- From: Tim Bray <tbray@textuality.com>
- Date: Fri, 06 Dec 2002 10:26:12 -0800
- To: noah_mendelsohn@us.ibm.com
- Cc: Norman Walsh <Norman.Walsh@Sun.COM>, www-tag@w3.org
noah_mendelsohn@us.ibm.com wrote: >>>It seems to me that supporting the possibility of >>>managing entities should have little impact on >>>performance for documents that don't have >>>any. > > Not true, in my experience. Depending on one's implementation strategies, > the very fact that things can move, expand, and in the case of external > entities be in different encodings all can potentially complicate an > implementation. It's not unusual for such factors to lead to an > assumption that data will be copied, something which may be hard to avoid > in the no-entity special case. Hmm, my intuition is that if you (a) removed the possibility of recursion from entities, and (b) forbid any form of external entity that would drive the implementation cost down to where it would vanish in the static of more expensive stuff like Unicode character handling and attribute-value munging. You're going to have to have code there anyhow to do & and < and 몾 anyhow, so it's really hard for me to believe that the extra cost would be noticeable. But I'm old and grizzled enough to distrust intuition on this kind of thing, so I wouldn't be too surprised to be proved wrong. Speaking on the (shaky) basis of intuition, it seems like a profile of XML with brutally-restricted internal entities (in an internal subset only) might hit a real sweet spot, simultaneously solving MathML's problems and usable in high-performance protocols a la SOAP. Worth thinking about anyhow. -Tim
Received on Friday, 6 December 2002 13:26:13 UTC