Re: XML tools for Octave

[Andy Adler]

On Thu, 29 Jun 2006, Bill Denney wrote:

> On Thu, 29 Jun 2006, Andy Adler wrote:
>
> > I honestly don't know how to address this. Your suggestion would basically 
> > mean that we expose the full DOM API. Matlab did this with a thin wrapper 
> > over Java's DOM.
> >
> > However, this is a really bad idea. It means that all the effort of
> > XML parsing falls on the user - who will either make mistakes or
> > shortcuts, with the result of really fragile code.
> >
> > For example a user will parse
> >     <data><item> 1 </item></data>
> >
> > using
> >   v.data.CHILD{1}.item.TEXT{1}
> >
> > But this will break when you have
> >     <data> <item> 1 </item></data>
> >
> > or
> >     <data><metadata/><item> 1 </item></data>
>
> That's true, but users will always write fragile code like that.  One option 
> around this would be to have options like "strip-space" (taking a cue from 
> XSL: http://www.w3schools.com/xsl/el_preserve-space.asp) that would 
> relatively intelligently help the user.  Perhaps make stripping spaces the 
> default would be most helpful to the users.

I don't think parsers should take options like that. I think the
interpreter variables that John recently got rid of in Octave are a 
good example.

But the issue here is the extensibility at the heart of XML. The point
is that you should be able to add extra information (the <metadata/>)
and a parser for the old format should still work

Here is my latest idea for the format:
 <a b="c" d="e"> text <f g="h"/> more <é->text</é-> <f>data</f></a>

 v.a.UTFNAME         : "a"
 v.a.NAMESPACE       : ""
 v.a.ORDER           : 1
 v.a.ATTS.b          : "c"
 v.a.ATTS.d          : "e"
 v.a.TEXT{1}         : " text "
 v.a.TEXT{2}         : " more "
 v.a.TEXT{3}         : " "

 v.a.f{1}.UTFNAME    : "f"
 v.a.f{1}.NAMESPACE  : ""
 v.a.f{1}.ORDER      : 2
 v.a.f{1}.ATTS.g     : "h"

 v.a.f{2}.UTFNAME    : "f"
 v.a.f{2}.NAMESPACE  : ""
 v.a.f{2}.ORDER      : 6
 v.a.f{2}.TEXT{1}    : "data"

 v.a.e_{1}.UTFNAME    : "é-"
 v.a.e_{1}.NAMESPACE  : ""
 v.a.e_{1}.ORDER      : 4
 v.a.e_{1}.TEXT{1}    : "text"

Here I keep the order of the tags in each tag. The text elements are
then interspersed between them. Names (like é- are modified, but
the original is kept, as required).

Comments?

--
Andy Adler <address@hidden> 1(613)562-5800x6218