339047 - XML.prototype.parent() returns undefined for lists with multiple parents

Status: VERIFIED INVALID

(Core :: JavaScript Engine, defect)

Description

[Michael Daumling]

Assume a bookstore containing books, containing titles.

<bookstore>
  <book>
    <title>...</title>
  </book>
  ...
</bookstore>

The following statement returns undefined:

xml.book.title.parent()

The standard does not mention this situation, but I would at least expect an empty XMLList. XPath returns a list containing all parents of all elements if the elements have multiple parents, and I think that this is a good solution.

Comment 1

[Biju]

XMLList.prototype.function::parents = function parents(){
  var r = new XMLList();
  for(var i=0; i < this.length(); i++) r += this[i].parent();
  return r;
}

xml =
<bookstore>
  <book>
    <title>book 1</title>
  </book>
  <book>
    <title>book 2</title>
  </book>
  <book>
    <title>book 3</title>
  </book>
</bookstore>

xml.book.title.parents()

//gives
<book>
  <title>book 1</title>
</book>
<book>
  <title>book 2</title>
</book>
<book>
  <title>book 3</title>
</book>

Comment 2

[Brendan Eich [:brendan]]

(In reply to comment #0)
> 
> The standard does not mention this situation,

It does -- see 13.5.4.16 in http://www.mozilla.org/js/language/ECMA-357.pdf.

/be

Comment 3

[Michael Daumling]

Why cannot I read?

Withdrawn.

I am sure that there is a good reason to differ from XPath...

Comment 4

[Brendan Eich [:brendan]]

(In reply to comment #3)
> Why cannot I read?
> 
> Withdrawn.
> 
> I am sure that there is a good reason to differ from XPath...

I'm not, but this is an issue for ECMA TG1, when we have time for son-of-E4X with good use of the Edition 4 / JS2 type system.  Let's call it E5X!

/be