xml-dev - Re: SAX2 Namespace Support

[Stefan Haustein <haustein@ls8.cs.uni-dortmund.de>]

David Megginson wrote:
> 
> > class QName {
> > public:
> >     wstring ns () const;           // http://www.w3c.org/1999/xhtml
> >     wstring name () const;         // p
> >     wstring nsPrefix () const;     // html
> >     wstring prefixedName () const; // html:p
> >
> >     bool operator== (const QName &rhs) const;
> >                                    // ns & name both equal
> > private:
> >     // Probably just a simple pointer to your internal data structures
> > };
> 
> My biggest problem with this (and its Java equivalent) is figuring out
> how to handle equality: are two QNames with the same URI part and same
> local part equal?  What if the prefix is different?

What about adding a second method "identical 
(QName compare)" that takes also the prefix 
into account?  I think it's consistent if the
default method (equals () / ==) ignores the "noise".

A QName object could also help for the attributes: 
If the Sax2 AttributeListImpl is implemented like the
Sax1 list, it would have up to four Vectors:

class AttributeListImpl {
   Vector prefixedNames;
   Vector localNames;
   Vector prefixes;
   Vector namespaces;

   ...
}

Adding an attribute and creating or clearing an 
AttributeList (= manipulating four Vectors) would 
be extremely expensive.

class AttributeList {
   Vector QNames;      // better: ArrayList !

   Qname getAttribute (int index);
   ...
}

seems much cheaper, especially if the QName objects are interned.....

Best regards

Stefan

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