よくやる処理のHaskell流のやり方

  • 全列挙:\{x|x\in X}
[x^2 | x <- [1,3,5]]
  • 総当りペア:\{(x,y)|x \in X, y \in Y\}
[(x,y) | x <- [1..4], y <- [3..5]]
  • ペア\{(x1,x2)|x1 \in X,x2 \in X, x1 < x2\}
[(x1,x2) | x1 <- [1..4],x2 <- [1..4],x1 < x2]
  • 隣接ペア
zip [1..4] (tail [1..4])
  • より詳しく集合の内包表現:\{x|x \in X,x `mod`3==0\}
[x|x <-[1..20],x `mod` 3 ==0]