Safe Haskell	None
Language	Haskell2010

Test.Hspec.Discover

Description

Warning: This module is used by hspec-discover. It is not part of the public API and may change at any time.

Synopsis

type Spec = SpecWith ()
hspec :: Spec -> IO ()
class IsFormatter a where
- toFormatter :: a -> IO Formatter
hspecWithFormatter :: IsFormatter a => a -> Spec -> IO ()
postProcessSpec :: FilePath -> Spec -> Spec
describe :: HasCallStack => String -> SpecWith a -> SpecWith a
(++) :: [a] -> [a] -> [a]
seq :: a -> b -> b
filter :: (a -> Bool) -> [a] -> [a]
zip :: [a] -> [b] -> [(a, b)]
print :: Show a => a -> IO ()
fst :: (a, b) -> a
snd :: (a, b) -> b
otherwise :: Bool
map :: (a -> b) -> [a] -> [b]
($) :: (a -> b) -> a -> b
fromIntegral :: (Integral a, Num b) => a -> b
realToFrac :: (Real a, Fractional b) => a -> b
class Bounded a where
- minBound :: a
- maxBound :: a
class Enum a where
- succ :: a -> a
- pred :: a -> a
- toEnum :: Int -> a
- fromEnum :: a -> Int
- enumFrom :: a -> [a]
- enumFromThen :: a -> a -> [a]
- enumFromTo :: a -> a -> [a]
- enumFromThenTo :: a -> a -> a -> [a]
class Eq a where
- (==) :: a -> a -> Bool
- (/=) :: a -> a -> Bool
class Fractional a => Floating a where
- pi :: a
- exp :: a -> a
- log :: a -> a
- sqrt :: a -> a
- (**) :: a -> a -> a
- logBase :: a -> a -> a
- sin :: a -> a
- cos :: a -> a
- tan :: a -> a
- asin :: a -> a
- acos :: a -> a
- atan :: a -> a
- sinh :: a -> a
- cosh :: a -> a
- tanh :: a -> a
- asinh :: a -> a
- acosh :: a -> a
- atanh :: a -> a
class Num a => Fractional a where
- (/) :: a -> a -> a
- recip :: a -> a
- fromRational :: Rational -> a
class (Real a, Enum a) => Integral a where
- quot :: a -> a -> a
- rem :: a -> a -> a
- div :: a -> a -> a
- mod :: a -> a -> a
- quotRem :: a -> a -> (a, a)
- divMod :: a -> a -> (a, a)
- toInteger :: a -> Integer
class Applicative m => Monad (m :: Type -> Type) where
- (>>=) :: m a -> (a -> m b) -> m b
- (>>) :: m a -> m b -> m b
- return :: a -> m a
- fail :: String -> m a
class Functor (f :: Type -> Type) where
- fmap :: (a -> b) -> f a -> f b
- (<$) :: a -> f b -> f a
class Num a where
- (+) :: a -> a -> a
- (-) :: a -> a -> a
- (*) :: a -> a -> a
- negate :: a -> a
- abs :: a -> a
- signum :: a -> a
- fromInteger :: Integer -> a
class Eq a => Ord a where
- compare :: a -> a -> Ordering
- (<) :: a -> a -> Bool
- (<=) :: a -> a -> Bool
- (>) :: a -> a -> Bool
- (>=) :: a -> a -> Bool
- max :: a -> a -> a
- min :: a -> a -> a
class Read a where
- readsPrec :: Int -> ReadS a
- readList :: ReadS [a]
class (Num a, Ord a) => Real a where
- toRational :: a -> Rational
class (RealFrac a, Floating a) => RealFloat a where
- floatRadix :: a -> Integer
- floatDigits :: a -> Int
- floatRange :: a -> (Int, Int)
- decodeFloat :: a -> (Integer, Int)
- encodeFloat :: Integer -> Int -> a
- exponent :: a -> Int
- significand :: a -> a
- scaleFloat :: Int -> a -> a
- isNaN :: a -> Bool
- isInfinite :: a -> Bool
- isDenormalized :: a -> Bool
- isNegativeZero :: a -> Bool
- isIEEE :: a -> Bool
- atan2 :: a -> a -> a
class (Real a, Fractional a) => RealFrac a where
- properFraction :: Integral b => a -> (b, a)
- truncate :: Integral b => a -> b
- round :: Integral b => a -> b
- ceiling :: Integral b => a -> b
- floor :: Integral b => a -> b
class Show a where
- showsPrec :: Int -> a -> ShowS
- show :: a -> String
- showList :: [a] -> ShowS
class Functor f => Applicative (f :: Type -> Type) where
- pure :: a -> f a
- (<*>) :: f (a -> b) -> f a -> f b
- (*>) :: f a -> f b -> f b
- (<*) :: f a -> f b -> f a
class Foldable (t :: Type -> Type) where
- foldMap :: Monoid m => (a -> m) -> t a -> m
- foldr :: (a -> b -> b) -> b -> t a -> b
- foldl :: (b -> a -> b) -> b -> t a -> b
- foldr1 :: (a -> a -> a) -> t a -> a
- foldl1 :: (a -> a -> a) -> t a -> a
- null :: t a -> Bool
- length :: t a -> Int
- elem :: Eq a => a -> t a -> Bool
- maximum :: Ord a => t a -> a
- minimum :: Ord a => t a -> a
- sum :: Num a => t a -> a
- product :: Num a => t a -> a
class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where
- traverse :: Applicative f => (a -> f b) -> t a -> f (t b)
- sequenceA :: Applicative f => t (f a) -> f (t a)
- sequence :: Monad m => t (m a) -> m (t a)
class Semigroup a where
- (<>) :: a -> a -> a
class Semigroup a => Monoid a where
- mempty :: a
- mappend :: a -> a -> a
- mconcat :: [a] -> a
data Bool
- = False
- | True
data Char
data Double
data Float
data Int
data Integer
data Maybe a
- = Nothing
- | Just a
data Ordering
- = LT
- | EQ
- | GT
type Rational = Ratio Integer
data IO a
data Word
data Either a b
- = Left a
- | Right b
type String = [Char]
readIO :: Read a => String -> IO a
readLn :: Read a => IO a
appendFile :: FilePath -> String -> IO ()
writeFile :: FilePath -> String -> IO ()
readFile :: FilePath -> IO String
interact :: (String -> String) -> IO ()
getContents :: IO String
getLine :: IO String
getChar :: IO Char
putStrLn :: String -> IO ()
putStr :: String -> IO ()
putChar :: Char -> IO ()
ioError :: IOError -> IO a
type FilePath = String
userError :: String -> IOError
type IOError = IOException
notElem :: (Foldable t, Eq a) => a -> t a -> Bool
all :: Foldable t => (a -> Bool) -> t a -> Bool
any :: Foldable t => (a -> Bool) -> t a -> Bool
or :: Foldable t => t Bool -> Bool
and :: Foldable t => t Bool -> Bool
concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
concat :: Foldable t => t [a] -> [a]
sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
unwords :: [String] -> String
words :: String -> [String]
unlines :: [String] -> String
lines :: String -> [String]
read :: Read a => String -> a
reads :: Read a => ReadS a
either :: (a -> c) -> (b -> c) -> Either a b -> c
lex :: ReadS String
readParen :: Bool -> ReadS a -> ReadS a
type ReadS a = String -> [(a, String)]
(<$>) :: Functor f => (a -> b) -> f a -> f b
lcm :: Integral a => a -> a -> a
gcd :: Integral a => a -> a -> a
(^^) :: (Fractional a, Integral b) => a -> b -> a
(^) :: (Num a, Integral b) => a -> b -> a
odd :: Integral a => a -> Bool
even :: Integral a => a -> Bool
showParen :: Bool -> ShowS -> ShowS
showString :: String -> ShowS
showChar :: Char -> ShowS
shows :: Show a => a -> ShowS
type ShowS = String -> String
unzip3 :: [(a, b, c)] -> ([a], [b], [c])
unzip :: [(a, b)] -> ([a], [b])
zipWith3 :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d]
zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
(!!) :: [a] -> Int -> a
lookup :: Eq a => a -> [(a, b)] -> Maybe b
reverse :: [a] -> [a]
break :: (a -> Bool) -> [a] -> ([a], [a])
span :: (a -> Bool) -> [a] -> ([a], [a])
splitAt :: Int -> [a] -> ([a], [a])
drop :: Int -> [a] -> [a]
take :: Int -> [a] -> [a]
dropWhile :: (a -> Bool) -> [a] -> [a]
takeWhile :: (a -> Bool) -> [a] -> [a]
cycle :: [a] -> [a]
replicate :: Int -> a -> [a]
repeat :: a -> [a]
iterate :: (a -> a) -> a -> [a]
scanr1 :: (a -> a -> a) -> [a] -> [a]
scanr :: (a -> b -> b) -> b -> [a] -> [b]
scanl1 :: (a -> a -> a) -> [a] -> [a]
scanl :: (b -> a -> b) -> b -> [a] -> [b]
init :: [a] -> [a]
last :: [a] -> a
tail :: [a] -> [a]
head :: [a] -> a
maybe :: b -> (a -> b) -> Maybe a -> b
uncurry :: (a -> b -> c) -> (a, b) -> c
curry :: ((a, b) -> c) -> a -> b -> c
subtract :: Num a => a -> a -> a
asTypeOf :: a -> a -> a
until :: (a -> Bool) -> (a -> a) -> a -> a
($!) :: (a -> b) -> a -> b
flip :: (a -> b -> c) -> b -> a -> c
(.) :: (b -> c) -> (a -> b) -> a -> c
const :: a -> b -> a
id :: a -> a
(=<<) :: Monad m => (a -> m b) -> m a -> m b
undefined :: HasCallStack => a
errorWithoutStackTrace :: [Char] -> a
error :: HasCallStack => [Char] -> a
(&&) :: Bool -> Bool -> Bool
(||) :: Bool -> Bool -> Bool
not :: Bool -> Bool

Documentation

type Spec = SpecWith () Source #

hspec :: Spec -> IO () Source #

Run a given spec and write a report to stdout. Exit with exitFailure if at least one spec item fails.

Note: hspec handles command-line options and reads config files. This is not always desired. Use runSpec if you need more control over these aspects.

class IsFormatter a where Source #

Methods

toFormatter :: a -> IO Formatter Source #

Instances

IsFormatter Formatter Source #
Instance details Defined in Test.Hspec.Discover Methods toFormatter :: Formatter -> IO Formatter Source #
IsFormatter (IO Formatter) Source #
Instance details Defined in Test.Hspec.Discover Methods toFormatter :: IO Formatter -> IO Formatter Source #

hspecWithFormatter :: IsFormatter a => a -> Spec -> IO () Source #

postProcessSpec :: FilePath -> Spec -> Spec Source #

describe :: HasCallStack => String -> SpecWith a -> SpecWith a Source #

The describe function combines a list of specs into a larger spec.

(++) :: [a] -> [a] -> [a] infixr 5 Source #

Append two lists, i.e.,

[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn]
[x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]

If the first list is not finite, the result is the first list.

seq :: a -> b -> b Source #

The value of seq a b is bottom if a is bottom, and otherwise equal to b. In other words, it evaluates the first argument a to weak head normal form (WHNF). seq is usually introduced to improve performance by avoiding unneeded laziness.

A note on evaluation order: the expression seq a b does not guarantee that a will be evaluated before b. The only guarantee given by seq is that the both a and b will be evaluated before seq returns a value. In particular, this means that b may be evaluated before a. If you need to guarantee a specific order of evaluation, you must use the function pseq from the "parallel" package.

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

filter, applied to a predicate and a list, returns the list of those elements that satisfy the predicate; i.e.,

filter p xs = [ x | x <- xs, p x]

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

zip takes two lists and returns a list of corresponding pairs.

zip [1, 2] ['a', 'b'] = [(1, 'a'), (2, 'b')]

If one input list is short, excess elements of the longer list are discarded:

zip [1] ['a', 'b'] = [(1, 'a')]
zip [1, 2] ['a'] = [(1, 'a')]

zip is right-lazy:

zip [] _|_ = []
zip _|_ [] = _|_

print :: Show a => a -> IO () Source #

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]])

fst :: (a, b) -> a Source #

Extract the first component of a pair.

snd :: (a, b) -> b Source #

Extract the second component of a pair.

otherwise :: Bool Source #

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

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

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

map f xs is the list obtained by applying f to each element of xs, i.e.,

map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn]
map f [x1, x2, ...] == [f x1, f x2, ...]

($) :: (a -> b) -> a -> b infixr 0 Source #

Application operator. This operator is redundant, since ordinary application (f x) means the same as (f $ x). However, $ has low, right-associative binding precedence, so it sometimes allows parentheses to be omitted; for example:

f $ g $ h x  =  f (g (h x))

It is also useful in higher-order situations, such as map ($ 0) xs, or zipWith ($) fs xs.

Note that ($) is levity-polymorphic in its result type, so that foo $ True where foo :: Bool -> Int# is well-typed

fromIntegral :: (Integral a, Num b) => a -> b Source #

general coercion from integral types

realToFrac :: (Real a, Fractional b) => a -> b Source #

general coercion to fractional types

class Bounded a where Source #

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.

Methods

minBound :: a Source #

maxBound :: a Source #

Instances

Bounded Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Bool Source # maxBound :: Bool Source #
Bounded Char	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Char Source # maxBound :: Char Source #
Bounded Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Int Source # maxBound :: Int Source #
Bounded Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Ordering Source # maxBound :: Ordering Source #
Bounded Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Word Source # maxBound :: Word Source #
Bounded VecCount	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods minBound :: VecCount Source # maxBound :: VecCount Source #
Bounded VecElem	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods minBound :: VecElem Source # maxBound :: VecElem Source #
Bounded ()	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: () Source # maxBound :: () Source #
(Bounded a, Bounded b) => Bounded (a, b)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b) Source # maxBound :: (a, b) Source #
(Bounded a, Bounded b, Bounded c) => Bounded (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c) Source # maxBound :: (a, b, c) Source #
(Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d) Source # maxBound :: (a, b, c, d) Source #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e) Source # maxBound :: (a, b, c, d, e) Source #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f) Source # maxBound :: (a, b, c, d, e, f) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g) Source # maxBound :: (a, b, c, d, e, f, g) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h) Source # maxBound :: (a, b, c, d, e, f, g, h) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i) Source # maxBound :: (a, b, c, d, e, f, g, h, i) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j) Source # maxBound :: (a, b, c, d, e, f, g, h, i, j) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k) Source # maxBound :: (a, b, c, d, e, f, g, h, i, j, k) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l) Source # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m) Source # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) Source # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) Source #
(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
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) Source # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) Source #

class Enum a where Source #

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

Methods

succ :: a -> a Source #

the successor of a value. For numeric types, succ adds 1.

pred :: a -> a Source #

the predecessor of a value. For numeric types, pred subtracts 1.

toEnum :: Int -> a Source #

Convert from an Int.

fromEnum :: a -> Int Source #

Convert to an Int. It is implementation-dependent what fromEnum returns when applied to a value that is too large to fit in an Int.

enumFrom :: a -> [a] Source #

Used in Haskell's translation of [n..] with [n..] = enumFrom n, a possible implementation being enumFrom n = n : enumFrom (succ n). For example:

```
enumFrom 4 :: [Integer] = [4,5,6,7,...]
```

enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]

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

Used in Haskell's translation of [n,n'..] with [n,n'..] = enumFromThen n n', a possible implementation being enumFromThen n n' = n : n' : worker (f x) (f x n'), worker s v = v : worker s (s v), x = fromEnum n' - fromEnum n and f n y | n > 0 = f (n - 1) (succ y) | n < 0 = f (n + 1) (pred y) | otherwise = y For example:

enumFromThen 4 6 :: [Integer] = [4,6,8,10...]

enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]

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

Used in Haskell's translation of [n..m] with [n..m] = enumFromTo n m, a possible implementation being enumFromTo n m | n <= m = n : enumFromTo (succ n) m | otherwise = []. For example:

```
enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
```
```
enumFromTo 42 1 :: [Integer] = []
```

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

Used in Haskell's translation of [n,n'..m] with [n,n'..m] = enumFromThenTo n n' m, a possible implementation being enumFromThenTo n n' m = worker (f x) (c x) n m, x = fromEnum n' - fromEnum n, c x = bool (>=) ((x 0) f n y | n > 0 = f (n - 1) (succ y) | n < 0 = f (n + 1) (pred y) | otherwise = y and worker s c v m | c v m = v : worker s c (s v) m | otherwise = [] For example:

enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]

```
enumFromThenTo 6 8 2 :: [Int] = []
```

Instances

Enum Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Bool -> Bool Source # pred :: Bool -> Bool Source # toEnum :: Int -> Bool Source # fromEnum :: Bool -> Int Source # enumFrom :: Bool -> [Bool] Source # enumFromThen :: Bool -> Bool -> [Bool] Source # enumFromTo :: Bool -> Bool -> [Bool] Source # enumFromThenTo :: Bool -> Bool -> Bool -> [Bool] Source #
Enum Char	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Char -> Char Source # pred :: Char -> Char Source # toEnum :: Int -> Char Source # fromEnum :: Char -> Int Source # enumFrom :: Char -> [Char] Source # enumFromThen :: Char -> Char -> [Char] Source # enumFromTo :: Char -> Char -> [Char] Source # enumFromThenTo :: Char -> Char -> Char -> [Char] Source #
Enum Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Int -> Int Source # pred :: Int -> Int Source # toEnum :: Int -> Int Source # fromEnum :: Int -> Int Source # enumFrom :: Int -> [Int] Source # enumFromThen :: Int -> Int -> [Int] Source # enumFromTo :: Int -> Int -> [Int] Source # enumFromThenTo :: Int -> Int -> Int -> [Int] Source #
Enum Integer	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Integer -> Integer Source # pred :: Integer -> Integer Source # toEnum :: Int -> Integer Source # fromEnum :: Integer -> Int Source # enumFrom :: Integer -> [Integer] Source # enumFromThen :: Integer -> Integer -> [Integer] Source # enumFromTo :: Integer -> Integer -> [Integer] Source # enumFromThenTo :: Integer -> Integer -> Integer -> [Integer] Source #
Enum Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Enum Methods succ :: Natural -> Natural Source # pred :: Natural -> Natural Source # toEnum :: Int -> Natural Source # fromEnum :: Natural -> Int Source # enumFrom :: Natural -> [Natural] Source # enumFromThen :: Natural -> Natural -> [Natural] Source # enumFromTo :: Natural -> Natural -> [Natural] Source # enumFromThenTo :: Natural -> Natural -> Natural -> [Natural] Source #
Enum Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Ordering -> Ordering Source # pred :: Ordering -> Ordering Source # toEnum :: Int -> Ordering Source # fromEnum :: Ordering -> Int Source # enumFrom :: Ordering -> [Ordering] Source # enumFromThen :: Ordering -> Ordering -> [Ordering] Source # enumFromTo :: Ordering -> Ordering -> [Ordering] Source # enumFromThenTo :: Ordering -> Ordering -> Ordering -> [Ordering] Source #
Enum Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Word -> Word Source # pred :: Word -> Word Source # toEnum :: Int -> Word Source # fromEnum :: Word -> Int Source # enumFrom :: Word -> [Word] Source # enumFromThen :: Word -> Word -> [Word] Source # enumFromTo :: Word -> Word -> [Word] Source # enumFromThenTo :: Word -> Word -> Word -> [Word] Source #
Enum VecCount	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods succ :: VecCount -> VecCount Source # pred :: VecCount -> VecCount Source # toEnum :: Int -> VecCount Source # fromEnum :: VecCount -> Int Source # enumFrom :: VecCount -> [VecCount] Source # enumFromThen :: VecCount -> VecCount -> [VecCount] Source # enumFromTo :: VecCount -> VecCount -> [VecCount] Source # enumFromThenTo :: VecCount -> VecCount -> VecCount -> [VecCount] Source #
Enum VecElem	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods succ :: VecElem -> VecElem Source # pred :: VecElem -> VecElem Source # toEnum :: Int -> VecElem Source # fromEnum :: VecElem -> Int Source # enumFrom :: VecElem -> [VecElem] Source # enumFromThen :: VecElem -> VecElem -> [VecElem] Source # enumFromTo :: VecElem -> VecElem -> [VecElem] Source # enumFromThenTo :: VecElem -> VecElem -> VecElem -> [VecElem] Source #
Enum ()	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: () -> () Source # pred :: () -> () Source # toEnum :: Int -> () Source # fromEnum :: () -> Int Source # enumFrom :: () -> [()] Source # enumFromThen :: () -> () -> [()] Source # enumFromTo :: () -> () -> [()] Source # enumFromThenTo :: () -> () -> () -> [()] Source #
Integral a => Enum (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods succ :: Ratio a -> Ratio a Source # pred :: Ratio a -> Ratio a Source # toEnum :: Int -> Ratio a Source # fromEnum :: Ratio a -> Int Source # enumFrom :: Ratio a -> [Ratio a] Source # enumFromThen :: Ratio a -> Ratio a -> [Ratio a] Source # enumFromTo :: Ratio a -> Ratio a -> [Ratio a] Source # enumFromThenTo :: Ratio a -> Ratio a -> Ratio a -> [Ratio a] Source #
Enum a => Enum (Blind a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: Blind a -> Blind a Source # pred :: Blind a -> Blind a Source # toEnum :: Int -> Blind a Source # fromEnum :: Blind a -> Int Source # enumFrom :: Blind a -> [Blind a] Source # enumFromThen :: Blind a -> Blind a -> [Blind a] Source # enumFromTo :: Blind a -> Blind a -> [Blind a] Source # enumFromThenTo :: Blind a -> Blind a -> Blind a -> [Blind a] Source #
Enum a => Enum (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: Fixed a -> Fixed a Source # pred :: Fixed a -> Fixed a Source # toEnum :: Int -> Fixed a Source # fromEnum :: Fixed a -> Int Source # enumFrom :: Fixed a -> [Fixed a] Source # enumFromThen :: Fixed a -> Fixed a -> [Fixed a] Source # enumFromTo :: Fixed a -> Fixed a -> [Fixed a] Source # enumFromThenTo :: Fixed a -> Fixed a -> Fixed a -> [Fixed a] Source #
Enum a => Enum (Positive a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: Positive a -> Positive a Source # pred :: Positive a -> Positive a Source # toEnum :: Int -> Positive a Source # fromEnum :: Positive a -> Int Source # enumFrom :: Positive a -> [Positive a] Source # enumFromThen :: Positive a -> Positive a -> [Positive a] Source # enumFromTo :: Positive a -> Positive a -> [Positive a] Source # enumFromThenTo :: Positive a -> Positive a -> Positive a -> [Positive a] Source #
Enum a => Enum (NonZero a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: NonZero a -> NonZero a Source # pred :: NonZero a -> NonZero a Source # toEnum :: Int -> NonZero a Source # fromEnum :: NonZero a -> Int Source # enumFrom :: NonZero a -> [NonZero a] Source # enumFromThen :: NonZero a -> NonZero a -> [NonZero a] Source # enumFromTo :: NonZero a -> NonZero a -> [NonZero a] Source # enumFromThenTo :: NonZero a -> NonZero a -> NonZero a -> [NonZero a] Source #
Enum a => Enum (NonNegative a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: NonNegative a -> NonNegative a Source # pred :: NonNegative a -> NonNegative a Source # toEnum :: Int -> NonNegative a Source # fromEnum :: NonNegative a -> Int Source # enumFrom :: NonNegative a -> [NonNegative a] Source # enumFromThen :: NonNegative a -> NonNegative a -> [NonNegative a] Source # enumFromTo :: NonNegative a -> NonNegative a -> [NonNegative a] Source # enumFromThenTo :: NonNegative a -> NonNegative a -> NonNegative a -> [NonNegative a] Source #
Enum a => Enum (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: Large a -> Large a Source # pred :: Large a -> Large a Source # toEnum :: Int -> Large a Source # fromEnum :: Large a -> Int Source # enumFrom :: Large a -> [Large a] Source # enumFromThen :: Large a -> Large a -> [Large a] Source # enumFromTo :: Large a -> Large a -> [Large a] Source # enumFromThenTo :: Large a -> Large a -> Large a -> [Large a] Source #
Enum a => Enum (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: Small a -> Small a Source # pred :: Small a -> Small a Source # toEnum :: Int -> Small a Source # fromEnum :: Small a -> Int Source # enumFrom :: Small a -> [Small a] Source # enumFromThen :: Small a -> Small a -> [Small a] Source # enumFromTo :: Small a -> Small a -> [Small a] Source # enumFromThenTo :: Small a -> Small a -> Small a -> [Small a] Source #
Enum a => Enum (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods succ :: Shrink2 a -> Shrink2 a Source # pred :: Shrink2 a -> Shrink2 a Source # toEnum :: Int -> Shrink2 a Source # fromEnum :: Shrink2 a -> Int Source # enumFrom :: Shrink2 a -> [Shrink2 a] Source # enumFromThen :: Shrink2 a -> Shrink2 a -> [Shrink2 a] Source # enumFromTo :: Shrink2 a -> Shrink2 a -> [Shrink2 a] Source # enumFromThenTo :: Shrink2 a -> Shrink2 a -> Shrink2 a -> [Shrink2 a] Source #

class Eq a where Source #

The Eq class defines equality (==) and inequality (/=). All the basic datatypes exported by the Prelude are instances of Eq, and Eq may be derived for any datatype whose constituents are also instances of Eq.

The Haskell Report defines no laws for Eq. However, == is customarily expected to implement an equivalence relationship where two values comparing equal are indistinguishable by "public" functions, with a "public" function being one not allowing to see implementation details. For example, for a type representing non-normalised natural numbers modulo 100, a "public" function doesn't make the difference between 1 and 201. It is expected to have the following properties:

Reflexivity: x == x = True
Symmetry: x == y = y == x
Transitivity: if x == y && y == z = True, then x == z = True
Substitutivity: if x == y = True and f is a "public" 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 Source #

(/=) :: a -> a -> Bool infix 4 Source #

Instances

Eq Bool
Instance details Defined in GHC.Classes Methods (==) :: Bool -> Bool -> Bool Source # (/=) :: Bool -> Bool -> Bool Source #
Eq Char
Instance details Defined in GHC.Classes Methods (==) :: Char -> Char -> Bool Source # (/=) :: Char -> Char -> Bool Source #
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 Methods (==) :: Double -> Double -> Bool Source # (/=) :: Double -> Double -> Bool Source #
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 substitutivity: `>>>` `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 #
Eq Int
Instance details Defined in GHC.Classes Methods (==) :: Int -> Int -> Bool Source # (/=) :: Int -> Int -> Bool Source #
Eq Integer
Instance details Defined in GHC.Integer.Type Methods (==) :: Integer -> Integer -> Bool Source # (/=) :: Integer -> Integer -> Bool Source #
Eq Ordering
Instance details Defined in GHC.Classes Methods (==) :: Ordering -> Ordering -> Bool Source # (/=) :: Ordering -> Ordering -> Bool Source #
Eq Word
Instance details Defined in GHC.Classes Methods (==) :: Word -> Word -> Bool Source # (/=) :: Word -> Word -> Bool Source #
Eq ()
Instance details Defined in GHC.Classes Methods (==) :: () -> () -> Bool Source # (/=) :: () -> () -> Bool Source #
Eq TyCon
Instance details Defined in GHC.Classes Methods (==) :: TyCon -> TyCon -> Bool Source # (/=) :: TyCon -> TyCon -> Bool Source #
Eq Module
Instance details Defined in GHC.Classes Methods (==) :: Module -> Module -> Bool Source # (/=) :: Module -> Module -> Bool Source #
Eq TrName
Instance details Defined in GHC.Classes Methods (==) :: TrName -> TrName -> Bool Source # (/=) :: TrName -> TrName -> Bool Source #
Eq Version	Since: base-2.1
Instance details Defined in Data.Version Methods (==) :: Version -> Version -> Bool Source # (/=) :: Version -> Version -> Bool Source #
Eq ASCIIString
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: ASCIIString -> ASCIIString -> Bool Source # (/=) :: ASCIIString -> ASCIIString -> Bool Source #
Eq UnicodeString
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: UnicodeString -> UnicodeString -> Bool Source # (/=) :: UnicodeString -> UnicodeString -> Bool Source #
Eq PrintableString
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: PrintableString -> PrintableString -> Bool Source # (/=) :: PrintableString -> PrintableString -> Bool Source #
Eq Handle	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: Handle -> Handle -> Bool Source # (/=) :: Handle -> Handle -> Bool Source #
Eq BigNat
Instance details Defined in GHC.Integer.Type Methods (==) :: BigNat -> BigNat -> Bool Source # (/=) :: BigNat -> BigNat -> Bool Source #
Eq AsyncException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: AsyncException -> AsyncException -> Bool Source # (/=) :: AsyncException -> AsyncException -> Bool Source #
Eq ArrayException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: ArrayException -> ArrayException -> Bool Source # (/=) :: ArrayException -> ArrayException -> Bool Source #
Eq ExitCode
Instance details Defined in GHC.IO.Exception Methods (==) :: ExitCode -> ExitCode -> Bool Source # (/=) :: ExitCode -> ExitCode -> Bool Source #
Eq IOErrorType	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: IOErrorType -> IOErrorType -> Bool Source # (/=) :: IOErrorType -> IOErrorType -> Bool Source #
Eq BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: BufferMode -> BufferMode -> Bool Source # (/=) :: BufferMode -> BufferMode -> Bool Source #
Eq Newline	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: Newline -> Newline -> Bool Source # (/=) :: Newline -> Newline -> Bool Source #
Eq NewlineMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: NewlineMode -> NewlineMode -> Bool Source # (/=) :: NewlineMode -> NewlineMode -> Bool Source #
Eq MaskingState	Since: base-4.3.0.0
Instance details Defined in GHC.IO Methods (==) :: MaskingState -> MaskingState -> Bool Source # (/=) :: MaskingState -> MaskingState -> Bool Source #
Eq IOException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: IOException -> IOException -> Bool Source # (/=) :: IOException -> IOException -> Bool Source #
Eq ArithException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods (==) :: ArithException -> ArithException -> Bool Source # (/=) :: ArithException -> ArithException -> Bool Source #
Eq SrcLoc	Since: base-4.9.0.0
Instance details Defined in GHC.Stack.Types Methods (==) :: SrcLoc -> SrcLoc -> Bool Source # (/=) :: SrcLoc -> SrcLoc -> Bool Source #
Eq Summary
Instance details Defined in Test.Hspec.Core.Runner Methods (==) :: Summary -> Summary -> Bool Source # (/=) :: Summary -> Summary -> Bool Source #
Eq ColorMode
Instance details Defined in Test.Hspec.Core.Config.Options Methods (==) :: ColorMode -> ColorMode -> Bool Source # (/=) :: ColorMode -> ColorMode -> Bool Source #
Eq Location
Instance details Defined in Test.Hspec.Core.Example.Location Methods (==) :: Location -> Location -> Bool Source # (/=) :: Location -> Location -> Bool Source #
Eq Seconds
Instance details Defined in Test.Hspec.Core.Clock Methods (==) :: Seconds -> Seconds -> Bool Source # (/=) :: Seconds -> Seconds -> Bool Source #
Eq LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods (==) :: LocalTime -> LocalTime -> Bool Source # (/=) :: LocalTime -> LocalTime -> Bool Source #
Eq HUnitFailure
Instance details Defined in Test.HUnit.Lang Methods (==) :: HUnitFailure -> HUnitFailure -> Bool Source # (/=) :: HUnitFailure -> HUnitFailure -> Bool Source #
Eq FailureReason
Instance details Defined in Test.HUnit.Lang Methods (==) :: FailureReason -> FailureReason -> Bool Source # (/=) :: FailureReason -> FailureReason -> Bool Source #
Eq Result
Instance details Defined in Test.HUnit.Lang Methods (==) :: Result -> Result -> Bool Source # (/=) :: Result -> Result -> Bool Source #
Eq Shrunk
Instance details Defined in Test.QuickCheck.Function Methods (==) :: Shrunk -> Shrunk -> Bool Source # (/=) :: Shrunk -> Shrunk -> Bool Source #
Eq a => Eq [a]
Instance details Defined in GHC.Classes Methods (==) :: [a] -> [a] -> Bool Source # (/=) :: [a] -> [a] -> Bool Source #
Eq a => Eq (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods (==) :: Maybe a -> Maybe a -> Bool Source # (/=) :: Maybe a -> Maybe a -> Bool Source #
Eq a => Eq (Ratio a)	Since: base-2.1
Instance details Defined in GHC.Real Methods (==) :: Ratio a -> Ratio a -> Bool Source # (/=) :: Ratio a -> Ratio a -> Bool Source #
Eq a => Eq (Blind a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: Blind a -> Blind a -> Bool Source # (/=) :: Blind a -> Blind a -> Bool Source #
Eq a => Eq (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: Fixed a -> Fixed a -> Bool Source # (/=) :: Fixed a -> Fixed a -> Bool Source #
Eq a => Eq (OrderedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: OrderedList a -> OrderedList a -> Bool Source # (/=) :: OrderedList a -> OrderedList a -> Bool Source #
Eq a => Eq (NonEmptyList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: NonEmptyList a -> NonEmptyList a -> Bool Source # (/=) :: NonEmptyList a -> NonEmptyList a -> Bool Source #
Eq a => Eq (SortedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: SortedList a -> SortedList a -> Bool Source # (/=) :: SortedList a -> SortedList a -> Bool Source #
Eq a => Eq (Positive a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: Positive a -> Positive a -> Bool Source # (/=) :: Positive a -> Positive a -> Bool Source #
Eq a => Eq (NonZero a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: NonZero a -> NonZero a -> Bool Source # (/=) :: NonZero a -> NonZero a -> Bool Source #
Eq a => Eq (NonNegative a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: NonNegative a -> NonNegative a -> Bool Source # (/=) :: NonNegative a -> NonNegative a -> Bool Source #
Eq a => Eq (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: Large a -> Large a -> Bool Source # (/=) :: Large a -> Large a -> Bool Source #
Eq a => Eq (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: Small a -> Small a -> Bool Source # (/=) :: Small a -> Small a -> Bool Source #
Eq a => Eq (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (==) :: Shrink2 a -> Shrink2 a -> Bool Source # (/=) :: Shrink2 a -> Shrink2 a -> Bool Source #
Eq a => Eq (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (==) :: NonEmpty a -> NonEmpty a -> Bool Source # (/=) :: NonEmpty a -> NonEmpty a -> Bool Source #
(Eq a, Eq b) => Eq (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods (==) :: Either a b -> Either a b -> Bool Source # (/=) :: Either a b -> Either a b -> Bool Source #
(Eq a, Eq b) => Eq (a, b)
Instance details Defined in GHC.Classes Methods (==) :: (a, b) -> (a, b) -> Bool Source # (/=) :: (a, b) -> (a, b) -> Bool Source #
(Eq c, Eq a) => Eq (Tree c a)
Instance details Defined in Test.Hspec.Core.Tree Methods (==) :: Tree c a -> Tree c a -> Bool Source # (/=) :: Tree c a -> Tree c a -> Bool Source #
(Eq a, Eq b, Eq c) => Eq (a, b, c)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c) -> (a, b, c) -> Bool Source # (/=) :: (a, b, c) -> (a, b, c) -> Bool Source #
(Eq e, Eq1 m, Eq a) => Eq (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods (==) :: ErrorT e m a -> ErrorT e m a -> Bool Source # (/=) :: ErrorT e m a -> ErrorT e m a -> Bool Source #
(Eq a, Eq b, Eq c, Eq d) => Eq (a, b, c, d)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source # (/=) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source #
(Eq a, Eq b, Eq c, Eq d, Eq e) => Eq (a, b, c, d, e)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source # (/=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source # (/=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g) => Eq (a, b, c, d, e, f, g)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source # (/=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source #
(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)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source # (/=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source #
(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)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source # (/=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source #
(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)
Instance details 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 Source # (/=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool Source #
(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)
Instance details 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 Source # (/=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool Source #
(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)
Instance details 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 Source # (/=) :: (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 Source #
(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)
Instance details 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 Source # (/=) :: (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 Source #
(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)
Instance details 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 Source # (/=) :: (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 Source #
(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)
Instance details 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 Source # (/=) :: (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 Source #

class Fractional a => Floating a where Source #

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

pi :: a Source #

exp :: a -> a Source #

log :: a -> a Source #

sqrt :: a -> a Source #

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

logBase :: a -> a -> a Source #

sin :: a -> a Source #

cos :: a -> a Source #

tan :: a -> a Source #

asin :: a -> a Source #

acos :: a -> a Source #

atan :: a -> a Source #

sinh :: a -> a Source #

cosh :: a -> a Source #

tanh :: a -> a Source #

asinh :: a -> a Source #

acosh :: a -> a Source #

atanh :: a -> a Source #

Instances

Floating Double	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Double Source # exp :: Double -> Double Source # log :: Double -> Double Source # sqrt :: Double -> Double Source # (**) :: Double -> Double -> Double Source # logBase :: Double -> Double -> Double Source # sin :: Double -> Double Source # cos :: Double -> Double Source # tan :: Double -> Double Source # asin :: Double -> Double Source # acos :: Double -> Double Source # atan :: Double -> Double Source # sinh :: Double -> Double Source # cosh :: Double -> Double Source # tanh :: Double -> Double Source # asinh :: Double -> Double Source # acosh :: Double -> Double Source # atanh :: Double -> Double Source # log1p :: Double -> Double Source # expm1 :: Double -> Double Source # log1pexp :: Double -> Double Source # log1mexp :: Double -> Double Source #
Floating Float	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Float Source # exp :: Float -> Float Source # log :: Float -> Float Source # sqrt :: Float -> Float Source # (**) :: Float -> Float -> Float Source # logBase :: Float -> Float -> Float Source # sin :: Float -> Float Source # cos :: Float -> Float Source # tan :: Float -> Float Source # asin :: Float -> Float Source # acos :: Float -> Float Source # atan :: Float -> Float Source # sinh :: Float -> Float Source # cosh :: Float -> Float Source # tanh :: Float -> Float Source # asinh :: Float -> Float Source # acosh :: Float -> Float Source # atanh :: Float -> Float Source # log1p :: Float -> Float Source # expm1 :: Float -> Float Source # log1pexp :: Float -> Float Source # log1mexp :: Float -> Float Source #

class Num a => Fractional a where Source #

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

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 Source #

fractional division

recip :: a -> a Source #

reciprocal fraction

fromRational :: Rational -> a Source #

Conversion from a Rational (that is Ratio Integer). A floating literal stands for an application of fromRational to a value of type Rational, so such literals have type (Fractional a) => a.

Instances

Fractional Seconds
Instance details Defined in Test.Hspec.Core.Clock Methods (/) :: Seconds -> Seconds -> Seconds Source # recip :: Seconds -> Seconds Source # fromRational :: Rational -> Seconds Source #
Integral a => Fractional (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods (/) :: Ratio a -> Ratio a -> Ratio a Source # recip :: Ratio a -> Ratio a Source # fromRational :: Rational -> Ratio a Source #

class (Real a, Enum a) => Integral a where Source #

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.

Minimal complete definition

quotRem, toInteger

Methods

quot :: a -> a -> a infixl 7 Source #

integer division truncated toward zero

rem :: a -> a -> a infixl 7 Source #

integer remainder, satisfying

(x `quot` y)*y + (x `rem` y) == x

div :: a -> a -> a infixl 7 Source #

integer division truncated toward negative infinity

mod :: a -> a -> a infixl 7 Source #

integer modulus, satisfying

(x `div` y)*y + (x `mod` y) == x

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

simultaneous quot and rem

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

simultaneous div and mod

toInteger :: a -> Integer Source #

conversion to Integer

Instances

Integral Int	Since: base-2.0.1
Instance details Defined in GHC.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 #
Integral Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods quot :: Integer -> Integer -> Integer Source # rem :: Integer -> Integer -> Integer Source # div :: Integer -> Integer -> Integer Source # mod :: Integer -> Integer -> Integer Source # quotRem :: Integer -> Integer -> (Integer, Integer) Source # divMod :: Integer -> Integer -> (Integer, Integer) Source # toInteger :: Integer -> Integer Source #
Integral Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Real Methods quot :: Natural -> Natural -> Natural Source # rem :: Natural -> Natural -> Natural Source # div :: Natural -> Natural -> Natural Source # mod :: Natural -> Natural -> Natural Source # quotRem :: Natural -> Natural -> (Natural, Natural) Source # divMod :: Natural -> Natural -> (Natural, Natural) Source # toInteger :: Natural -> Integer Source #
Integral Word	Since: base-2.1
Instance details Defined in GHC.Real Methods quot :: Word -> Word -> Word Source # rem :: Word -> Word -> Word Source # div :: Word -> Word -> Word Source # mod :: Word -> Word -> Word Source # quotRem :: Word -> Word -> (Word, Word) Source # divMod :: Word -> Word -> (Word, Word) Source # toInteger :: Word -> Integer Source #
Integral a => Integral (Blind a)
Instance details Defined in Test.QuickCheck.Modifiers Methods quot :: Blind a -> Blind a -> Blind a Source # rem :: Blind a -> Blind a -> Blind a Source # div :: Blind a -> Blind a -> Blind a Source # mod :: Blind a -> Blind a -> Blind a Source # quotRem :: Blind a -> Blind a -> (Blind a, Blind a) Source # divMod :: Blind a -> Blind a -> (Blind a, Blind a) Source # toInteger :: Blind a -> Integer Source #
Integral a => Integral (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods quot :: Fixed a -> Fixed a -> Fixed a Source # rem :: Fixed a -> Fixed a -> Fixed a Source # div :: Fixed a -> Fixed a -> Fixed a Source # mod :: Fixed a -> Fixed a -> Fixed a Source # quotRem :: Fixed a -> Fixed a -> (Fixed a, Fixed a) Source # divMod :: Fixed a -> Fixed a -> (Fixed a, Fixed a) Source # toInteger :: Fixed a -> Integer Source #
Integral a => Integral (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods quot :: Large a -> Large a -> Large a Source # rem :: Large a -> Large a -> Large a Source # div :: Large a -> Large a -> Large a Source # mod :: Large a -> Large a -> Large a Source # quotRem :: Large a -> Large a -> (Large a, Large a) Source # divMod :: Large a -> Large a -> (Large a, Large a) Source # toInteger :: Large a -> Integer Source #
Integral a => Integral (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods quot :: Small a -> Small a -> Small a Source # rem :: Small a -> Small a -> Small a Source # div :: Small a -> Small a -> Small a Source # mod :: Small a -> Small a -> Small a Source # quotRem :: Small a -> Small a -> (Small a, Small a) Source # divMod :: Small a -> Small a -> (Small a, Small a) Source # toInteger :: Small a -> Integer Source #
Integral a => Integral (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods quot :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # rem :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # div :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # mod :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # quotRem :: Shrink2 a -> Shrink2 a -> (Shrink2 a, Shrink2 a) Source # divMod :: Shrink2 a -> Shrink2 a -> (Shrink2 a, Shrink2 a) Source # toInteger :: Shrink2 a -> Integer Source #

class Applicative m => Monad (m :: Type -> Type) where Source #

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 laws:

```
return a >>= k  =  k a
```
```
m >>= return  =  m
```

m >>= (\x -> k x >>= h)  =  (m >>= k) >>= h

Furthermore, the Monad and Applicative operations should relate as follows:

```
pure = return
```
```
(<*>) = ap
```

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 Source #

Sequentially compose two actions, passing any value produced by the first as an argument to the second.

(>>) :: m a -> m b -> m b infixl 1 Source #

Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.

return :: a -> m a Source #

Inject a value into the monadic type.

fail :: String -> m a Source #

Fail with a message. This operation is not part of the mathematical definition of a monad, but is invoked on pattern-match failure in a do expression.

As part of the MonadFail proposal (MFP), this function is moved to its own class MonadFail (see Control.Monad.Fail for more details). The definition here will be removed in a future release.

Instances

Monad []	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: [a] -> (a -> [b]) -> [b] Source # (>>) :: [a] -> [b] -> [b] Source # return :: a -> [a] Source # fail :: String -> [a] Source #
Monad Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b Source # (>>) :: Maybe a -> Maybe b -> Maybe b Source # return :: a -> Maybe a Source # fail :: String -> Maybe a Source #
Monad IO	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: IO a -> (a -> IO b) -> IO b Source # (>>) :: IO a -> IO b -> IO b Source # return :: a -> IO a Source # fail :: String -> IO a Source #
Monad Rose
Instance details Defined in Test.QuickCheck.Property Methods (>>=) :: Rose a -> (a -> Rose b) -> Rose b Source # (>>) :: Rose a -> Rose b -> Rose b Source # return :: a -> Rose a Source # fail :: String -> Rose a Source #
Monad Gen
Instance details Defined in Test.QuickCheck.Gen Methods (>>=) :: Gen a -> (a -> Gen b) -> Gen b Source # (>>) :: Gen a -> Gen b -> Gen b Source # return :: a -> Gen a Source # fail :: String -> Gen a Source #
Monad ReadP	Since: base-2.1
Instance details Defined in Text.ParserCombinators.ReadP Methods (>>=) :: ReadP a -> (a -> ReadP b) -> ReadP b Source # (>>) :: ReadP a -> ReadP b -> ReadP b Source # return :: a -> ReadP a Source # fail :: String -> ReadP a Source #
Monad NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b Source # (>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b Source # return :: a -> NonEmpty a Source # fail :: String -> NonEmpty a Source #
Monad P	Since: base-2.1
Instance details Defined in Text.ParserCombinators.ReadP Methods (>>=) :: P a -> (a -> P b) -> P b Source # (>>) :: P a -> P b -> P b Source # return :: a -> P a Source # fail :: String -> P a Source #
Monad (Either e)	Since: base-4.4.0.0
Instance details Defined in Data.Either Methods (>>=) :: Either e a -> (a -> Either e b) -> Either e b Source # (>>) :: Either e a -> Either e b -> Either e b Source # return :: a -> Either e a Source # fail :: String -> Either e a Source #
Monoid a => Monad ((,) a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (>>=) :: (a, a0) -> (a0 -> (a, b)) -> (a, b) Source # (>>) :: (a, a0) -> (a, b) -> (a, b) Source # return :: a0 -> (a, a0) Source # fail :: String -> (a, a0) Source #
Monad (SpecM a)
Instance details Defined in Test.Hspec.Core.Spec.Monad Methods (>>=) :: SpecM a a0 -> (a0 -> SpecM a b) -> SpecM a b Source # (>>) :: SpecM a a0 -> SpecM a b -> SpecM a b Source # return :: a0 -> SpecM a a0 Source # fail :: String -> SpecM a a0 Source #
(Monad m, Error e) => Monad (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods (>>=) :: ErrorT e m a -> (a -> ErrorT e m b) -> ErrorT e m b Source # (>>) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m b Source # return :: a -> ErrorT e m a Source # fail :: String -> ErrorT e m a Source #
Monad ((->) r :: Type -> Type)	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: (r -> a) -> (a -> r -> b) -> r -> b Source # (>>) :: (r -> a) -> (r -> b) -> r -> b Source # return :: a -> r -> a Source # fail :: String -> r -> a Source #

class Functor (f :: Type -> Type) where Source #

The Functor class is used for types that can be mapped over. Instances of Functor should satisfy the following laws:

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

The instances of Functor for lists, Maybe and IO satisfy these laws.

Minimal complete definition

fmap

Methods

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

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

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.

Instances

Functor []	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> [a] -> [b] Source # (<$) :: a -> [b] -> [a] Source #
Functor Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> Maybe a -> Maybe b Source # (<$) :: a -> Maybe b -> Maybe a Source #
Functor IO	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> IO a -> IO b Source # (<$) :: a -> IO b -> IO a Source #
Functor Rose
Instance details Defined in Test.QuickCheck.Property Methods fmap :: (a -> b) -> Rose a -> Rose b Source # (<$) :: a -> Rose b -> Rose a Source #
Functor Blind
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Blind a -> Blind b Source # (<$) :: a -> Blind b -> Blind a Source #
Functor Fixed
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Fixed a -> Fixed b Source # (<$) :: a -> Fixed b -> Fixed a Source #
Functor OrderedList
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> OrderedList a -> OrderedList b Source # (<$) :: a -> OrderedList b -> OrderedList a Source #
Functor NonEmptyList
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> NonEmptyList a -> NonEmptyList b Source # (<$) :: a -> NonEmptyList b -> NonEmptyList a Source #
Functor SortedList
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> SortedList a -> SortedList b Source # (<$) :: a -> SortedList b -> SortedList a Source #
Functor Positive
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Positive a -> Positive b Source # (<$) :: a -> Positive b -> Positive a Source #
Functor NonZero
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> NonZero a -> NonZero b Source # (<$) :: a -> NonZero b -> NonZero a Source #
Functor NonNegative
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> NonNegative a -> NonNegative b Source # (<$) :: a -> NonNegative b -> NonNegative a Source #
Functor Large
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Large a -> Large b Source # (<$) :: a -> Large b -> Large a Source #
Functor Small
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Small a -> Small b Source # (<$) :: a -> Small b -> Small a Source #
Functor Shrink2
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Shrink2 a -> Shrink2 b Source # (<$) :: a -> Shrink2 b -> Shrink2 a Source #
Functor Smart
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Smart a -> Smart b Source # (<$) :: a -> Smart b -> Smart a Source #
Functor Gen
Instance details Defined in Test.QuickCheck.Gen Methods fmap :: (a -> b) -> Gen a -> Gen b Source # (<$) :: a -> Gen b -> Gen a Source #
Functor Handler	Since: base-4.6.0.0
Instance details Defined in Control.Exception Methods fmap :: (a -> b) -> Handler a -> Handler b Source # (<$) :: a -> Handler b -> Handler a Source #
Functor ReadP	Since: base-2.1
Instance details Defined in Text.ParserCombinators.ReadP Methods fmap :: (a -> b) -> ReadP a -> ReadP b Source # (<$) :: a -> ReadP b -> ReadP a Source #
Functor NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> NonEmpty a -> NonEmpty b Source # (<$) :: a -> NonEmpty b -> NonEmpty a Source #
Functor P	Since: base-4.8.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods fmap :: (a -> b) -> P a -> P b Source # (<$) :: a -> P b -> P a Source #
Functor FormatF
Instance details Defined in Test.Hspec.Core.Formatters.Monad Methods fmap :: (a -> b) -> FormatF a -> FormatF b Source # (<$) :: a -> FormatF b -> FormatF a Source #
Functor (Either a)	Since: base-3.0
Instance details Defined in Data.Either Methods fmap :: (a0 -> b) -> Either a a0 -> Either a b Source # (<$) :: a0 -> Either a b -> Either a a0 Source #
Functor ((,) a)	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a0 -> b) -> (a, a0) -> (a, b) Source # (<$) :: a0 -> (a, b) -> (a, a0) Source #
Functor ((:->) a)
Instance details Defined in Test.QuickCheck.Function Methods fmap :: (a0 -> b) -> (a :-> a0) -> a :-> b Source # (<$) :: a0 -> (a :-> b) -> a :-> a0 Source #
Functor (Fun a)
Instance details Defined in Test.QuickCheck.Function Methods fmap :: (a0 -> b) -> Fun a a0 -> Fun a b Source # (<$) :: a0 -> Fun a b -> Fun a a0 Source #
Functor (Shrinking s)
Instance details Defined in Test.QuickCheck.Modifiers Methods fmap :: (a -> b) -> Shrinking s a -> Shrinking s b Source # (<$) :: a -> Shrinking s b -> Shrinking s a Source #
Functor (SpecM a)
Instance details Defined in Test.Hspec.Core.Spec.Monad Methods fmap :: (a0 -> b) -> SpecM a a0 -> SpecM a b Source # (<$) :: a0 -> SpecM a b -> SpecM a a0 Source #
Functor (Tree c)
Instance details Defined in Test.Hspec.Core.Tree Methods fmap :: (a -> b) -> Tree c a -> Tree c b Source # (<$) :: a -> Tree c b -> Tree c a Source #
Functor m => Functor (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods fmap :: (a -> b) -> ErrorT e m a -> ErrorT e m b Source # (<$) :: a -> ErrorT e m b -> ErrorT e m a Source #
Functor ((->) r :: Type -> Type)	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> (r -> a) -> r -> b Source # (<$) :: a -> (r -> b) -> r -> a Source #

class Num a where Source #

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)

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 Source #

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

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

negate :: a -> a Source #

Unary negation.

abs :: a -> a Source #

Absolute value.

signum :: a -> a Source #

Sign of a number. The functions abs and signum should satisfy the law:

abs x * signum x == x

For real numbers, the signum is either -1 (negative), 0 (zero) or 1 (positive).

fromInteger :: Integer -> a Source #

Conversion from an Integer. An integer literal represents the application of the function fromInteger to the appropriate value of type Integer, so such literals have type (Num a) => a.

Instances

Num Int	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Int -> Int -> Int Source # (-) :: Int -> Int -> Int Source # (*) :: Int -> Int -> Int Source # negate :: Int -> Int Source # abs :: Int -> Int Source # signum :: Int -> Int Source # fromInteger :: Integer -> Int Source #
Num Integer	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Integer -> Integer -> Integer Source # (-) :: Integer -> Integer -> Integer Source # (*) :: Integer -> Integer -> Integer Source # negate :: Integer -> Integer Source # abs :: Integer -> Integer Source # signum :: Integer -> Integer Source # fromInteger :: Integer -> Integer Source #
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
Instance details Defined in GHC.Num Methods (+) :: Natural -> Natural -> Natural Source # (-) :: Natural -> Natural -> Natural Source # (*) :: Natural -> Natural -> Natural Source # negate :: Natural -> Natural Source # abs :: Natural -> Natural Source # signum :: Natural -> Natural Source # fromInteger :: Integer -> Natural Source #
Num Word	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Word -> Word -> Word Source # (-) :: Word -> Word -> Word Source # (*) :: Word -> Word -> Word Source # negate :: Word -> Word Source # abs :: Word -> Word Source # signum :: Word -> Word Source # fromInteger :: Integer -> Word Source #
Num Seconds
Instance details Defined in Test.Hspec.Core.Clock Methods (+) :: Seconds -> Seconds -> Seconds Source # (-) :: Seconds -> Seconds -> Seconds Source # (*) :: Seconds -> Seconds -> Seconds Source # negate :: Seconds -> Seconds Source # abs :: Seconds -> Seconds Source # signum :: Seconds -> Seconds Source # fromInteger :: Integer -> Seconds Source #
Integral a => Num (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods (+) :: Ratio a -> Ratio a -> Ratio a Source # (-) :: Ratio a -> Ratio a -> Ratio a Source # (*) :: Ratio a -> Ratio a -> Ratio a Source # negate :: Ratio a -> Ratio a Source # abs :: Ratio a -> Ratio a Source # signum :: Ratio a -> Ratio a Source # fromInteger :: Integer -> Ratio a Source #
Num a => Num (Blind a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (+) :: Blind a -> Blind a -> Blind a Source # (-) :: Blind a -> Blind a -> Blind a Source # (*) :: Blind a -> Blind a -> Blind a Source # negate :: Blind a -> Blind a Source # abs :: Blind a -> Blind a Source # signum :: Blind a -> Blind a Source # fromInteger :: Integer -> Blind a Source #
Num a => Num (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (+) :: Fixed a -> Fixed a -> Fixed a Source # (-) :: Fixed a -> Fixed a -> Fixed a Source # (*) :: Fixed a -> Fixed a -> Fixed a Source # negate :: Fixed a -> Fixed a Source # abs :: Fixed a -> Fixed a Source # signum :: Fixed a -> Fixed a Source # fromInteger :: Integer -> Fixed a Source #
Num a => Num (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (+) :: Large a -> Large a -> Large a Source # (-) :: Large a -> Large a -> Large a Source # (*) :: Large a -> Large a -> Large a Source # negate :: Large a -> Large a Source # abs :: Large a -> Large a Source # signum :: Large a -> Large a Source # fromInteger :: Integer -> Large a Source #
Num a => Num (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (+) :: Small a -> Small a -> Small a Source # (-) :: Small a -> Small a -> Small a Source # (*) :: Small a -> Small a -> Small a Source # negate :: Small a -> Small a Source # abs :: Small a -> Small a Source # signum :: Small a -> Small a Source # fromInteger :: Integer -> Small a Source #
Num a => Num (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods (+) :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # (-) :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # (*) :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # negate :: Shrink2 a -> Shrink2 a Source # abs :: Shrink2 a -> Shrink2 a Source # signum :: Shrink2 a -> Shrink2 a Source # fromInteger :: Integer -> Shrink2 a Source #

class Eq a => Ord a where Source #

The Ord class is used for totally ordered datatypes.

Instances of Ord can be derived for any user-defined datatype whose constituent types are in Ord. The declared order of the constructors in the data declaration determines the ordering in derived Ord instances. The Ordering datatype allows a single comparison to determine the precise ordering of two objects.

The Haskell Report defines no laws for Ord. However, <= is customarily expected to implement a non-strict partial order and have the following properties:

Transitivity: if x <= y && y <= z = True, then x <= z = True
Reflexivity: x <= x = True
Antisymmetry: if x <= y && y <= x = True, then x == y = True

Note that the following operator interactions are expected to hold:

x >= y = y <= x
x < y = x <= y && x /= y
x > y = y < x
x < y = compare x y == LT
x > y = compare x y == GT
x == y = compare x y == EQ
min x y == if x <= y then x else y = True
max x y == if x >= y then x else y = True

Minimal complete definition: either compare or <=. Using compare can be more efficient for complex types.

Minimal complete definition

compare | (<=)

Methods

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

(<) :: a -> a -> Bool infix 4 Source #

(<=) :: a -> a -> Bool infix 4 Source #

(>) :: a -> a -> Bool infix 4 Source #

(>=) :: a -> a -> Bool infix 4 Source #

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

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

Instances

Ord Bool
Instance details Defined in GHC.Classes Methods compare :: Bool -> Bool -> Ordering Source # (<) :: Bool -> Bool -> Bool Source # (<=) :: Bool -> Bool -> Bool Source # (>) :: Bool -> Bool -> Bool Source # (>=) :: Bool -> Bool -> Bool Source # max :: Bool -> Bool -> Bool Source # min :: Bool -> Bool -> Bool Source #
Ord Char
Instance details Defined in GHC.Classes Methods compare :: Char -> Char -> Ordering Source # (<) :: Char -> Char -> Bool Source # (<=) :: Char -> Char -> Bool Source # (>) :: Char -> Char -> Bool Source # (>=) :: Char -> Char -> Bool Source # max :: Char -> Char -> Char Source # min :: Char -> Char -> Char Source #
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
Instance details Defined in GHC.Classes Methods compare :: Double -> Double -> Ordering Source # (<) :: Double -> Double -> Bool Source # (<=) :: Double -> Double -> Bool Source # (>) :: Double -> Double -> Bool Source # (>=) :: Double -> Double -> Bool Source # max :: Double -> Double -> Double Source # min :: Double -> Double -> Double Source #
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
Instance details Defined in GHC.Classes Methods compare :: Float -> Float -> Ordering Source # (<) :: Float -> Float -> Bool Source # (<=) :: Float -> Float -> Bool Source # (>) :: Float -> Float -> Bool Source # (>=) :: Float -> Float -> Bool Source # max :: Float -> Float -> Float Source # min :: Float -> Float -> Float 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 #
Ord Integer
Instance details Defined in GHC.Integer.Type Methods compare :: Integer -> Integer -> Ordering Source # (<) :: Integer -> Integer -> Bool Source # (<=) :: Integer -> Integer -> Bool Source # (>) :: Integer -> Integer -> Bool Source # (>=) :: Integer -> Integer -> Bool Source # max :: Integer -> Integer -> Integer Source # min :: Integer -> Integer -> Integer Source #
Ord Ordering
Instance details Defined in GHC.Classes Methods compare :: Ordering -> Ordering -> Ordering Source # (<) :: Ordering -> Ordering -> Bool Source # (<=) :: Ordering -> Ordering -> Bool Source # (>) :: Ordering -> Ordering -> Bool Source # (>=) :: Ordering -> Ordering -> Bool Source # max :: Ordering -> Ordering -> Ordering Source # min :: Ordering -> Ordering -> Ordering Source #
Ord Word
Instance details Defined in GHC.Classes Methods compare :: Word -> Word -> Ordering Source # (<) :: Word -> Word -> Bool Source # (<=) :: Word -> Word -> Bool Source # (>) :: Word -> Word -> Bool Source # (>=) :: Word -> Word -> Bool Source # max :: Word -> Word -> Word Source # min :: Word -> Word -> Word Source #
Ord ()
Instance details Defined in GHC.Classes Methods compare :: () -> () -> Ordering Source # (<) :: () -> () -> Bool Source # (<=) :: () -> () -> Bool Source # (>) :: () -> () -> Bool Source # (>=) :: () -> () -> Bool Source # max :: () -> () -> () Source # min :: () -> () -> () Source #
Ord TyCon
Instance details Defined in GHC.Classes Methods compare :: TyCon -> TyCon -> Ordering Source # (<) :: TyCon -> TyCon -> Bool Source # (<=) :: TyCon -> TyCon -> Bool Source # (>) :: TyCon -> TyCon -> Bool Source # (>=) :: TyCon -> TyCon -> Bool Source # max :: TyCon -> TyCon -> TyCon Source # min :: TyCon -> TyCon -> TyCon Source #
Ord Version	Since: base-2.1
Instance details Defined in Data.Version Methods compare :: Version -> Version -> Ordering Source # (<) :: Version -> Version -> Bool Source # (<=) :: Version -> Version -> Bool Source # (>) :: Version -> Version -> Bool Source # (>=) :: Version -> Version -> Bool Source # max :: Version -> Version -> Version Source # min :: Version -> Version -> Version Source #
Ord ASCIIString
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: ASCIIString -> ASCIIString -> Ordering Source # (<) :: ASCIIString -> ASCIIString -> Bool Source # (<=) :: ASCIIString -> ASCIIString -> Bool Source # (>) :: ASCIIString -> ASCIIString -> Bool Source # (>=) :: ASCIIString -> ASCIIString -> Bool Source # max :: ASCIIString -> ASCIIString -> ASCIIString Source # min :: ASCIIString -> ASCIIString -> ASCIIString Source #
Ord UnicodeString
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: UnicodeString -> UnicodeString -> Ordering Source # (<) :: UnicodeString -> UnicodeString -> Bool Source # (<=) :: UnicodeString -> UnicodeString -> Bool Source # (>) :: UnicodeString -> UnicodeString -> Bool Source # (>=) :: UnicodeString -> UnicodeString -> Bool Source # max :: UnicodeString -> UnicodeString -> UnicodeString Source # min :: UnicodeString -> UnicodeString -> UnicodeString Source #
Ord PrintableString
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: PrintableString -> PrintableString -> Ordering Source # (<) :: PrintableString -> PrintableString -> Bool Source # (<=) :: PrintableString -> PrintableString -> Bool Source # (>) :: PrintableString -> PrintableString -> Bool Source # (>=) :: PrintableString -> PrintableString -> Bool Source # max :: PrintableString -> PrintableString -> PrintableString Source # min :: PrintableString -> PrintableString -> PrintableString Source #
Ord BigNat
Instance details Defined in GHC.Integer.Type Methods compare :: BigNat -> BigNat -> Ordering Source # (<) :: BigNat -> BigNat -> Bool Source # (<=) :: BigNat -> BigNat -> Bool Source # (>) :: BigNat -> BigNat -> Bool Source # (>=) :: BigNat -> BigNat -> Bool Source # max :: BigNat -> BigNat -> BigNat Source # min :: BigNat -> BigNat -> BigNat Source #
Ord AsyncException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods compare :: AsyncException -> AsyncException -> Ordering Source # (<) :: AsyncException -> AsyncException -> Bool Source # (<=) :: AsyncException -> AsyncException -> Bool Source # (>) :: AsyncException -> AsyncException -> Bool Source # (>=) :: AsyncException -> AsyncException -> Bool Source # max :: AsyncException -> AsyncException -> AsyncException Source # min :: AsyncException -> AsyncException -> AsyncException Source #
Ord ArrayException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods compare :: ArrayException -> ArrayException -> Ordering Source # (<) :: ArrayException -> ArrayException -> Bool Source # (<=) :: ArrayException -> ArrayException -> Bool Source # (>) :: ArrayException -> ArrayException -> Bool Source # (>=) :: ArrayException -> ArrayException -> Bool Source # max :: ArrayException -> ArrayException -> ArrayException Source # min :: ArrayException -> ArrayException -> ArrayException Source #
Ord ExitCode
Instance details Defined in GHC.IO.Exception Methods compare :: ExitCode -> ExitCode -> Ordering Source # (<) :: ExitCode -> ExitCode -> Bool Source # (<=) :: ExitCode -> ExitCode -> Bool Source # (>) :: ExitCode -> ExitCode -> Bool Source # (>=) :: ExitCode -> ExitCode -> Bool Source # max :: ExitCode -> ExitCode -> ExitCode Source # min :: ExitCode -> ExitCode -> ExitCode Source #
Ord BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods compare :: BufferMode -> BufferMode -> Ordering Source # (<) :: BufferMode -> BufferMode -> Bool Source # (<=) :: BufferMode -> BufferMode -> Bool Source # (>) :: BufferMode -> BufferMode -> Bool Source # (>=) :: BufferMode -> BufferMode -> Bool Source # max :: BufferMode -> BufferMode -> BufferMode Source # min :: BufferMode -> BufferMode -> BufferMode Source #
Ord Newline	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods compare :: Newline -> Newline -> Ordering Source # (<) :: Newline -> Newline -> Bool Source # (<=) :: Newline -> Newline -> Bool Source # (>) :: Newline -> Newline -> Bool Source # (>=) :: Newline -> Newline -> Bool Source # max :: Newline -> Newline -> Newline Source # min :: Newline -> Newline -> Newline Source #
Ord NewlineMode	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods compare :: NewlineMode -> NewlineMode -> Ordering Source # (<) :: NewlineMode -> NewlineMode -> Bool Source # (<=) :: NewlineMode -> NewlineMode -> Bool Source # (>) :: NewlineMode -> NewlineMode -> Bool Source # (>=) :: NewlineMode -> NewlineMode -> Bool Source # max :: NewlineMode -> NewlineMode -> NewlineMode Source # min :: NewlineMode -> NewlineMode -> NewlineMode Source #
Ord ArithException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods compare :: ArithException -> ArithException -> Ordering Source # (<) :: ArithException -> ArithException -> Bool Source # (<=) :: ArithException -> ArithException -> Bool Source # (>) :: ArithException -> ArithException -> Bool Source # (>=) :: ArithException -> ArithException -> Bool Source # max :: ArithException -> ArithException -> ArithException Source # min :: ArithException -> ArithException -> ArithException Source #
Ord LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods compare :: LocalTime -> LocalTime -> Ordering Source # (<) :: LocalTime -> LocalTime -> Bool Source # (<=) :: LocalTime -> LocalTime -> Bool Source # (>) :: LocalTime -> LocalTime -> Bool Source # (>=) :: LocalTime -> LocalTime -> Bool Source # max :: LocalTime -> LocalTime -> LocalTime Source # min :: LocalTime -> LocalTime -> LocalTime 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 #
Ord a => Ord (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods compare :: Maybe a -> Maybe a -> Ordering Source # (<) :: Maybe a -> Maybe a -> Bool Source # (<=) :: Maybe a -> Maybe a -> Bool Source # (>) :: Maybe a -> Maybe a -> Bool Source # (>=) :: Maybe a -> Maybe a -> Bool Source # max :: Maybe a -> Maybe a -> Maybe a Source # min :: Maybe a -> Maybe a -> Maybe a Source #
Integral a => Ord (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods compare :: Ratio a -> Ratio a -> Ordering Source # (<) :: Ratio a -> Ratio a -> Bool Source # (<=) :: Ratio a -> Ratio a -> Bool Source # (>) :: Ratio a -> Ratio a -> Bool Source # (>=) :: Ratio a -> Ratio a -> Bool Source # max :: Ratio a -> Ratio a -> Ratio a Source # min :: Ratio a -> Ratio a -> Ratio a Source #
Ord a => Ord (Blind a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: Blind a -> Blind a -> Ordering Source # (<) :: Blind a -> Blind a -> Bool Source # (<=) :: Blind a -> Blind a -> Bool Source # (>) :: Blind a -> Blind a -> Bool Source # (>=) :: Blind a -> Blind a -> Bool Source # max :: Blind a -> Blind a -> Blind a Source # min :: Blind a -> Blind a -> Blind a Source #
Ord a => Ord (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: Fixed a -> Fixed a -> Ordering Source # (<) :: Fixed a -> Fixed a -> Bool Source # (<=) :: Fixed a -> Fixed a -> Bool Source # (>) :: Fixed a -> Fixed a -> Bool Source # (>=) :: Fixed a -> Fixed a -> Bool Source # max :: Fixed a -> Fixed a -> Fixed a Source # min :: Fixed a -> Fixed a -> Fixed a Source #
Ord a => Ord (OrderedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: OrderedList a -> OrderedList a -> Ordering Source # (<) :: OrderedList a -> OrderedList a -> Bool Source # (<=) :: OrderedList a -> OrderedList a -> Bool Source # (>) :: OrderedList a -> OrderedList a -> Bool Source # (>=) :: OrderedList a -> OrderedList a -> Bool Source # max :: OrderedList a -> OrderedList a -> OrderedList a Source # min :: OrderedList a -> OrderedList a -> OrderedList a Source #
Ord a => Ord (NonEmptyList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: NonEmptyList a -> NonEmptyList a -> Ordering Source # (<) :: NonEmptyList a -> NonEmptyList a -> Bool Source # (<=) :: NonEmptyList a -> NonEmptyList a -> Bool Source # (>) :: NonEmptyList a -> NonEmptyList a -> Bool Source # (>=) :: NonEmptyList a -> NonEmptyList a -> Bool Source # max :: NonEmptyList a -> NonEmptyList a -> NonEmptyList a Source # min :: NonEmptyList a -> NonEmptyList a -> NonEmptyList a Source #
Ord a => Ord (SortedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: SortedList a -> SortedList a -> Ordering Source # (<) :: SortedList a -> SortedList a -> Bool Source # (<=) :: SortedList a -> SortedList a -> Bool Source # (>) :: SortedList a -> SortedList a -> Bool Source # (>=) :: SortedList a -> SortedList a -> Bool Source # max :: SortedList a -> SortedList a -> SortedList a Source # min :: SortedList a -> SortedList a -> SortedList a Source #
Ord a => Ord (Positive a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: Positive a -> Positive a -> Ordering Source # (<) :: Positive a -> Positive a -> Bool Source # (<=) :: Positive a -> Positive a -> Bool Source # (>) :: Positive a -> Positive a -> Bool Source # (>=) :: Positive a -> Positive a -> Bool Source # max :: Positive a -> Positive a -> Positive a Source # min :: Positive a -> Positive a -> Positive a Source #
Ord a => Ord (NonZero a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: NonZero a -> NonZero a -> Ordering Source # (<) :: NonZero a -> NonZero a -> Bool Source # (<=) :: NonZero a -> NonZero a -> Bool Source # (>) :: NonZero a -> NonZero a -> Bool Source # (>=) :: NonZero a -> NonZero a -> Bool Source # max :: NonZero a -> NonZero a -> NonZero a Source # min :: NonZero a -> NonZero a -> NonZero a Source #
Ord a => Ord (NonNegative a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: NonNegative a -> NonNegative a -> Ordering Source # (<) :: NonNegative a -> NonNegative a -> Bool Source # (<=) :: NonNegative a -> NonNegative a -> Bool Source # (>) :: NonNegative a -> NonNegative a -> Bool Source # (>=) :: NonNegative a -> NonNegative a -> Bool Source # max :: NonNegative a -> NonNegative a -> NonNegative a Source # min :: NonNegative a -> NonNegative a -> NonNegative a Source #
Ord a => Ord (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: Large a -> Large a -> Ordering Source # (<) :: Large a -> Large a -> Bool Source # (<=) :: Large a -> Large a -> Bool Source # (>) :: Large a -> Large a -> Bool Source # (>=) :: Large a -> Large a -> Bool Source # max :: Large a -> Large a -> Large a Source # min :: Large a -> Large a -> Large a Source #
Ord a => Ord (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: Small a -> Small a -> Ordering Source # (<) :: Small a -> Small a -> Bool Source # (<=) :: Small a -> Small a -> Bool Source # (>) :: Small a -> Small a -> Bool Source # (>=) :: Small a -> Small a -> Bool Source # max :: Small a -> Small a -> Small a Source # min :: Small a -> Small a -> Small a Source #
Ord a => Ord (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods compare :: Shrink2 a -> Shrink2 a -> Ordering Source # (<) :: Shrink2 a -> Shrink2 a -> Bool Source # (<=) :: Shrink2 a -> Shrink2 a -> Bool Source # (>) :: Shrink2 a -> Shrink2 a -> Bool Source # (>=) :: Shrink2 a -> Shrink2 a -> Bool Source # max :: Shrink2 a -> Shrink2 a -> Shrink2 a Source # min :: Shrink2 a -> Shrink2 a -> Shrink2 a Source #
Ord a => Ord (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods compare :: NonEmpty a -> NonEmpty a -> Ordering Source # (<) :: NonEmpty a -> NonEmpty a -> Bool Source # (<=) :: NonEmpty a -> NonEmpty a -> Bool Source # (>) :: NonEmpty a -> NonEmpty a -> Bool Source # (>=) :: NonEmpty a -> NonEmpty a -> Bool Source # max :: NonEmpty a -> NonEmpty a -> NonEmpty a Source # min :: NonEmpty a -> NonEmpty a -> NonEmpty a Source #
(Ord a, Ord b) => Ord (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods compare :: Either a b -> Either a b -> Ordering Source # (<) :: Either a b -> Either a b -> Bool Source # (<=) :: Either a b -> Either a b -> Bool Source # (>) :: Either a b -> Either a b -> Bool Source # (>=) :: Either a b -> Either a b -> Bool Source # max :: Either a b -> Either a b -> Either a b Source # min :: Either a b -> Either a b -> Either a b Source #
(Ord a, Ord b) => Ord (a, b)
Instance details Defined in GHC.Classes Methods compare :: (a, b) -> (a, b) -> Ordering Source # (<) :: (a, b) -> (a, b) -> Bool Source # (<=) :: (a, b) -> (a, b) -> Bool Source # (>) :: (a, b) -> (a, b) -> Bool Source # (>=) :: (a, b) -> (a, b) -> Bool Source # max :: (a, b) -> (a, b) -> (a, b) Source # min :: (a, b) -> (a, b) -> (a, b) Source #
(Ord a, Ord b, Ord c) => Ord (a, b, c)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c) -> (a, b, c) -> Ordering Source # (<) :: (a, b, c) -> (a, b, c) -> Bool Source # (<=) :: (a, b, c) -> (a, b, c) -> Bool Source # (>) :: (a, b, c) -> (a, b, c) -> Bool Source # (>=) :: (a, b, c) -> (a, b, c) -> Bool Source # max :: (a, b, c) -> (a, b, c) -> (a, b, c) Source # min :: (a, b, c) -> (a, b, c) -> (a, b, c) Source #
(Ord e, Ord1 m, Ord a) => Ord (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods compare :: ErrorT e m a -> ErrorT e m a -> Ordering Source # (<) :: ErrorT e m a -> ErrorT e m a -> Bool Source # (<=) :: ErrorT e m a -> ErrorT e m a -> Bool Source # (>) :: ErrorT e m a -> ErrorT e m a -> Bool Source # (>=) :: ErrorT e m a -> ErrorT e m a -> Bool Source # max :: ErrorT e m a -> ErrorT e m a -> ErrorT e m a Source # min :: ErrorT e m a -> ErrorT e m a -> ErrorT e m a Source #
(Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d) -> (a, b, c, d) -> Ordering Source # (<) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source # (<=) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source # (>) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source # (>=) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source # max :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) Source # min :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) Source #
(Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e) -> (a, b, c, d, e) -> Ordering Source # (<) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source # (<=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source # (>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source # (>=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source # max :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) Source # min :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) Source #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f) => Ord (a, b, c, d, e, f)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Ordering Source # (<) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source # (<=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source # (>) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source # (>=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source # max :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f) Source # min :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f) Source #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g) => Ord (a, b, c, d, e, f, g)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Ordering Source # (<) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source # (<=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source # (>) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source # (>=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source # max :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) Source # min :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) Source #
(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)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Ordering Source # (<) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source # (<=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source # (>) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source # (>=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source # 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) Source # 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) Source #
(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)
Instance details 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 Source # (<) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source # (<=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source # (>) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source # (>=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source # 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) Source # 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) Source #
(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)
Instance details 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 Source # (<) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool Source # (<=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool Source # (>) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool Source # (>=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool Source # 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) Source # 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) Source #
(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)
Instance details 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 Source # (<) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool Source # (<=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool Source # (>) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool Source # (>=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool Source # 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) Source # 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) Source #
(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)
Instance details 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 Source # (<) :: (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 Source # (<=) :: (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 Source # (>) :: (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 Source # (>=) :: (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 Source # 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) Source # 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) Source #
(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)
Instance details 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 Source # (<) :: (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 Source # (<=) :: (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 Source # (>) :: (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 Source # (>=) :: (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 Source # 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) Source # 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) Source #
(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)
Instance details 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 Source # (<) :: (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 Source # (<=) :: (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 Source # (>) :: (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 Source # (>=) :: (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 Source # 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) Source # 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) Source #
(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)
Instance details 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 Source # (<) :: (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 Source # (<=) :: (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 Source # (>) :: (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 Source # (>=) :: (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 Source # 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) Source # 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) Source #

class Read a where Source #

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

Methods

readsPrec Source #

Arguments

:: Int	the operator precedence of the enclosing context (a number from `0` to `11`). Function application has precedence `10`.
-> ReadS a

attempts to parse a value from the front of the string, returning a list of (parsed value, remaining string) pairs. If there is no successful parse, the returned list is empty.

Derived instances of Read and Show satisfy the following:

(x,"") is an element of (readsPrec d (showsPrec d x "")).

That is, readsPrec parses the string produced by showsPrec, and delivers the value that showsPrec started with.

readList :: ReadS [a] Source #

The method readList is provided to allow the programmer to give a specialised way of parsing lists of values. For example, this is used by the predefined Read instance of the Char type, where values of type String should be are expected to use double quotes, rather than square brackets.

Instances

Read Bool	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Bool Source # readList :: ReadS [Bool] Source # readPrec :: ReadPrec Bool Source # readListPrec :: ReadPrec [Bool] Source #
Read Char	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Char Source # readList :: ReadS [Char] Source # readPrec :: ReadPrec Char Source # readListPrec :: ReadPrec [Char] Source #
Read Double	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Double Source # readList :: ReadS [Double] Source # readPrec :: ReadPrec Double Source # readListPrec :: ReadPrec [Double] Source #
Read Float	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Float Source # readList :: ReadS [Float] Source # readPrec :: ReadPrec Float Source # readListPrec :: ReadPrec [Float] Source #
Read Int	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Int Source # readList :: ReadS [Int] Source # readPrec :: ReadPrec Int Source # readListPrec :: ReadPrec [Int] Source #
Read Integer	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Integer Source # readList :: ReadS [Integer] Source # readPrec :: ReadPrec Integer Source # readListPrec :: ReadPrec [Integer] Source #
Read Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Natural Source # readList :: ReadS [Natural] Source # readPrec :: ReadPrec Natural Source # readListPrec :: ReadPrec [Natural] Source #
Read Ordering	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Ordering Source # readList :: ReadS [Ordering] Source # readPrec :: ReadPrec Ordering Source # readListPrec :: ReadPrec [Ordering] Source #
Read Word	Since: base-4.5.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word Source # readList :: ReadS [Word] Source # readPrec :: ReadPrec Word Source # readListPrec :: ReadPrec [Word] Source #
Read Word8	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word8 Source # readList :: ReadS [Word8] Source # readPrec :: ReadPrec Word8 Source # readListPrec :: ReadPrec [Word8] Source #
Read Word16	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word16 Source # readList :: ReadS [Word16] Source # readPrec :: ReadPrec Word16 Source # readListPrec :: ReadPrec [Word16] Source #
Read Word32	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word32 Source # readList :: ReadS [Word32] Source # readPrec :: ReadPrec Word32 Source # readListPrec :: ReadPrec [Word32] Source #
Read Word64	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word64 Source # readList :: ReadS [Word64] Source # readPrec :: ReadPrec Word64 Source # readListPrec :: ReadPrec [Word64] Source #
Read ()	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS () Source # readList :: ReadS [()] Source # readPrec :: ReadPrec () Source # readListPrec :: ReadPrec [()] Source #
Read Version	Since: base-2.1
Instance details Defined in Data.Version Methods readsPrec :: Int -> ReadS Version Source # readList :: ReadS [Version] Source # readPrec :: ReadPrec Version Source # readListPrec :: ReadPrec [Version] Source #
Read Args
Instance details Defined in Test.QuickCheck.Test Methods readsPrec :: Int -> ReadS Args Source # readList :: ReadS [Args] Source # readPrec :: ReadPrec Args Source # readListPrec :: ReadPrec [Args] Source #
Read ASCIIString
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS ASCIIString Source # readList :: ReadS [ASCIIString] Source # readPrec :: ReadPrec ASCIIString Source # readListPrec :: ReadPrec [ASCIIString] Source #
Read UnicodeString
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS UnicodeString Source # readList :: ReadS [UnicodeString] Source # readPrec :: ReadPrec UnicodeString Source # readListPrec :: ReadPrec [UnicodeString] Source #
Read PrintableString
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS PrintableString Source # readList :: ReadS [PrintableString] Source # readPrec :: ReadPrec PrintableString Source # readListPrec :: ReadPrec [PrintableString] Source #
Read ExitCode
Instance details Defined in GHC.IO.Exception Methods readsPrec :: Int -> ReadS ExitCode Source # readList :: ReadS [ExitCode] Source # readPrec :: ReadPrec ExitCode Source # readListPrec :: ReadPrec [ExitCode] Source #
Read BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS BufferMode Source # readList :: ReadS [BufferMode] Source # readPrec :: ReadPrec BufferMode Source # readListPrec :: ReadPrec [BufferMode] Source #
Read Newline	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS Newline Source # readList :: ReadS [Newline] Source # readPrec :: ReadPrec Newline Source # readListPrec :: ReadPrec [Newline] Source #
Read NewlineMode	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS NewlineMode Source # readList :: ReadS [NewlineMode] Source # readPrec :: ReadPrec NewlineMode Source # readListPrec :: ReadPrec [NewlineMode] Source #
Read Lexeme	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Lexeme Source # readList :: ReadS [Lexeme] Source # readPrec :: ReadPrec Lexeme Source # readListPrec :: ReadPrec [Lexeme] Source #
Read GeneralCategory	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS GeneralCategory Source # readList :: ReadS [GeneralCategory] Source # readPrec :: ReadPrec GeneralCategory Source # readListPrec :: ReadPrec [GeneralCategory] Source #
Read Location
Instance details Defined in Test.Hspec.Core.Example.Location Methods readsPrec :: Int -> ReadS Location Source # readList :: ReadS [Location] Source # readPrec :: ReadPrec Location Source # readListPrec :: ReadPrec [Location] Source #
Read a => Read [a]	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS [a] Source # readList :: ReadS [[a]] Source # readPrec :: ReadPrec [a] Source # readListPrec :: ReadPrec [[a]] Source #
Read a => Read (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Maybe a) Source # readList :: ReadS [Maybe a] Source # readPrec :: ReadPrec (Maybe a) Source # readListPrec :: ReadPrec [Maybe a] Source #
(Integral a, Read a) => Read (Ratio a)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Ratio a) Source # readList :: ReadS [Ratio a] Source # readPrec :: ReadPrec (Ratio a) Source # readListPrec :: ReadPrec [Ratio a] Source #
Read a => Read (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (Fixed a) Source # readList :: ReadS [Fixed a] Source # readPrec :: ReadPrec (Fixed a) Source # readListPrec :: ReadPrec [Fixed a] Source #
Read a => Read (OrderedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (OrderedList a) Source # readList :: ReadS [OrderedList a] Source # readPrec :: ReadPrec (OrderedList a) Source # readListPrec :: ReadPrec [OrderedList a] Source #
Read a => Read (NonEmptyList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (NonEmptyList a) Source # readList :: ReadS [NonEmptyList a] Source # readPrec :: ReadPrec (NonEmptyList a) Source # readListPrec :: ReadPrec [NonEmptyList a] Source #
Read a => Read (SortedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (SortedList a) Source # readList :: ReadS [SortedList a] Source # readPrec :: ReadPrec (SortedList a) Source # readListPrec :: ReadPrec [SortedList a] Source #
Read a => Read (Positive a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (Positive a) Source # readList :: ReadS [Positive a] Source # readPrec :: ReadPrec (Positive a) Source # readListPrec :: ReadPrec [Positive a] Source #
Read a => Read (NonZero a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (NonZero a) Source # readList :: ReadS [NonZero a] Source # readPrec :: ReadPrec (NonZero a) Source # readListPrec :: ReadPrec [NonZero a] Source #
Read a => Read (NonNegative a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (NonNegative a) Source # readList :: ReadS [NonNegative a] Source # readPrec :: ReadPrec (NonNegative a) Source # readListPrec :: ReadPrec [NonNegative a] Source #
Read a => Read (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (Large a) Source # readList :: ReadS [Large a] Source # readPrec :: ReadPrec (Large a) Source # readListPrec :: ReadPrec [Large a] Source #
Read a => Read (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (Small a) Source # readList :: ReadS [Small a] Source # readPrec :: ReadPrec (Small a) Source # readListPrec :: ReadPrec [Small a] Source #
Read a => Read (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods readsPrec :: Int -> ReadS (Shrink2 a) Source # readList :: ReadS [Shrink2 a] Source # readPrec :: ReadPrec (Shrink2 a) Source # readListPrec :: ReadPrec [Shrink2 a] Source #
Read a => Read (NonEmpty a)	Since: base-4.11.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (NonEmpty a) Source # readList :: ReadS [NonEmpty a] Source # readPrec :: ReadPrec (NonEmpty a) Source # readListPrec :: ReadPrec [NonEmpty a] Source #
(Read a, Read b) => Read (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods readsPrec :: Int -> ReadS (Either a b) Source # readList :: ReadS [Either a b] Source # readPrec :: ReadPrec (Either a b) Source # readListPrec :: ReadPrec [Either a b] Source #
(Read a, Read b) => Read (a, b)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b) Source # readList :: ReadS [(a, b)] Source # readPrec :: ReadPrec (a, b) Source # readListPrec :: ReadPrec [(a, b)] Source #
(Ix a, Read a, Read b) => Read (Array a b)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Array a b) Source # readList :: ReadS [Array a b] Source # readPrec :: ReadPrec (Array a b) Source # readListPrec :: ReadPrec [Array a b] Source #
(Read a, Read b, Read c) => Read (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c) Source # readList :: ReadS [(a, b, c)] Source # readPrec :: ReadPrec (a, b, c) Source # readListPrec :: ReadPrec [(a, b, c)] Source #
(Read e, Read1 m, Read a) => Read (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods readsPrec :: Int -> ReadS (ErrorT e m a) Source # readList :: ReadS [ErrorT e m a] Source # readPrec :: ReadPrec (ErrorT e m a) Source # readListPrec :: ReadPrec [ErrorT e m a] Source #
(Read a, Read b, Read c, Read d) => Read (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d) Source # readList :: ReadS [(a, b, c, d)] Source # readPrec :: ReadPrec (a, b, c, d) Source # readListPrec :: ReadPrec [(a, b, c, d)] Source #
(Read a, Read b, Read c, Read d, Read e) => Read (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e) Source # readList :: ReadS [(a, b, c, d, e)] Source # readPrec :: ReadPrec (a, b, c, d, e) Source # readListPrec :: ReadPrec [(a, b, c, d, e)] Source #
(Read a, Read b, Read c, Read d, Read e, Read f) => Read (a, b, c, d, e, f)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f) Source # readList :: ReadS [(a, b, c, d, e, f)] Source # readPrec :: ReadPrec (a, b, c, d, e, f) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g) Source # readList :: ReadS [(a, b, c, d, e, f, g)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h) Source # readList :: ReadS [(a, b, c, d, e, f, g, h)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i) Source # readList :: ReadS [(a, b, c, d, e, f, g, h, i)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j) Source # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k) Source # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l) Source # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m) Source # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m, n) Source # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m, n) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] Source #
(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
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) Source # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] Source # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) Source # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] Source #

class (Num a, Ord a) => Real a where Source #

Methods

toRational :: a -> Rational Source #

the rational equivalent of its real argument with full precision

Instances

Real Int	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Int -> Rational Source #
Real Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Integer -> Rational Source #
Real Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Real Methods toRational :: Natural -> Rational Source #
Real Word	Since: base-2.1
Instance details Defined in GHC.Real Methods toRational :: Word -> Rational Source #
Integral a => Real (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Ratio a -> Rational Source #
Real a => Real (Blind a)
Instance details Defined in Test.QuickCheck.Modifiers Methods toRational :: Blind a -> Rational Source #
Real a => Real (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods toRational :: Fixed a -> Rational Source #
Real a => Real (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods toRational :: Large a -> Rational Source #
Real a => Real (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods toRational :: Small a -> Rational Source #
Real a => Real (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods toRational :: Shrink2 a -> Rational Source #

class (RealFrac a, Floating a) => RealFloat a where Source #

Efficient, machine-independent access to the components of a floating-point number.

Minimal complete definition

floatRadix, floatDigits, floatRange, decodeFloat, encodeFloat, isNaN, isInfinite, isDenormalized, isNegativeZero, isIEEE

Methods

floatRadix :: a -> Integer Source #

a constant function, returning the radix of the representation (often 2)

floatDigits :: a -> Int Source #

a constant function, returning the number of digits of floatRadix in the significand

floatRange :: a -> (Int, Int) Source #

a constant function, returning the lowest and highest values the exponent may assume

decodeFloat :: a -> (Integer, Int) Source #

The function decodeFloat applied to a real floating-point number returns the significand expressed as an Integer and an appropriately scaled exponent (an Int). If decodeFloat x yields (m,n), then x is equal in value to m*b^^n, where b is the floating-point radix, and furthermore, either m and n are both zero or else b^(d-1) <= abs m < b^d, where d is the value of floatDigits x. In particular, decodeFloat 0 = (0,0). If the type contains a negative zero, also decodeFloat (-0.0) = (0,0). The result of decodeFloat x is unspecified if either of isNaN x or isInfinite x is True.

encodeFloat :: Integer -> Int -> a Source #

encodeFloat performs the inverse of decodeFloat in the sense that for finite x with the exception of -0.0, uncurry encodeFloat (decodeFloat x) = x. encodeFloat m n is one of the two closest representable floating-point numbers to m*b^^n (or ±Infinity if overflow occurs); usually the closer, but if m contains too many bits, the result may be rounded in the wrong direction.

exponent :: a -> Int Source #

exponent corresponds to the second component of decodeFloat. exponent 0 = 0 and for finite nonzero x, exponent x = snd (decodeFloat x) + floatDigits x. If x is a finite floating-point number, it is equal in value to significand x * b ^^ exponent x, where b is the floating-point radix. The behaviour is unspecified on infinite or NaN values.

significand :: a -> a Source #

The first component of decodeFloat, scaled to lie in the open interval (-1,1), either 0.0 or of absolute value >= 1/b, where b is the floating-point radix. The behaviour is unspecified on infinite or NaN values.

scaleFloat :: Int -> a -> a Source #

multiplies a floating-point number by an integer power of the radix

isNaN :: a -> Bool Source #

True if the argument is an IEEE "not-a-number" (NaN) value

isInfinite :: a -> Bool Source #

True if the argument is an IEEE infinity or negative infinity

isDenormalized :: a -> Bool Source #

True if the argument is too small to be represented in normalized format

isNegativeZero :: a -> Bool Source #

True if the argument is an IEEE negative zero

isIEEE :: a -> Bool Source #

True if the argument is an IEEE floating point number

atan2 :: a -> a -> a Source #

a version of arctangent taking two real floating-point arguments. For real floating x and y, atan2 y x computes the angle (from the positive x-axis) of the vector from the origin to the point (x,y). atan2 y x returns a value in the range [-pi, pi]. It follows the Common Lisp semantics for the origin when signed zeroes are supported. atan2 y 1, with y in a type that is RealFloat, should return the same value as atan y. A default definition of atan2 is provided, but implementors can provide a more accurate implementation.

Instances

RealFloat Double	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Double -> Integer Source # floatDigits :: Double -> Int Source # floatRange :: Double -> (Int, Int) Source # decodeFloat :: Double -> (Integer, Int) Source # encodeFloat :: Integer -> Int -> Double Source # exponent :: Double -> Int Source # significand :: Double -> Double Source # scaleFloat :: Int -> Double -> Double Source # isNaN :: Double -> Bool Source # isInfinite :: Double -> Bool Source # isDenormalized :: Double -> Bool Source # isNegativeZero :: Double -> Bool Source # isIEEE :: Double -> Bool Source # atan2 :: Double -> Double -> Double Source #
RealFloat Float	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Float -> Integer Source # floatDigits :: Float -> Int Source # floatRange :: Float -> (Int, Int) Source # decodeFloat :: Float -> (Integer, Int) Source # encodeFloat :: Integer -> Int -> Float Source # exponent :: Float -> Int Source # significand :: Float -> Float Source # scaleFloat :: Int -> Float -> Float Source # isNaN :: Float -> Bool Source # isInfinite :: Float -> Bool Source # isDenormalized :: Float -> Bool Source # isNegativeZero :: Float -> Bool Source # isIEEE :: Float -> Bool Source # atan2 :: Float -> Float -> Float Source #

class (Real a, Fractional a) => RealFrac a where Source #

Extracting components of fractions.

Minimal complete definition

properFraction

Methods

properFraction :: Integral b => a -> (b, a) Source #

The function properFraction takes a real fractional number x and returns a pair (n,f) such that x = n+f, and:

n is an integral number with the same sign as x; and
f is a fraction with the same type and sign as x, and with absolute value less than 1.

The default definitions of the ceiling, floor, truncate and round functions are in terms of properFraction.

truncate :: Integral b => a -> b Source #

truncate x returns the integer nearest x between zero and x

round :: Integral b => a -> b Source #

round x returns the nearest integer to x; the even integer if x is equidistant between two integers

ceiling :: Integral b => a -> b Source #

ceiling x returns the least integer not less than x

floor :: Integral b => a -> b Source #

floor x returns the greatest integer not greater than x

Instances

Integral a => RealFrac (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods properFraction :: Integral b => Ratio a -> (b, Ratio a) Source # truncate :: Integral b => Ratio a -> b Source # round :: Integral b => Ratio a -> b Source # ceiling :: Integral b => Ratio a -> b Source # floor :: Integral b => Ratio a -> b Source #

class Show a where Source #

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

showsPrec Source #

Arguments

:: Int	the operator precedence of the enclosing context (a number from `0` to `11`). Function application has precedence `10`.
-> a	the value to be converted to a `String`
-> ShowS

Convert a value to a readable String.

showsPrec should satisfy the law

showsPrec d x r ++ s  ==  showsPrec d x (r ++ s)

Derived instances of Read and Show satisfy the following:

(x,"") is an element of (readsPrec d (showsPrec d x "")).

That is, readsPrec parses the string produced by showsPrec, and delivers the value that showsPrec started with.

show :: a -> String Source #

A specialised variant of showsPrec, using precedence context zero, and returning an ordinary String.

showList :: [a] -> ShowS Source #

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 Bool	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Bool -> ShowS Source # show :: Bool -> String Source # showList :: [Bool] -> ShowS Source #
Show Char	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Char -> ShowS Source # show :: Char -> String Source # showList :: [Char] -> ShowS Source #
Show Int	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Int -> ShowS Source # show :: Int -> String Source # showList :: [Int] -> ShowS Source #
Show Integer	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Integer -> ShowS Source # show :: Integer -> String Source # showList :: [Integer] -> ShowS Source #
Show Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Natural -> ShowS Source # show :: Natural -> String Source # showList :: [Natural] -> ShowS Source #
Show Ordering	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Ordering -> ShowS Source # show :: Ordering -> String Source # showList :: [Ordering] -> ShowS Source #
Show Word	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Word -> ShowS Source # show :: Word -> String Source # showList :: [Word] -> ShowS Source #
Show RuntimeRep	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> RuntimeRep -> ShowS Source # show :: RuntimeRep -> String Source # showList :: [RuntimeRep] -> ShowS Source #
Show VecCount	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> VecCount -> ShowS Source # show :: VecCount -> String Source # showList :: [VecCount] -> ShowS Source #
Show VecElem	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> VecElem -> ShowS Source # show :: VecElem -> String Source # showList :: [VecElem] -> ShowS Source #
Show CallStack	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> CallStack -> ShowS Source # show :: CallStack -> String Source # showList :: [CallStack] -> ShowS Source #
Show ()	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> () -> ShowS Source # show :: () -> String Source # showList :: [()] -> ShowS Source #
Show TyCon	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> TyCon -> ShowS Source # show :: TyCon -> String Source # showList :: [TyCon] -> ShowS Source #
Show Module	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Module -> ShowS Source # show :: Module -> String Source # showList :: [Module] -> ShowS Source #
Show TrName	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> TrName -> ShowS Source # show :: TrName -> String Source # showList :: [TrName] -> ShowS Source #
Show KindRep
Instance details Defined in GHC.Show Methods showsPrec :: Int -> KindRep -> ShowS Source # show :: KindRep -> String Source # showList :: [KindRep] -> ShowS Source #
Show TypeLitSort	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> TypeLitSort -> ShowS Source # show :: TypeLitSort -> String Source # showList :: [TypeLitSort] -> ShowS Source #
Show Version	Since: base-2.1
Instance details Defined in Data.Version Methods showsPrec :: Int -> Version -> ShowS Source # show :: Version -> String Source # showList :: [Version] -> ShowS Source #
Show Args
Instance details Defined in Test.QuickCheck.Test Methods showsPrec :: Int -> Args -> ShowS Source # show :: Args -> String Source # showList :: [Args] -> ShowS Source #
Show Result
Instance details Defined in Test.QuickCheck.Test Methods showsPrec :: Int -> Result -> ShowS Source # show :: Result -> String Source # showList :: [Result] -> ShowS Source #
Show Confidence
Instance details Defined in Test.QuickCheck.State Methods showsPrec :: Int -> Confidence -> ShowS Source # show :: Confidence -> String Source # showList :: [Confidence] -> ShowS Source #
Show ASCIIString
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> ASCIIString -> ShowS Source # show :: ASCIIString -> String Source # showList :: [ASCIIString] -> ShowS Source #
Show UnicodeString
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> UnicodeString -> ShowS Source # show :: UnicodeString -> String Source # showList :: [UnicodeString] -> ShowS Source #
Show PrintableString
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> PrintableString -> ShowS Source # show :: PrintableString -> String Source # showList :: [PrintableString] -> ShowS Source #
Show Handle	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> Handle -> ShowS Source # show :: Handle -> String Source # showList :: [Handle] -> ShowS Source #
Show HandleType	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> HandleType -> ShowS Source # show :: HandleType -> String Source # showList :: [HandleType] -> ShowS Source #
Show BlockedIndefinitelyOnMVar	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS Source # show :: BlockedIndefinitelyOnMVar -> String Source # showList :: [BlockedIndefinitelyOnMVar] -> ShowS Source #
Show BlockedIndefinitelyOnSTM	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS Source # show :: BlockedIndefinitelyOnSTM -> String Source # showList :: [BlockedIndefinitelyOnSTM] -> ShowS Source #
Show Deadlock	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> Deadlock -> ShowS Source # show :: Deadlock -> String Source # showList :: [Deadlock] -> ShowS Source #
Show AllocationLimitExceeded	Since: base-4.7.1.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> AllocationLimitExceeded -> ShowS Source # show :: AllocationLimitExceeded -> String Source # showList :: [AllocationLimitExceeded] -> ShowS Source #
Show CompactionFailed	Since: base-4.10.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> CompactionFailed -> ShowS Source # show :: CompactionFailed -> String Source # showList :: [CompactionFailed] -> ShowS Source #
Show AssertionFailed	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> AssertionFailed -> ShowS Source # show :: AssertionFailed -> String Source # showList :: [AssertionFailed] -> ShowS Source #
Show SomeAsyncException	Since: base-4.7.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> SomeAsyncException -> ShowS Source # show :: SomeAsyncException -> String Source # showList :: [SomeAsyncException] -> ShowS Source #
Show AsyncException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> AsyncException -> ShowS Source # show :: AsyncException -> String Source # showList :: [AsyncException] -> ShowS Source #
Show ArrayException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> ArrayException -> ShowS Source # show :: ArrayException -> String Source # showList :: [ArrayException] -> ShowS Source #
Show FixIOException	Since: base-4.11.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> FixIOException -> ShowS Source # show :: FixIOException -> String Source # showList :: [FixIOException] -> ShowS Source #
Show ExitCode
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> ExitCode -> ShowS Source # show :: ExitCode -> String Source # showList :: [ExitCode] -> ShowS Source #
Show IOErrorType	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> IOErrorType -> ShowS Source # show :: IOErrorType -> String Source # showList :: [IOErrorType] -> ShowS Source #
Show BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> BufferMode -> ShowS Source # show :: BufferMode -> String Source # showList :: [BufferMode] -> ShowS Source #
Show Newline	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> Newline -> ShowS Source # show :: Newline -> String Source # showList :: [Newline] -> ShowS Source #
Show NewlineMode	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> NewlineMode -> ShowS Source # show :: NewlineMode -> String Source # showList :: [NewlineMode] -> ShowS Source #
Show MaskingState	Since: base-4.3.0.0
Instance details Defined in GHC.IO Methods showsPrec :: Int -> MaskingState -> ShowS Source # show :: MaskingState -> String Source # showList :: [MaskingState] -> ShowS Source #
Show IOException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> IOException -> ShowS Source # show :: IOException -> String Source # showList :: [IOException] -> ShowS Source #
Show ArithException	Since: base-4.0.0.0
Instance details Defined in GHC.Exception.Type Methods showsPrec :: Int -> ArithException -> ShowS Source # show :: ArithException -> String Source # showList :: [ArithException] -> ShowS Source #
Show SrcLoc	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> SrcLoc -> ShowS Source # show :: SrcLoc -> String Source # showList :: [SrcLoc] -> ShowS Source #
Show SomeException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS Source # show :: SomeException -> String Source # showList :: [SomeException] -> ShowS Source #
Show Summary
Instance details Defined in Test.Hspec.Core.Runner Methods showsPrec :: Int -> Summary -> ShowS Source # show :: Summary -> String Source # showList :: [Summary] -> ShowS Source #
Show ColorMode
Instance details Defined in Test.Hspec.Core.Config.Options Methods showsPrec :: Int -> ColorMode -> ShowS Source # show :: ColorMode -> String Source # showList :: [ColorMode] -> ShowS Source #
Show Params
Instance details Defined in Test.Hspec.Core.Example Methods showsPrec :: Int -> Params -> ShowS Source # show :: Params -> String Source # showList :: [Params] -> ShowS Source #
Show Result
Instance details Defined in Test.Hspec.Core.Example Methods showsPrec :: Int -> Result -> ShowS Source # show :: Result -> String Source # showList :: [Result] -> ShowS Source #
Show ResultStatus
Instance details Defined in Test.Hspec.Core.Example Methods showsPrec :: Int -> ResultStatus -> ShowS Source # show :: ResultStatus -> String Source # showList :: [ResultStatus] -> ShowS Source #
Show FailureReason
Instance details Defined in Test.Hspec.Core.Example Methods showsPrec :: Int -> FailureReason -> ShowS Source # show :: FailureReason -> String Source # showList :: [FailureReason] -> ShowS Source #
Show Location
Instance details Defined in Test.Hspec.Core.Example.Location Methods showsPrec :: Int -> Location -> ShowS Source # show :: Location -> String Source # showList :: [Location] -> ShowS Source #
Show Seconds
Instance details Defined in Test.Hspec.Core.Clock Methods showsPrec :: Int -> Seconds -> ShowS Source # show :: Seconds -> String Source # showList :: [Seconds] -> ShowS Source #
Show ZonedTime
Instance details Defined in Data.Time.LocalTime.Internal.ZonedTime Methods showsPrec :: Int -> ZonedTime -> ShowS Source # show :: ZonedTime -> String Source # showList :: [ZonedTime] -> ShowS Source #
Show LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods showsPrec :: Int -> LocalTime -> ShowS Source # show :: LocalTime -> String Source # showList :: [LocalTime] -> ShowS Source #
Show HUnitFailure
Instance details Defined in Test.HUnit.Lang Methods showsPrec :: Int -> HUnitFailure -> ShowS Source # show :: HUnitFailure -> String Source # showList :: [HUnitFailure] -> ShowS Source #
Show DateFormatSpec
Instance details Defined in Data.Time.Format.Parse Methods showsPrec :: Int -> DateFormatSpec -> ShowS Source # show :: DateFormatSpec -> String Source # showList :: [DateFormatSpec] -> ShowS Source #
Show Padding
Instance details Defined in Data.Time.Format.Parse Methods showsPrec :: Int -> Padding -> ShowS Source # show :: Padding -> String Source # showList :: [Padding] -> ShowS Source #
Show FailureReason
Instance details Defined in Test.HUnit.Lang Methods showsPrec :: Int -> FailureReason -> ShowS Source # show :: FailureReason -> String Source # showList :: [FailureReason] -> ShowS Source #
Show Result
Instance details Defined in Test.HUnit.Lang Methods showsPrec :: Int -> Result -> ShowS Source # show :: Result -> String Source # showList :: [Result] -> ShowS Source #
Show a => Show [a]	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> [a] -> ShowS Source # show :: [a] -> String Source # showList :: [[a]] -> ShowS Source #
Show a => Show (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Maybe a -> ShowS Source # show :: Maybe a -> String Source # showList :: [Maybe a] -> ShowS Source #
Show a => Show (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods showsPrec :: Int -> Ratio a -> ShowS Source # show :: Ratio a -> String Source # showList :: [Ratio a] -> ShowS Source #
Show (Blind a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Blind a -> ShowS Source # show :: Blind a -> String Source # showList :: [Blind a] -> ShowS Source #
Show a => Show (Fixed a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Fixed a -> ShowS Source # show :: Fixed a -> String Source # showList :: [Fixed a] -> ShowS Source #
Show a => Show (OrderedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> OrderedList a -> ShowS Source # show :: OrderedList a -> String Source # showList :: [OrderedList a] -> ShowS Source #
Show a => Show (NonEmptyList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> NonEmptyList a -> ShowS Source # show :: NonEmptyList a -> String Source # showList :: [NonEmptyList a] -> ShowS Source #
Show a => Show (InfiniteList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> InfiniteList a -> ShowS Source # show :: InfiniteList a -> String Source # showList :: [InfiniteList a] -> ShowS Source #
Show a => Show (SortedList a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> SortedList a -> ShowS Source # show :: SortedList a -> String Source # showList :: [SortedList a] -> ShowS Source #
Show a => Show (Positive a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Positive a -> ShowS Source # show :: Positive a -> String Source # showList :: [Positive a] -> ShowS Source #
Show a => Show (NonZero a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> NonZero a -> ShowS Source # show :: NonZero a -> String Source # showList :: [NonZero a] -> ShowS Source #
Show a => Show (NonNegative a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> NonNegative a -> ShowS Source # show :: NonNegative a -> String Source # showList :: [NonNegative a] -> ShowS Source #
Show a => Show (Large a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Large a -> ShowS Source # show :: Large a -> String Source # showList :: [Large a] -> ShowS Source #
Show a => Show (Small a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Small a -> ShowS Source # show :: Small a -> String Source # showList :: [Small a] -> ShowS Source #
Show a => Show (Shrink2 a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Shrink2 a -> ShowS Source # show :: Shrink2 a -> String Source # showList :: [Shrink2 a] -> ShowS Source #
Show a => Show (Smart a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Smart a -> ShowS Source # show :: Smart a -> String Source # showList :: [Smart a] -> ShowS Source #
Show a => Show (NonEmpty a)	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> NonEmpty a -> ShowS Source # show :: NonEmpty a -> String Source # showList :: [NonEmpty a] -> ShowS Source #
(Show a, Show b) => Show (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods showsPrec :: Int -> Either a b -> ShowS Source # show :: Either a b -> String Source # showList :: [Either a b] -> ShowS Source #
(Show a, Show b) => Show (a, b)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b) -> ShowS Source # show :: (a, b) -> String Source # showList :: [(a, b)] -> ShowS Source #
(Show a, Show b) => Show (a :-> b)
Instance details Defined in Test.QuickCheck.Function Methods showsPrec :: Int -> (a :-> b) -> ShowS Source # show :: (a :-> b) -> String Source # showList :: [a :-> b] -> ShowS Source #
(Show a, Show b) => Show (Fun a b)
Instance details Defined in Test.QuickCheck.Function Methods showsPrec :: Int -> Fun a b -> ShowS Source # show :: Fun a b -> String Source # showList :: [Fun a b] -> ShowS Source #
Show a => Show (Shrinking s a)
Instance details Defined in Test.QuickCheck.Modifiers Methods showsPrec :: Int -> Shrinking s a -> ShowS Source # show :: Shrinking s a -> String Source # showList :: [Shrinking s a] -> ShowS Source #
(Show c, Show a) => Show (Tree c a)
Instance details Defined in Test.Hspec.Core.Tree Methods showsPrec :: Int -> Tree c a -> ShowS Source # show :: Tree c a -> String Source # showList :: [Tree c a] -> ShowS Source #
(Show a, Show b, Show c) => Show (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c) -> ShowS Source # show :: (a, b, c) -> String Source # showList :: [(a, b, c)] -> ShowS Source #
(Show e, Show1 m, Show a) => Show (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods showsPrec :: Int -> ErrorT e m a -> ShowS Source # show :: ErrorT e m a -> String Source # showList :: [ErrorT e m a] -> ShowS Source #
(Show a, Show b, Show c, Show d) => Show (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d) -> ShowS Source # show :: (a, b, c, d) -> String Source # showList :: [(a, b, c, d)] -> ShowS Source #
(Show a, Show b, Show c, Show d, Show e) => Show (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e) -> ShowS Source # show :: (a, b, c, d, e) -> String Source # showList :: [(a, b, c, d, e)] -> ShowS Source #
(Show a, Show b, Show c, Show d, Show e, Show f) => Show (a, b, c, d, e, f)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f) -> ShowS Source # show :: (a, b, c, d, e, f) -> String Source # showList :: [(a, b, c, d, e, f)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g) -> ShowS Source # show :: (a, b, c, d, e, f, g) -> String Source # showList :: [(a, b, c, d, e, f, g)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h) -> ShowS Source # show :: (a, b, c, d, e, f, g, h) -> String Source # showList :: [(a, b, c, d, e, f, g, h)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i) -> ShowS Source # show :: (a, b, c, d, e, f, g, h, i) -> String Source # showList :: [(a, b, c, d, e, f, g, h, i)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j) -> ShowS Source # show :: (a, b, c, d, e, f, g, h, i, j) -> String Source # showList :: [(a, b, c, d, e, f, g, h, i, j)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k) -> ShowS Source # show :: (a, b, c, d, e, f, g, h, i, j, k) -> String Source # showList :: [(a, b, c, d, e, f, g, h, i, j, k)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l) -> ShowS Source # show :: (a, b, c, d, e, f, g, h, i, j, k, l) -> String Source # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> ShowS Source # show :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> String Source # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> ShowS Source # show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> String Source # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] -> ShowS Source #
(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
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> ShowS Source # show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> String Source # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] -> ShowS Source #

class Functor f => Applicative (f :: Type -> Type) where Source #

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
```
```
(<*>) = ap
```
```
(*>) = (>>)
```

(which implies that pure and <*> satisfy the applicative functor laws).

Minimal complete definition

pure, ((<*>) | liftA2)

Methods

pure :: a -> f a Source #

Lift a value.

(<*>) :: f (a -> b) -> f a -> f b infixl 4 Source #

Sequential application.

A few functors support an implementation of <*> that is more efficient than the default one.

(*>) :: f a -> f b -> f b infixl 4 Source #

Sequence actions, discarding the value of the first argument.

(<*) :: f a -> f b -> f a infixl 4 Source #

Sequence actions, discarding the value of the second argument.

Instances

Applicative []	Since: base-2.1
Instance details Defined in GHC.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 #
Applicative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> Maybe a Source # (<>) :: Maybe (a -> b) -> Maybe a -> Maybe b Source # liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c Source # (>) :: Maybe a -> Maybe b -> Maybe b Source # (<*) :: Maybe a -> Maybe b -> Maybe a Source #
Applicative IO	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> IO a Source # (<>) :: IO (a -> b) -> IO a -> IO b Source # liftA2 :: (a -> b -> c) -> IO a -> IO b -> IO c Source # (>) :: IO a -> IO b -> IO b Source # (<*) :: IO a -> IO b -> IO a Source #
Applicative Rose
Instance details Defined in Test.QuickCheck.Property Methods pure :: a -> Rose a Source # (<>) :: Rose (a -> b) -> Rose a -> Rose b Source # liftA2 :: (a -> b -> c) -> Rose a -> Rose b -> Rose c Source # (>) :: Rose a -> Rose b -> Rose b Source # (<*) :: Rose a -> Rose b -> Rose a Source #
Applicative Gen
Instance details Defined in Test.QuickCheck.Gen Methods pure :: a -> Gen a Source # (<>) :: Gen (a -> b) -> Gen a -> Gen b Source # liftA2 :: (a -> b -> c) -> Gen a -> Gen b -> Gen c Source # (>) :: Gen a -> Gen b -> Gen b Source # (<*) :: Gen a -> Gen b -> Gen a Source #
Applicative ReadP	Since: base-4.6.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods pure :: a -> ReadP a Source # (<>) :: ReadP (a -> b) -> ReadP a -> ReadP b Source # liftA2 :: (a -> b -> c) -> ReadP a -> ReadP b -> ReadP c Source # (>) :: ReadP a -> ReadP b -> ReadP b Source # (<*) :: ReadP a -> ReadP b -> ReadP a Source #
Applicative NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods pure :: a -> NonEmpty a Source # (<>) :: NonEmpty (a -> b) -> NonEmpty a -> NonEmpty b Source # liftA2 :: (a -> b -> c) -> NonEmpty a -> NonEmpty b -> NonEmpty c Source # (>) :: NonEmpty a -> NonEmpty b -> NonEmpty b Source # (<*) :: NonEmpty a -> NonEmpty b -> NonEmpty a Source #
Applicative P	Since: base-4.5.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods pure :: a -> P a Source # (<>) :: P (a -> b) -> P a -> P b Source # liftA2 :: (a -> b -> c) -> P a -> P b -> P c Source # (>) :: P a -> P b -> P b Source # (<*) :: P a -> P b -> P a Source #
Applicative (Either e)	Since: base-3.0
Instance details Defined in Data.Either Methods pure :: a -> Either e a Source # (<>) :: Either e (a -> b) -> Either e a -> Either e b Source # liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c Source # (>) :: Either e a -> Either e b -> Either e b Source # (<*) :: Either e a -> Either e b -> Either e a Source #
Monoid a => Applicative ((,) a)	For tuples, the `Monoid` constraint on `a` determines how the first values merge. For example, `String`s concatenate: ("hello ", (+15)) <> ("world!", 2002) ("hello world!",2017) Since: base-2.1*
Instance details Defined in GHC.Base Methods pure :: a0 -> (a, a0) Source # (<>) :: (a, a0 -> b) -> (a, a0) -> (a, b) Source # liftA2 :: (a0 -> b -> c) -> (a, a0) -> (a, b) -> (a, c) Source # (>) :: (a, a0) -> (a, b) -> (a, b) Source # (<*) :: (a, a0) -> (a, b) -> (a, a0) Source #
Applicative (SpecM a)
Instance details Defined in Test.Hspec.Core.Spec.Monad Methods pure :: a0 -> SpecM a a0 Source # (<>) :: SpecM a (a0 -> b) -> SpecM a a0 -> SpecM a b Source # liftA2 :: (a0 -> b -> c) -> SpecM a a0 -> SpecM a b -> SpecM a c Source # (>) :: SpecM a a0 -> SpecM a b -> SpecM a b Source # (<*) :: SpecM a a0 -> SpecM a b -> SpecM a a0 Source #
(Functor m, Monad m) => Applicative (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods pure :: a -> ErrorT e m a Source # (<>) :: ErrorT e m (a -> b) -> ErrorT e m a -> ErrorT e m b Source # liftA2 :: (a -> b -> c) -> ErrorT e m a -> ErrorT e m b -> ErrorT e m c Source # (>) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m b Source # (<*) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m a Source #
Applicative ((->) a :: Type -> Type)	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a0 -> a -> a0 Source # (<>) :: (a -> (a0 -> b)) -> (a -> a0) -> a -> b Source # liftA2 :: (a0 -> b -> c) -> (a -> a0) -> (a -> b) -> a -> c Source # (>) :: (a -> a0) -> (a -> b) -> a -> b Source # (<*) :: (a -> a0) -> (a -> b) -> a -> a0 Source #

class Foldable (t :: Type -> Type) where Source #

Data structures that can be folded.

For example, given a data type

data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)

a suitable instance would be

instance Foldable Tree where
   foldMap f Empty = mempty
   foldMap f (Leaf x) = f x
   foldMap f (Node l k r) = foldMap f l `mappend` f k `mappend` foldMap f r

This is suitable even for abstract types, as the monoid is assumed to satisfy the monoid laws. Alternatively, one could define foldr:

instance Foldable Tree where
   foldr f z Empty = z
   foldr f z (Leaf x) = f x z
   foldr f z (Node l k r) = foldr f (f k (foldr f z r)) l

Foldable instances are expected to satisfy the following laws:

foldr f z t = appEndo (foldMap (Endo . f) t ) z

foldl f z t = appEndo (getDual (foldMap (Dual . Endo . flip f) t)) z

fold = foldMap id

length = getSum . foldMap (Sum . const  1)

sum, product, maximum, and minimum should all be essentially equivalent to foldMap forms, such as

sum = getSum . foldMap Sum

but may be less defined.

If the type is also a Functor instance, it should satisfy

foldMap f = fold . fmap f

which implies that

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

Minimal complete definition

foldMap | foldr

Methods

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

Map each element of the structure to a monoid, and combine the results.

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

Right-associative fold of a structure.

In the case of lists, foldr, when applied to a binary operator, a starting value (typically the right-identity of the operator), and a list, reduces the list using the binary operator, from right to left:

foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)

Note that, since the head of the resulting expression is produced by an application of the operator to the first element of the list, foldr can produce a terminating expression from an infinite list.

For a general Foldable structure this should be semantically identical to,

foldr f z = foldr f z . toList

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

Left-associative fold of a structure.

In the case of lists, foldl, when applied to a binary operator, a starting value (typically the left-identity of the operator), and a list, reduces the list using the binary operator, from left to right:

foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn

Note that to produce the outermost application of the operator the entire input list must be traversed. This means that foldl' will diverge if given an infinite list.

Also note that if you want an efficient left-fold, you probably want to use foldl' instead of foldl. The reason for this is that latter does not force the "inner" results (e.g. z f x1 in the above example) before applying them to the operator (e.g. to (f x2)). This results in a thunk chain O(n) elements long, which then must be evaluated from the outside-in.

For a general Foldable structure this should be semantically identical to,

foldl f z = foldl f z . toList

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

A variant of foldr that has no base case, and thus may only be applied to non-empty structures.

foldr1 f = foldr1 f . toList

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

A variant of foldl that has no base case, and thus may only be applied to non-empty structures.

foldl1 f = foldl1 f . toList

null :: t a -> Bool Source #

Test whether the structure is empty. The default implementation is optimized for structures that are similar to cons-lists, because there is no general way to do better.

length :: t a -> Int Source #

Returns the size/length of a finite structure as an Int. The default implementation is optimized for structures that are similar to cons-lists, because there is no general way to do better.

elem :: Eq a => a -> t a -> Bool infix 4 Source #

Does the element occur in the structure?

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

The largest element of a non-empty structure.

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

The least element of a non-empty structure.

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

The sum function computes the sum of the numbers of a structure.

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

The product function computes the product of the numbers of a structure.

Instances

Foldable []	Since: base-2.1
Instance details Defined in Data.Foldable Methods fold :: Monoid m => [m] -> 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 #
Foldable Maybe	Since: base-2.1
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m Source # foldMap :: Monoid m => (a -> m) -> Maybe a -> m Source # foldr :: (a -> b -> b) -> b -> Maybe a -> b Source # foldr' :: (a -> b -> b) -> b -> Maybe a -> b Source # foldl :: (b -> a -> b) -> b -> Maybe a -> b Source # foldl' :: (b -> a -> b) -> b -> Maybe a -> b Source # foldr1 :: (a -> a -> a) -> Maybe a -> a Source # foldl1 :: (a -> a -> a) -> Maybe a -> a Source # toList :: Maybe a -> [a] Source # null :: Maybe a -> Bool Source # length :: Maybe a -> Int Source # elem :: Eq a => a -> Maybe a -> Bool Source # maximum :: Ord a => Maybe a -> a Source # minimum :: Ord a => Maybe a -> a Source # sum :: Num a => Maybe a -> a Source # product :: Num a => Maybe a -> a Source #
Foldable Par1	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Par1 m -> m Source # foldMap :: Monoid m => (a -> m) -> Par1 a -> m Source # foldr :: (a -> b -> b) -> b -> Par1 a -> b Source # foldr' :: (a -> b -> b) -> b -> Par1 a -> b Source # foldl :: (b -> a -> b) -> b -> Par1 a -> b Source # foldl' :: (b -> a -> b) -> b -> Par1 a -> b Source # foldr1 :: (a -> a -> a) -> Par1 a -> a Source # foldl1 :: (a -> a -> a) -> Par1 a -> a Source # toList :: Par1 a -> [a] Source # null :: Par1 a -> Bool Source # length :: Par1 a -> Int Source # elem :: Eq a => a -> Par1 a -> Bool Source # maximum :: Ord a => Par1 a -> a Source # minimum :: Ord a => Par1 a -> a Source # sum :: Num a => Par1 a -> a Source # product :: Num a => Par1 a -> a Source #
Foldable First	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => First m -> m Source # foldMap :: Monoid m => (a -> m) -> First a -> m Source # foldr :: (a -> b -> b) -> b -> First a -> b Source # foldr' :: (a -> b -> b) -> b -> First a -> b Source # foldl :: (b -> a -> b) -> b -> First a -> b Source # foldl' :: (b -> a -> b) -> b -> First a -> b Source # foldr1 :: (a -> a -> a) -> First a -> a Source # foldl1 :: (a -> a -> a) -> First a -> a Source # toList :: First a -> [a] Source # null :: First a -> Bool Source # length :: First a -> Int Source # elem :: Eq a => a -> First a -> Bool Source # maximum :: Ord a => First a -> a Source # minimum :: Ord a => First a -> a Source # sum :: Num a => First a -> a Source # product :: Num a => First a -> a Source #
Foldable Last	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Last m -> m Source # foldMap :: Monoid m => (a -> m) -> Last a -> m Source # foldr :: (a -> b -> b) -> b -> Last a -> b Source # foldr' :: (a -> b -> b) -> b -> Last a -> b Source # foldl :: (b -> a -> b) -> b -> Last a -> b Source # foldl' :: (b -> a -> b) -> b -> Last a -> b Source # foldr1 :: (a -> a -> a) -> Last a -> a Source # foldl1 :: (a -> a -> a) -> Last a -> a Source # toList :: Last a -> [a] Source # null :: Last a -> Bool Source # length :: Last a -> Int Source # elem :: Eq a => a -> Last a -> Bool Source # maximum :: Ord a => Last a -> a Source # minimum :: Ord a => Last a -> a Source # sum :: Num a => Last a -> a Source # product :: Num a => Last a -> a Source #
Foldable Dual	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Dual m -> m Source # foldMap :: Monoid m => (a -> m) -> Dual a -> m Source # foldr :: (a -> b -> b) -> b -> Dual a -> b Source # foldr' :: (a -> b -> b) -> b -> Dual a -> b Source # foldl :: (b -> a -> b) -> b -> Dual a -> b Source # foldl' :: (b -> a -> b) -> b -> Dual a -> b Source # foldr1 :: (a -> a -> a) -> Dual a -> a Source # foldl1 :: (a -> a -> a) -> Dual a -> a Source # toList :: Dual a -> [a] Source # null :: Dual a -> Bool Source # length :: Dual a -> Int Source # elem :: Eq a => a -> Dual a -> Bool Source # maximum :: Ord a => Dual a -> a Source # minimum :: Ord a => Dual a -> a Source # sum :: Num a => Dual a -> a Source # product :: Num a => Dual a -> a Source #
Foldable Sum	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Sum m -> m Source # foldMap :: Monoid m => (a -> m) -> Sum a -> m Source # foldr :: (a -> b -> b) -> b -> Sum a -> b Source # foldr' :: (a -> b -> b) -> b -> Sum a -> b Source # foldl :: (b -> a -> b) -> b -> Sum a -> b Source # foldl' :: (b -> a -> b) -> b -> Sum a -> b Source # foldr1 :: (a -> a -> a) -> Sum a -> a Source # foldl1 :: (a -> a -> a) -> Sum a -> a Source # toList :: Sum a -> [a] Source # null :: Sum a -> Bool Source # length :: Sum a -> Int Source # elem :: Eq a => a -> Sum a -> Bool Source # maximum :: Ord a => Sum a -> a Source # minimum :: Ord a => Sum a -> a Source # sum :: Num a => Sum a -> a Source # product :: Num a => Sum a -> a Source #
Foldable Product	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Product m -> m Source # foldMap :: Monoid m => (a -> m) -> Product a -> m Source # foldr :: (a -> b -> b) -> b -> Product a -> b Source # foldr' :: (a -> b -> b) -> b -> Product a -> b Source # foldl :: (b -> a -> b) -> b -> Product a -> b Source # foldl' :: (b -> a -> b) -> b -> Product a -> b Source # foldr1 :: (a -> a -> a) -> Product a -> a Source # foldl1 :: (a -> a -> a) -> Product a -> a Source # toList :: Product a -> [a] Source # null :: Product a -> Bool Source # length :: Product a -> Int Source # elem :: Eq a => a -> Product a -> Bool Source # maximum :: Ord a => Product a -> a Source # minimum :: Ord a => Product a -> a Source # sum :: Num a => Product a -> a Source # product :: Num a => Product a -> a Source #
Foldable Down	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m Source # foldMap :: Monoid m => (a -> m) -> Down a -> m Source # foldr :: (a -> b -> b) -> b -> Down a -> b Source # foldr' :: (a -> b -> b) -> b -> Down a -> b Source # foldl :: (b -> a -> b) -> b -> Down a -> b Source # foldl' :: (b -> a -> b) -> b -> Down a -> b Source # foldr1 :: (a -> a -> a) -> Down a -> a Source # foldl1 :: (a -> a -> a) -> Down a -> a Source # toList :: Down a -> [a] Source # null :: Down a -> Bool Source # length :: Down a -> Int Source # elem :: Eq a => a -> Down a -> Bool Source # maximum :: Ord a => Down a -> a Source # minimum :: Ord a => Down a -> a Source # sum :: Num a => Down a -> a Source # product :: Num a => Down a -> a Source #
Foldable NonEmpty	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => NonEmpty m -> m Source # foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m Source # foldr :: (a -> b -> b) -> b -> NonEmpty a -> b Source # foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b Source # foldl :: (b -> a -> b) -> b -> NonEmpty a -> b Source # foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b Source # foldr1 :: (a -> a -> a) -> NonEmpty a -> a Source # foldl1 :: (a -> a -> a) -> NonEmpty a -> a Source # toList :: NonEmpty a -> [a] Source # null :: NonEmpty a -> Bool Source # length :: NonEmpty a -> Int Source # elem :: Eq a => a -> NonEmpty a -> Bool Source # maximum :: Ord a => NonEmpty a -> a Source # minimum :: Ord a => NonEmpty a -> a Source # sum :: Num a => NonEmpty a -> a Source # product :: Num a => NonEmpty a -> a Source #
Foldable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m Source # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m Source # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b Source # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b Source # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b Source # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b Source # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 Source # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 Source # toList :: Either a a0 -> [a0] Source # null :: Either a a0 -> Bool Source # length :: Either a a0 -> Int Source # elem :: Eq a0 => a0 -> Either a a0 -> Bool Source # maximum :: Ord a0 => Either a a0 -> a0 Source # minimum :: Ord a0 => Either a a0 -> a0 Source # sum :: Num a0 => Either a a0 -> a0 Source # product :: Num a0 => Either a a0 -> a0 Source #
Foldable (V1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => V1 m -> m Source # foldMap :: Monoid m => (a -> m) -> V1 a -> m Source # foldr :: (a -> b -> b) -> b -> V1 a -> b Source # foldr' :: (a -> b -> b) -> b -> V1 a -> b Source # foldl :: (b -> a -> b) -> b -> V1 a -> b Source # foldl' :: (b -> a -> b) -> b -> V1 a -> b Source # foldr1 :: (a -> a -> a) -> V1 a -> a Source # foldl1 :: (a -> a -> a) -> V1 a -> a Source # toList :: V1 a -> [a] Source # null :: V1 a -> Bool Source # length :: V1 a -> Int Source # elem :: Eq a => a -> V1 a -> Bool Source # maximum :: Ord a => V1 a -> a Source # minimum :: Ord a => V1 a -> a Source # sum :: Num a => V1 a -> a Source # product :: Num a => V1 a -> a Source #
Foldable (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => U1 m -> m Source # foldMap :: Monoid m => (a -> m) -> U1 a -> m Source # foldr :: (a -> b -> b) -> b -> U1 a -> b Source # foldr' :: (a -> b -> b) -> b -> U1 a -> b Source # foldl :: (b -> a -> b) -> b -> U1 a -> b Source # foldl' :: (b -> a -> b) -> b -> U1 a -> b Source # foldr1 :: (a -> a -> a) -> U1 a -> a Source # foldl1 :: (a -> a -> a) -> U1 a -> a Source # toList :: U1 a -> [a] Source # null :: U1 a -> Bool Source # length :: U1 a -> Int Source # elem :: Eq a => a -> U1 a -> Bool Source # maximum :: Ord a => U1 a -> a Source # minimum :: Ord a => U1 a -> a Source # sum :: Num a => U1 a -> a Source # product :: Num a => U1 a -> a Source #
Foldable ((,) a)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (a, m) -> m Source # foldMap :: Monoid m => (a0 -> m) -> (a, a0) -> m Source # foldr :: (a0 -> b -> b) -> b -> (a, a0) -> b Source # foldr' :: (a0 -> b -> b) -> b -> (a, a0) -> b Source # foldl :: (b -> a0 -> b) -> b -> (a, a0) -> b Source # foldl' :: (b -> a0 -> b) -> b -> (a, a0) -> b Source # foldr1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 Source # foldl1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 Source # toList :: (a, a0) -> [a0] Source # null :: (a, a0) -> Bool Source # length :: (a, a0) -> Int Source # elem :: Eq a0 => a0 -> (a, a0) -> Bool Source # maximum :: Ord a0 => (a, a0) -> a0 Source # minimum :: Ord a0 => (a, a0) -> a0 Source # sum :: Num a0 => (a, a0) -> a0 Source # product :: Num a0 => (a, a0) -> a0 Source #
Foldable (Array i)	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Array i m -> m Source # foldMap :: Monoid m => (a -> m) -> Array i a -> m Source # foldr :: (a -> b -> b) -> b -> Array i a -> b Source # foldr' :: (a -> b -> b) -> b -> Array i a -> b Source # foldl :: (b -> a -> b) -> b -> Array i a -> b Source # foldl' :: (b -> a -> b) -> b -> Array i a -> b Source # foldr1 :: (a -> a -> a) -> Array i a -> a Source # foldl1 :: (a -> a -> a) -> Array i a -> a Source # toList :: Array i a -> [a] Source # null :: Array i a -> Bool Source # length :: Array i a -> Int Source # elem :: Eq a => a -> Array i a -> Bool Source # maximum :: Ord a => Array i a -> a Source # minimum :: Ord a => Array i a -> a Source # sum :: Num a => Array i a -> a Source # product :: Num a => Array i a -> a Source #
Foldable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m Source # foldMap :: Monoid m => (a -> m) -> Proxy a -> m Source # foldr :: (a -> b -> b) -> b -> Proxy a -> b Source # foldr' :: (a -> b -> b) -> b -> Proxy a -> b Source # foldl :: (b -> a -> b) -> b -> Proxy a -> b Source # foldl' :: (b -> a -> b) -> b -> Proxy a -> b Source # foldr1 :: (a -> a -> a) -> Proxy a -> a Source # foldl1 :: (a -> a -> a) -> Proxy a -> a Source # toList :: Proxy a -> [a] Source # null :: Proxy a -> Bool Source # length :: Proxy a -> Int Source # elem :: Eq a => a -> Proxy a -> Bool Source # maximum :: Ord a => Proxy a -> a Source # minimum :: Ord a => Proxy a -> a Source # sum :: Num a => Proxy a -> a Source # product :: Num a => Proxy a -> a Source #
Foldable (Tree c)
Instance details Defined in Test.Hspec.Core.Tree Methods fold :: Monoid m => Tree c m -> m Source # foldMap :: Monoid m => (a -> m) -> Tree c a -> m Source # foldr :: (a -> b -> b) -> b -> Tree c a -> b Source # foldr' :: (a -> b -> b) -> b -> Tree c a -> b Source # foldl :: (b -> a -> b) -> b -> Tree c a -> b Source # foldl' :: (b -> a -> b) -> b -> Tree c a -> b Source # foldr1 :: (a -> a -> a) -> Tree c a -> a Source # foldl1 :: (a -> a -> a) -> Tree c a -> a Source # toList :: Tree c a -> [a] Source # null :: Tree c a -> Bool Source # length :: Tree c a -> Int Source # elem :: Eq a => a -> Tree c a -> Bool Source # maximum :: Ord a => Tree c a -> a Source # minimum :: Ord a => Tree c a -> a Source # sum :: Num a => Tree c a -> a Source # product :: Num a => Tree c a -> a Source #
Foldable f => Foldable (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Rec1 f m -> m Source # foldMap :: Monoid m => (a -> m) -> Rec1 f a -> m Source # foldr :: (a -> b -> b) -> b -> Rec1 f a -> b Source # foldr' :: (a -> b -> b) -> b -> Rec1 f a -> b Source # foldl :: (b -> a -> b) -> b -> Rec1 f a -> b Source # foldl' :: (b -> a -> b) -> b -> Rec1 f a -> b Source # foldr1 :: (a -> a -> a) -> Rec1 f a -> a Source # foldl1 :: (a -> a -> a) -> Rec1 f a -> a Source # toList :: Rec1 f a -> [a] Source # null :: Rec1 f a -> Bool Source # length :: Rec1 f a -> Int Source # elem :: Eq a => a -> Rec1 f a -> Bool Source # maximum :: Ord a => Rec1 f a -> a Source # minimum :: Ord a => Rec1 f a -> a Source # sum :: Num a => Rec1 f a -> a Source # product :: Num a => Rec1 f a -> a Source #
Foldable (URec Char :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Char m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Char a -> m Source # foldr :: (a -> b -> b) -> b -> URec Char a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Char a -> b Source # foldl :: (b -> a -> b) -> b -> URec Char a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Char a -> b Source # foldr1 :: (a -> a -> a) -> URec Char a -> a Source # foldl1 :: (a -> a -> a) -> URec Char a -> a Source # toList :: URec Char a -> [a] Source # null :: URec Char a -> Bool Source # length :: URec Char a -> Int Source # elem :: Eq a => a -> URec Char a -> Bool Source # maximum :: Ord a => URec Char a -> a Source # minimum :: Ord a => URec Char a -> a Source # sum :: Num a => URec Char a -> a Source # product :: Num a => URec Char a -> a Source #
Foldable (URec Double :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Double m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Double a -> m Source # foldr :: (a -> b -> b) -> b -> URec Double a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Double a -> b Source # foldl :: (b -> a -> b) -> b -> URec Double a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Double a -> b Source # foldr1 :: (a -> a -> a) -> URec Double a -> a Source # foldl1 :: (a -> a -> a) -> URec Double a -> a Source # toList :: URec Double a -> [a] Source # null :: URec Double a -> Bool Source # length :: URec Double a -> Int Source # elem :: Eq a => a -> URec Double a -> Bool Source # maximum :: Ord a => URec Double a -> a Source # minimum :: Ord a => URec Double a -> a Source # sum :: Num a => URec Double a -> a Source # product :: Num a => URec Double a -> a Source #
Foldable (URec Float :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Float m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Float a -> m Source # foldr :: (a -> b -> b) -> b -> URec Float a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Float a -> b Source # foldl :: (b -> a -> b) -> b -> URec Float a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Float a -> b Source # foldr1 :: (a -> a -> a) -> URec Float a -> a Source # foldl1 :: (a -> a -> a) -> URec Float a -> a Source # toList :: URec Float a -> [a] Source # null :: URec Float a -> Bool Source # length :: URec Float a -> Int Source # elem :: Eq a => a -> URec Float a -> Bool Source # maximum :: Ord a => URec Float a -> a Source # minimum :: Ord a => URec Float a -> a Source # sum :: Num a => URec Float a -> a Source # product :: Num a => URec Float a -> a Source #
Foldable (URec Int :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Int m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Int a -> m Source # foldr :: (a -> b -> b) -> b -> URec Int a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Int a -> b Source # foldl :: (b -> a -> b) -> b -> URec Int a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Int a -> b Source # foldr1 :: (a -> a -> a) -> URec Int a -> a Source # foldl1 :: (a -> a -> a) -> URec Int a -> a Source # toList :: URec Int a -> [a] Source # null :: URec Int a -> Bool Source # length :: URec Int a -> Int Source # elem :: Eq a => a -> URec Int a -> Bool Source # maximum :: Ord a => URec Int a -> a Source # minimum :: Ord a => URec Int a -> a Source # sum :: Num a => URec Int a -> a Source # product :: Num a => URec Int a -> a Source #
Foldable (URec Word :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Word m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Word a -> m Source # foldr :: (a -> b -> b) -> b -> URec Word a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Word a -> b Source # foldl :: (b -> a -> b) -> b -> URec Word a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Word a -> b Source # foldr1 :: (a -> a -> a) -> URec Word a -> a Source # foldl1 :: (a -> a -> a) -> URec Word a -> a Source # toList :: URec Word a -> [a] Source # null :: URec Word a -> Bool Source # length :: URec Word a -> Int Source # elem :: Eq a => a -> URec Word a -> Bool Source # maximum :: Ord a => URec Word a -> a Source # minimum :: Ord a => URec Word a -> a Source # sum :: Num a => URec Word a -> a Source # product :: Num a => URec Word a -> a Source #
Foldable (URec (Ptr ()) :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec (Ptr ()) m -> m Source # foldMap :: Monoid m => (a -> m) -> URec (Ptr ()) a -> m Source # foldr :: (a -> b -> b) -> b -> URec (Ptr ()) a -> b Source # foldr' :: (a -> b -> b) -> b -> URec (Ptr ()) a -> b Source # foldl :: (b -> a -> b) -> b -> URec (Ptr ()) a -> b Source # foldl' :: (b -> a -> b) -> b -> URec (Ptr ()) a -> b Source # foldr1 :: (a -> a -> a) -> URec (Ptr ()) a -> a Source # foldl1 :: (a -> a -> a) -> URec (Ptr ()) a -> a Source # toList :: URec (Ptr ()) a -> [a] Source # null :: URec (Ptr ()) a -> Bool Source # length :: URec (Ptr ()) a -> Int Source # elem :: Eq a => a -> URec (Ptr ()) a -> Bool Source # maximum :: Ord a => URec (Ptr ()) a -> a Source # minimum :: Ord a => URec (Ptr ()) a -> a Source # sum :: Num a => URec (Ptr ()) a -> a Source # product :: Num a => URec (Ptr ()) a -> a Source #
Foldable f => Foldable (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Ap f m -> m Source # foldMap :: Monoid m => (a -> m) -> Ap f a -> m Source # foldr :: (a -> b -> b) -> b -> Ap f a -> b Source # foldr' :: (a -> b -> b) -> b -> Ap f a -> b Source # foldl :: (b -> a -> b) -> b -> Ap f a -> b Source # foldl' :: (b -> a -> b) -> b -> Ap f a -> b Source # foldr1 :: (a -> a -> a) -> Ap f a -> a Source # foldl1 :: (a -> a -> a) -> Ap f a -> a Source # toList :: Ap f a -> [a] Source # null :: Ap f a -> Bool Source # length :: Ap f a -> Int Source # elem :: Eq a => a -> Ap f a -> Bool Source # maximum :: Ord a => Ap f a -> a Source # minimum :: Ord a => Ap f a -> a Source # sum :: Num a => Ap f a -> a Source # product :: Num a => Ap f a -> a Source #
Foldable f => Foldable (Alt f)	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m Source # foldMap :: Monoid m => (a -> m) -> Alt f a -> m Source # foldr :: (a -> b -> b) -> b -> Alt f a -> b Source # foldr' :: (a -> b -> b) -> b -> Alt f a -> b Source # foldl :: (b -> a -> b) -> b -> Alt f a -> b Source # foldl' :: (b -> a -> b) -> b -> Alt f a -> b Source # foldr1 :: (a -> a -> a) -> Alt f a -> a Source # foldl1 :: (a -> a -> a) -> Alt f a -> a Source # toList :: Alt f a -> [a] Source # null :: Alt f a -> Bool Source # length :: Alt f a -> Int Source # elem :: Eq a => a -> Alt f a -> Bool Source # maximum :: Ord a => Alt f a -> a Source # minimum :: Ord a => Alt f a -> a Source # sum :: Num a => Alt f a -> a Source # product :: Num a => Alt f a -> a Source #
Foldable f => Foldable (ErrorT e f)
Instance details Defined in Control.Monad.Trans.Error Methods fold :: Monoid m => ErrorT e f m -> m Source # foldMap :: Monoid m => (a -> m) -> ErrorT e f a -> m Source # foldr :: (a -> b -> b) -> b -> ErrorT e f a -> b Source # foldr' :: (a -> b -> b) -> b -> ErrorT e f a -> b Source # foldl :: (b -> a -> b) -> b -> ErrorT e f a -> b Source # foldl' :: (b -> a -> b) -> b -> ErrorT e f a -> b Source # foldr1 :: (a -> a -> a) -> ErrorT e f a -> a Source # foldl1 :: (a -> a -> a) -> ErrorT e f a -> a Source # toList :: ErrorT e f a -> [a] Source # null :: ErrorT e f a -> Bool Source # length :: ErrorT e f a -> Int Source # elem :: Eq a => a -> ErrorT e f a -> Bool Source # maximum :: Ord a => ErrorT e f a -> a Source # minimum :: Ord a => ErrorT e f a -> a Source # sum :: Num a => ErrorT e f a -> a Source # product :: Num a => ErrorT e f a -> a Source #
Foldable (K1 i c :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => K1 i c m -> m Source # foldMap :: Monoid m => (a -> m) -> K1 i c a -> m Source # foldr :: (a -> b -> b) -> b -> K1 i c a -> b Source # foldr' :: (a -> b -> b) -> b -> K1 i c a -> b Source # foldl :: (b -> a -> b) -> b -> K1 i c a -> b Source # foldl' :: (b -> a -> b) -> b -> K1 i c a -> b Source # foldr1 :: (a -> a -> a) -> K1 i c a -> a Source # foldl1 :: (a -> a -> a) -> K1 i c a -> a Source # toList :: K1 i c a -> [a] Source # null :: K1 i c a -> Bool Source # length :: K1 i c a -> Int Source # elem :: Eq a => a -> K1 i c a -> Bool Source # maximum :: Ord a => K1 i c a -> a Source # minimum :: Ord a => K1 i c a -> a Source # sum :: Num a => K1 i c a -> a Source # product :: Num a => K1 i c a -> a Source #
(Foldable f, Foldable g) => Foldable (f :+: g)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (f :+: g) m -> m Source # foldMap :: Monoid m => (a -> m) -> (f :+: g) a -> m Source # foldr :: (a -> b -> b) -> b -> (f :+: g) a -> b Source # foldr' :: (a -> b -> b) -> b -> (f :+: g) a -> b Source # foldl :: (b -> a -> b) -> b -> (f :+: g) a -> b Source # foldl' :: (b -> a -> b) -> b -> (f :+: g) a -> b Source # foldr1 :: (a -> a -> a) -> (f :+: g) a -> a Source # foldl1 :: (a -> a -> a) -> (f :+: g) a -> a Source # toList :: (f :+: g) a -> [a] Source # null :: (f :+: g) a -> Bool Source # length :: (f :+: g) a -> Int Source # elem :: Eq a => a -> (f :+: g) a -> Bool Source # maximum :: Ord a => (f :+: g) a -> a Source # minimum :: Ord a => (f :+: g) a -> a Source # sum :: Num a => (f :+: g) a -> a Source # product :: Num a => (f :+: g) a -> a Source #
(Foldable f, Foldable g) => Foldable (f :*: g)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (f :: g) m -> m Source # foldMap :: Monoid m => (a -> m) -> (f :: g) a -> m Source # foldr :: (a -> b -> b) -> b -> (f :: g) a -> b Source # foldr' :: (a -> b -> b) -> b -> (f :: g) a -> b Source # foldl :: (b -> a -> b) -> b -> (f :: g) a -> b Source # foldl' :: (b -> a -> b) -> b -> (f :: g) a -> b Source # foldr1 :: (a -> a -> a) -> (f :: g) a -> a Source # foldl1 :: (a -> a -> a) -> (f :: g) a -> a Source # toList :: (f :: g) a -> [a] Source # null :: (f :: g) a -> Bool Source # length :: (f :: g) a -> Int Source # elem :: Eq a => a -> (f :: g) a -> Bool Source # maximum :: Ord a => (f :: g) a -> a Source # minimum :: Ord a => (f :: g) a -> a Source # sum :: Num a => (f :: g) a -> a Source # product :: Num a => (f :: g) a -> a Source #
Foldable f => Foldable (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => M1 i c f m -> m Source # foldMap :: Monoid m => (a -> m) -> M1 i c f a -> m Source # foldr :: (a -> b -> b) -> b -> M1 i c f a -> b Source # foldr' :: (a -> b -> b) -> b -> M1 i c f a -> b Source # foldl :: (b -> a -> b) -> b -> M1 i c f a -> b Source # foldl' :: (b -> a -> b) -> b -> M1 i c f a -> b Source # foldr1 :: (a -> a -> a) -> M1 i c f a -> a Source # foldl1 :: (a -> a -> a) -> M1 i c f a -> a Source # toList :: M1 i c f a -> [a] Source # null :: M1 i c f a -> Bool Source # length :: M1 i c f a -> Int Source # elem :: Eq a => a -> M1 i c f a -> Bool Source # maximum :: Ord a => M1 i c f a -> a Source # minimum :: Ord a => M1 i c f a -> a Source # sum :: Num a => M1 i c f a -> a Source # product :: Num a => M1 i c f a -> a Source #
(Foldable f, Foldable g) => Foldable (f :.: g)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (f :.: g) m -> m Source # foldMap :: Monoid m => (a -> m) -> (f :.: g) a -> m Source # foldr :: (a -> b -> b) -> b -> (f :.: g) a -> b Source # foldr' :: (a -> b -> b) -> b -> (f :.: g) a -> b Source # foldl :: (b -> a -> b) -> b -> (f :.: g) a -> b Source # foldl' :: (b -> a -> b) -> b -> (f :.: g) a -> b Source # foldr1 :: (a -> a -> a) -> (f :.: g) a -> a Source # foldl1 :: (a -> a -> a) -> (f :.: g) a -> a Source # toList :: (f :.: g) a -> [a] Source # null :: (f :.: g) a -> Bool Source # length :: (f :.: g) a -> Int Source # elem :: Eq a => a -> (f :.: g) a -> Bool Source # maximum :: Ord a => (f :.: g) a -> a Source # minimum :: Ord a => (f :.: g) a -> a Source # sum :: Num a => (f :.: g) a -> a Source # product :: Num a => (f :.: g) a -> a Source #

class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where Source #

Functors representing data structures that can be traversed from left to right.

A definition of traverse must satisfy the following laws:

naturality: t . traverse f = traverse (t . f) for every applicative transformation t
identity: traverse Identity = Identity
composition: traverse (Compose . fmap g . f) = Compose . fmap (traverse g) . traverse f

A definition of sequenceA must satisfy the following laws:

naturality: t . sequenceA = sequenceA . fmap t for every applicative transformation t
identity: sequenceA . fmap Identity = Identity
composition: sequenceA . fmap Compose = Compose . fmap sequenceA . sequenceA

where an applicative transformation is a function

t :: (Applicative f, Applicative g) => f a -> g a

preserving the Applicative operations, i.e.

```
t (pure x) = pure x
```
```
t (x <*> y) = t x <*> t y
```

and the identity functor Identity and composition of functors Compose are defined as

  newtype Identity a = Identity a

  instance Functor Identity where
    fmap f (Identity x) = Identity (f x)

  instance Applicative Identity where
    pure x = Identity x
    Identity f <*> Identity x = Identity (f x)

  newtype Compose f g a = Compose (f (g a))

  instance (Functor f, Functor g) => Functor (Compose f g) where
    fmap f (Compose x) = Compose (fmap (fmap f) x)

  instance (Applicative f, Applicative g) => Applicative (Compose f g) where
    pure x = Compose (pure (pure x))
    Compose f <*> Compose x = Compose ((<*>) <$> f <*> x)

(The naturality law is implied by parametricity.)

Instances are similar to Functor, e.g. given a data type

data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)

a suitable instance would be

instance Traversable Tree where
   traverse f Empty = pure Empty
   traverse f (Leaf x) = Leaf <$> f x
   traverse f (Node l k r) = Node <$> traverse f l <*> f k <*> traverse f r

This is suitable even for abstract types, as the laws for <*> imply a form of associativity.

The superclass instances should satisfy the following:

In the Functor instance, fmap should be equivalent to traversal with the identity applicative functor (fmapDefault).
In the Foldable instance, foldMap should be equivalent to traversal with a constant applicative functor (foldMapDefault).

Minimal complete definition

traverse | sequenceA

Methods

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

Map each element of a structure to an action, evaluate these actions from left to right, and collect the results. For a version that ignores the results see traverse_.

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

Evaluate each action in the structure from left to right, and collect the results. For a version that ignores the results see sequenceA_.

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

Evaluate each monadic action in the structure from left to right, and collect the results. For a version that ignores the results see sequence_.

Instances

Traversable []	Since: base-2.1
Instance details Defined in 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 #
Traversable Maybe	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Maybe a -> f (Maybe b) Source # sequenceA :: Applicative f => Maybe (f a) -> f (Maybe a) Source # mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b) Source # sequence :: Monad m => Maybe (m a) -> m (Maybe a) Source #
Traversable Par1	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Par1 a -> f (Par1 b) Source # sequenceA :: Applicative f => Par1 (f a) -> f (Par1 a) Source # mapM :: Monad m => (a -> m b) -> Par1 a -> m (Par1 b) Source # sequence :: Monad m => Par1 (m a) -> m (Par1 a) Source #
Traversable ZipList	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b) Source # sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a) Source # mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b) Source # sequence :: Monad m => ZipList (m a) -> m (ZipList a) Source #
Traversable Identity	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Identity a -> f (Identity b) Source # sequenceA :: Applicative f => Identity (f a) -> f (Identity a) Source # mapM :: Monad m => (a -> m b) -> Identity a -> m (Identity b) Source # sequence :: Monad m => Identity (m a) -> m (Identity a) Source #
Traversable First	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> First a -> f (First b) Source # sequenceA :: Applicative f => First (f a) -> f (First a) Source # mapM :: Monad m => (a -> m b) -> First a -> m (First b) Source # sequence :: Monad m => First (m a) -> m (First a) Source #
Traversable Last	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Last a -> f (Last b) Source # sequenceA :: Applicative f => Last (f a) -> f (Last a) Source # mapM :: Monad m => (a -> m b) -> Last a -> m (Last b) Source # sequence :: Monad m => Last (m a) -> m (Last a) Source #
Traversable Dual	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Dual a -> f (Dual b) Source # sequenceA :: Applicative f => Dual (f a) -> f (Dual a) Source # mapM :: Monad m => (a -> m b) -> Dual a -> m (Dual b) Source # sequence :: Monad m => Dual (m a) -> m (Dual a) Source #
Traversable Sum	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Sum a -> f (Sum b) Source # sequenceA :: Applicative f => Sum (f a) -> f (Sum a) Source # mapM :: Monad m => (a -> m b) -> Sum a -> m (Sum b) Source # sequence :: Monad m => Sum (m a) -> m (Sum a) Source #
Traversable Product	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Product a -> f (Product b) Source # sequenceA :: Applicative f => Product (f a) -> f (Product a) Source # mapM :: Monad m => (a -> m b) -> Product a -> m (Product b) Source # sequence :: Monad m => Product (m a) -> m (Product a) Source #
Traversable Down	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Down a -> f (Down b) Source # sequenceA :: Applicative f => Down (f a) -> f (Down a) Source # mapM :: Monad m => (a -> m b) -> Down a -> m (Down b) Source # sequence :: Monad m => Down (m a) -> m (Down a) Source #
Traversable NonEmpty	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> NonEmpty a -> f (NonEmpty b) Source # sequenceA :: Applicative f => NonEmpty (f a) -> f (NonEmpty a) Source # mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b) Source # sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a) Source #
Traversable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a0 -> f b) -> Either a a0 -> f (Either a b) Source # sequenceA :: Applicative f => Either a (f a0) -> f (Either a a0) Source # mapM :: Monad m => (a0 -> m b) -> Either a a0 -> m (Either a b) Source # sequence :: Monad m => Either a (m a0) -> m (Either a a0) Source #
Traversable (V1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> V1 a -> f (V1 b) Source # sequenceA :: Applicative f => V1 (f a) -> f (V1 a) Source # mapM :: Monad m => (a -> m b) -> V1 a -> m (V1 b) Source # sequence :: Monad m => V1 (m a) -> m (V1 a) Source #
Traversable (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> U1 a -> f (U1 b) Source # sequenceA :: Applicative f => U1 (f a) -> f (U1 a) Source # mapM :: Monad m => (a -> m b) -> U1 a -> m (U1 b) Source # sequence :: Monad m => U1 (m a) -> m (U1 a) Source #
Traversable ((,) a)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a0 -> f b) -> (a, a0) -> f (a, b) Source # sequenceA :: Applicative f => (a, f a0) -> f (a, a0) Source # mapM :: Monad m => (a0 -> m b) -> (a, a0) -> m (a, b) Source # sequence :: Monad m => (a, m a0) -> m (a, a0) Source #
Ix i => Traversable (Array i)	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Array i a -> f (Array i b) Source # sequenceA :: Applicative f => Array i (f a) -> f (Array i a) Source # mapM :: Monad m => (a -> m b) -> Array i a -> m (Array i b) Source # sequence :: Monad m => Array i (m a) -> m (Array i a) Source #
Traversable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b) Source # sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a) Source # mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b) Source # sequence :: Monad m => Proxy (m a) -> m (Proxy a) Source #
Traversable (Tree c)
Instance details Defined in Test.Hspec.Core.Tree Methods traverse :: Applicative f => (a -> f b) -> Tree c a -> f (Tree c b) Source # sequenceA :: Applicative f => Tree c (f a) -> f (Tree c a) Source # mapM :: Monad m => (a -> m b) -> Tree c a -> m (Tree c b) Source # sequence :: Monad m => Tree c (m a) -> m (Tree c a) Source #
Traversable f => Traversable (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> Rec1 f a -> f0 (Rec1 f b) Source # sequenceA :: Applicative f0 => Rec1 f (f0 a) -> f0 (Rec1 f a) Source # mapM :: Monad m => (a -> m b) -> Rec1 f a -> m (Rec1 f b) Source # sequence :: Monad m => Rec1 f (m a) -> m (Rec1 f a) Source #
Traversable (URec Char :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Char a -> f (URec Char b) Source # sequenceA :: Applicative f => URec Char (f a) -> f (URec Char a) Source # mapM :: Monad m => (a -> m b) -> URec Char a -> m (URec Char b) Source # sequence :: Monad m => URec Char (m a) -> m (URec Char a) Source #
Traversable (URec Double :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Double a -> f (URec Double b) Source # sequenceA :: Applicative f => URec Double (f a) -> f (URec Double a) Source # mapM :: Monad m => (a -> m b) -> URec Double a -> m (URec Double b) Source # sequence :: Monad m => URec Double (m a) -> m (URec Double a) Source #
Traversable (URec Float :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Float a -> f (URec Float b) Source # sequenceA :: Applicative f => URec Float (f a) -> f (URec Float a) Source # mapM :: Monad m => (a -> m b) -> URec Float a -> m (URec Float b) Source # sequence :: Monad m => URec Float (m a) -> m (URec Float a) Source #
Traversable (URec Int :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Int a -> f (URec Int b) Source # sequenceA :: Applicative f => URec Int (f a) -> f (URec Int a) Source # mapM :: Monad m => (a -> m b) -> URec Int a -> m (URec Int b) Source # sequence :: Monad m => URec Int (m a) -> m (URec Int a) Source #
Traversable (URec Word :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Word a -> f (URec Word b) Source # sequenceA :: Applicative f => URec Word (f a) -> f (URec Word a) Source # mapM :: Monad m => (a -> m b) -> URec Word a -> m (URec Word b) Source # sequence :: Monad m => URec Word (m a) -> m (URec Word a) Source #
Traversable (URec (Ptr ()) :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec (Ptr ()) a -> f (URec (Ptr ()) b) Source # sequenceA :: Applicative f => URec (Ptr ()) (f a) -> f (URec (Ptr ()) a) Source # mapM :: Monad m => (a -> m b) -> URec (Ptr ()) a -> m (URec (Ptr ()) b) Source # sequence :: Monad m => URec (Ptr ()) (m a) -> m (URec (Ptr ()) a) Source #
Traversable (Const m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Const m a -> f (Const m b) Source # sequenceA :: Applicative f => Const m (f a) -> f (Const m a) Source # mapM :: Monad m0 => (a -> m0 b) -> Const m a -> m0 (Const m b) Source # sequence :: Monad m0 => Const m (m0 a) -> m0 (Const m a) Source #
Traversable f => Traversable (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> Ap f a -> f0 (Ap f b) Source # sequenceA :: Applicative f0 => Ap f (f0 a) -> f0 (Ap f a) Source # mapM :: Monad m => (a -> m b) -> Ap f a -> m (Ap f b) Source # sequence :: Monad m => Ap f (m a) -> m (Ap f a) Source #
Traversable f => Traversable (Alt f)	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> Alt f a -> f0 (Alt f b) Source # sequenceA :: Applicative f0 => Alt f (f0 a) -> f0 (Alt f a) Source # mapM :: Monad m => (a -> m b) -> Alt f a -> m (Alt f b) Source # sequence :: Monad m => Alt f (m a) -> m (Alt f a) Source #
Traversable f => Traversable (ErrorT e f)
Instance details Defined in Control.Monad.Trans.Error Methods traverse :: Applicative f0 => (a -> f0 b) -> ErrorT e f a -> f0 (ErrorT e f b) Source # sequenceA :: Applicative f0 => ErrorT e f (f0 a) -> f0 (ErrorT e f a) Source # mapM :: Monad m => (a -> m b) -> ErrorT e f a -> m (ErrorT e f b) Source # sequence :: Monad m => ErrorT e f (m a) -> m (ErrorT e f a) Source #
Traversable (K1 i c :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> K1 i c a -> f (K1 i c b) Source # sequenceA :: Applicative f => K1 i c (f a) -> f (K1 i c a) Source # mapM :: Monad m => (a -> m b) -> K1 i c a -> m (K1 i c b) Source # sequence :: Monad m => K1 i c (m a) -> m (K1 i c a) Source #
(Traversable f, Traversable g) => Traversable (f :+: g)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> (f :+: g) a -> f0 ((f :+: g) b) Source # sequenceA :: Applicative f0 => (f :+: g) (f0 a) -> f0 ((f :+: g) a) Source # mapM :: Monad m => (a -> m b) -> (f :+: g) a -> m ((f :+: g) b) Source # sequence :: Monad m => (f :+: g) (m a) -> m ((f :+: g) a) Source #
(Traversable f, Traversable g) => Traversable (f :*: g)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> (f :: g) a -> f0 ((f :: g) b) Source # sequenceA :: Applicative f0 => (f :: g) (f0 a) -> f0 ((f :: g) a) Source # mapM :: Monad m => (a -> m b) -> (f :: g) a -> m ((f :: g) b) Source # sequence :: Monad m => (f :: g) (m a) -> m ((f :: g) a) Source #
Traversable f => Traversable (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> M1 i c f a -> f0 (M1 i c f b) Source # sequenceA :: Applicative f0 => M1 i c f (f0 a) -> f0 (M1 i c f a) Source # mapM :: Monad m => (a -> m b) -> M1 i c f a -> m (M1 i c f b) Source # sequence :: Monad m => M1 i c f (m a) -> m (M1 i c f a) Source #
(Traversable f, Traversable g) => Traversable (f :.: g)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> (f :.: g) a -> f0 ((f :.: g) b) Source # sequenceA :: Applicative f0 => (f :.: g) (f0 a) -> f0 ((f :.: g) a) Source # mapM :: Monad m => (a -> m b) -> (f :.: g) a -> m ((f :.: g) b) Source # sequence :: Monad m => (f :.: g) (m a) -> m ((f :.: g) a) Source #

class Semigroup a where Source #

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

Instances should satisfy the associativity law:

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

Since: base-4.9.0.0

Methods

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

An associative operation.

Instances

Semigroup Ordering	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Ordering -> Ordering -> Ordering Source # sconcat :: NonEmpty Ordering -> Ordering Source # stimes :: Integral b => b -> Ordering -> Ordering Source #
Semigroup ()	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: () -> () -> () Source # sconcat :: NonEmpty () -> () Source # stimes :: Integral b => b -> () -> () Source #
Semigroup Summary
Instance details Defined in Test.Hspec.Core.Runner Methods (<>) :: Summary -> Summary -> Summary Source # sconcat :: NonEmpty Summary -> Summary Source # stimes :: Integral b => b -> Summary -> Summary Source #
Semigroup [a]	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: [a] -> [a] -> [a] Source # sconcat :: NonEmpty [a] -> [a] Source # stimes :: Integral b => b -> [a] -> [a] Source #
Semigroup a => Semigroup (Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Maybe a -> Maybe a -> Maybe a Source # sconcat :: NonEmpty (Maybe a) -> Maybe a Source # stimes :: Integral b => b -> Maybe a -> Maybe a Source #
Semigroup a => Semigroup (IO a)	Since: base-4.10.0.0
Instance details Defined in GHC.Base Methods (<>) :: IO a -> IO a -> IO a Source # sconcat :: NonEmpty (IO a) -> IO a Source # stimes :: Integral b => b -> IO a -> IO a Source #
Semigroup (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: NonEmpty a -> NonEmpty a -> NonEmpty a Source # sconcat :: NonEmpty (NonEmpty a) -> NonEmpty a Source # stimes :: Integral b => b -> NonEmpty a -> NonEmpty a Source #
Semigroup b => Semigroup (a -> b)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a -> b) -> (a -> b) -> a -> b Source # sconcat :: NonEmpty (a -> b) -> a -> b Source # stimes :: Integral b0 => b0 -> (a -> b) -> a -> b Source #
Semigroup (Either a b)	Since: base-4.9.0.0
Instance details Defined in Data.Either Methods (<>) :: Either a b -> Either a b -> Either a b Source # sconcat :: NonEmpty (Either a b) -> Either a b Source # stimes :: Integral b0 => b0 -> Either a b -> Either a b Source #
(Semigroup a, Semigroup b) => Semigroup (a, b)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b) -> (a, b) -> (a, b) Source # sconcat :: NonEmpty (a, b) -> (a, b) Source # stimes :: Integral b0 => b0 -> (a, b) -> (a, b) Source #
(Semigroup a, Semigroup b, Semigroup c) => Semigroup (a, b, c)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b, c) -> (a, b, c) -> (a, b, c) Source # sconcat :: NonEmpty (a, b, c) -> (a, b, c) Source # stimes :: Integral b0 => b0 -> (a, b, c) -> (a, b, c) Source #
(Semigroup a, Semigroup b, Semigroup c, Semigroup d) => Semigroup (a, b, c, d)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) Source # sconcat :: NonEmpty (a, b, c, d) -> (a, b, c, d) Source # stimes :: Integral b0 => b0 -> (a, b, c, d) -> (a, b, c, d) Source #
(Semigroup a, Semigroup b, Semigroup c, Semigroup d, Semigroup e) => Semigroup (a, b, c, d, e)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) Source # sconcat :: NonEmpty (a, b, c, d, e) -> (a, b, c, d, e) Source # stimes :: Integral b0 => b0 -> (a, b, c, d, e) -> (a, b, c, d, e) Source #

class Semigroup a => Monoid a where Source #

The class of monoids (types with an associative binary operation that has an identity). Instances should satisfy the following laws:

```
x <> mempty = x
```
```
mempty <> x = x
```
x <> (y <> z) = (x <> y) <> z (Semigroup law)
```
mconcat = foldr '(<>)' mempty
```

The method names refer to the monoid of lists under concatenation, but there are many other instances.

Some types can be viewed as a monoid in more than one way, e.g. both addition and multiplication on numbers. In such cases we often define newtypes and make those instances of Monoid, e.g. Sum and Product.

NOTE: Semigroup is a superclass of Monoid since base-4.11.0.0.

Minimal complete definition

mempty

Methods

mempty :: a Source #

Identity of mappend

mappend :: a -> a -> a Source #

An associative operation

NOTE: This method is redundant and has the default implementation mappend = '(<>)' since base-4.11.0.0.

mconcat :: [a] -> a Source #

Fold a list using the monoid.

For most types, the default definition for mconcat will be used, but the function is included in the class definition so that an optimized version can be provided for specific types.

Instances

Monoid Ordering	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: Ordering Source # mappend :: Ordering -> Ordering -> Ordering Source # mconcat :: [Ordering] -> Ordering Source #
Monoid ()	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: () Source # mappend :: () -> () -> () Source # mconcat :: [()] -> () Source #
Monoid Summary
Instance details Defined in Test.Hspec.Core.Runner Methods mempty :: Summary Source # mappend :: Summary -> Summary -> Summary Source # mconcat :: [Summary] -> Summary Source #
Monoid [a]	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: [a] Source # mappend :: [a] -> [a] -> [a] Source # mconcat :: [[a]] -> [a] Source #
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 `ee = e` and `es = s = se` for all `s ∈ S`." Since 4.11.0: constraint on inner `a` value generalised from `Monoid` to `Semigroup`. Since: base-2.1*
Instance details Defined in GHC.Base Methods mempty :: Maybe a Source # mappend :: Maybe a -> Maybe a -> Maybe a Source # mconcat :: [Maybe a] -> Maybe a Source #
Monoid a => Monoid (IO a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods mempty :: IO a Source # mappend :: IO a -> IO a -> IO a Source # mconcat :: [IO a] -> IO a Source #
Monoid b => Monoid (a -> b)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: a -> b Source # mappend :: (a -> b) -> (a -> b) -> a -> b Source # mconcat :: [a -> b] -> a -> b Source #
(Monoid a, Monoid b) => Monoid (a, b)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b) Source # mappend :: (a, b) -> (a, b) -> (a, b) Source # mconcat :: [(a, b)] -> (a, b) Source #
(Monoid a, Monoid b, Monoid c) => Monoid (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b, c) Source # mappend :: (a, b, c) -> (a, b, c) -> (a, b, c) Source # mconcat :: [(a, b, c)] -> (a, b, c) Source #
(Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b, c, d) Source # mappend :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) Source # mconcat :: [(a, b, c, d)] -> (a, b, c, d) Source #
(Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b, c, d, e) Source # mappend :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) Source # mconcat :: [(a, b, c, d, e)] -> (a, b, c, d, e) Source #

data Bool Source #

Constructors

False
True

Instances

Bounded Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Bool Source # maxBound :: Bool Source #
Enum Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Bool -> Bool Source # pred :: Bool -> Bool Source # toEnum :: Int -> Bool Source # fromEnum :: Bool -> Int Source # enumFrom :: Bool -> [Bool] Source # enumFromThen :: Bool -> Bool -> [Bool] Source # enumFromTo :: Bool -> Bool -> [Bool] Source # enumFromThenTo :: Bool -> Bool -> Bool -> [Bool] Source #
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 Methods compare :: Bool -> Bool -> Ordering Source # (<) :: Bool -> Bool -> Bool Source # (<=) :: Bool -> Bool -> Bool Source # (>) :: Bool -> Bool -> Bool Source # (>=) :: Bool -> Bool -> Bool Source # max :: Bool -> Bool -> Bool Source # min :: Bool -> Bool -> Bool Source #
Read Bool	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Bool Source # readList :: ReadS [Bool] Source # readPrec :: ReadPrec Bool Source # readListPrec :: ReadPrec [Bool] Source #
Show Bool	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Bool -> ShowS Source # show :: Bool -> String Source # showList :: [Bool] -> ShowS Source #
Testable Bool
Instance details Defined in Test.QuickCheck.Property Methods property :: Bool -> Property Source #
Function Bool
Instance details Defined in Test.QuickCheck.Function Methods function :: (Bool -> b) -> Bool :-> b Source #
Arbitrary Bool
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Bool Source # shrink :: Bool -> [Bool] Source #
CoArbitrary Bool
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Bool -> Gen b -> Gen b Source #
Example Bool
Instance details Defined in Test.Hspec.Core.Example Associated Types type Arg Bool :: Type Source # Methods evaluateExample :: Bool -> Params -> (ActionWith (Arg Bool) -> IO ()) -> ProgressCallback -> IO Result Source #
Example (a -> Bool)
Instance details Defined in Test.Hspec.Core.Example Associated Types type Arg (a -> Bool) :: Type Source # Methods evaluateExample :: (a -> Bool) -> Params -> (ActionWith (Arg (a -> Bool)) -> IO ()) -> ProgressCallback -> IO Result Source #
type Arg Bool
Instance details Defined in Test.Hspec.Core.Example type Arg Bool = ()
type Arg (a -> Bool)
Instance details Defined in Test.Hspec.Core.Example type Arg (a -> Bool) = a

data Char Source #

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
Instance details Defined in GHC.Enum Methods minBound :: Char Source # maxBound :: Char Source #
Enum Char	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Char -> Char Source # pred :: Char -> Char Source # toEnum :: Int -> Char Source # fromEnum :: Char -> Int Source # enumFrom :: Char -> [Char] Source # enumFromThen :: Char -> Char -> [Char] Source # enumFromTo :: Char -> Char -> [Char] Source # enumFromThenTo :: Char -> Char -> Char -> [Char] Source #
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 Methods compare :: Char -> Char -> Ordering Source # (<) :: Char -> Char -> Bool Source # (<=) :: Char -> Char -> Bool Source # (>) :: Char -> Char -> Bool Source # (>=) :: Char -> Char -> Bool Source # max :: Char -> Char -> Char Source # min :: Char -> Char -> Char Source #
Read Char	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Char Source # readList :: ReadS [Char] Source # readPrec :: ReadPrec Char Source # readListPrec :: ReadPrec [Char] Source #
Show Char	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Char -> ShowS Source # show :: Char -> String Source # showList :: [Char] -> ShowS Source #
Function Char
Instance details Defined in Test.QuickCheck.Function Methods function :: (Char -> b) -> Char :-> b Source #
Arbitrary Char
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Char Source # shrink :: Char -> [Char] Source #
CoArbitrary Char
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Char -> Gen b -> Gen b Source #
ErrorList Char
Instance details Defined in Control.Monad.Trans.Error Methods listMsg :: String -> [Char] Source #
Foldable (URec Char :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Char m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Char a -> m Source # foldr :: (a -> b -> b) -> b -> URec Char a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Char a -> b Source # foldl :: (b -> a -> b) -> b -> URec Char a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Char a -> b Source # foldr1 :: (a -> a -> a) -> URec Char a -> a Source # foldl1 :: (a -> a -> a) -> URec Char a -> a Source # toList :: URec Char a -> [a] Source # null :: URec Char a -> Bool Source # length :: URec Char a -> Int Source # elem :: Eq a => a -> URec Char a -> Bool Source # maximum :: Ord a => URec Char a -> a Source # minimum :: Ord a => URec Char a -> a Source # sum :: Num a => URec Char a -> a Source # product :: Num a => URec Char a -> a Source #
Traversable (URec Char :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Char a -> f (URec Char b) Source # sequenceA :: Applicative f => URec Char (f a) -> f (URec Char a) Source # mapM :: Monad m => (a -> m b) -> URec Char a -> m (URec Char b) Source # sequence :: Monad m => URec Char (m a) -> m (URec Char a) Source #

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.

Instances

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 Methods (==) :: Double -> Double -> Bool Source # (/=) :: Double -> Double -> Bool Source #
Floating Double	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Double Source # exp :: Double -> Double Source # log :: Double -> Double Source # sqrt :: Double -> Double Source # (**) :: Double -> Double -> Double Source # logBase :: Double -> Double -> Double Source # sin :: Double -> Double Source # cos :: Double -> Double Source # tan :: Double -> Double Source # asin :: Double -> Double Source # acos :: Double -> Double Source # atan :: Double -> Double Source # sinh :: Double -> Double Source # cosh :: Double -> Double Source # tanh :: Double -> Double Source # asinh :: Double -> Double Source # acosh :: Double -> Double Source # atanh :: Double -> Double Source # log1p :: Double -> Double Source # expm1 :: Double -> Double Source # log1pexp :: Double -> Double Source # log1mexp :: Double -> Double Source #
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
Instance details Defined in GHC.Classes Methods compare :: Double -> Double -> Ordering Source # (<) :: Double -> Double -> Bool Source # (<=) :: Double -> Double -> Bool Source # (>) :: Double -> Double -> Bool Source # (>=) :: Double -> Double -> Bool Source # max :: Double -> Double -> Double Source # min :: Double -> Double -> Double Source #
Read Double	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Double Source # readList :: ReadS [Double] Source # readPrec :: ReadPrec Double Source # readListPrec :: ReadPrec [Double] Source #
RealFloat Double	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Double -> Integer Source # floatDigits :: Double -> Int Source # floatRange :: Double -> (Int, Int) Source # decodeFloat :: Double -> (Integer, Int) Source # encodeFloat :: Integer -> Int -> Double Source # exponent :: Double -> Int Source # significand :: Double -> Double Source # scaleFloat :: Int -> Double -> Double Source # isNaN :: Double -> Bool Source # isInfinite :: Double -> Bool Source # isDenormalized :: Double -> Bool Source # isNegativeZero :: Double -> Bool Source # isIEEE :: Double -> Bool Source # atan2 :: Double -> Double -> Double Source #
Function Double
Instance details Defined in Test.QuickCheck.Function Methods function :: (Double -> b) -> Double :-> b Source #
Arbitrary Double
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Double Source # shrink :: Double -> [Double] Source #
CoArbitrary Double
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Double -> Gen b -> Gen b Source #
Foldable (URec Double :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Double m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Double a -> m Source # foldr :: (a -> b -> b) -> b -> URec Double a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Double a -> b Source # foldl :: (b -> a -> b) -> b -> URec Double a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Double a -> b Source # foldr1 :: (a -> a -> a) -> URec Double a -> a Source # foldl1 :: (a -> a -> a) -> URec Double a -> a Source # toList :: URec Double a -> [a] Source # null :: URec Double a -> Bool Source # length :: URec Double a -> Int Source # elem :: Eq a => a -> URec Double a -> Bool Source # maximum :: Ord a => URec Double a -> a Source # minimum :: Ord a => URec Double a -> a Source # sum :: Num a => URec Double a -> a Source # product :: Num a => URec Double a -> a Source #
Traversable (URec Double :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Double a -> f (URec Double b) Source # sequenceA :: Applicative f => URec Double (f a) -> f (URec Double a) Source # mapM :: Monad m => (a -> m b) -> URec Double a -> m (URec Double b) Source # sequence :: Monad m => URec Double (m a) -> m (URec Double a) Source #

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.

Instances

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 substitutivity: `>>>` `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 #
Floating Float	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Float Source # exp :: Float -> Float Source # log :: Float -> Float Source # sqrt :: Float -> Float Source # (**) :: Float -> Float -> Float Source # logBase :: Float -> Float -> Float Source # sin :: Float -> Float Source # cos :: Float -> Float Source # tan :: Float -> Float Source # asin :: Float -> Float Source # acos :: Float -> Float Source # atan :: Float -> Float Source # sinh :: Float -> Float Source # cosh :: Float -> Float Source # tanh :: Float -> Float Source # asinh :: Float -> Float Source # acosh :: Float -> Float Source # atanh :: Float -> Float Source # log1p :: Float -> Float Source # expm1 :: Float -> Float Source # log1pexp :: Float -> Float Source # log1mexp :: Float -> Float Source #
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
Instance details Defined in GHC.Classes Methods compare :: Float -> Float -> Ordering Source # (<) :: Float -> Float -> Bool Source # (<=) :: Float -> Float -> Bool Source # (>) :: Float -> Float -> Bool Source # (>=) :: Float -> Float -> Bool Source # max :: Float -> Float -> Float Source # min :: Float -> Float -> Float Source #
Read Float	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Float Source # readList :: ReadS [Float] Source # readPrec :: ReadPrec Float Source # readListPrec :: ReadPrec [Float] Source #
RealFloat Float	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Float -> Integer Source # floatDigits :: Float -> Int Source # floatRange :: Float -> (Int, Int) Source # decodeFloat :: Float -> (Integer, Int) Source # encodeFloat :: Integer -> Int -> Float Source # exponent :: Float -> Int Source # significand :: Float -> Float Source # scaleFloat :: Int -> Float -> Float Source # isNaN :: Float -> Bool Source # isInfinite :: Float -> Bool Source # isDenormalized :: Float -> Bool Source # isNegativeZero :: Float -> Bool Source # isIEEE :: Float -> Bool Source # atan2 :: Float -> Float -> Float Source #
Function Float
Instance details Defined in Test.QuickCheck.Function Methods function :: (Float -> b) -> Float :-> b Source #
Arbitrary Float
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Float Source # shrink :: Float -> [Float] Source #
CoArbitrary Float
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Float -> Gen b -> Gen b Source #
Foldable (URec Float :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Float m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Float a -> m Source # foldr :: (a -> b -> b) -> b -> URec Float a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Float a -> b Source # foldl :: (b -> a -> b) -> b -> URec Float a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Float a -> b Source # foldr1 :: (a -> a -> a) -> URec Float a -> a Source # foldl1 :: (a -> a -> a) -> URec Float a -> a Source # toList :: URec Float a -> [a] Source # null :: URec Float a -> Bool Source # length :: URec Float a -> Int Source # elem :: Eq a => a -> URec Float a -> Bool Source # maximum :: Ord a => URec Float a -> a Source # minimum :: Ord a => URec Float a -> a Source # sum :: Num a => URec Float a -> a Source # product :: Num a => URec Float a -> a Source #
Traversable (URec Float :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Float a -> f (URec Float b) Source # sequenceA :: Applicative f => URec Float (f a) -> f (URec Float a) Source # mapM :: Monad m => (a -> m b) -> URec Float a -> m (URec Float b) Source # sequence :: Monad m => URec Float (m a) -> m (URec Float a) Source #

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.

Instances

Bounded Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Int Source # maxBound :: Int Source #
Enum Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Int -> Int Source # pred :: Int -> Int Source # toEnum :: Int -> Int Source # fromEnum :: Int -> Int Source # enumFrom :: Int -> [Int] Source # enumFromThen :: Int -> Int -> [Int] Source # enumFromTo :: Int -> Int -> [Int] Source # enumFromThenTo :: Int -> Int -> Int -> [Int] Source #
Eq Int
Instance details Defined in GHC.Classes Methods (==) :: Int -> Int -> Bool Source # (/=) :: Int -> Int -> Bool Source #
Integral Int	Since: base-2.0.1
Instance details Defined in GHC.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 #
Num Int	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Int -> Int -> Int Source # (-) :: Int -> Int -> Int Source # (*) :: Int -> Int -> Int Source # negate :: Int -> Int Source # abs :: Int -> Int Source # signum :: Int -> Int Source # fromInteger :: Integer -> Int 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 #
Read Int	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Int Source # readList :: ReadS [Int] Source # readPrec :: ReadPrec Int Source # readListPrec :: ReadPrec [Int] Source #
Real Int	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Int -> Rational Source #
Show Int	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Int -> ShowS Source # show :: Int -> String Source # showList :: [Int] -> ShowS Source #
Function Int
Instance details Defined in Test.QuickCheck.Function Methods function :: (Int -> b) -> Int :-> b Source #
Arbitrary Int
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Int Source # shrink :: Int -> [Int] Source #
CoArbitrary Int
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Int -> Gen b -> Gen b Source #
Foldable (URec Int :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Int m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Int a -> m Source # foldr :: (a -> b -> b) -> b -> URec Int a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Int a -> b Source # foldl :: (b -> a -> b) -> b -> URec Int a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Int a -> b Source # foldr1 :: (a -> a -> a) -> URec Int a -> a Source # foldl1 :: (a -> a -> a) -> URec Int a -> a Source # toList :: URec Int a -> [a] Source # null :: URec Int a -> Bool Source # length :: URec Int a -> Int Source # elem :: Eq a => a -> URec Int a -> Bool Source # maximum :: Ord a => URec Int a -> a Source # minimum :: Ord a => URec Int a -> a Source # sum :: Num a => URec Int a -> a Source # product :: Num a => URec Int a -> a Source #
Traversable (URec Int :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Int a -> f (URec Int b) Source # sequenceA :: Applicative f => URec Int (f a) -> f (URec Int a) Source # mapM :: Monad m => (a -> m b) -> URec Int a -> m (URec Int b) Source # sequence :: Monad m => URec Int (m a) -> m (URec Int a) Source #

data Integer Source #

Invariant: Jn# and Jp# are used iff value doesn't fit in S#

Useful properties resulting from the invariants:

```
abs (S# _) <= abs (Jp# _)
```
```
abs (S# _) <  abs (Jn# _)
```

Instances

Enum Integer	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Integer -> Integer Source # pred :: Integer -> Integer Source # toEnum :: Int -> Integer Source # fromEnum :: Integer -> Int Source # enumFrom :: Integer -> [Integer] Source # enumFromThen :: Integer -> Integer -> [Integer] Source # enumFromTo :: Integer -> Integer -> [Integer] Source # enumFromThenTo :: Integer -> Integer -> Integer -> [Integer] Source #
Eq Integer
Instance details Defined in GHC.Integer.Type Methods (==) :: Integer -> Integer -> Bool Source # (/=) :: Integer -> Integer -> Bool Source #
Integral Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods quot :: Integer -> Integer -> Integer Source # rem :: Integer -> Integer -> Integer Source # div :: Integer -> Integer -> Integer Source # mod :: Integer -> Integer -> Integer Source # quotRem :: Integer -> Integer -> (Integer, Integer) Source # divMod :: Integer -> Integer -> (Integer, Integer) Source # toInteger :: Integer -> Integer Source #
Num Integer	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Integer -> Integer -> Integer Source # (-) :: Integer -> Integer -> Integer Source # (*) :: Integer -> Integer -> Integer Source # negate :: Integer -> Integer Source # abs :: Integer -> Integer Source # signum :: Integer -> Integer Source # fromInteger :: Integer -> Integer Source #
Ord Integer
Instance details Defined in GHC.Integer.Type Methods compare :: Integer -> Integer -> Ordering Source # (<) :: Integer -> Integer -> Bool Source # (<=) :: Integer -> Integer -> Bool Source # (>) :: Integer -> Integer -> Bool Source # (>=) :: Integer -> Integer -> Bool Source # max :: Integer -> Integer -> Integer Source # min :: Integer -> Integer -> Integer Source #
Read Integer	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Integer Source # readList :: ReadS [Integer] Source # readPrec :: ReadPrec Integer Source # readListPrec :: ReadPrec [Integer] Source #
Real Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Integer -> Rational Source #
Show Integer	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Integer -> ShowS Source # show :: Integer -> String Source # showList :: [Integer] -> ShowS Source #
Function Integer
Instance details Defined in Test.QuickCheck.Function Methods function :: (Integer -> b) -> Integer :-> b Source #
Arbitrary Integer
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Integer Source # shrink :: Integer -> [Integer] Source #
CoArbitrary Integer
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Integer -> Gen b -> Gen b Source #

data Maybe a Source #

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

Monad Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b Source # (>>) :: Maybe a -> Maybe b -> Maybe b Source # return :: a -> Maybe a Source # fail :: String -> Maybe a Source #
Functor Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> Maybe a -> Maybe b Source # (<$) :: a -> Maybe b -> Maybe a Source #
Applicative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> Maybe a Source # (<>) :: Maybe (a -> b) -> Maybe a -> Maybe b Source # liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c Source # (>) :: Maybe a -> Maybe b -> Maybe b Source # (<*) :: Maybe a -> Maybe b -> Maybe a Source #
Foldable Maybe	Since: base-2.1
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m Source # foldMap :: Monoid m => (a -> m) -> Maybe a -> m Source # foldr :: (a -> b -> b) -> b -> Maybe a -> b Source # foldr' :: (a -> b -> b) -> b -> Maybe a -> b Source # foldl :: (b -> a -> b) -> b -> Maybe a -> b Source # foldl' :: (b -> a -> b) -> b -> Maybe a -> b Source # foldr1 :: (a -> a -> a) -> Maybe a -> a Source # foldl1 :: (a -> a -> a) -> Maybe a -> a Source # toList :: Maybe a -> [a] Source # null :: Maybe a -> Bool Source # length :: Maybe a -> Int Source # elem :: Eq a => a -> Maybe a -> Bool Source # maximum :: Ord a => Maybe a -> a Source # minimum :: Ord a => Maybe a -> a Source # sum :: Num a => Maybe a -> a Source # product :: Num a => Maybe a -> a Source #
Traversable Maybe	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Maybe a -> f (Maybe b) Source # sequenceA :: Applicative f => Maybe (f a) -> f (Maybe a) Source # mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b) Source # sequence :: Monad m => Maybe (m a) -> m (Maybe a) Source #
Arbitrary1 Maybe
Instance details Defined in Test.QuickCheck.Arbitrary Methods liftArbitrary :: Gen a -> Gen (Maybe a) Source # liftShrink :: (a -> [a]) -> Maybe a -> [Maybe a] Source #
Alternative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods empty :: Maybe a Source # (<\|>) :: Maybe a -> Maybe a -> Maybe a Source # some :: Maybe a -> Maybe [a] Source # many :: Maybe a -> Maybe [a] Source #
MonadPlus Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods mzero :: Maybe a Source # mplus :: Maybe a -> Maybe a -> Maybe a Source #
Eq a => Eq (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods (==) :: Maybe a -> Maybe a -> Bool Source # (/=) :: Maybe a -> Maybe a -> Bool Source #
Ord a => Ord (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods compare :: Maybe a -> Maybe a -> Ordering Source # (<) :: Maybe a -> Maybe a -> Bool Source # (<=) :: Maybe a -> Maybe a -> Bool Source # (>) :: Maybe a -> Maybe a -> Bool Source # (>=) :: Maybe a -> Maybe a -> Bool Source # max :: Maybe a -> Maybe a -> Maybe a Source # min :: Maybe a -> Maybe a -> Maybe a Source #
Read a => Read (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Maybe a) Source # readList :: ReadS [Maybe a] Source # readPrec :: ReadPrec (Maybe a) Source # readListPrec :: ReadPrec [Maybe a] Source #
Show a => Show (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Maybe a -> ShowS Source # show :: Maybe a -> String Source # showList :: [Maybe a] -> ShowS Source #
Semigroup a => Semigroup (Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Maybe a -> Maybe a -> Maybe a Source # sconcat :: NonEmpty (Maybe a) -> Maybe a Source # stimes :: Integral b => b -> Maybe a -> Maybe a Source #
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 `ee = e` and `es = s = se` for all `s ∈ S`." Since 4.11.0: constraint on inner `a` value generalised from `Monoid` to `Semigroup`. Since: base-2.1*
Instance details Defined in GHC.Base Methods mempty :: Maybe a Source # mappend :: Maybe a -> Maybe a -> Maybe a Source # mconcat :: [Maybe a] -> Maybe a Source #
Function a => Function (Maybe a)
Instance details Defined in Test.QuickCheck.Function Methods function :: (Maybe a -> b) -> Maybe a :-> b Source #
Arbitrary a => Arbitrary (Maybe a)
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen (Maybe a) Source # shrink :: Maybe a -> [Maybe a] Source #
CoArbitrary a => CoArbitrary (Maybe a)
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Maybe a -> Gen b -> Gen b Source #

data Ordering Source #

Constructors

LT
EQ
GT

Instances

Bounded Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Ordering Source # maxBound :: Ordering Source #
Enum Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Ordering -> Ordering Source # pred :: Ordering -> Ordering Source # toEnum :: Int -> Ordering Source # fromEnum :: Ordering -> Int Source # enumFrom :: Ordering -> [Ordering] Source # enumFromThen :: Ordering -> Ordering -> [Ordering] Source # enumFromTo :: Ordering -> Ordering -> [Ordering] Source # enumFromThenTo :: Ordering -> Ordering -> Ordering -> [Ordering] Source #
Eq Ordering
Instance details Defined in GHC.Classes Methods (==) :: Ordering -> Ordering -> Bool Source # (/=) :: Ordering -> Ordering -> Bool Source #
Ord Ordering
Instance details Defined in GHC.Classes Methods compare :: Ordering -> Ordering -> Ordering Source # (<) :: Ordering -> Ordering -> Bool Source # (<=) :: Ordering -> Ordering -> Bool Source # (>) :: Ordering -> Ordering -> Bool Source # (>=) :: Ordering -> Ordering -> Bool Source # max :: Ordering -> Ordering -> Ordering Source # min :: Ordering -> Ordering -> Ordering Source #
Read Ordering	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Ordering Source # readList :: ReadS [Ordering] Source # readPrec :: ReadPrec Ordering Source # readListPrec :: ReadPrec [Ordering] Source #
Show Ordering	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Ordering -> ShowS Source # show :: Ordering -> String Source # showList :: [Ordering] -> ShowS Source #
Semigroup Ordering	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Ordering -> Ordering -> Ordering Source # sconcat :: NonEmpty Ordering -> Ordering Source # stimes :: Integral b => b -> Ordering -> Ordering Source #
Monoid Ordering	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: Ordering Source # mappend :: Ordering -> Ordering -> Ordering Source # mconcat :: [Ordering] -> Ordering Source #
Function Ordering
Instance details Defined in Test.QuickCheck.Function Methods function :: (Ordering -> b) -> Ordering :-> b Source #
Arbitrary Ordering
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Ordering Source # shrink :: Ordering -> [Ordering] Source #
CoArbitrary Ordering
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Ordering -> Gen b -> Gen b Source #

type Rational = Ratio Integer Source #

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

data IO a Source #

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

Monad IO	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: IO a -> (a -> IO b) -> IO b Source # (>>) :: IO a -> IO b -> IO b Source # return :: a -> IO a Source # fail :: String -> IO a Source #
Functor IO	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> IO a -> IO b Source # (<$) :: a -> IO b -> IO a Source #
Applicative IO	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> IO a Source # (<>) :: IO (a -> b) -> IO a -> IO b Source # liftA2 :: (a -> b -> c) -> IO a -> IO b -> IO c Source # (>) :: IO a -> IO b -> IO b Source # (<*) :: IO a -> IO b -> IO a Source #
Alternative IO	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods empty :: IO a Source # (<\|>) :: IO a -> IO a -> IO a Source # some :: IO a -> IO [a] Source # many :: IO a -> IO [a] Source #
MonadPlus IO	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods mzero :: IO a Source # mplus :: IO a -> IO a -> IO a Source #
Example Expectation
Instance details Defined in Test.Hspec.Core.Example Associated Types type Arg Expectation :: Type Source # Methods evaluateExample :: Expectation -> Params -> (ActionWith (Arg Expectation) -> IO ()) -> ProgressCallback -> IO Result Source #
Semigroup a => Semigroup (IO a)	Since: base-4.10.0.0
Instance details Defined in GHC.Base Methods (<>) :: IO a -> IO a -> IO a Source # sconcat :: NonEmpty (IO a) -> IO a Source # stimes :: Integral b => b -> IO a -> IO a Source #
Monoid a => Monoid (IO a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods mempty :: IO a Source # mappend :: IO a -> IO a -> IO a Source # mconcat :: [IO a] -> IO a Source #
IsFormatter (IO Formatter) Source #
Instance details Defined in Test.Hspec.Discover Methods toFormatter :: IO Formatter -> IO Formatter Source #
Example (a -> Expectation)
Instance details Defined in Test.Hspec.Core.Example Associated Types type Arg (a -> Expectation) :: Type Source # Methods evaluateExample :: (a -> Expectation) -> Params -> (ActionWith (Arg (a -> Expectation)) -> IO ()) -> ProgressCallback -> IO Result Source #
type Arg Expectation
Instance details Defined in Test.Hspec.Core.Example type Arg Expectation = ()
type Arg (a -> Expectation)
Instance details Defined in Test.Hspec.Core.Example type Arg (a -> Expectation) = a

data Word Source #

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

Instances

Bounded Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Word Source # maxBound :: Word Source #
Enum Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Word -> Word Source # pred :: Word -> Word Source # toEnum :: Int -> Word Source # fromEnum :: Word -> Int Source # enumFrom :: Word -> [Word] Source # enumFromThen :: Word -> Word -> [Word] Source # enumFromTo :: Word -> Word -> [Word] Source # enumFromThenTo :: Word -> Word -> Word -> [Word] Source #
Eq Word
Instance details Defined in GHC.Classes Methods (==) :: Word -> Word -> Bool Source # (/=) :: Word -> Word -> Bool Source #
Integral Word	Since: base-2.1
Instance details Defined in GHC.Real Methods quot :: Word -> Word -> Word Source # rem :: Word -> Word -> Word Source # div :: Word -> Word -> Word Source # mod :: Word -> Word -> Word Source # quotRem :: Word -> Word -> (Word, Word) Source # divMod :: Word -> Word -> (Word, Word) Source # toInteger :: Word -> Integer Source #
Num Word	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Word -> Word -> Word Source # (-) :: Word -> Word -> Word Source # (*) :: Word -> Word -> Word Source # negate :: Word -> Word Source # abs :: Word -> Word Source # signum :: Word -> Word Source # fromInteger :: Integer -> Word Source #
Ord Word
Instance details Defined in GHC.Classes Methods compare :: Word -> Word -> Ordering Source # (<) :: Word -> Word -> Bool Source # (<=) :: Word -> Word -> Bool Source # (>) :: Word -> Word -> Bool Source # (>=) :: Word -> Word -> Bool Source # max :: Word -> Word -> Word Source # min :: Word -> Word -> Word Source #
Read Word	Since: base-4.5.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word Source # readList :: ReadS [Word] Source # readPrec :: ReadPrec Word Source # readListPrec :: ReadPrec [Word] Source #
Real Word	Since: base-2.1
Instance details Defined in GHC.Real Methods toRational :: Word -> Rational Source #
Show Word	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Word -> ShowS Source # show :: Word -> String Source # showList :: [Word] -> ShowS Source #
Function Word
Instance details Defined in Test.QuickCheck.Function Methods function :: (Word -> b) -> Word :-> b Source #
Arbitrary Word
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen Word Source # shrink :: Word -> [Word] Source #
CoArbitrary Word
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Word -> Gen b -> Gen b Source #
Foldable (URec Word :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => URec Word m -> m Source # foldMap :: Monoid m => (a -> m) -> URec Word a -> m Source # foldr :: (a -> b -> b) -> b -> URec Word a -> b Source # foldr' :: (a -> b -> b) -> b -> URec Word a -> b Source # foldl :: (b -> a -> b) -> b -> URec Word a -> b Source # foldl' :: (b -> a -> b) -> b -> URec Word a -> b Source # foldr1 :: (a -> a -> a) -> URec Word a -> a Source # foldl1 :: (a -> a -> a) -> URec Word a -> a Source # toList :: URec Word a -> [a] Source # null :: URec Word a -> Bool Source # length :: URec Word a -> Int Source # elem :: Eq a => a -> URec Word a -> Bool Source # maximum :: Ord a => URec Word a -> a Source # minimum :: Ord a => URec Word a -> a Source # sum :: Num a => URec Word a -> a Source # product :: Num a => URec Word a -> a Source #
Traversable (URec Word :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> URec Word a -> f (URec Word b) Source # sequenceA :: Applicative f => URec Word (f a) -> f (URec Word a) Source # mapM :: Monad m => (a -> m b) -> URec Word a -> m (URec Word b) Source # sequence :: Monad m => URec Word (m a) -> m (URec Word a) Source #

data Either a b Source #

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

Expand

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

Arbitrary2 Either
Instance details Defined in Test.QuickCheck.Arbitrary Methods liftArbitrary2 :: Gen a -> Gen b -> Gen (Either a b) Source # liftShrink2 :: (a -> [a]) -> (b -> [b]) -> Either a b -> [Either a b] Source #
Monad (Either e)	Since: base-4.4.0.0
Instance details Defined in Data.Either Methods (>>=) :: Either e a -> (a -> Either e b) -> Either e b Source # (>>) :: Either e a -> Either e b -> Either e b Source # return :: a -> Either e a Source # fail :: String -> Either e a Source #
Functor (Either a)	Since: base-3.0
Instance details Defined in Data.Either Methods fmap :: (a0 -> b) -> Either a a0 -> Either a b Source # (<$) :: a0 -> Either a b -> Either a a0 Source #
Applicative (Either e)	Since: base-3.0
Instance details Defined in Data.Either Methods pure :: a -> Either e a Source # (<>) :: Either e (a -> b) -> Either e a -> Either e b Source # liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c Source # (>) :: Either e a -> Either e b -> Either e b Source # (<*) :: Either e a -> Either e b -> Either e a Source #
Foldable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m Source # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m Source # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b Source # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b Source # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b Source # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b Source # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 Source # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 Source # toList :: Either a a0 -> [a0] Source # null :: Either a a0 -> Bool Source # length :: Either a a0 -> Int Source # elem :: Eq a0 => a0 -> Either a a0 -> Bool Source # maximum :: Ord a0 => Either a a0 -> a0 Source # minimum :: Ord a0 => Either a a0 -> a0 Source # sum :: Num a0 => Either a a0 -> a0 Source # product :: Num a0 => Either a a0 -> a0 Source #
Traversable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a0 -> f b) -> Either a a0 -> f (Either a b) Source # sequenceA :: Applicative f => Either a (f a0) -> f (Either a a0) Source # mapM :: Monad m => (a0 -> m b) -> Either a a0 -> m (Either a b) Source # sequence :: Monad m => Either a (m a0) -> m (Either a a0) Source #
Arbitrary a => Arbitrary1 (Either a)
Instance details Defined in Test.QuickCheck.Arbitrary Methods liftArbitrary :: Gen a0 -> Gen (Either a a0) Source # liftShrink :: (a0 -> [a0]) -> Either a a0 -> [Either a a0] Source #
(Eq a, Eq b) => Eq (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods (==) :: Either a b -> Either a b -> Bool Source # (/=) :: Either a b -> Either a b -> Bool Source #
(Ord a, Ord b) => Ord (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods compare :: Either a b -> Either a b -> Ordering Source # (<) :: Either a b -> Either a b -> Bool Source # (<=) :: Either a b -> Either a b -> Bool Source # (>) :: Either a b -> Either a b -> Bool Source # (>=) :: Either a b -> Either a b -> Bool Source # max :: Either a b -> Either a b -> Either a b Source # min :: Either a b -> Either a b -> Either a b Source #
(Read a, Read b) => Read (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods readsPrec :: Int -> ReadS (Either a b) Source # readList :: ReadS [Either a b] Source # readPrec :: ReadPrec (Either a b) Source # readListPrec :: ReadPrec [Either a b] Source #
(Show a, Show b) => Show (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods showsPrec :: Int -> Either a b -> ShowS Source # show :: Either a b -> String Source # showList :: [Either a b] -> ShowS Source #
Semigroup (Either a b)	Since: base-4.9.0.0
Instance details Defined in Data.Either Methods (<>) :: Either a b -> Either a b -> Either a b Source # sconcat :: NonEmpty (Either a b) -> Either a b Source # stimes :: Integral b0 => b0 -> Either a b -> Either a b Source #
(Function a, Function b) => Function (Either a b)
Instance details Defined in Test.QuickCheck.Function Methods function :: (Either a b -> b0) -> Either a b :-> b0 Source #
(Arbitrary a, Arbitrary b) => Arbitrary (Either a b)
Instance details Defined in Test.QuickCheck.Arbitrary Methods arbitrary :: Gen (Either a b) Source # shrink :: Either a b -> [Either a b] Source #
(CoArbitrary a, CoArbitrary b) => CoArbitrary (Either a b)
Instance details Defined in Test.QuickCheck.Arbitrary Methods coarbitrary :: Either a b -> Gen b0 -> Gen b0 Source #

type String = [Char] Source #

A String is a list of characters. String constants in Haskell are values of type String.

readIO :: Read a => String -> IO a Source #

The readIO function is similar to read except that it signals parse failure to the IO monad instead of terminating the program.

readLn :: Read a => IO a Source #

The readLn function combines getLine and readIO.

appendFile :: FilePath -> String -> IO () Source #

The computation appendFile file str function appends the string str, to the file file.

Note that writeFile and appendFile write a literal string to a file. To write a value of any printable type, as with print, use the show function to convert the value to a string first.

main = appendFile "squares" (show [(x,x*x) | x <- [0,0.1..2]])

writeFile :: FilePath -> String -> IO () Source #

The computation writeFile file str function writes the string str, to the file file.

readFile :: FilePath -> IO String Source #

The readFile function reads a file and returns the contents of the file as a string. The file is read lazily, on demand, as with getContents.

interact :: (String -> String) -> IO () Source #

The interact function takes a function of type String->String as its argument. The entire input from the standard input device is passed to this function as its argument, and the resulting string is output on the standard output device.

getContents :: IO String Source #

The getContents operation returns all user input as a single string, which is read lazily as it is needed (same as hGetContents stdin).

getLine :: IO String Source #

Read a line from the standard input device (same as hGetLine stdin).

getChar :: IO Char Source #

Read a character from the standard input device (same as hGetChar stdin).

putStrLn :: String -> IO () Source #

The same as putStr, but adds a newline character.

putStr :: String -> IO () Source #

Write a string to the standard output device (same as hPutStr stdout).

putChar :: Char -> IO () Source #

Write a character to the standard output device (same as hPutChar stdout).

ioError :: IOError -> IO a Source #

Raise an IOException in the IO monad.

type FilePath = String Source #

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.

userError :: String -> IOError Source #

Construct an IOException value with a string describing the error. The fail method of the IO instance of the Monad class raises a userError, thus:

instance Monad IO where
  ...
  fail s = ioError (userError s)

type IOError = IOException Source #

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.

notElem :: (Foldable t, Eq a) => a -> t a -> Bool infix 4 Source #

notElem is the negation of elem.

all :: Foldable t => (a -> Bool) -> t a -> Bool Source #

Determines whether all elements of the structure satisfy the predicate.

any :: Foldable t => (a -> Bool) -> t a -> Bool Source #

Determines whether any element of the structure satisfies the predicate.

or :: Foldable t => t Bool -> Bool Source #

or returns the disjunction of a container of Bools. For the result to be False, the container must be finite; True, however, results from a True value finitely far from the left end.

and :: Foldable t => t Bool -> Bool Source #

and returns the conjunction of a container of Bools. For the result to be True, the container must be finite; False, however, results from a False value finitely far from the left end.

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

Map a function over all the elements of a container and concatenate the resulting lists.

concat :: Foldable t => t [a] -> [a] Source #

The concatenation of all the elements of a container of lists.

sequence_ :: (Foldable t, Monad m) => t (m a) -> m () Source #

Evaluate each monadic action in the structure from left to right, and ignore the results. For a version that doesn't ignore the results see sequence.

As of base 4.8.0.0, sequence_ is just sequenceA_, specialized to Monad.

mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m () Source #

Map each element of a structure to a monadic action, evaluate these actions from left to right, and ignore the results. For a version that doesn't ignore the results see mapM.

As of base 4.8.0.0, mapM_ is just traverse_, specialized to Monad.

unwords :: [String] -> String Source #

unwords is an inverse operation to words. It joins words with separating spaces.

>>> unwords ["Lorem", "ipsum", "dolor"]
"Lorem ipsum dolor"

words :: String -> [String] Source #

words breaks a string up into a list of words, which were delimited by white space.

>>> words "Lorem ipsum\ndolor"
["Lorem","ipsum","dolor"]

unlines :: [String] -> String Source #

unlines is an inverse operation to lines. It joins lines, after appending a terminating newline to each.

>>> unlines ["Hello", "World", "!"]
"Hello\nWorld\n!\n"

lines :: String -> [String] Source #

lines breaks a string up into a list of strings at newline characters. The resulting strings do not contain newlines.

Note that after splitting the string at newline characters, the last part of the string is considered a line even if it doesn't end with a newline. For example,

>>> lines ""
[]

>>> lines "\n"
[""]

>>> lines "one"
["one"]

>>> lines "one\n"
["one"]

>>> lines "one\n\n"
["one",""]

>>> lines "one\ntwo"
["one","two"]

>>> lines "one\ntwo\n"
["one","two"]

Thus lines s contains at least as many elements as newlines in s.

read :: Read a => String -> a Source #

The read function reads input from a string, which must be completely consumed by the input process. read fails with an error if the parse is unsuccessful, and it is therefore discouraged from being used in real applications. Use readMaybe or readEither for safe alternatives.

>>> read "123" :: Int
123

>>> read "hello" :: Int
*** Exception: Prelude.read: no parse

reads :: Read a => ReadS a Source #

equivalent to readsPrec with a precedence of 0.

either :: (a -> c) -> (b -> c) -> Either a b -> c Source #

Case analysis for the Either type. If the value is Left a, apply the first function to a; if it is Right b, apply the second function to b.

Examples

Expand

We create two values of type Either String Int, one using the Left constructor and another using the Right constructor. Then we apply "either" the length function (if we have a String) or the "times-two" function (if we have an Int):

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

lex :: ReadS String Source #

The lex function reads a single lexeme from the input, discarding initial white space, and returning the characters that constitute the lexeme. If the input string contains only white space, lex returns a single successful `lexeme' consisting of the empty string. (Thus lex "" = [("","")].) If there is no legal lexeme at the beginning of the input string, lex fails (i.e. returns []).

This lexer is not completely faithful to the Haskell lexical syntax in the following respects:

Qualified names are not handled properly
Octal and hexadecimal numerics are not recognized as a single token
Comments are not treated properly

readParen :: Bool -> ReadS a -> ReadS a Source #

readParen True p parses what p parses, but surrounded with parentheses.

readParen False p parses what p parses, but optionally surrounded with parentheses.

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

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).

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

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

Expand

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)

lcm :: Integral a => a -> a -> a Source #

lcm x y is the smallest positive integer that both x and y divide.

gcd :: Integral a => a -> a -> a Source #

gcd x y is the non-negative factor of both x and y of which every common factor of x and y is also a factor; for example gcd 4 2 = 2, gcd (-4) 6 = 2, gcd 0 4 = 4. gcd 0 0 = 0. (That is, the common divisor that is "greatest" in the divisibility preordering.)

Note: Since for signed fixed-width integer types, abs minBound < 0, the result may be negative if one of the arguments is minBound (and necessarily is if the other is 0 or minBound) for such types.

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

raise a number to an integral power

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

raise a number to a non-negative integral power

odd :: Integral a => a -> Bool Source #

even :: Integral a => a -> Bool Source #

showParen :: Bool -> ShowS -> ShowS Source #

utility function that surrounds the inner show function with parentheses when the Bool parameter is True.

showString :: String -> ShowS Source #

utility function converting a String to a show function that simply prepends the string unchanged.

showChar :: Char -> ShowS Source #

utility function converting a Char to a show function that simply prepends the character unchanged.

shows :: Show a => a -> ShowS Source #

equivalent to showsPrec with a precedence of 0.

type ShowS = String -> String Source #

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.

unzip3 :: [(a, b, c)] -> ([a], [b], [c]) Source #

The unzip3 function takes a list of triples and returns three lists, analogous to unzip.

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

unzip transforms a list of pairs into a list of first components and a list of second components.

zipWith3 :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d] Source #

The zipWith3 function takes a function which combines three elements, as well as three lists and returns a list of their point-wise combination, analogous to zipWith.

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

zipWith generalises zip by zipping with the function given as the first argument, instead of a tupling function. For example, zipWith (+) is applied to two lists to produce the list of corresponding sums.

zipWith is right-lazy:

zipWith f [] _|_ = []

zip3 :: [a] -> [b] -> [c] -> [(a, b, c)] Source #

zip3 takes three lists and returns a list of triples, analogous to zip.

(!!) :: [a] -> Int -> a infixl 9 Source #

List index (subscript) operator, starting from 0. It is an instance of the more general genericIndex, which takes an index of any integral type.

lookup :: Eq a => a -> [(a, b)] -> Maybe b Source #

lookup key assocs looks up a key in an association list.

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

reverse xs returns the elements of xs in reverse order. xs must be finite.

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

break, applied to a predicate p and a list xs, returns a tuple where first element is longest prefix (possibly empty) of xs of elements that do not satisfy p and second element is the remainder of the list:

break (> 3) [1,2,3,4,1,2,3,4] == ([1,2,3],[4,1,2,3,4])
break (< 9) [1,2,3] == ([],[1,2,3])
break (> 9) [1,2,3] == ([1,2,3],[])

break p is equivalent to span (not . p).

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

span, applied to a predicate p and a list xs, returns a tuple where first element is longest prefix (possibly empty) of xs of elements that satisfy p and second element is the remainder of the list:

span (< 3) [1,2,3,4,1,2,3,4] == ([1,2],[3,4,1,2,3,4])
span (< 9) [1,2,3] == ([1,2,3],[])
span (< 0) [1,2,3] == ([],[1,2,3])

span p xs is equivalent to (takeWhile p xs, dropWhile p xs)

splitAt :: Int -> [a] -> ([a], [a]) Source #

splitAt n xs returns a tuple where first element is xs prefix of length n and second element is the remainder of the list:

splitAt 6 "Hello World!" == ("Hello ","World!")
splitAt 3 [1,2,3,4,5] == ([1,2,3],[4,5])
splitAt 1 [1,2,3] == ([1],[2,3])
splitAt 3 [1,2,3] == ([1,2,3],[])
splitAt 4 [1,2,3] == ([1,2,3],[])
splitAt 0 [1,2,3] == ([],[1,2,3])
splitAt (-1) [1,2,3] == ([],[1,2,3])

It is equivalent to (take n xs, drop n xs) when n is not _|_ (splitAt _|_ xs = _|_). splitAt is an instance of the more general genericSplitAt, in which n may be of any integral type.

drop :: Int -> [a] -> [a] Source #

drop n xs returns the suffix of xs after the first n elements, or [] if n > length xs:

drop 6 "Hello World!" == "World!"
drop 3 [1,2,3,4,5] == [4,5]
drop 3 [1,2] == []
drop 3 [] == []
drop (-1) [1,2] == [1,2]
drop 0 [1,2] == [1,2]

It is an instance of the more general genericDrop, in which n may be of any integral type.

take :: Int -> [a] -> [a] Source #

take n, applied to a list xs, returns the prefix of xs of length n, or xs itself if n > length xs:

take 5 "Hello World!" == "Hello"
take 3 [1,2,3,4,5] == [1,2,3]
take 3 [1,2] == [1,2]
take 3 [] == []
take (-1) [1,2] == []
take 0 [1,2] == []

It is an instance of the more general genericTake, in which n may be of any integral type.

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

dropWhile p xs returns the suffix remaining after takeWhile p xs:

dropWhile (< 3) [1,2,3,4,5,1,2,3] == [3,4,5,1,2,3]
dropWhile (< 9) [1,2,3] == []
dropWhile (< 0) [1,2,3] == [1,2,3]

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

takeWhile, applied to a predicate p and a list xs, returns the longest prefix (possibly empty) of xs of elements that satisfy p:

takeWhile (< 3) [1,2,3,4,1,2,3,4] == [1,2]
takeWhile (< 9) [1,2,3] == [1,2,3]
takeWhile (< 0) [1,2,3] == []

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

cycle ties a finite list into a circular one, or equivalently, the infinite repetition of the original list. It is the identity on infinite lists.

replicate :: Int -> a -> [a] Source #

replicate n x is a list of length n with x the value of every element. It is an instance of the more general genericReplicate, in which n may be of any integral type.

repeat :: a -> [a] Source #

repeat x is an infinite list, with x the value of every element.

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

iterate f x returns an infinite list of repeated applications of f to x:

iterate f x == [x, f x, f (f x), ...]

Note that iterate is lazy, potentially leading to thunk build-up if the consumer doesn't force each iterate. See 'iterate\'' for a strict variant of this function.

scanr1 :: (a -> a -> a) -> [a] -> [a] Source #

scanr1 is a variant of scanr that has no starting value argument.

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

scanr is the right-to-left dual of scanl. Note that

head (scanr f z xs) == foldr f z xs.

scanl1 :: (a -> a -> a) -> [a] -> [a] Source #

scanl1 is a variant of scanl that has no starting value argument:

scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]

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

scanl is similar to foldl, but returns a list of successive reduced values from the left:

scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]

Note that

last (scanl f z xs) == foldl f z xs.

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

Return all the elements of a list except the last one. The list must be non-empty.

last :: [a] -> a Source #

Extract the last element of a list, which must be finite and non-empty.

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

Extract the elements after the head of a list, which must be non-empty.

head :: [a] -> a Source #

Extract the first element of a list, which must be non-empty.

maybe :: b -> (a -> b) -> Maybe a -> b Source #

The maybe function takes a default value, a function, and a Maybe value. If the Maybe value is Nothing, the function returns the default value. Otherwise, it applies the function to the value inside the Just and returns the result.

Examples

Expand

Basic usage:

>>> maybe False odd (Just 3)
True

>>> maybe False odd Nothing
False

Read an integer from a string using readMaybe. If we succeed, return twice the integer; that is, apply (*2) to it. If instead we fail to parse an integer, return 0 by default:

>>> import Text.Read ( readMaybe )
>>> maybe 0 (*2) (readMaybe "5")
10
>>> maybe 0 (*2) (readMaybe "")
0

Apply show to a Maybe Int. If we have Just n, we want to show the underlying Int n. But if we have Nothing, we return the empty string instead of (for example) "Nothing":

>>> maybe "" show (Just 5)
"5"
>>> maybe "" show Nothing
""

uncurry :: (a -> b -> c) -> (a, b) -> c Source #

uncurry converts a curried function to a function on pairs.

Examples

Expand

>>> uncurry (+) (1,2)
3

>>> uncurry ($) (show, 1)
"1"

>>> map (uncurry max) [(1,2), (3,4), (6,8)]
[2,4,8]

curry :: ((a, b) -> c) -> a -> b -> c Source #

curry converts an uncurried function to a curried function.

Examples

Expand

>>> curry fst 1 2
1

subtract :: Num a => a -> a -> a Source #

the same as flip (-).

Because - is treated specially in the Haskell grammar, (- e) is not a section, but an application of prefix negation. However, (subtract exp) is equivalent to the disallowed section.

asTypeOf :: a -> a -> a Source #

asTypeOf is a type-restricted version of const. It is usually used as an infix operator, and its typing forces its first argument (which is usually overloaded) to have the same type as the second.

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

until p f yields the result of applying f until p holds.

($!) :: (a -> b) -> a -> b infixr 0 Source #

Strict (call-by-value) application operator. It takes a function and an argument, evaluates the argument to weak head normal form (WHNF), then calls the function with that value.

flip :: (a -> b -> c) -> b -> a -> c Source #

flip f takes its (first) two arguments in the reverse order of f.

>>> flip (++) "hello" "world"
"worldhello"

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

Function composition.

const :: a -> b -> a Source #

const x is a unary function which evaluates to x for all inputs.

>>> const 42 "hello"
42

>>> map (const 42) [0..3]
[42,42,42,42]

id :: a -> a Source #

Identity function.

id x = x

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

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

undefined :: HasCallStack => a Source #

A special case of error. It is expected that compilers will recognize this and insert error messages which are more appropriate to the context in which undefined appears.

errorWithoutStackTrace :: [Char] -> a Source #

A variant of error that does not produce a stack trace.

Since: base-4.9.0.0

error :: HasCallStack => [Char] -> a Source #

error stops execution and displays an error message.

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

Boolean "and"

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

Boolean "or"

not :: Bool -> Bool Source #

Boolean "not"