Re: [w3c sml] [4775] Change "skip" to "lax" processing

yeah, what he said (+1 from me)
I never understood why we would prevent a validator from using schema 
components it could locate (skip), as long as they are not required (lax).

Best Regards, John

Street address: 2455 South Road, Poughkeepsie, NY USA 12601
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"Wilson, Kirk D" <> 
Sent by:
08/24/2007 10:49 AM


[w3c sml] [4775] Change "skip" to "lax" processing

The email will serve to initiate the discussion of whether we should 
specify processControl=”lax” rather than the current “skip” for wildcards 
in the SML XML Schemas.
There is only one occurrence of processControl=”skip” in the SML 
specification: for the content of the smlerr:errorDataType.
The original issue was raised with respect SML-IF in which 
processControl=”skip” is used for all extension elements (both xs:any and 
xs:anyAttribute) in the type definitions of this specification.
Since I wasn’t involved in the original authorship of the spec, I’m not 
sure what the rationale was for the original use of “skip”.  I assume it 
was for efficiency of the SML-IF consumer, the assumption being that the 
SML-IF would need to concern itself only with sml elements according to 
the semantics specified in SML-IF.  In my notes I have found the following 
definition of an SML-IF consumer: “processes SML-IF documents in whole or 
in part by the semantics of this specification” (emphasis added).  Since, 
by definition, extension elements lie beyond the semantics of the spec, 
there appears to be no reason for the processor’s attempting to validate 
the extension elements.  But I would consider this a poor argument.
“Skip” seems too finalistic and may not meet the requirements of SML-IF 
consumer creators and SML-IF document authors who need to build in special 
information, eg., into the ModelType, and can provide the schema for 
validation (assessment).  I suspect that something like this rationale 
underlies what appears to be the industry “best practice” of using “lax” 
processing.   The cost of using lax processing is undoubtedly absolutely 
I will recommend changing the spec to “lax”, according to what is industry 
best practice. 
Kirk Wilson, Ph.D.
CA Inc.
Research Staff Member, CA Labs
Intellectual Property and Standards
Council of Technical Excellence
W3C Advisory Committee Representative
Tele: + 1 603 823-7146
Fax:   + 1 603 823-7148

Received on Friday, 24 August 2007 16:01:40 UTC