Test.LeanCheck.Function.ShowFunction

This module is part of LeanCheck, a simple enumerative property-based testing library.

This module exports the ShowFunction typeclass, its instances and related functions.

Using this module, it is possible to implement a Show instance for functions:

import Test.LeanCheck.ShowFunction
instance (Show a, Listable a, ShowFunction b) => Show (a->b) where
  show = showFunction 8

This shows functions as a case pattern with up to 8 cases.

The module Test.LeanCheck.Function.Show (Show) exports an instance like the one above.

Documentation

showFunction :: ShowFunction a => Int -> a -> String

Given a number of patterns to show, shows a ShowFunction value.

showFunction undefined True == "True"
showFunction 3 (id::Int) == "\\x -> case x of\n\
                             \        0 -> 0\n\
                             \        1 -> 1\n\
                             \        -1 -> -1\n\
                             \        ...\n"
showFunction 4 (&&) == "\\x y -> case (x,y) of\n\
                        \          (False,False) -> False\n\
                        \          (False,True) -> False\n\
                        \          (True,False) -> False\n\
                        \          (True,True) -> True\n"

This can be used as an implementation of show for functions:

instance (Show a, Listable a, ShowFunction b) => Show (a->b) where
  show = showFunction 8

showFunctionLine :: ShowFunction a => Int -> a -> String

Same as showFunction, but has no line breaks.

showFunction 2 (id::Int) == "\\x -> case x of 0 -> 0; 1 -> 1; ..."

type Binding = ([String], Maybe String)

A functional binding in a showable format.

bindings :: ShowFunction a => a -> [Binding]

Given a ShowFunction value, return a list of bindings for printing. Examples:

bindings True == [([],True)]
bindings (id::Int) == [(["0"],"0"), (["1"],"1"), (["-1"],"-1"), ...
bindings (&&) == [ (["False","False"], "False")
                 , (["False","True"], "False")
                 , (["True","False"], "False")
                 , (["True","True"], "True")
                 ]

class ShowFunction a where

ShowFunction values are those for which we can return a list of functional bindings.

As a user, you probably want showFunction and showFunctionLine.

Non functional instances should be defined by:

instance ShowFunction Ty where tBindings = tBindingsShow

Minimal complete definition

tBindings

Methods

tBindings :: a -> [[Binding]]

Instances

ShowFunction Bool

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Bool -> [[Binding]]

ShowFunction Char

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Char -> [[Binding]]

ShowFunction Double

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Double -> [[Binding]]

ShowFunction Float

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Float -> [[Binding]]

ShowFunction Int

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Int -> [[Binding]]

ShowFunction Integer

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Integer -> [[Binding]]

ShowFunction Ordering

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Ordering -> [[Binding]]

ShowFunction ()

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: () -> [[Binding]]

ShowFunction Nat7

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat7 -> [[Binding]]

ShowFunction Nat6

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat6 -> [[Binding]]

ShowFunction Nat5

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat5 -> [[Binding]]

ShowFunction Nat4

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat4 -> [[Binding]]

ShowFunction Nat3

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat3 -> [[Binding]]

ShowFunction Nat2

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat2 -> [[Binding]]

ShowFunction Nat1

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat1 -> [[Binding]]

ShowFunction Nat

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Nat -> [[Binding]]

ShowFunction Word4

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Word4 -> [[Binding]]

ShowFunction Word3

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Word3 -> [[Binding]]

ShowFunction Word2

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Word2 -> [[Binding]]

ShowFunction Word1

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Word1 -> [[Binding]]

ShowFunction Int4

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Int4 -> [[Binding]]

ShowFunction Int3

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Int3 -> [[Binding]]

ShowFunction Int2

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Int2 -> [[Binding]]

ShowFunction Int1

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Int1 -> [[Binding]]

Show a => ShowFunction [a]

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: [a] -> [[Binding]]

Show a => ShowFunction (Maybe a)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Maybe a -> [[Binding]]

(Show a, Listable a, ShowFunction b) => ShowFunction (a -> b)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: (a -> b) -> [[Binding]]

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

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: Either a b -> [[Binding]]

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

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: (a, b) -> [[Binding]]

(Show a, Show b, Show c) => ShowFunction (a, b, c)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: (a, b, c) -> [[Binding]]

(Show a, Show b, Show c, Show d) => ShowFunction (a, b, c, d)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

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

(Show a, Show b, Show c, Show d, Show e) => ShowFunction (a, b, c, d, e)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

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

(Show a, Show b, Show c, Show d, Show e, Show f) => ShowFunction (a, b, c, d, e, f)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: (a, b, c, d, e, f) -> [[Binding]]

(Show a, Show b, Show c, Show d, Show e, Show f, Show g) => ShowFunction (a, b, c, d, e, f, g)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: (a, b, c, d, e, f, g) -> [[Binding]]

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h) => ShowFunction (a, b, c, d, e, f, g, h)

Defined in Test.LeanCheck.Function.ShowFunction

Methods

tBindings :: (a, b, c, d, e, f, g, h) -> [[Binding]]

tBindingsShow :: Show a => a -> [[Binding]]

A default implementation of tBindings for already Show-able types.

Re-exports

class Listable a

A type is Listable when there exists a function that is able to list (ideally all of) its values.

Ideally, instances should be defined by a tiers function that returns a (potentially infinite) list of finite sub-lists (tiers): the first sub-list contains elements of size 0, the second sub-list contains elements of size 1 and so on. Size here is defined by the implementor of the type-class instance.

For algebraic data types, the general form for tiers is

tiers = cons<N> ConstructorA
     \/ cons<N> ConstructorB
     \/ ...
     \/ cons<N> ConstructorZ

where N is the number of arguments of each constructor A...Z.

Instances can be alternatively defined by list. In this case, each sub-list in tiers is a singleton list (each succeeding element of list has +1 size).

The function deriveListable from Test.LeanCheck.Derive can automatically derive instances of this typeclass.

A Listable instance for functions is also available but is not exported by default. Import Test.LeanCheck.Function if you need to test higher-order properties.

Minimal complete definition

list | tiers

Instances

Listable Bool

tiers :: [[Bool]] = [[False,True]]
list :: [[Bool]] = [False,True]

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Bool]]

list :: [Bool]

Listable Char

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Char]]

list :: [Char]

Listable Double

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Double]]

list :: [Double]

Listable Float

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Float]]

list :: [Float]

Listable Int

tiers :: [[Int]] = [[0], [1], [-1], [2], [-2], [3], [-3], ...]
list :: [Int] = [0, 1, -1, 2, -2, 3, -3, 4, -4, 5, -5, 6, ...]

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Int]]

list :: [Int]

Listable Integer

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Integer]]

list :: [Integer]

Listable Ordering

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Ordering]]

list :: [Ordering]

Listable Word

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[Word]]

list :: [Word]

Listable ()

Defined in Test.LeanCheck.Core

Methods

tiers :: [[()]]

list :: [()]

Listable Nat7

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat7]]

list :: [Nat7]

Listable Nat6

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat6]]

list :: [Nat6]

Listable Nat5

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat5]]

list :: [Nat5]

Listable Nat4

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat4]]

list :: [Nat4]

Listable Nat3

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat3]]

list :: [Nat3]

Listable Nat2

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat2]]

list :: [Nat2]

Listable Nat1

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat1]]

list :: [Nat1]

Listable Nat

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Nat]]

list :: [Nat]

Listable Natural

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Natural]]

list :: [Natural]

Listable Word4

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Word4]]

list :: [Word4]

Listable Word3

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Word3]]

list :: [Word3]

Listable Word2

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Word2]]

list :: [Word2]

Listable Word1

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Word1]]

list :: [Word1]

Listable Int4

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Int4]]

list :: [Int4]

Listable Int3

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Int3]]

list :: [Int3]

Listable Int2

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Int2]]

list :: [Int2]

Listable Int1

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Int1]]

list :: [Int1]

Listable a => Listable [a]

tiers :: [[ [Int] ]] = [ [ [] ]
                       , [ [0] ]
                       , [ [0,0], [1] ]
                       , [ [0,0,0], [0,1], [1,0], [-1] ]
                       , ... ]
list :: [ [Int] ] = [ [], [0], [0,0], [1], [0,0,0], ... ]

Defined in Test.LeanCheck.Core

Methods

tiers :: [[[a]]]

list :: [[a]]

Listable a => Listable (Maybe a)

tiers :: [[Maybe Int]] = [[Nothing], [Just 0], [Just 1], ...]
tiers :: [[Maybe Bool]] = [[Nothing], [Just False, Just True]]

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Maybe a]]

list :: [Maybe a]

(Integral a, Listable a) => Listable (Ratio a)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[Ratio a]]

list :: [Ratio a]

(Integral a, Bounded a) => Listable (Xs a)

Lists with elements of the X type.

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Xs a]]

list :: [Xs a]

(Integral a, Bounded a) => Listable (X a)

Extremily large integers are intercalated with small integers.

list :: [X Int] = map X
  [ 0, 1, -1, maxBound,   minBound
     , 2, -2, maxBound-1, minBound+1
     , 3, -3, maxBound-2, minBound+2
     , ... ]

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[X a]]

list :: [X a]

Listable a => Listable (Set a)

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Set a]]

list :: [Set a]

Listable a => Listable (Bag a)

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Bag a]]

list :: [Bag a]

Listable a => Listable (NoDup a)

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[NoDup a]]

list :: [NoDup a]

(Eq a, Listable a, Listable b) => Listable (a -> b)

Defined in Test.LeanCheck.Function.Listable.ListsOfPairs

Methods

tiers :: [[a -> b]]

list :: [a -> b]

(Eq a, Eq b, Listable a, Listable b) => Listable (a -> b)

Defined in Test.LeanCheck.Function.Listable.Periodic

Methods

tiers :: [[a -> b]]

list :: [a -> b]

(FunListable a, Listable b) => Listable (a -> b)

Defined in Test.LeanCheck.Function.Listable.FunListable

Methods

tiers :: [[a -> b]]

list :: [a -> b]

(Eq a, Listable a, CoListable a, Listable b) => Listable (a -> b)

Defined in Test.LeanCheck.Function.Listable.Mixed

Methods

tiers :: [[a -> b]]

list :: [a -> b]

(CoListable a, Listable b) => Listable (a -> b)

Defined in Test.LeanCheck.Function.Listable.CoListable

Methods

tiers :: [[a -> b]]

list :: [a -> b]

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

Defined in Test.LeanCheck.Core

Methods

tiers :: [[Either a b]]

list :: [Either a b]

(Listable a, Listable b) => Listable (a, b)

tiers :: [[(Int,Int)]] =
[ [(0,0)]
, [(0,1),(1,0)]
, [(0,-1),(1,1),(-1,0)]
, ...]
list :: [(Int,Int)] = [ (0,0), (0,1), (1,0), (0,-1), (1,1), ...]

Defined in Test.LeanCheck.Core

Methods

tiers :: [[(a, b)]]

list :: [(a, b)]

(Listable a, Listable b) => Listable (Map a b)

Defined in Test.LeanCheck.Utils.Types

Methods

tiers :: [[Map a b]]

list :: [Map a b]

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

Defined in Test.LeanCheck.Core

Methods

tiers :: [[(a, b, c)]]

list :: [(a, b, c)]

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

Defined in Test.LeanCheck.Core

Methods

tiers :: [[(a, b, c, d)]]

list :: [(a, b, c, d)]

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

Defined in Test.LeanCheck.Core

Methods

tiers :: [[(a, b, c, d, e)]]

list :: [(a, b, c, d, e)]

(Listable a, Listable b, Listable c, Listable d, Listable e, Listable f) => Listable (a, b, c, d, e, f)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[(a, b, c, d, e, f)]]

list :: [(a, b, c, d, e, f)]

(Listable a, Listable b, Listable c, Listable d, Listable e, Listable f, Listable g) => Listable (a, b, c, d, e, f, g)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[(a, b, c, d, e, f, g)]]

list :: [(a, b, c, d, e, f, g)]

(Listable a, Listable b, Listable c, Listable d, Listable e, Listable f, Listable g, Listable h) => Listable (a, b, c, d, e, f, g, h)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[(a, b, c, d, e, f, g, h)]]

list :: [(a, b, c, d, e, f, g, h)]

(Listable a, Listable b, Listable c, Listable d, Listable e, Listable f, Listable g, Listable h, Listable i) => Listable (a, b, c, d, e, f, g, h, i)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[(a, b, c, d, e, f, g, h, i)]]

list :: [(a, b, c, d, e, f, g, h, i)]

(Listable a, Listable b, Listable c, Listable d, Listable e, Listable f, Listable g, Listable h, Listable i, Listable j) => Listable (a, b, c, d, e, f, g, h, i, j)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[(a, b, c, d, e, f, g, h, i, j)]]

list :: [(a, b, c, d, e, f, g, h, i, j)]

(Listable a, Listable b, Listable c, Listable d, Listable e, Listable f, Listable g, Listable h, Listable i, Listable j, Listable k) => Listable (a, b, c, d, e, f, g, h, i, j, k)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[(a, b, c, d, e, f, g, h, i, j, k)]]

list :: [(a, b, c, d, e, f, g, h, i, j, k)]

(Listable a, Listable b, Listable c, Listable d, Listable e, Listable f, Listable g, Listable h, Listable i, Listable j, Listable k, Listable l) => Listable (a, b, c, d, e, f, g, h, i, j, k, l)

Defined in Test.LeanCheck.Basic

Methods

tiers :: [[(a, b, c, d, e, f, g, h, i, j, k, l)]]

list :: [(a, b, c, d, e, f, g, h, i, j, k, l)]