313949 - E4X Edition 2 changes XML.prototype.child

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Brendan Eich [:brendan]]

so that it always returns an XML list.  The new semantics are:

When the child method of an XML object x is called, it performs the following step:

1. If ToString(ToUint32(propertyName)) == propertyName
  a. Let children be the result of calling the [[Get]] method of x with argument "*"
  b. Let temporary be the result of calling the [[Get]] method of children with argument propertyName
c.If temporary is undefined, let temporary = new XMLList()
d.return temporary
2.Let temporary be the result of calling the [[Get]] method of x with argument propertyName
3.Return ToXMLList(temporary)

Patch coming up.  This is so new, and so late in 1.8, that I don't propose to fix it for 1.8/fx1.5/js1.6.

/be

Comment 1

[Brendan Eich [:brendan]]

Attachment: fix, plus common subroutine

Comment 2

[Blake Kaplan (:mrbkap) (inactive)]

Comment on attachment 200936 [details] [diff] [review]
fix, plus common subroutine

>Index: jsxml.c
>+    /* ECMA-357 Edition 2 13.3.4.6 (note 13.3, not 13.4 as in Edition 2. */

Nit: Missing ')' in the comment.

r=mrbkap

Comment 3

[Brendan Eich [:brendan]]

Thanks, I closed that paren!

Fixed on trunk.  Thanks,

/be

Comment 4

[Bob Clary [:bc] (inactive)]

ECMA 357 1st Edition says in the overview to 11.3.2 The typeof Operator: <Q>When UnaryExpression evaluates to a value of type XMLList, the typeof operator returns the string "xmllist".</Q>, but in the conversion table it says typeof XMLList is "xml" which is what our test for 11.3.2 uses. Which part is the typo? Without this to distinguish the two cases, how can I develop a test for this bug?

Comment 5

[Brendan Eich [:brendan]]

The spec is wrong to say typeof ever returns "xmllist", and this was answered in n.p.m.jseng.  It's fixed in the ISO version.

/be

Comment 6

[Bob Clary [:bc] (inactive)]

(In reply to comment #5)
ok.
1) how can you distinguish XML from XMLList?
2) where is the ISO version?

Comment 7

[Brendan Eich [:brendan]]

(In reply to comment #6)
> (In reply to comment #5)
> ok.
> 1) how can you distinguish XML from XMLList?

You can't easily.  The late-breaking intention of the E4X designers was to unify XML and XMLList, but they didn't have time before ECMA-357 was due to be marked "done" -- too bad, but the spec had lots of more serious problems.  Unifying XML and XMLList will break backward compatibility, but that's probably a good thing.

> 2) where is the ISO version?

I can't find it.  I'll ping TG1 colleagues and comment again when I hear back.

/be