On Mon, Apr 9, 2012 at 5:05 PM, David Herman <[email protected]> wrote:
> On Apr 7, 2012, at 1:40 PM, Erik Arvidsson wrote: > > > This does not work for rest parameter since ... is only allowed inside > > array literals. > > > > var tail = (x, ...xs) => xs; > > > > This can of course be solved in numerous ways but it is not true that > > the Expression is a cover grammar for FormalParameterList. > > > > Another option is to allow ...expression in an expression which would > > have the same semantics as a comma expression where the expression has > > been spread: > > Or allow it in the grammar and then disallow it in the post-processing. > IOW, a cover grammar doesn't have to force us to introduce new syntactic > forms, they just force us to put them in the *grammar*. The > post-processing, which essentially defines the two sub-grammars for the two > separate contexts, can remove the syntactic forms we don't want to provide > semantics for. > Hmm...a deviously simple solution, and yet - it feels so wrong. Grammatically legal and yet illegal. I sense complaints by implementors. :) > > Dave > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss >
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