Either

The Either type represents a value of one of two possible types (a disjoint union), referred to by left or right .

Factory methods Either#left(Object) and Either#right(Object) correspond to the two possible values.

API

Either.java

interface Either<L, R> {
  Either<L, R> left(L left)
  Either<L, R> right(R right)
  Optional<L> left()
  Optional<R> right()
  L leftIfAny()
  R rightIfAny()
  boolean isLeft()
  boolean isRight()
  Either<T, R> mapLeft(Function<L, T> leftMapper)
  Either<L, T> mapRight(Function<R, T> rightMapper)
  Either<X, Y> map(Function<L, X> leftMapper, Function<R, Y> rightMapper)
  T fold(BiFunction<L, R, T> biMapper)
  T fold(Function<L, T> leftMapper, Function<R, T> rightMapper)
  void accept(Consumer<L> leftConsumer, Consumer<R> rightConsumer)
}