- From: Elliotte Harold <elharo@metalab.unc.edu>
- Date: Sat, 02 Dec 2006 11:42:01 -0500
Lachlan Hunt wrote: > HTML 2.0 to 4.01 documents could, in the same way you're insisting on > using XML tools on the back end, be reliably parsed using SGML tools. Surely you jest. First of all, I believe there was only ever one parser that implemented all of the SGML specification, SP from James Clark. In practice, SGML documents and parsers were not interoperable. Documents and document types were designed to fit the limitations of one specific parser. Secondly, anyone who actually tried to use an SGML parser to handle HTML rapidly hit a wall since most HTML documents were not even close to actually conformant to the SGML spec or the HTML DTD. XML, by contrast, learned enough from the experience of SGML to make interoperable parsers and documents a reality. It also learned to separate well-formedness from validity, which is certainly the single most underrated contribution of XML to the field. Well-formedness gives 80% of the benefit of validity for 20% of the cost. In fact, a lot of the time I'd say it gives 120% of the benefit of validity at 20% of the cost. Well-formedness sans validity is a large part of extensibility. It is what puts the X is XML. A well-formed XML document is a much lower bar to aim for than a valid SGML one. -- ?Elliotte Rusty Harold elharo at metalab.unc.edu Java I/O 2nd Edition Just Published! http://www.cafeaulait.org/books/javaio2/ http://www.amazon.com/exec/obidos/ISBN=0596527500/ref=nosim/cafeaulaitA/
Received on Saturday, 2 December 2006 08:42:01 UTC