Subj : Re: Rhino E4X bug or feature?
To   : Olinda Spider
From : Brendan Eich
Date : Thu Jul 21 2005 06:15 pm

Olinda Spider wrote:

> In other words, right now the parser recognizes the difference between
> accessing an object's property and accessing an object's method.  Given
> the following two statements:
> 
>   var num = object.length()
>   var element = object.length
> 
> The parser generates different opcodes for accessing each of the
> "length" items.  Is there a reason the same parsing process can not be
> applied to the following two statements?
> 
>   var num = length()
>   var element = length


Indeed that could be done, but ECMA-357 must fully specify what happens 
here, and it fails to do so.  11.2.2 step 1 evaluates MemberExpression 
in this production:

   CallExpression: MemberExpression Arguments

without providing any parametric hint that a different kind of 
[[HasProperty]] from the one in ECMA-262 Edition 3, 10.1.4 step 2, 
should be used.  But ECMA-357 does specify [[HasProperty]] for XML 
objects (ECMA-357, 9.1.1.6) in a way that excludes the XML methods 
defined on XML.prototype.  So there is no way to find an XML method by 
scope resolution of its unqualified identifier.

Rhino and SpiderMonkey follow the spec.  The spec has the bug here.

/be

.