RE: [namespaceDocument-8] 14 Theses, take 2

At 09:31 PM 18/02/02 -0600, Dan Connolly wrote:
>Tim Bray said something like "the world thinks schemas are
>for expressing syntactic constraints, so if
>we decide otherwise, we'll have to re-educate them."

And given that the W3C chartered an activity named "XML schema"
that produced a spec named "XML Schema" that's about constraining
syntax, the world thinks the W3C thinks that schemas are about 
constraining syntax.  Whatever we may think, I wonder if it's 
too late to fight it.

In the general population of programmers, my instinct is that
Dave Orchard's right and they think schemas are DTDs/WSD/RelaxNG/
whatever.  The smaller but important population of language
designers may see it differently - Dan's anecdotal evidence from
the Cover pages is convincing on this.

>Languages are more than just syntax. When folks
>talk about schemas, they're talking about language
>definitions, including both syntax and semantics.
>Hmm... maybe that's a useful term or collection of terms:
>        language definition -- a (written) agreement about
>        some syntactic constructs (aka a set of documents)
>        and what they mean.
>        syntax specification -- a document that
>        includes enough information to tell whether
>        some other document is syntactically good or not;
>        perhaps including enough information to make
>        a parse tree and decorate it while you're deciding.

I think you're on the right track.  Why not just go with the
flow and use schema for the second, and start evangelizing
the term "language definition" for the first, because, well...
it's accurate; it is a language definition.  Clearly a 
language definition usually includes but is almost never
limited to a schema.

And the claims under the first could be stronger: the language
definition can include syntax, semantics, I could even swallow
"meaning" in this paragraph, rendering constraints, you name it.

>Am I completely off the mark?

No. we have creeping consensus here, which cheers me no end
as we were flailing mightily a week ago.

>I don't mind reserving the term 'schema' to mean
>something syntactic in TAG use, if that's really
>the way it's used in the wild. I just wonder
>if that's the way it's used in the wild.

As often as not, I'd say.  Simon's not convinced.  Anyone have 
any more evidence?  -Tim

Received on Tuesday, 19 February 2002 00:00:29 UTC