Re: Parameter entity references

1)  This is to second the plea that we look very very
carefully at requirements on this one.  Could someone
state what we all feel they are? please?

2) Can we also look at this as a cost (and to whom) and
benefit (and to whom).

Parameter entities in DTDs:
   - are the mechanism DOCBOOK, TEI, and others
     have used for extensibility and customizing
   - are a godsend in DTD maintenance and legibility
   - make multi-DTD libraries practical

Cost = to parser, browser developers 
       (small number, but critical constituency)
       This is a development loss.
Gain = to DTD writers, maintainers, (larger number, at
       least this has been true for SGML)
Cost to Users/Authors = not much. this is a setup problem and
       setup is not done all that often
Gain to User/Authors = again definite, but hard to see.  The
       fine art of customization becomes less an obstacle
       This is a production system gain.

3) Soapbox: 
We can finesse this: Yes, it will be necessary (as of this writing) to 
preprocess an SGML DTD to make an XML DTD anyway, and the PEs could be
resolved at that point.  But why throw out the good bits?
Wasn't the XML subset supposed to include the most useful 
parts of SGML while omitting the marginal, the broken, the overly 
complex, and the arcane?  PEs in DTDS are one of the few universally
useful concepts.  Why should it be harder to write and
maintain a good XML DTD than it is to do the same in SGML?
End soapbox.  Sorry :-)  --dal


=======================================================================
Deborah A. Lapeyre                   Phone: 301-231-6933
Mulberry Technologies, Inc.          Fax:   301-231-6935
6010 Executive Blvd.  Suite 608      E-mail: dlapeyre@mulberrytech.com
Rockville, MD USA 20852
=======================================================================

Received on Thursday, 29 May 1997 12:01:50 UTC