Hacker News Reader

Comment by riffraff | Hacker News Reader

interesting, how do you model multiple dispatch in an efficient way over a vm that (I believe) wasn't designed for it?

Via pattern-matching at the moment:

    X foo: Y := ...
    X foo: Z := ...

Both of these are inserted on X, which is used as `self` in the method body (so instance variables, etc. work as expected too). It's one method, `foo:`, which pattern-matches on its arguments to determine which branch to evaluate.

I see, but does this play well with the jit? What I mean is: wouldn't multimethods with many variants cause exponentially bigger thunks to inline, thus causing the JIT to not perform inlining at all?

Thanks for your answer anyway, it looks like a really fun project.

Looking at the bytecode, the JIT handles it fine. atomo pattern matching is the equivalent of using a case;when in the body. And because it's scoped to a certain class and name, I doubt it would have the overflow problem that lisp multimethods have, where you only have the name to bind functionality to.

Reply on news.ycombinator.com