- From: Rick Jelliffe <ricko@allette.com.au>
- Date: Sat, 21 Jun 1997 14:56:31 +1000
- To: <w3c-sgml-wg@w3.org>
> From: len bullard <cbullard@hiwaay.net> > David G. Durand wrote: > > > > the harders thing about learning PEs is that the string > > substitution model is _not_ correct. > > Please explain this. String substitution is > precisely what they appear to be. So, I am missing > something and wish tutoring. Even though I don't think XML particularly needs PEs, I think they are being wrongly criticised because they are not like CPP macros. If you demand CPP macros, use them at your server! PEs are very well-behaved "macros". The constraints on their placement make them less easy to abuse. In particular, they stop a "macro" from including text that goes outside the scope of the current production. So when you read a DTD and you see a parameter entity reference, you always know that you can skip over it and visually keep parsing: it will not contain any nasty suprises. Rick Jelliffe
Received on Saturday, 21 June 1997 01:26:08 UTC