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On Thu, 18 May 2000, Michael Champion wrote: > From: "David Brownell" <david-b@p...> > > > > Actually I think the XML spec would have been substantially improved, > > in the technical sense, were it to have been directly validated by an > > implementation -- using only the standardized productions. > > I strongly agree, and hope this is addressed in the corrected version of XML > 1.0 if it ever comes out, or in XML 1.1 / 2.0. A colleague implementing an > XML parser "from scratch" -- that is, without previous exposure to all the > folklore that one picks up from SGML, XML-DEV, deconstructing other people's > code, etc. -- stumbled over all sorts of little problems with the > standardized productions. I have to at least partially disagree. Many practical, widely used languages cannot be specified *entirely* by EBNF productions and thus the formal definition of their syntax includes prose in the language specification. For example, a context-free grammar cannot specify that all identifiers in a programming language be declared before they're used, or that a function must be called with the exact number of parameters specfied in its declaration (Aho & Ullman, p.179). Thus processors for more-than-toy languages generally enforce such syntactic constraints via "ad-hoc" code rather than through their parsing tables, and only the prose in the spec can inform the processor's author how to write that code. *************************************************************************** This is xml-dev, the mailing list for XML developers. To unsubscribe, mailto:majordomo@x...&BODY=unsubscribe%20xml-dev List archives are available at http://xml.org/archives/xml-dev/ ***************************************************************************
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