On Jan 17, 2015, at 11:57 AM, Fabrício Matté wrote:
> > Currently in ES6, the only reserved keywords that can appear immediately
> > before a `.` are `this` and `super`.
>
> The `this` binding resolves to a value, so MemberExpressions make sense. The
> `super` keyword is being implemented in ES6, so there are no precedents to
> set expectations.
>
> > Any other reserved word followed by a `.` is a syntax error. So reserved
> > words followed by period and an identifier is one of the few available
> > extension alternatives we have available. And is a natural ready syntax
> > think of new.target' as meaning give me the target value of the currently
> > active `new` operator.
>
> I agree `new.target` is very natural and pleasant to read. It just feels
> rather alien to see an operator in the beginning of a MemberExpression, which
> currently would only be allowed in this very specific scenario. Of course, if
> this syntax extension form would be useful for other use cases as Kevin and
> you have outlined, then I don't oppose it.
>
> > I suspect the hypothetical naive JS programmer postulated above wound't be
> > aware of any of those concepts.
>
> A naive one probably not, but a curious avid developer most definitely would.
> ;)
>
> > hopefully they will say what is `new.target', "google it" and immediately
> > find the answer.
>
> You mean, land on a Stack Overflow answer with thousands of upvotes and very
> little explanation about why/how a MemberExpression can begin with an
> operator. Of course, if you interpret `new` as simply a ReservedWord token
> instead of an operator, then everything makes perfect sense.
The way I accomplish in the grammar was to add the productions:
MemberExpression :
MetaProperty
MetaProperty :
'new' '.' 'target'
So we could start talking about "meta properties" as a MemberExpression
alternative and say `new.target` is a "meta property".
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