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コードの整理とプロジェクトのビルド Monad型クラス QuickCheckを使ったプロパティテスト プロジェクト

入門Haskellプログラミング (Will Kurt(著)、株式会社クイープ(監修、翻訳)、翔泳社)のUNIT6(コードの整理とプロジェクトのビルド)、LESSON36(QuickCheckを使ったプロパティテスト)、36.5(練習問題)Q36-1の解答を求めてみる。

package.yaml

name:                palindrome-testing
version:             0.1.0.0
github:              "githubuser/palindrome-testing"
license:             BSD3
author:              "Author name here"
maintainer:          "example@example.com"
copyright:           "2022 Author name here"

extra-source-files:
- README.md
- ChangeLog.md

# Metadata used when publishing your package
# synopsis:            Short description of your package
# category:            Web

# To avoid duplicated efforts in documentation and dealing with the
# complications of embedding Haddock markup inside cabal files, it is
# common to point users to the README.md file.
description:         Please see the README on GitHub at <https://github.com/githubuser/palindrome-testing#readme>

dependencies:
- base >= 4.7 && < 5
- text

library:
  source-dirs: src
  extensions: OverloadedStrings

executables:
  palindrome-testing-exe:
    main:                Main.hs
    source-dirs:         app
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - palindrome-testing
    default-extensions: OverloadedStrings
tests:
  palindrome-testing-test:
    main:                Spec.hs
    source-dirs:         test
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - palindrome-testing
    - quickcheck-instances
    - QuickCheck
    - quickcheck-text
    default-extensions: OverloadedStrings

palindrome-testing.cabal

cabal-version: 1.12

-- This file has been generated from package.yaml by hpack version 0.34.4.
--
-- see: https://github.com/sol/hpack

name:           palindrome-testing
version:        0.1.0.0
description:    Please see the README on GitHub at <https://github.com/githubuser/palindrome-testing#readme>
homepage:       https://github.com/githubuser/palindrome-testing#readme
bug-reports:    https://github.com/githubuser/palindrome-testing/issues
author:         Author name here
maintainer:     example@example.com
copyright:      2022 Author name here
license:        BSD3
license-file:   LICENSE
build-type:     Simple
extra-source-files:
    README.md
    ChangeLog.md

source-repository head
  type: git
  location: https://github.com/githubuser/palindrome-testing

library
  exposed-modules:
      Lib
  other-modules:
      Paths_palindrome_testing
  hs-source-dirs:
      src
  build-depends:
      base >=4.7 && <5
    , text
  default-language: Haskell2010

executable palindrome-testing-exe
  main-is: Main.hs
  other-modules:
      Paths_palindrome_testing
  hs-source-dirs:
      app
  default-extensions:
      OverloadedStrings
  ghc-options: -threaded -rtsopts -with-rtsopts=-N
  build-depends:
      base >=4.7 && <5
    , palindrome-testing
    , text
  default-language: Haskell2010

test-suite palindrome-testing-test
  type: exitcode-stdio-1.0
  main-is: Spec.hs
  other-modules:
      Paths_palindrome_testing
  hs-source-dirs:
      test
  default-extensions:
      OverloadedStrings
  ghc-options: -threaded -rtsopts -with-rtsopts=-N
  build-depends:
      QuickCheck
    , base >=4.7 && <5
    , palindrome-testing
    , quickcheck-instances
    , quickcheck-text
    , text
  default-language: Haskell2010

コード

test/Spec.hs

import Data.Char (isPunctuation)
import Data.Text as T
import Lib (isPalindrome, preprocess)
import Test.QuickCheck
import Test.QuickCheck.Instances

prop_reverseInvariant text =
  isPalindrome text == isPalindrome (T.reverse text)

prop_punctuationInvariant text =
  let noPuncTest = T.filter (not . isPunctuation) text
   in preprocess text == preprocess noPuncTest

main :: IO ()
main = do
  quickCheck prop_reverseInvariant
  quickCheckWith
    stdArgs {maxSuccess = 1000}
    prop_punctuationInvariant
  putStrLn "done!"

コード

src/Lib.hs

module Lib
  ( isPalindrome,
    preprocess,
  )
where

import Data.Char (isPunctuation, isSpace)
import Data.Text as T (Text, filter, reverse, toLower)

isPalindrome :: T.Text -> Bool
isPalindrome text =
  let cleanText = preprocess text
   in cleanText == T.reverse cleanText

preprocess :: T.Text -> T.Text
preprocess = stripWhiteSpace . stripPunctuation . T.toLower

stripWhiteSpace :: T.Text -> T.Text
stripWhiteSpace = T.filter (not . isSpace)

stripPunctuation :: T.Text -> T.Text
stripPunctuation = T.filter $ not . isPunctuation

入出力結果(Terminal, Zsh)

% stack test
/Users/…/palindrome-testing/package.yaml: Ignoring unrecognized field $.library.extensions
palindrome-testing-0.1.0.0: unregistering (local file changes: test/Spec.hs)
palindrome-testing> build (lib + exe + test)
Preprocessing library for palindrome-testing-0.1.0.0..
Building library for palindrome-testing-0.1.0.0..
Preprocessing executable 'palindrome-testing-exe' for palindrome-testing-0.1.0.0..
Building executable 'palindrome-testing-exe' for palindrome-testing-0.1.0.0..
Preprocessing test suite 'palindrome-testing-test' for palindrome-testing-0.1.0.0..
Building test suite 'palindrome-testing-test' for palindrome-testing-0.1.0.0..
[2 of 2] Compiling Main
            
/Users/…/palindrome-testing/test/Spec.hs:15:3: error:
    • No instance for (Arbitrary Text)
        arising from a use of ‘quickCheck’
    • In a stmt of a 'do' block: quickCheck prop_reverseInvariant
      In the expression:
        do quickCheck prop_reverseInvariant
           quickCheckWith
             stdArgs {maxSuccess = 1000} prop_punctuationInvariant
           putStrLn "done!"
      In an equation for ‘main’:
          main
            = do quickCheck prop_reverseInvariant
                 quickCheckWith
                   stdArgs {maxSuccess = 1000} prop_punctuationInvariant
                 putStrLn "done!"
   |        
15 |   quickCheck prop_reverseInvariant
   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
            
Progress 1/2

--  While building package palindrome-testing-0.1.0.0 (scroll up to its section to see the error) using:
      /Users/…/.stack/setup-exe-cache/x86_64-osx/Cabal-simple_mPHDZzAJ_3.2.1.0_ghc-8.10.7 --builddir=.stack-work/dist/x86_64-osx/Cabal-3.2.1.0 build lib:palindrome-testing exe:palindrome-testing-exe test:palindrome-testing-test --ghc-options " -fdiagnostics-color=always"
    Process exited with code: ExitFailure 1
% stack test
/Users/…/palindrome-testing/package.yaml: Ignoring unrecognized field $.library.extensions
palindrome-testing> build (lib + exe + test)
Preprocessing library for palindrome-testing-0.1.0.0..
Building library for palindrome-testing-0.1.0.0..
Preprocessing executable 'palindrome-testing-exe' for palindrome-testing-0.1.0.0..
Building executable 'palindrome-testing-exe' for palindrome-testing-0.1.0.0..
Preprocessing test suite 'palindrome-testing-test' for palindrome-testing-0.1.0.0..
Building test suite 'palindrome-testing-test' for palindrome-testing-0.1.0.0..
[2 of 2] Compiling Main
Linking .stack-work/dist/x86_64-osx/Cabal-3.2.1.0/build/palindrome-testing-test/palindrome-testing-test ...
palindrome-testing> copy/register
Installing library in /Users/…/palindrome-testing/.stack-work/install/x86_64-osx/160203b3c1b5851ee38cefff1898f2ea31f9dd27504c585eee0da67dd7dc8bb2/8.10.7/lib/x86_64-osx-ghc-8.10.7/palindrome-testing-0.1.0.0-KHlFaoxsHbT2E4vDjysA3S
Installing executable palindrome-testing-exe in /Users/…/palindrome-testing/.stack-work/install/x86_64-osx/160203b3c1b5851ee38cefff1898f2ea31f9dd27504c585eee0da67dd7dc8bb2/8.10.7/bin
Registering library for palindrome-testing-0.1.0.0..
palindrome-testing> test (suite: palindrome-testing-test)
                                
+++ OK, passed 100 tests.
+++ OK, passed 1000 tests.
done!

palindrome-testing> Test suite palindrome-testing-test passed
Completed 2 action(s).
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