circular-enum (empty) → 0.1.0.0

raw patch · 5 files changed

+125/−0 lines, 5 filesdep +basedep +circular-enumdep +hspec

Dependencies added: base, circular-enum, hspec

Files

• CHANGELOG.md +5/−0
• LICENSE +20/−0
• circular-enum.cabal +39/−0
• src/Data/Enum/Circular.hs +35/−0
• test/Main.hs +26/−0

@@ -0,0 +1,5 @@+# Revision history for circular-enum++## 0.1.0.0 -- 2023-05-31++* First version. Released on an unsuspecting world.

@@ -0,0 +1,20 @@+Copyright (c) 2023 Mirko Westermeier++Permission is hereby granted, free of charge, to any person obtaining+a copy of this software and associated documentation files (the+"Software"), to deal in the Software without restriction, including+without limitation the rights to use, copy, modify, merge, publish,+distribute, sublicense, and/or sell copies of the Software, and to+permit persons to whom the Software is furnished to do so, subject to+the following conditions:++The above copyright notice and this permission notice shall be included+in all copies or substantial portions of the Software.++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

@@ -0,0 +1,39 @@+cabal-version:    3.0+name:             circular-enum+version:          0.1.0.0+synopsis:         Make bounded enum types circular+description:      Circular successor & predecessor for bounded enum types+homepage:         https://github.com/memowe/circular-enum+bug-reports:      https://github.com/memowe/circular-enum/issues+license:          MIT+license-file:     LICENSE+author:           Mirko Westermeier+maintainer:       mirko@westermeier.de+copyright:        (c) 2023 Mirko Westermeier+category:         Data+build-type:       Simple+extra-doc-files:  CHANGELOG.md+source-repository head+    type:       git+    branch:     main+    location:   git://github.com/memowe/circular-enum.git++common warnings+    ghc-options: -Wall++library+    import:           warnings+    exposed-modules:  Data.Enum.Circular+    build-depends:    base >=4.14.0.0 && < 5+    hs-source-dirs:   src+    default-language: Haskell2010++test-suite circular-enum-test+    import:           warnings+    default-language: Haskell2010+    type:             exitcode-stdio-1.0+    hs-source-dirs:   test+    main-is:          Main.hs+    build-depends:    base >=4.14.0.0+                    , circular-enum+                    , hspec >= 2.10 && < 3

@@ -0,0 +1,35 @@+{-|+Module      : Data.Enum.Circular+Description : Circular successor & predecessor for bounded enum types+Copyright   : (c) 2023 Mirko Westermeier+License     : MIT++Sometimes, bounded enum types should be circular. Consider this enum+type of directions:++@+data Direction  = North+                | East+                | South+                | West+                deriving (Eq, Enum, Bounded)+@++The 'Enum' instance allows for @succ North@ to be @East@ and @succ East@+to be @South@. But in this case, one would like to have some kind of+@succ@ with @succ West = North@ again. With 'Eq' and 'Bounded' instances,+the functions defined in this module act like circular versions of 'succ'+and 'pred'.+-}++module Data.Enum.Circular (csucc, cpred) where++-- | Circular version of 'succ'+csucc :: (Eq a, Enum a, Bounded a) => a -> a+csucc x | x == maxBound = minBound+        | otherwise     = succ x++-- | Circular version of 'pred'+cpred :: (Eq a, Enum a, Bounded a) => a -> a+cpred x | x == minBound = maxBound+        | otherwise     = pred x

@@ -0,0 +1,26 @@+module Main (main) where++import Data.Enum.Circular+import Data.Function+import Test.Hspec++data Direction = N | E | S | W deriving (Show, Eq, Enum, Bounded)++circularDirections :: Spec+circularDirections = describe "Circular directions" $ do++  describe "Boundaries" $ do+    it "North after West"   $ csucc W `shouldBe` N+    it "West before North"  $ cpred N `shouldBe` W++  describe "Compatible with Enum instance" $ do+    it "Successors" $+      iterate csucc minBound `startShouldBe` cycle allDirs+    it "Predecessors" $+      iterate cpred maxBound `startShouldBe` cycle (reverse allDirs)++  where allDirs         = enumFrom minBound :: [Direction]+        startShouldBe   = shouldBe `on` take (length allDirs * 2)++main :: IO ()+main = hspec circularDirections