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Within LTS Haskell 24.33 (ghc-9.10.3)

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1. alphaNum :: MonadGen m => m Char

   hedgehog	Hedgehog.Internal.Gen

   Generates an ASCII letter or digit: 'a'..'z', 'A'..'Z', '0'..'9'

2. enum :: (MonadGen m, Enum a) => a -> a -> m a

   hedgehog	Hedgehog.Internal.Gen

   Generates an element from an enumeration. This generator shrinks towards the first argument. For example:

   enum 'a' 'z' :: Gen Char
   

3. enumBounded :: (MonadGen m, Enum a, Bounded a) => m a

   hedgehog	Hedgehog.Internal.Gen

   Generates a random value from a bounded enumeration. This generator shrinks towards minBound. For example:

   enumBounded :: Gen Bool
   

   This is implemented in terms of the Enum class, and thus may be partial for integral types larger than Int, e.g. Word64.

4. class Enum a

   hedgehog	Hedgehog.Internal.Prelude

   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
   

5. enumFrom :: Enum a => a -> [a]

   hedgehog	Hedgehog.Internal.Prelude

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

   Examples

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

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

6. enumFromThen :: Enum a => a -> a -> [a]

   hedgehog	Hedgehog.Internal.Prelude

   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
   
   

   Examples

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

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

7. enumFromThenTo :: Enum a => a -> a -> a -> [a]

   hedgehog	Hedgehog.Internal.Prelude

   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 = []
   
   

   Examples

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

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

8. enumFromTo :: Enum a => a -> a -> [a]

   hedgehog	Hedgehog.Internal.Prelude

   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 = []
   
   

   Examples

   • enumFromTo 6 10 :: [Int] = [6,7,8,9,10]

   • enumFromTo 42 1 :: [Integer] = []

9. fromEnum :: Enum a => a -> Int

   hedgehog	Hedgehog.Internal.Prelude

   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.

10. signum :: Num a => a -> a

    hedgehog	Hedgehog.Internal.Prelude

    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).

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