Java collections library support

[johnsonr]

Modern Java is pretty good, but collection handling is still painful with the need to lift to/from streams. This can complicated code, as in embabel-agent-examples.

Wanted to gauge interest in whether we should add integration with a library such as Vavr or Eclipse Collections.

Probably not in the main module but in an embabel-agent-collections module.

Thoughts welcome.

[nmarasoiu]

Hi, an honor to give my humble opnion here.

Absolutely in favor of this. Stream Gatherers help but Java streams remain painfully limited for real FP workflows.

The zip problem alone justifies Vavr: Try zipping three infinite streams in Java - you'll end up with nested flatMap hell or collect intermediate results. Java has no zip3, zipWith, or zipWithIndex for infinite sequences. Want to cycle through values infinitely? No cycle(). Need unfold or scanl for stateful infinite generation? Roll your own with Stream.iterate boilerplate.

Vavr solves this properly:

// Clean infinite sequence ops
Stream.of(1,2,3).cycle()
Stream.zipWith(s1, s2, s3, (a,b,c) -> combine(a,b,c))
Stream.unfold(seed, f -> Option.of(tuple(next, newSeed)))

vs Java's verbose collect(Collector.of(...)) gymnastics for anything beyond basic operations.

Eclipse Collections excels at finite collection performance but lacks the infinite sequence combinators we need. For lazy FP workflows, Vavr's the clear choice.

embabel-agent-collections module approach is perfect - keeps core clean while giving us proper functional primitives.