Prefix rewriting considerations

Hi all,

continuing with today's discussion on prefix rewriting I wanted to bring
up the prefix-free canonicalization we published last year (ACM SWS
2009). The approach basically consists in rewriting every XML element to
a representation like this: <localname xmlns="namespace-uri">
This way, you don't need prefixes at all (besides for the attributes),
the resulting XML is still well-formed, there is no "unsigned"
information besides the prefix name, and you don't need doing
digests+base64 stuff nor excessive search for predefined prefix
mappings. Maybe we could consider this as one option for the rewriting
parameter.

Bigger example:

<nsA:A xmlns:nsA="http://A.ns" xmlns:nsB="http://B.ns">
  <nsB:B>
     <nsA:A2 />
  </nsB:B>
</nsA:A>

becomes sth. like

<A xmlns="http://A.ns">
  <B xmlns="http://B.ns">
    <A2 xmlns="http://A.ns" />
  </B>
</A>

In order to optimize performance one could suppress the xmlns=".."
output if it would be identical to that of its parent element. However,
this again may become a source of confusion.

What do you think?

best regards

Meiko