[topicmapmail] multiple Source Locators

[Lars Marius Garshol]

* Thomas B. Passin
|=20
| To be a bit more precise about http: URLs - What you get back when
| you make a GET or POST request is considered to be a
| *representation* of (the state of) the addressed resource.  However,
| this is not necessarily true of an arbitrary URI scheme.

Yep. File URIs would be one example of this.
=20
| I am going to have to fess up and admit that I have never been quite
| sure what these "locators" are supposed to be.  In particular, I am
| unclear about the relationship between a locator and a good old
| fashioned topic id.  Please enlighten me!

A locator is pretty much the same as a URI, except that in HyTM, for
example, they are HyTime locators. Official support for HyTM has been
discontinued, but the locator concept is still with us.

A topic id, in the sense of the value of the -id- attribute of a
<topic> element, for example, is in TMDM mapped to a source locator.
This is an absolute URI that refers back to the <topic> element with
the URI of the enclosing XTM file and #id appended to it. This
approach lets us handle merging of multiple XTM files, etc.

The section on "Topic references" in my "Extending tolog" paper from
Montr=E9al last year has some background on this, as does the XTM 1.1
specification.

--=20
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >