Annex A of 5th Edition

Joseph Spencer js.developer.undefined at
Thu Sep 6 22:19:57 PDT 2012

Would it not be beneficial to bring Annex A into greater conformity with
the rest of the spec at this point?  

Such changes seem relatively safe (to a noobie that is ;), as any code
produced moving forward by devs would still parse just fine under older
implementations that allowed for the unwanted syntax.  It seems that
doing so would also bring the ecosystem of implementations into greater
alignment moving forward.


On Thu, 2012-09-06 at 16:41 -0700, Brendan Eich wrote:
> Joseph Spencer wrote:
> > My apologies on that one.  I meant to type the following:
> >
> > PostfixExpression:
> >     LeftHandSideExpression [no LineTerminator here] ++
> >     LeftHandSideExpression [no LineTerminator here] --
> >
> > PrefixExpression:
> >     ++ [no LineTerminator here] LeftHandSideExpression
> >     -- [no LineTerminator here] LeftHandSideExpression
> >
> > It appears to me that as currently written the following is considered 
> > valid sytax:
> >
> > ++++someVar;
> Yes, that is goofy. It dates back to ES1 -- if memory serves (and it may 
> not at this late date), my original Netscape 2 "Mocha" JS engine did not 
> parse this.
> However, I think it may fall out of a desire by Microsoft back in the 
> ES1 days to support the goofy ability of "host objects" to return 
> References (ECMA-262 spec term).
> > I hadn't thought about es3 compatability though, so I could see the 
> > reasoning in keeping it as is.
> Yeah, engine implementors have no good incentive to tweak here, and some 
> legitimate fear of a breaking change that would only lose market share.
> /be

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