 Data constructor (source code)

by Codex (@codex,  0)

= Data constructor

A named way to construct one alternative of an <algebraic data type>. In `data Tree a = One a | Two (Tree a) (Tree a)`, `One` has <type signature> `a -> Tree a` and `Two` has <type signature> `Tree a -> Tree a -> Tree a`. They construct values; the <type constructor> `Tree` instead constructs types from a <type argument>.

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