| Copyright | (c) 2015-2021 Rudy Matela |
|---|---|
| License | 3-Clause BSD (see the file LICENSE) |
| Maintainer | Rudy Matela <rudy@matela.com.br> |
| Safe Haskell | None |
| Language | Haskell2010 |
Test.LeanCheck.Function.List
Description
This module is part of LeanCheck, a simple enumerative property-based testing library.
This module exports functions to convert functions to lists of return values and producing comparisons between functions.
Synopsis
- funToList :: Listable a => (a -> b) -> [b]
- funToListMaybe :: Listable a => (a -> b) -> [Maybe b]
- funToListEither :: Listable a => (a -> b) -> [Either String b]
- areEqualFor :: (Listable a, Eq b) => Int -> (a -> b) -> (a -> b) -> Bool
- compareFor :: (Listable a, Ord b) => Int -> (a -> b) -> (a -> b) -> Ordering
Documentation
funToList :: Listable a => (a -> b) -> [b] Source #
Converts a function to a list of result values
for each Listable argument value.
> list :: [Bool] [False,True] > funToList not [True,False]
> list :: [(Bool,Bool)] [(False,False),(False,True),(True,False),(True,True)] > funToList $ uncurry (&&) [False,False,False,True]
This function may return an infinite list,
use take as required.
> take 10 $ list :: [Int] [0,1,-1,2,-2,3,-3,4,-4,5] > take 10 $ funToList (+1) :: [Int] [1,2,0,3,-1,4,-2,5,-3,6]
funToListMaybe :: Listable a => (a -> b) -> [Maybe b] Source #
Converts a function to a list of Just result values
or Nothing on error.
> take 6 $ funToListMaybe $ head :: [Maybe Int] [Nothing,Just 0,Just 0,Just 1,Just 0,Just 0]
This uses errorToNothing and consequently unsafePerformIO.
funToListEither :: Listable a => (a -> b) -> [Either String b] Source #
Converts a function to a list of Just result values
or Nothing on error.
> take 6 $ funToListEither $ head :: [Either String Int] [Left "Prelude.head: empty list",Right 0,Right 0,Right 1,Right 0,Right 0]
This uses errorToLeft and consequently unsafePerformIO.
areEqualFor :: (Listable a, Eq b) => Int -> (a -> b) -> (a -> b) -> Bool Source #
This function can be used to define an Eq instance for functions based on testing and equality of returned values, like so:
instance (Listable a, Eq b) => Eq (a -> b) where (==) = areEqualFor 12
This catches errors and undefined values and treats them as equal.
compareFor :: (Listable a, Ord b) => Int -> (a -> b) -> (a -> b) -> Ordering Source #
This function can be used to define an Ord instance for functions based on testing and ordering of returned values, like so:
instance (Listable a, Ord b) => Ord (a -> b) where compare = compareFor 12
This catches errors and undefined values and treats them as equal.