javaslang.algebra

Interface Semigroup<A>

Type Parameters:

A - A type.

All Known Subinterfaces:

Monoid<A>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface Semigroup<A>

A Semigroup is a type with an associative binary operation combine(Object, Object).

Given a type A, instances of Semigroup should satisfy the following law:

• Associativity: combine(combine(x,y),z) == combine(x,combine(y,z)) for any x,y,z of type A.

Note: Technically a Semigroup is the same as a java.util.function.BiFunction<A,A,A>. Introducing this new type clarifies that the operation combine is associative.

Since:

1.1.0

Author:

Daniel Dietrich

Method Summary

Modifier and Type	Method and Description
A	combine(A a1, A a2) Combines two elements of the same type, which is also returned.

Method Detail

combine

A combine(A a1,
          A a2)

Combines two elements of the same type, which is also returned.

Parameters:

a1 - An element

a2 - Another element

Returns:

The combination of a1 and a2