javaslang.algebra

Interface Functor<T>

Type Parameters:

T - component type of this functor

All Known Subinterfaces:

Arbitrary<T>, Future<T>, Gen<T>, IndexedSeq<T>, Iterator<T>, Lazy<T>, LinearSeq<T>, List<T>, Map<K,V>, Match.MatchMonad<R>, Monad<T>, Option<T>, Seq<T>, Set<T>, SortedMap<K,V>, SortedSet<T>, Stack<T>, Stream<T>, Traversable<T>, Tree<T>, Try<T>, Value<T>

All Known Implementing Classes:

Array, CharSeq, Either.LeftProjection, Either.RightProjection, Failure, HashMap, HashSet, Lazy.Defined, Lazy.Undefined, LinkedHashMap, LinkedHashSet, List.Cons, List.Nil, Match.MatchMonad.Otherwise, Match.MatchMonad.When.Then, None, Queue, Some, Stream.Cons, Stream.Empty, Success, Tree.Empty, Tree.Node, TreeMap, TreeSet, Vector

public interface Functor<T>

Defines a Functor by generalizing the map.

All instances of the Functor interface should obey the two functor laws:

• m.map(a -> a) ≡ m
• m.map(f.compose(g)) ≡ m.map(g).map(f)

where "f, g ∈ Function".

Since:

1.1.0

Author:

Daniel Dietrich

See Also:

The functor design pattern

Method Summary

Modifier and Type	Method and Description
<U> Functor<U>	map(java.util.function.Function<? super T,? extends U> mapper) Applies a function f to the components of this Functor.

Method Detail

map

<U> Functor<U> map(java.util.function.Function<? super T,? extends U> mapper)

Applies a function f to the components of this Functor.

Type Parameters:

U - type of the component of the resulting Functor

Parameters:

mapper - a Function which maps the component of this Functor

Returns:

a new Functor

Throws:

NullPointerException - if f is null