Using default function parameters on native

Question

A haxe function has some parameters whose default values I'd like to use, so I don't need to import anything (they're basic types underneath). If they were last in the parameter order, I could get away with just not including them. But they're first, before some defaults I do want to override.

I'm not allowed to null them on native. _ doesn't compile (I don't think it's meant for this context.) Am I forced to import and copy the defaults in verbatim, or is there another way?

I tried .bind(_, ...)() but that gives Usage of _ is not supported for optional non-nullable arguments.

Answer 1

That error comes from the argument having a non-nullable type (Int, Float or Bool on a static target). If this function is part of your code and not some library, you could just make it nullable with Null<T> or ?.

As long as the arguments are nullable, Haxe also allows you to simply skip them if they are distuingishable (i.e. the type of the value passed must be different from the one(s) you want to skip). This means you don't have to use bind() or explicitly pass null. See the fourth example on the manual's Optional Arguments page.

If making the arguments nullable isn't an option for you in this particular case, you're probably going to have to copy the defaults (although I'm sure it's possible to come up with a clever macro solution for this).