直積型

複数の値を同時に保持するデータ構造

TSでは普通にobjectで定義したような型はこれになるのか？

code:hs

-- 結合律

assocL2R :: Product (Product a b) c -> Product a (Product b c)

assocL2R (Product (Product a b) c) = Product a (Product b c)

-- 結合律

assocR2L :: Product a (Product b c) -> Product (Product a b) c

assocR2L (Product a (Product b c)) = Product (Product a b) c

-- 交換律

commute :: Product a b -> Product b a

commute (Product a b) = Product b a

言語例

sml

code:ml

datatype person = Person of string * int

Haskell

code:hs

data Product a b = Product a b

参考