XSchema: existing ID attributes considered harmful (was: XSchema Spec Section 2.2, Draft 1)

[John Cowan]

Paul Prescod wrote:

> The DTD syntax would indicate
> that there is no relationship, but the fact that under the namespace
> proposal they can be namespace qualified suggests that attributes can be
> shared.

Yes.  Namespaces allow us to identify attributes across element types;
DTDs do not.

> > I disagree.  I am willing to accept a shorthand, either by way
> > of general entities in XSchemas or otherwise, for copying
> > attribute declarations from one element to another by way of
> > shorthand, but not for reifying attributes independently of the
> > elements they are attached to.
> 
> General entities are an ackward mechanism for reuse, and have essentially
> all of the flaws of XML parameter entities. One of our goals should be to
> reduce the need for them.

On reflection, I agree.

> I can't think of another syntax that

Whatever you intended got truncated here.

However, consider an extension to XSchema syntax that allowed one
to tag (with ID attributes) various XSchema elements and then to
refer to them using empty XLink elements.

In aid of this, I am PROPOSING that we not use any ID attributes
in XSchema 1.0; change the "id ID #REQUIRED" attributes in ElementDecl
elements to "name NMTOKEN #REQUIRED" instead.  That will allow us
to reserved XML IDs for structure-sharing.

This would involve a very minor change to the existing Section 2.2.

Comments?

-- 
John Cowan	http://www.ccil.org/~cowan		cowan at ccil.org
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)

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