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Re: PIFLE (was Re: Are PIs useful?)

From: Paul Prescod <papresco@calum.csclub.uwaterloo.ca>
Date: Thu, 15 May 1997 10:49:07 -0400
Message-ID: <337B2263.35082B90@calum.csclub.uwaterloo.ca>
To: w3c-sgml-wg@w3.org
Bert Bos wrote:
> If you have
>     <?my-info foo="bar" q="8"?>
> why not change it to
>     <my-info foo="bar" q="8"/>
> Is there any difference in what a parser hands to the application? 

Yes. In the first case it hands "(type: PI, target:my-info, foo:bar,
q:8). In the second it hands (***VALIDITY ERROR*** THIS DOCUMENT DOES
NOT CONFORM TO ITS DTD***) and pops up an error message and perhaps
halts the transfer of medical information that was underway.

Big difference.

> So how is it possible that PIs are still in the draft? I think that
> all the people that said "I don't use them..."  thought that there
> actually were other people that did. And nobody asked for a show of
> hands.

We all use them: every single XML user does. XML could not exist as it
does today if it were not for PIs in SGML. We would have had to declare
"implicit elements" and tromp on the user's namespace and on SGML
compatibility for the XML declaration. User PI's similarly belong *in*
XML because ten years from now some sub-group of some organization will
want to make an application profile *of* XML.

Charles Goldfarb lives totally in the SGML universe. He would never
expect anyone to want to make an application profile of XML when they
could just go back to the "source" (the SGML spec.). I tend to prefer to
allow people to derive from XML if they want, or back from SGML if they
choose that instead.

 Paul Prescod
Received on Thursday, 15 May 1997 10:52:59 UTC

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