Rename extern.internalize/extern.externalize?

[eqrion]

In discussions around adding an 'exnref' type (WebAssembly/exception-handling#280), it seemed like there was desire for it to be a new type hierarchy, like any and extern. If this is the case, it could be useful to have instructions to convert from 'exnref' to 'externref' or 'anyref'. This has sort of come up before (WebAssembly/exception-handling#202).

I can't think of a good name for these though, as 'extern.internalize/externalize' seem to have a builtin assumption that you just want to convert between those two hierarchies.

What would folks think about renaming to: any.from_extern and extern.from_any? This would allow a natural any.from_exn or extern.from_exn?

[tlively]

I would be fine with this.

[rossberg]

Isn't the plan of record not to allow exnrefs to be passed to JavaScript? Then such a conversion wouldn't be very useful.

That said, I don't mind a more extensible naming scheme. Instead of from I'd probably use convert as a prefix, however, which is more consistent with how we spell numeric conversions.

[eqrion]

Isn't the plan of record not to allow exnrefs to be passed to JavaScript? Then such a conversion wouldn't be very useful.

Hmm, my understanding was that this wasn't well discussed yet. It's fine if we disallow it, but I do think there is a good case for allowing it (and will make that on the EH issue).

That said, I don't mind a more extensible naming scheme. Instead of from I'd probably use convert as a prefix, however, which is more consistent with how we spell numeric conversions.

Yeah, that's fine with me. Even if we don't immediately allow this for exnref, I do think this is something that is likely to come up in some future extension.

[tlively]

I think the next step is to make a PR implementing this change. @rossberg, would you be up for that?

[rossberg]

Sure, though I might not get to it for the next couple of weeks.