Re: Proposal XML Toolbox for Octave

[Andy Adler]

On Fri, 9 Feb 2007, Thomas Geiger wrote:

> 2. I quite like the format of the XMLtoolbox output. I just have a few
> > issues:
> >
> >      - if each tag is converted into an identifier, how does
> >        it handle XML like <é- ï$="1" />?
>
> Honestly, I've never seen such element tag in an XML before, and as far as I
> understand XML,
> it should be a human readable format. Do you have an example for this?

I haven't seen stuff like that (but it exists, I'm sure). However, I have
seen
          <123 456="789" />

This will cause problems because octave/matlab identifiers can't
start with numbers

   xmlstr= xmlparseany(' <123 456="789" /> ');
would give:
   xmlstr.ATTRIBUTE.123 = '789'

>    - the converted format is slightly non-unique. The following
> >        XML files will  parse identically:
> >
> >        1. <a> <b> <c> <b> </a>
> >        2. <a> <b> <b> <c> </a>
>
> Assuming the XML is well-formed (otherwise the parser will reject it),

My mistake, I mean that both
   xmls1= xmlparseany('<a><b/><c/><b/></a>');
   xmls2= xmlparseany('<a><b/><b/><c/></a>');
would give:
   xmls1.b{1} ... =
   xmls1.b{2} ... =
   xmls1.c{1} ... =

This could be solved by adding an TAGORDER attribute, so we have
   xmls2.b{1}.TAGORDER = 1;
   xmls2.b{2}.TAGORDER = 3;
   xmls2.c{1}.TAGORDER = 2;


> 3. I would very much like to see a parser that accepts an XPath
> >      statement to only parse a part of a file. It may be possible
> >      to add this later.
>
>
> Xerces-C just implements parts of XPath which are necessary to handle
> schemas.
> For fully supprt Xalan-C (http://xml.apache.org/xalan-c/) might be an
> option, there's
> lots to think about regarding this and as you mention it could be added in a
> later version.

An XPath expression would help coding speed (users are
 normally are only interested in a small part of the XML file) and 
memory user (only a small part need be loaded)

I would suggest that this is a good way to go (as long as the
code from geodise works well - I haven't tested it).

HOwever, I suggest we ask geodise to clarify their licence first.
It may be possible to reuse some of the code - saving you time.

--
Andy Adler