On Sep 25, 2012, at 1:27 PM, Brendan Eich wrote:
> Allen Wirfs-Brock wrote:
>> I note that in your toy grammar you avoid the comma issue at the front and
>> in the for clauses by using AssignmentExpression in those positions.
>>
>> The current ES6 spec. draft has AssignmentExpression at the front, and
>> Expression in the for and if clauses. However, there is also a editor's
>> note that suggests that AssignmentExpression should be considered for all
>> three positions.
>
> There's still no ambiguity if the toy grammar changes to
agreed, this isn't about formal parsing ambiguity.
> ...;
>
> The "readability" concern would matter if people actually wrote
> unparenthesized comma expressions in such comprehensions, but Nanny-me says
> they won't, and Mary Poppins agrees.
>
> Again, it's not our job to prevent people from writing something that might
> confuse someone. JS has lots of room in its grammar for that. I agree with
> Dave, in absence of evidence of real ambiguity or another technical grammar
> problem.
So, from that perspective, why didn't you make it:
ArrLit:
'[' AssExpList ']'
| '[' Exp FOR ID OF Exp IF Exp ']'
Allen_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
