Re: [topicmaps-comment] mergeMap Pointing to MoreThanOnetopicMapElement

["W. Eliot Kimber" <eliot@isogen.com>]

Lars Marius Garshol wrote:

> | This seems like it might be reasonable change--the syntax hit is
> | small--really you only need to move the xlink:href attribute into
> | the XTM name space.
> 
> Well, yes and no. It means changing the mechanism by which the arcs
> in a topic map graph are asserted. It's kind of like changing '<' to
> be '[' (and '>' to be ']') in XML.

I'm not sure I'm following you here--if by "mechanism" you mean the
attribute that specifies the pointer, then the only thing that's
changing is the attribute name (or rather the name space in which the
name is placed)--the pointer syntax and the semantics of that pointer
are unchanged. If by "mechanism" you mean something else, then you've
lost me, because I don't know what you mean by "mechanism" in that case.

> The change is small in one sense, but in another it's clearly not, in
> the sense that if you use an unsupported version of the syntax (with
> some software) the result is total breakage. Nothing will work.

Clearly there would be a transitional period during which both forms of
the attribute would need to be recognized--but I don't think this is any
different from deprecating a method in an API. 

At the moment, XTM is at best underspecified with respect to the
interpretation of XPointers and the limitations on them, with the side
effect that, for example, different otherwise conforming implementations
may have different, equally justifiable, behaviors for interpretation of
bare ID references when there is no governing schema or DTD. So
regardless of what attribute name is used there does need to be
additional language about how XPointers are interpreted, at a minimum,
if not additional constraints on the type of XPointers that can be used
(although I don't think there need to be any given that there are
already clear rules for what the allowed result are in particular
contexts, as Lars Marius points out).

Cheers,

E.
-- 
W. Eliot Kimber, eliot@isogen.com
Consultant, ISOGEN International

1016 La Posada Dr., Suite 240
Austin, TX  78752 Phone: 512.656.4139