On 4/2/08, Lars Hansen <[EMAIL PROTECTED]> wrote: > > > > I meant something like: > > > > var foo::[bar] = baz; > > > > My objection to expr::[expr] in earlier messages was based on > > the assumption that these computed names could be used on the > > left-hand side of an assignment expression -- which, I'm > > pretty sure, is syntactically valid. > > > But that by itself can't introduce bindings (except global ones).
I didn't know that, but I'm happy to hear it. I figured, from the syntactic form alone, that: var foo::[bar] = ... ... would introduce a function-local binding (if the name wasn't already bound) -- since that's what var normally does. > If you want to introduce a new binding then you have to do eg > > ns var x = E > > to introduce ns::x, and ns has to reference a namespace > definition, so it's not variable. Nor is the x, obviously. Good. But then why allow: var expr::[expr] = ... ... at all? (I'm specifically referring to the fact that 'var' appears before the name.) This has the syntactic form of a definition, but it can't actually be one, according to what you've written. It could only be an assignment. (Okay, I guess it could introduce a property on the global object, but that's already a special case and doesn't require definition syntax.) > But in that case: > > var v1 = ns > var v2 = "x" > v1::[v2] = 20 > > updates ns::x, AFAIK. Nothing you can't do with lexically > scoped eval. That, by itself, isn't exactly an selling point; no one likes lexically scoped eval. I find computed names less objectionable now that I know local bindings can't be introduced by them. (I thought that shadowing could occur, which wouldn't be detectable until runtime. Of course, that is true of 'with' -- but, again, hardly a selling point.) Can't say I'd be sorry if they were removed from the language, though. Is this already in AS3? If so, is it often used? -Jon > > > --lars > > _______________________________________________ Es4-discuss mailing list Es4-discuss@mozilla.org https://mail.mozilla.org/listinfo/es4-discuss
