Core.Functor

PréludeChargé par défaut — aucun import nécessaire.

Functor

Synopsis

interface Functor f where
(<$>) : Functor f => (a -> b) -> f a -> f b

interface Functor f where
map : (a -> b) -> f a -> f b

A Functor is a container you can map a function over, preserving the shape. map g xs applies g to every element of xs — over a List it is the ordinary list map; over a Maybe, it maps inside a Just.

Instances : Either, Gen, LazyList, List, Map, Maybe, Pair, Property, Result, Stream, Tree, Vector

(<$>) : Functor f => (a -> b) -> f a -> f b

(<$>) is the operator spelling of map — handy in applicative-style pipelines, e.g. f <$> px <*> py.