Re: Problems with xml-parse-string

[Chong Yidong <cyd@stupidchicken.com>]

Lars Magne Ingebrigtsen <larsi@gnus.org> writes:

> Euhm.  Actually, I spent quite a bit of thought on the parse tree format
> that the functions spit out to make it regular, easy and fast to deal
> with.  The format that xml.el spits out is more arcane and less
> comfortable to use.  You can't say `(assq 'img (cdr node))' and stuff to
> get the image nodes, because the child nodes aren't a regular assoc
> list (because of the string fields) and stuff.
>
> So I protest the change.
>
> If you're concerned about previous users of xml.el being confused by the
> change in parse tree format, I don't think you have to worry all that
> much, because there are zero (0) users of the xml.el `xml-parse-string'
> in the Emacs tree.

The issue isn't xml-parse-string, it's xml-parse-region and
xml-parse-file, which are used by several parts of Emacs including,
ahem, Gnus.  I don't want to have two parts of Emacs providing xml
parsing that provide slightly incompatible parse tree formats.

So either the new libxml functions have to provide the same format as
xml.el, or xml.el has to be changed to used the new format, breaking
existing uses.  I am amenable to the latter if the new format is so much
better than the old one that it's worth dealing with the backward
compatibility headaches.