Re: Notable declarative expressions?

[ht@markup.co.uk (Henry S. Thompson)]

John Cowan <johnwcowan@gmail.com> writes:

> It's mostly a grammar, but not exclusively.  In particular, subtyping by
> extension and restriction are data-model-like features that have nothing to
> do with whether a particular document conforms to a particular grammar, as
> it is always possible to compile them out of the schema.

I hesitate to disagree, but using OO-inspired techniques as a concise
way to express multiple grammar rules doesn't mean the result isn't
still a grammar -- it's just like the use of metarules in GPSG, a
notational device.  The explicit grammar is expanded by the
interpretation/application of the metarules, producing an expanded
(implicit) grammar, which is in turn what is used to determine
language membership/schema validity.

ht
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