Re: [topicmaps-comment] Topic, reifiying an adressable subject as rolein an association

[Lars Marius Garshol <larsga@garshol.priv.no>]

* Lars Marius Garshol
|
| I've made a note of this issue, and would like to hear other
| people's opinions on this issue, and the possible utility of such a
| constraint.  Personally I'd be happy to not bother about it. We can
| probably think of lots of things one could do that make no sense,
| but how good an idea it is to require all implementations to detect
| and reject them is another matter.

* Thomas B. Passin
| 
| Well, it's an interesting area to ponder.  A processor has to do so
| many things as it is, what with all the alternative forms and all,
| that one doesn't want to make it even busier.  On the other hand, we
| want to have a fighting chance of understanding what any legal
| construction is intended to convey.

This is more or less the issue. There's also in a sense a slippery
slope here, in that there are no doubt many other similar constraints
that one might want to impose. The downside is more work for
implementors, more to do for the already-busy processors, and we may
also find (though probably not in this case) that we've outlawed
something that actually is quite sensible.

The question is also: where is the benefit? How often is anyone going
to make this mistake, and if they do, will being told about it be of
any gain to them? Might it be better to just make tools that check
topic maps for sanity and allow people to use those when they want to
have a check?
 
| In my view, there are going to be a lot of idioms that some
| processor will make use of but others won't really "understand".
| One example would be if you needed an hierarchical, ordered list.
| There are several reasonable approaches, but it's hard to believe
| that a general purpose processor would be able to properly interpret
| all of them.  This argues for spelling more things out in the specs.
| Perhaps we could discuss alternatives for creating and handling such
| "idioms"?

That's a suggestion that has something going for it. A topic map
"patterns" document might be the way to capture these idioms while we
(the community) gather experience with representing different kinds of
structures in topic maps.

--Lars M.