[wg11] RE: [step-os] thoughts on documenting STEPmod

[David Price]

Josh,

Those are all good ideas. 

How much work would that add to the Part 28 E2 project which, it appears,
will shortly be without an editor?

Also, please remember that the only reason the STEPMod DTD exists is as part
of a system for creating documentation. It assumes the validity of the
EXPRESS schema is checked by any parser that outputs an XML document
representing the schema. As I think I said in an email somewhere, it did not
need to be perfect, just good enough for its intended use.

A thought just occurred to me (it does happen occasionally), what about
including the STEPMod DTD as part of Part 25 E2? We could use it as part of
the UML/EXPRESS mapping specification. Is there any reason it must be
standardized in Part 28 E2?

Cheers,
David

> -----Original Message-----
> From: step-os-bounces at ned.gsfc.nasa.gov 
> [mailto:step-os-bounces at ned.gsfc.nasa.gov] On Behalf Of Josh Lubell
> Sent: 10 September 2004 17:26
> To: step-os at ned.gsfc.nasa.gov
> Subject: [step-os] thoughts on documenting STEPmod
> 
> 
> Orthogonal to all the discussion on the relationship between 
> the STEPmod 
> EXPRESS model XML format and the Japan ballot comment on Part 28e2, I 
> have been looking at the current STEPmod DTD and existing XML-tagged 
> EXPRESS models in the modules repository conforming to the DTD.
> 
> I notice that the DTD is looser than (what I believe to be) 
> the actual 
> constraints on STEPmod. Two examples:
> 
> 1. The DTD permits an EXPRESS attribute to have a named type 
> where the 
> typename isn't specificed anywhere else in the XML data.
> 
> 2. The DTD does not enforce EXPRESS grammar rules for bound 
> specifications. For example, it allows you to specify an upper bound 
> without a lower bound.
> 
> Because the STEPmod DTD alone is insufficient for 
> constraining STEPmod 
> XML format, I believe that a specification documenting the 
> format should 
> not be DTD-specific, but rather should include the DTD as an 
> informative 
> annex, along with XML Schema and RELAX NG annexes. Actually, 
> RELAX NG is 
> probably the best XML schema language for representing the STEPmod 
> format. I say this because all of the information in STEPmod 
> is in XML 
> attributes, and RELAX NG is better at representing XML attribute 
> co-occurrence constraints than DTDs or XML Schema.
> 
> Regards,
> Josh
> 
> -- 
> Joshua Lubell
> National Institute of Standards and Technology
> Manufacturing Systems Integration Division
> 100 Bureau Drive, Stop 8263
> Gaithersburg MD 20899-8263, USA
> Phone: 1-301-975-3563, Fax: 1-301-975-4694
> Email: lubell at nist.gov
> 
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