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RE: Problem with resolution of Issue 221

From: Martin Gudgin <mgudgin@microsoft.com>
Date: Wed, 14 Aug 2002 08:12:03 -0700
Message-ID: <92456F6B84D1324C943905BEEAE0278E01FC62BF@RED-MSG-10.redmond.corp.microsoft.com>
To: "Williams, Stuart" <skw@hplb.hpl.hp.com>
Cc: <xml-dist-app@w3.org>

The whole point of making the detection of PIs SHOULD rather than MUST
was to allow high performance intermediaries to avoid the overhead of
doing the PI detection ( they would have to look at the entire message
). BUT if they are precluded from sending messages containing PIs then
they HAVE TO do the PI detection anyway, so any perf gain is lost.
 
So we may as well make both of them MUST ( or SHOULD ) or, my preference
would be to stop trying to subset XML, say nothing about DTDs or PIs
except that our spec doesn't define any processing rules for them.
 
Gudge

> -----Original Message-----
> From: Williams, Stuart [mailto:skw@hplb.hpl.hp.com] 
> Sent: 14 August 2002 14:40
> To: Martin Gudgin
> Cc: xml-dist-app@w3.org
> Subject: RE: Problem with resolution of Issue 221
> 
> 
> Hi Martin,
> 
> Hmmm... not sure that this really is inconsistent... 
> 
> The MUST NOT is on senders sending PIs in messages.
> 
> The emboldened SHOULD is on receivers generating errors (are 
> those faults and if so which one(s)) on receipt of PIs in messages.
> 
> There is a non-emboldened 'should' with "detect and fault" in 
> "Whenever possible, receivers should detect PIIIs and fault." 
> I took this as explainatory narrative, because the 'should' 
> is not a 'SHOULD'. 
> 
> The conjunction of PI detection and fault generation muddies 
> the intended strength of the imperative on detection and 
> fault generation ie. MUST detect and SHOULD fault, or SHOULD 
> detect and SHOULD fault etc...
> 
> To me the resolution seemed clear and consistent [1], ie MUST 
> NOT send PIs; SHOULD generate error/fault on receipt of PIs. 
> Detection of PIs becomes implicit in meeting those 
> imperatives and need not be spoken about explicitly ( I 
> think). Unless of course the intent of the WG in resolving 
> this issue was different than that... then I guess clarity 
> and consistency again fall into question.
> 
> Thanks,
> 
> Stuart
> [1] 
> http://lists.w3.org/Archives/Public/xmlp-comments/2002Aug/0046
.html

> -----Original Message-----
> From: Martin Gudgin [mailto:mgudgin@microsoft.com]
> Sent: 14 August 2002 10:42
> To: xml-dist-app@w3.org
> Subject: Problem with resolution of Issue 221
> 
> 
> 
> I was about to incorporate the resolution to issue 221[1]
> when I noticed
> an inconsistency:
> 
> We say that a sender MUST NOT send a message containing Processing 
> Instructions. However, for receivers we only say SHOULD detect PIs and

> generate a fault.
> 
> In the case of an intermediary ( the case we were thinking of when we 
> said 'SHOULD' for receivers ) this will not work, as the intermediary 
> is also a sender. Therefore, in order to comply with the MUST it has 
> to detect PIs in the inbound message, otherwise when it sends the 
> message onward, it might be violating the MUST.
> 
> On balance I think the best we can get away with is SHOULD NOT
> 
> Gudge
> 
> [1]
> http:///lists.w3.org/Archives/Public/xmlp-comments/2002Aug/0014.html
> 
Received on Wednesday, 14 August 2002 11:12:34 GMT

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