When to box parsers?

[jimmycuadra]

I've noticed compilation times can be quite slow in my program. I've read in the docs and a few discussions that this is not unexpected for programs with lots of long parser chains and that boxing parsers can help reduce compilation times. I'm wondering if there's guidance on how to decide which parsers to box for this purpose without too much of a trade off.

I'm suspect that for my small program, I could probably just box all parsers and the dynamic dispatch wouldn't matter much, but I'm guessing there's a better approach. Is it just trial and error, boxing one at a time to see which ones have an effect on compilation times? Or is there something I should be looking for in a parser that makes it a good candidate for boxing?

[zesterer]

There is!

[jimmycuadra]

Ah yes, these are the docs I was referring to. I'm already using choice over or in most places. I guess I'll just try boxing everything! Doesn't seem like there's much downside.

[zesterer]

You'll find that 10% of .boxed()s make 90% of the difference to compilation time. You should only need to put it at the end of significant chunks of parser declarations.