Is there an equivalent of Scala's Either in Java 8?

Question

Just like java.util.Optional in Java 8 is (somewhat) equivalent to Scala\'s Option[T] type, is there an equivalent to Scala\'s Eithe

Answer 1

cyclops-react has a 'right' biased either implementation called Xor.

 Xor.primary("hello")
    .map(s->s+" world")

 //Primary["hello world"]

 Xor.secondary("hello")
    .map(s->s+" world")

 //Secondary["hello"]

 Xor.secondary("hello")
    .swap()
    .map(s->s+" world")

 //Primary["hello world"]

Xor.accumulateSecondary(ListX.of(Xor.secondary("failed1"),
                                 Xor.secondary("failed2"),
                                 Xor.primary("success")),
                                 Semigroups.stringConcat)

//failed1failed2

There is also a related type Ior which can act as an either or a tuple2.

• disclosure I am the author of cyclops-react.