Learn You a Haskell for Great Good

• author: Miran Lipovac

Chap7: Making our own types and type classes

type parameters

data Maybe a = Nothing | Just a

"a" is the type parameter

ghci> Just 3 :: Maybe Int
Just 3

Dervied Instances

Type Synonyms

Recursive Data Structures

Type Classes 102

A Yes-No Type Class

The Functor Type Class

Kinds and Some Type-Foo