Re: multiple types

[Jonathan Borden <jborden@mediaone.net>]

Gavin Thomas Nicol wrote:
> > Maybe you could view an element as being instances of two types
> > at the same time: the type defined by the attribute set and
> > the type defined by the non-attribute content.  What a wierd
> > thought!
>
> I've come to believe that documents are always of an infinite
> number of types! So yes, I think you can easily say

[examples snipped]

>
> The operative word is *conforms*... type is painted on
> data by a set of assertions.
>

I think this is a really important point. Example of this are "Document
Types" aka DOCTYPE which defines a document type as validity w.r.t a DTD (a
set of constraints). Another example is XML Schema regular expressions which
define a type as a pattern conformed to. Another example is what Murata
Makoto recently posted about "Hedge Regular Expressions" which related to
TREX, RELAX and perhaps what Examplotron is growing into. Yet another
example is Schematron which directly defines conformance in terms of
assertions. So yes.

-Jonathan