[SCL] SCL spec

[Murray Altheim]

Chris Menzel wrote:
> I've put an SCL spec on the web: http://cl.tamu.edu/docs/scl.html .
> It is not highly polished, but it will do as a start to get ideas fixed.
> 
> Features (all negotiable):
[...]

Thanks Chris -- this looks interesting and digestable.

I have a rather "meta" comment about the CL and SCL specs that I'd
like to propose early on that might assist everyone in discussing
the drafts, as well as implementors in demonstrating compliance with
a specification. There are four aspects to this:

1. First, if all published drafts were to include version and or
   revision numbers, when somebody is either making a comment or
   reading someone else's on the mailing archives, it would be
   apparent which document they were talking about. This may help
   avoid people talking past each other, or accidentally about
   different versions of the text.

2. Secondly, it would be of great help if there were major and
    minor section numbers on the documents so that the sections
    could be discussed individually, unambiguously.

3. Third, individual productions of an abstract or concrete
    syntax should include production numbers, for the same
    reason as the above suggestion: that we can discuss them
    without having to provide examples, etc. This also assists
    implementors. The SGML and XML specifications are things
    that developers understand structurally.

4. Finally, as I've done in my XCL proposal, all components of
    the language that may be referred to conceptually either in
    discussions or more particularly by tools should be given a
    unique identifier. Topic Maps introduced a concept called
    Published Subject Indicators (PSIs) that are basically just
    stable URIs used as identifiers. The idea here (which would
    be useful in Topic Map, RDF, or any other web-related system)
    is that if two things identify themselves as having the same
    PSI, they are semantically equivalent. For example, if OWL
    has a concept "http://www.w3.org/2002/07/owl#" and my Ceryle
    project has a concept "http://purl.org/ceryle/psi/authoring/#Thing",
    these two things can be compared and equivalence between them
    stated, e.g., a machine-readable document could express the
    formal relationship between two different systems.

    This is a concept that will be quite comfortable for both
    those in the RDF and Topic Map communities, as well as being
    more and more common in web development generally (many Java
    projects nowadays set properties via URLs like this).

I certainly wouldn't expect the entirety of these suggestions
be implemented in early drafts, but the first three will make
discussion of the drafts much less prone to misunderstanding,
and people reading the archives will have a much better chance
of figuring out what someone is talking about.

Murray

......................................................................
Murray Altheim                    http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK               .

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