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Re: [XML11TF] (on the "restrictive" option)

From: <noah_mendelsohn@us.ibm.com>
Date: Wed, 17 Mar 2004 19:34:42 -0500
To: Yves Lafon <ylafon@w3.org>
Cc: Herve Ruellan <herve.ruellan@crf.canon.fr>, Mark Nottingham <mark.nottingham@bea.com>, "'XMLP Dist App'" <xml-dist-app@w3.org>
Message-ID: <OFE9258B1F.C667B78E-ON85256E5A.007C68D5@lotus.com>

Yves Lafon writes:

>> as allowing XML 1.0, 1.1 and different encoding 
>> is already a source of interoperability for 
>> perfectly valid SOAP infosets.

I guess I see this as a much smaller concern.  RFC 3023 basically defers 
to the XML Recommendation(s), and XML 1.0 says [1]

"All XML processors MUST be able to read entities in both the UTF-8 and 
UTF-16 encodings."

...both of which are encodings that are capable of conveying the full 
range of characters allowed by the {char} production.  While it's true 
that one can attempt to send encodings that either (a) would not be 
universally understood or (b) don't convey the full range of {char}, I 
think it's fair to say that our existing recommendations taken together 
provide fairly clear guidance on how to avoid such interoperability 
concerns:  send UTF-8 or UTF-16 and every legal Infoset will faithfully 
transmitted to a receiver that MUST be capable of parsing it.  I suppose 
we could add a note reiterating the use of other encodings may break 
interop.

I see the XML 1.1 infoset question as much deeper for the reasons already 
stated:  introduce a fully conforming SOAP 1.2 intermediary (coded a few 
months ago to the then-current recommendations) into a path where you're 
sending XML 1.1 content and your envelope will not get to or past the 
intermediary. 

So, I guess I'm still not convinced that the encoding example is in 
practice an indication that we have much of a precedent for lack of 
ability to guarantee interop.  It's true that we have allowed cooperating 
nodes to use things like alternate MIME types, but we have also so far 
always provided a lingua franca that reasonable implementors will assume 
is capable of successfully transmitting any legal SOAP envelope.  I think 
the question is whether this should remain true, or whether the benefits 
of allowing optional use of XML 1.1 outweigh the loss of interop.

Noah

[1] http://www.w3.org/TR/2004/REC-xml-20040204/#charencoding
 
--------------------------------------
Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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Received on Wednesday, 17 March 2004 19:52:48 GMT

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