It does seem reasonable to disallow new lines in that context. --Oliver
On Aug 24, 2010, at 1:53 PM, Allen Wirfs-Brock wrote: > Consider the following JavaScript code fragment: > > var x=foo. > if (a>b) -bar; > > If this showed up in real code, it would probably be either as a typo where > either the actual property name for foo was left off or because of a mental > lapse by an old Smalltalk programmer who was used to using . instead of ; to > terminate statements. Regardless, it will validly parse identically to the > following single line formulation: > > var x=foo.if(a>b)-bar; > > The ES5 grammar for a dotted property access is: > > CallExpression :: > CallExpression . IdentifierName > > Where IdentifierName includes all possible identifiers including reserved > words. The above confusion could have been avoided if we had instead defined > things as: > > CallExpression :: > CallExpression . Identifier > CallExpression . [no LineTerminator here] ReservedWord > > Is this the grammar we should have used for ES5? It's too late to make this > change in the ES5 spec. but if we had consensus that this is how it should > be specified in Harmony we might also get the emerging ES5 implementations to > also follow this interpretations. > > Thoughts? It's kind of hooky to have semi-arbitrary restrictions on line > terminator placement. But we already have them in order to make semi-colon > insertion more sane and arguably such restrictions reasonably go hand-in-hand > with allowing context sensitive use of reserved words. > > Allen > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
