lens-properties (empty) → 4.0

raw patch · 4 files changed

+161/−0 lines, 4 filesdep +QuickCheckdep +basedep +lenssetup-changed

Dependencies added: QuickCheck, base, lens, transformers

Files

• CHANGELOG.markdown +9/−0
• Setup.hs +2/−0
• lens-properties.cabal +32/−0
• src/Control/Lens/Properties.hs +118/−0

@@ -0,0 +1,9 @@+4.0+---++* Initial release containing the properties:+  * `isIso`+  * `isLens`+  * `isPrism`+  * `isSetter`+  * `isTraversal`

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

@@ -0,0 +1,32 @@+name:          lens-properties+category:      Data, Lenses+version:       4.0+license:       BSD3+cabal-version: >= 1.8+author:        Edward Kmett and Oliver Charles+maintainer:    Edward Kmett <ekmett@gmail.com>+stability:     provisional+homepage:      http://github.com/ekmett/lens/+bug-reports:   http://github.com/ekmett/lens/issues+copyright:     Copyright (C) 2012-2014 Edward A. Kmett, Copyright (C) 2014 Oliver Charles+synopsis:      QuickCheck properties for lens+build-type:    Simple++extra-source-files:+  CHANGELOG.markdown++source-repository head+  type: git+  location: git://github.com/ekmett/lens.git++library+  build-depends:+    base         >= 4.3 && < 5,+    lens         >= 4   && < 4.1,+    QuickCheck   >= 2.4 && < 2.7,+    transformers >= 0.2 && < 0.4++  exposed-modules:+    Control.Lens.Properties++  hs-source-dirs: src

@@ -0,0 +1,118 @@+{-# LANGUAGE Rank2Types #-}+{-# LANGUAGE LiberalTypeSynonyms #-}+{-# LANGUAGE ScopedTypeVariables #-}+-- | A collection of properties that can be tested with QuickCheck, to guarantee+-- that you are working with valid 'Lens'es, 'Setter's, 'Traversal's, 'Iso's and+-- 'Prism's.+module Control.Lens.Properties+    ( isLens+    , isTraversal+    , isSetter+    , isIso+    , isPrism+    ) where++import Control.Applicative+import Control.Lens+import Data.Functor.Compose+import Test.QuickCheck+import Test.QuickCheck.Function++--------------------------------------------------------------------------------+-- | A 'Setter' is only legal if the following 3 laws hold:+--+-- 1. @set l y (set l x a) ≡ set l y a@+--+-- 2. @over l id ≡ id@+--+-- 3. @over l f . over l g ≡ over l (f . g)@+isSetter :: (Arbitrary s, Arbitrary a, CoArbitrary a, Show s, Show a, Eq s, Function a)+         => Simple Setter s a -> Property+isSetter l = setter_id l .&. setter_composition l .&. setter_set_set l+++--------------------------------------------------------------------------------+-- | A 'Traversal' is only legal if it is a valid 'Setter' (see 'isSetter' for+-- what makes a 'Setter' valid), and the following laws hold:+--+-- 1. @t pure ≡ pure@+--+-- 2. @fmap (t f) . t g ≡ getCompose . t (Compose . fmap f . g)@+isTraversal :: (Arbitrary s, Arbitrary a, CoArbitrary a, Show s, Show a, Eq s, Function a)+         => Simple Traversal s a -> Property+isTraversal l = isSetter l .&. traverse_pureMaybe l .&. traverse_pureList l+                  .&. do as <- arbitrary+                         bs <- arbitrary+                         t <- arbitrary+                         property $ traverse_compose l (\x -> as++[x]++bs)+                                                       (\x -> if t then Just x else Nothing)+++--------------------------------------------------------------------------------+-- | A 'Lens' is only legal if it is a valid 'Traversal' (see 'isTraversal' for+-- what this means), and if the following laws hold:+--+-- 1. @view l (set l b a)  ≡ b@+--+-- 2. @set l (view l a) a  ≡ a@+--+-- 3. @set l c (set l b a) ≡ set l c a@+isLens :: (Arbitrary s, Arbitrary a, CoArbitrary a, Show s, Show a, Eq s, Eq a, Function a)+       => Simple Lens s a -> Property+isLens l = lens_set_view l .&. lens_view_set l .&. isTraversal l+++--------------------------------------------------------------------------------+isIso :: (Arbitrary s, Arbitrary a, CoArbitrary s, CoArbitrary a, Show s, Show a, Eq s, Eq a, Function s, Function a)+      => Simple Iso s a -> Property+isIso l = iso_hither l .&. iso_yon l .&. isLens l .&. isLens (from l)+++--------------------------------------------------------------------------------+isPrism :: (Arbitrary s, Arbitrary a, CoArbitrary a, Show s, Show a, Eq s, Eq a, Function a)+      => Simple Prism s a -> Property+isPrism l = isTraversal l .&. prism_yin l .&. prism_yang l+++--------------------------------------------------------------------------------+-- The first setter law:+setter_id :: Eq s => Simple Setter s a -> s -> Bool+setter_id l s = over l id s == s++--  The second setter law:+setter_composition :: Eq s => Simple Setter s a -> s -> Fun a a -> Fun a a -> Bool+setter_composition l s (Fun _ f) (Fun _ g) = over l f (over l g s) == over l (f . g) s++lens_set_view :: Eq s => Simple Lens s a -> s -> Bool+lens_set_view l s = set l (view l s) s == s++lens_view_set :: Eq a => Simple Lens s a -> s -> a -> Bool+lens_view_set l s a = view l (set l a s) == a++setter_set_set :: Eq s => Simple Setter s a -> s -> a -> a -> Bool+setter_set_set l s a b = set l b (set l a s) == set l b s++iso_hither :: Eq s => Simple AnIso s a -> s -> Bool+iso_hither l s = s ^.cloneIso l.from l == s++iso_yon :: Eq a => Simple AnIso s a -> a -> Bool+iso_yon l a = a^.from l.cloneIso l == a++prism_yin :: Eq a => Simple Prism s a -> a -> Bool+prism_yin l a = preview l (review l a) == Just a++prism_yang :: Eq s => Simple Prism s a -> s -> Bool+prism_yang l s = maybe s (review l) (preview l s) == s++traverse_pure :: forall f s a. (Applicative f, Eq (f s)) => LensLike' f s a -> s -> Bool+traverse_pure l s = l pure s == (pure s :: f s)++traverse_pureMaybe :: Eq s => LensLike' Maybe s a -> s -> Bool+traverse_pureMaybe = traverse_pure++traverse_pureList :: Eq s => LensLike' [] s a -> s -> Bool+traverse_pureList = traverse_pure++traverse_compose :: (Applicative f, Applicative g, Eq (f (g s)))+                    => Simple Traversal s a -> (a -> g a) -> (a -> f a) -> s -> Bool+traverse_compose t f g s = (fmap (t f) . t g) s == (getCompose . t (Compose . fmap f . g)) s