Haskell - コンテキストでの型の操作 - do表記を使ってMonadを扱いやすくする - do表記を使って同じコードを異なるコンテキストで再利用する

開発環境

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 UNIT5(コンテキストでの型の操作)、LESSON 31(do表記を使ってMonadを扱いやすくする)、31.2(do表記を使って同じコードを異なるコンテキストで再利用する)、クイックチェック 31-2の解答を求めてみる。

コード

sample2.hs

main :: IO ()
main = do
    mapM_ (\c -> print (mconcat [show c, " ", show (viable c)])) cs

data Grade = F | D | C | B | A deriving (Eq, Ord, Enum, Show, Read)
data Degree = HS | BA | MS | PhD deriving (Eq, Ord, Enum, Show, Read)
data Candidate = Candidate {
    candidateId :: Int,
    codeReview :: Grade,
    cultureFit :: Grade,
    education :: Degree
} deriving Show

viable :: Candidate -> Bool
viable candidate = all (== True) tests
    where passedCoding = codeReview candidate > B
          passedCultureFit = cultureFit candidate > C
          educationMin = education candidate >= MS
          tests = [passedCoding, passedCultureFit, educationMin]


cs :: [Candidate]
cs = Candidate 1 <$> [F .. A] <*> [F .. A] <*> [HS .. PhD]

入出力結果(Terminal, Zsh)

% runghc sample2.hs 
"Candidate {candidateId = 1, codeReview = F, cultureFit = F, education = HS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = F, education = BA} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = F, education = MS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = F, education = PhD} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = D, education = HS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = D, education = BA} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = D, education = MS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = D, education = PhD} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = C, education = HS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = C, education = BA} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = C, education = MS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = C, education = PhD} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = B, education = HS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = B, education = BA} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = B, education = MS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = B, education = PhD} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = A, education = HS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = A, education = BA} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = A, education = MS} False"
"Candidate {candidateId = 1, codeReview = F, cultureFit = A, education = PhD} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = F, education = HS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = F, education = BA} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = F, education = MS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = F, education = PhD} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = D, education = HS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = D, education = BA} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = D, education = MS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = D, education = PhD} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = C, education = HS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = C, education = BA} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = C, education = MS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = C, education = PhD} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = B, education = HS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = B, education = BA} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = B, education = MS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = B, education = PhD} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = A, education = HS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = A, education = BA} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = A, education = MS} False"
"Candidate {candidateId = 1, codeReview = D, cultureFit = A, education = PhD} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = F, education = HS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = F, education = BA} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = F, education = MS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = F, education = PhD} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = D, education = HS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = D, education = BA} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = D, education = MS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = D, education = PhD} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = C, education = HS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = C, education = BA} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = C, education = MS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = C, education = PhD} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = B, education = HS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = B, education = BA} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = B, education = MS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = B, education = PhD} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = A, education = HS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = A, education = BA} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = A, education = MS} False"
"Candidate {candidateId = 1, codeReview = C, cultureFit = A, education = PhD} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = F, education = HS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = F, education = BA} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = F, education = MS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = F, education = PhD} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = D, education = HS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = D, education = BA} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = D, education = MS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = D, education = PhD} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = C, education = HS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = C, education = BA} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = C, education = MS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = C, education = PhD} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = B, education = HS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = B, education = BA} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = B, education = MS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = B, education = PhD} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = A, education = HS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = A, education = BA} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = A, education = MS} False"
"Candidate {candidateId = 1, codeReview = B, cultureFit = A, education = PhD} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = F, education = HS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = F, education = BA} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = F, education = MS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = F, education = PhD} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = D, education = HS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = D, education = BA} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = D, education = MS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = D, education = PhD} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = C, education = HS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = C, education = BA} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = C, education = MS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = C, education = PhD} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = B, education = HS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = B, education = BA} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = B, education = MS} True"
"Candidate {candidateId = 1, codeReview = A, cultureFit = B, education = PhD} True"
"Candidate {candidateId = 1, codeReview = A, cultureFit = A, education = HS} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = A, education = BA} False"
"Candidate {candidateId = 1, codeReview = A, cultureFit = A, education = MS} True"
"Candidate {candidateId = 1, codeReview = A, cultureFit = A, education = PhD} True"
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