zip at arity N

zip combines independent values into a tuple; zipWith passes them to a function instead. Option, Either, Try, Validation and Lazy all have the same methods, with the same names and argument order.

Form	Arity	Returns
a.zip(b)	2	F<Tuple2<A, B>>
a.zipWith(b, f)	2	F<C>, f a BiFunction
a.zipLeft(b), a.zipRight(b)	2	F<A>, F<B>: both sides are inspected, one value is kept
F.zip(a1, ..., aN)	2 to 8	F<TupleN<...>>
F.zipWith(a1, ..., aN, f)	2 to 8	F<R>, f a BiFunction or Function3 to Function8

There is one static method per number of arguments, so combining three values gives a Tuple3, never a Tuple2<Tuple2<A, B>, C>. zipWith passes the values straight to f, without building a tuple.

Option<Integer> sum = Option.zipWith(Option.some(1), Option.some(2), Option.some(3), (a, b, c) -> a + b + c);
Option<Tuple3<Integer, String, Boolean>> triple = Option.zip(Option.some(1), Option.some("a"), Option.some(true));
// Some(6), Some((1, a, true))

What happens on failure

Type	Semantics
Option, Either, Try	fail fast, in argument order: the first None, Left or Failure is returned as is, f is not called and the later arguments are not inspected
Validation	accumulates: Invalid with the errors of every invalid argument, in argument order; Valid only when all are
Lazy	nothing fails: the result is an unevaluated Lazy that forces the arguments in order on first get()

Either<String, Integer> first = Either.zipWith(Either.left("no a"), Either.<String, Integer>right(2),
    Either.<String, Integer>left("no c"), (a, b, c) -> 0);
Validation<String, Integer> all = Validation.zipWith(Validation.<String, Integer>invalid("no a"),
    Validation.<String, Integer>valid(2), Validation.<String, Integer>invalid("no c"), (a, b, c) -> 0);
// Left(no a), Invalid(no a, no c)

zipLeft and zipRight keep one value, but still fail when either side fails. They are not orElse.

Option<Integer> left = Option.some(1).zipLeft(Option.none());
Option<String> right = Option.some(1).zipRight(Option.some("kept"));
// None, Some(kept)

Null

A null argument throws a NullPointerException. When f returns null:

• on Option, Either and Validation, the call throws a NullPointerException;
• on Try, the result is a Failure, as it is when f throws;
• on Lazy, the result holds null.