Should "constructor" be allowed as an argument name?

[Ms2ger]

See #700, whatwg/html#4869.

CC @annevk

[annevk]

If this is as easy as for async I think allowing this would be great. There's an emerging pattern of APIs taking constructors and not being able to use the obvious name would be rather unfortunate and a likely continuing source of confusion.

[bzbarsky]

Yes, we should do it. In particular, I think we should add "constructor" to ArgumentNameKeyword, and maybe allow it in dictionary member names (will need a new production). Not sure about AttributeNameKeyword; it's a little weird to add an attribute named "constructor", given that JS already has semantics for that.

I don't know why https://searchfox.org/mozilla-central/rev/325c1a707819602feff736f129cb36055ba6d94f/dom/webidl/CustomElementRegistry.webidl#8 was named "functionConstructor" instead of "constructor". :( It's that way in the first patches in https://bugzilla.mozilla.org/show_bug.cgi?id=1275833 which already don't match the spec IDL...