top-level bindings of let/const/var

[michaelficarra]

Is there a reason to allow top-level void bindings in let/const/var declarations? I don't ever want to see let void = procedure();. I would prefer these cases were not permitted.

[rbuckton]

The only real motivation is consistency with using. As I mentioned during plenary, there's a very minor benefit if you have code like const a = f(), b = (g(), h()), but that's not a very strong motivation. I'm fine with excluding these from the proposal.

[hotsphink]

I'm discussing the wrong proposal here, but if consistency with using is a concern, why is using void = Acquire() needed instead of just using Acquire()? The latter seems more straightforward to me. The former uses binding syntax only to explicitly say that it is not creating a binding.

[rbuckton]

using Acquire() seems fine at first glance, but using (Acquire()) or using (foo || bar).Acquire(), or any other expression that starts with parentheses is already legal JavaScript. Disambiguating it for just this case would be a huge footgun for users.

[rbuckton]

Also, per #3 the current spec text disallows top-level void bindings in let/const/var.

[michaelficarra]

using Acquire() seems fine at first glance, but using (Acquire()) or using (foo || bar).Acquire(), or any other expression that starts with parentheses is already legal JavaScript. Disambiguating it for just this case would be a huge footgun for users.

Isn't using [a] = Acquire() already valid though?

[rbuckton]

using Acquire() seems fine at first glance, but using (Acquire()) or using (foo || bar).Acquire(), or any other expression that starts with parentheses is already legal JavaScript. Disambiguating it for just this case would be a huge footgun for users.

Isn't using [a] = Acquire() already valid though?

Yes, but binding patterns are illegal in using. The issue with using expr is that it is far more ambiguous as to what is allowed. () is a PrimaryExpression and is allowed pretty much anywhere you might write an expression. Drawing an arbitrary line around parts of PrimaryExpression would be a huge footgun.

[michaelficarra]

Ah, I didn't see that you had added the Pattern flag to BindingList.