section 9.6 are available from fp-ieee package.

Instance details

Defined in GHC.Classes

Generic1 (URec Double :: k -> Type) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep1 (URec Double :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Double :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: k -> Type)))

Methods

from1 :: forall (a :: k). URec Double a -> Rep1 (URec Double :: k -> Type) a Source #

to1 :: forall (a :: k). Rep1 (URec Double :: k -> Type) a -> URec Double a Source #

Foldable (UDouble :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Foldable

Methods

fold :: Monoid m => UDouble m -> m Source #

foldMap :: Monoid m => (a -> m) -> UDouble a -> m Source #

foldMap' :: Monoid m => (a -> m) -> UDouble a -> m Source #

foldr :: (a -> b -> b) -> b -> UDouble a -> b Source #

foldr' :: (a -> b -> b) -> b -> UDouble a -> b Source #

foldl :: (b -> a -> b) -> b -> UDouble a -> b Source #

foldl' :: (b -> a -> b) -> b -> UDouble a -> b Source #

foldr1 :: (a -> a -> a) -> UDouble a -> a Source #

foldl1 :: (a -> a -> a) -> UDouble a -> a Source #

toList :: UDouble a -> [a] Source #

null :: UDouble a -> Bool Source #

length :: UDouble a -> Int Source #

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

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

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

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

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

Traversable (UDouble :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Traversable

Methods

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

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

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

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

Functor (URec Double :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

fmap :: (a -> b) -> URec Double a -> URec Double b Source #

(<$) :: a -> URec Double b -> URec Double a Source #

Generic (URec Double p) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep (URec Double p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec Double p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: Type -> Type)))

Methods

from :: URec Double p -> Rep (URec Double p) x Source #

to :: Rep (URec Double p) x -> URec Double p Source #

Show (URec Double p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Eq (URec Double p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

(==) :: URec Double p -> URec Double p -> Bool Source #

(/=) :: URec Double p -> URec Double p -> Bool Source #

Ord (URec Double p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

data URec Double (p :: k)

Used for marking occurrences of Double#

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

data URec Double (p :: k) = UDouble {}
type Rep1 (URec Double :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Double :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: k -> Type)))
type Rep (URec Double p)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep (URec Double p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: Type -> Type)))

data Float Source #

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.

Constructors

F# Float# 

Instances

Instances details
PrintfArg Float Source #

Since: base-2.1

Instance details

Defined in Text.Printf

Data Float

Since: base-4.0.0.0

Instance details

Defined in GHC.Internal.Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Float -> c Float Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Float Source #

toConstr :: Float -> Constr Source #

dataTypeOf :: Float -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Float) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Float) Source #

gmapT :: (forall b. Data b => b -> b) -> Float -> Float Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Float -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Float -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Float -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Float -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Float -> m Float Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Float -> m Float Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Float -> m Float Source #

Floating Float

Since: base-2.1

Instance details

Defined in GHC.Internal.Float

RealFloat Float

Since: base-2.1

Instance details

Defined in GHC.Internal.Float

Storable Float

Since: base-2.1

Instance details

Defined in GHC.Internal.Foreign.Storable

Read Float

Since: base-2.1

Instance details

Defined in GHC.Internal.Read

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
Instance details

Defined in GHC.Classes

Methods

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

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

Ord Float

See instance Ord Double for discussion of deviations from IEEE 754 standard.

Instance details

Defined in GHC.Classes

Generic1 (URec Float :: k -> Type) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep1 (URec Float :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Float :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: k -> Type)))

Methods

from1 :: forall (a :: k). URec Float a -> Rep1 (URec Float :: k -> Type) a Source #

to1 :: forall (a :: k). Rep1 (URec Float :: k -> Type) a -> URec Float a Source #

Foldable (UFloat :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Foldable

Methods

fold :: Monoid m => UFloat m -> m Source #

foldMap :: Monoid m => (a -> m) -> UFloat a -> m Source #

foldMap' :: Monoid m => (a -> m) -> UFloat a -> m Source #

foldr :: (a -> b -> b) -> b -> UFloat a -> b Source #

foldr' :: (a -> b -> b) -> b -> UFloat a -> b Source #

foldl :: (b -> a -> b) -> b -> UFloat a -> b Source #

foldl' :: (b -> a -> b) -> b -> UFloat a -> b Source #

foldr1 :: (a -> a -> a) -> UFloat a -> a Source #

foldl1 :: (a -> a -> a) -> UFloat a -> a Source #

toList :: UFloat a -> [a] Source #

null :: UFloat a -> Bool Source #

length :: UFloat a -> Int Source #

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

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

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

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

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

Traversable (UFloat :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Traversable

Methods

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

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

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

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

Functor (URec Float :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

Methods

fmap :: (a -> b) -> URec Float a -> URec Float b Source #

(<$) :: a -> URec Float b -> URec Float a Source #

Generic (URec Float p) 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep (URec Float p) 
Instance details

Defined in GHC.Internal.Generics

type Rep (URec Float p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: Type -> Type)))

Methods

from :: URec Float p -> Rep (URec Float p) x Source #

to :: Rep (URec Float p) x -> URec Float p Source #

Show (URec Float p) 
Instance details

Defined in GHC.Internal.Generics

Eq (URec Float p) 
Instance details

Defined in GHC.Internal.Generics

Methods

(==) :: URec Float p -> URec Float p -> Bool Source #

(/=) :: URec Float p -> URec Float p -> Bool Source #

Ord (URec Float p) 
Instance details

Defined in GHC.Internal.Generics

data URec Float (p :: k)

Used for marking occurrences of Float#

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

data URec Float (p :: k) = UFloat {}
type Rep1 (URec Float :: k -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep1 (URec Float :: k -> Type) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: k -> Type)))
type Rep (URec Float p) 
Instance details

Defined in GHC.Internal.Generics

type Rep (URec Float p) = D1 ('MetaData "URec" "GHC.Internal.Generics" "ghc-internal" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: Type ->