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[SLUG] Re: Why XML bites and why it is NOT a markup language
- To: slug@xxxxxxxxxxx
- Subject: [SLUG] Re: Why XML bites and why it is NOT a markup language
- From: Jan Newmarch <jan.newmarch@xxxxxxxxxxxxxxxxxxxxxx>
- Date: Thu, 9 Jun 2005 20:34:53 +1000 (EST)
- Reply-to: Jan Newmarch <jan.newmarch@xxxxxxxxxxxxxxxxxxxxxx>
Don't confuse the language with the parser. By this criterion even TeX
doesn't make it as a markup language - I have had many, many files fail to
parse over a single error. One TeX parser I used even had an "extra help"
key: when you pressed it, the response was usually "I've given you all the
help I can, if you can't understand the error then see a human." The onus
is on you to fix the error, not on the parser - automatic error recovery
isn't as easy as it seems. So as a human, I suggest you change the
offending char and reparse it - and send a flame email to the originator.
A markup language MUST be robust. Anything that claims to be portable
and all-purpose and the document processing format of the future simply
cannot be destroyed by a single bit-flip on a single character.
The fundamental difference between a programming language and a markup
language is that a programming language can have parser errors and
syntax errors whereas a markup language cannot (by definition) have
any errors at all under any circumstances. The parser for a markup
language must be fully robust to all possible inputs and although it
certainly can result in various severity of WARNINGs but nothing must
stop the parser.
Cheers (and sympathy...)
Jan Newmarch, School of Network Computing
Tel: +61 3 9904 4249, Fax: +61 3 9904 4124
(ESOS: Monash Provider No. 00008C)
Since it's hard to make machines think about the world, the new goal
[in the semantic web] is to describe the world in ways that are easy for
machines to think about (http://www.shirky.com/writings/semantic_syllogism.html)