The Peace Process: DOM and namespaces...

Tyler Baker tyler at
Thu Feb 11 12:43:07 GMT 1999

James Clark wrote:

> Tyler Baker wrote:
> > In terms of O notation (I hate to be academic here) that is N^2 plus the underlying cost of
> > string comparisons.
> Huh?  The time for each element is linear in the number of attributes
> that the element has.

I guess it all depends on how you look at things.  If you consider an XML document as a set of nodes
that you must iterate over and you consider all attributes to be sets of nodes within each element
node you get N^2 time.  If you consider attributes to be nodes of the XML document then you get N
time.  I guess it depends on how you look at things here.  I chose to look at the entire document as
a set of elements, with each element containing a set of zero or more attributes.

> > And you still need to reparse the entire document each time to safely create these bindings as
> > the source tree can mutate at any time.
> You need to do the namespace processing each time.  You don't have to do
> the parsing each time.

This is what I meant (sorry for the confusion).  I meant that you need to in effect reparse the
document whether it be a stream, sax events, or a DOM tree and rebuild your entire namespace map
each time.  Nevertheless, this is not cheap.


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