Re: TMQL: Direct (super|sub)types?
Benjamin Bock <[email protected]>
| Newsgroups | gmane.text.xml.xtm.general |
|---|---|
| Message-ID | <[email protected]> |
On Wed, Mar 2, 2011 at 4:58 PM, Robert Cerny <[email protected]> wrote: > Lars, > > Am 02.03.2011 um 11:04 schrieb Lars Heuer: > >> Hi Rani, >> >>> A simple use case will be just to provide a graphical visualization of >>> the hierarchies in the topic map. >> [...] >>> Or maybe, you prefer to avoid from having "direct-supertypes" and >>> "direct-subtypes" in TMQL because we can always use association pattern >>> as an alternative: >> >> I see. Well, I find the term "direct-" awkward. TMQL introduces a >> terminology which does not exist outside of TMQL (neither in TMDM nor >> TMRM nor (to my knowledge) in any other knowledge representation >> system) and I wonder if the mentioned use cases are common enough to >> satisfy a shortcut in TMQL. I guess my answer would be "no" and I >> wouldn't make these axes/paths first class citizens in TMQL. > > I think there will be a need to distinguish between direct and all instances of a topic type. I can hardly imagine a use case case for indirect but who knows. I think the TMQL standard is the right place to establish a clear terminology for this distinction since everybody tackles this issue a little bit different. Some call it "direct" or "deep" or whatever. Another name would be "transitive" (even though the transitivity comes from the supertype/subtype, not from the type/instance itself. When you do topic-maps-object-mapping (as in object-relational), you'll see a lot of cases where you want the transitivity. No matter how it is called. The "direct" is due to the fact that the transitive axes should (IMHO) be the default. > I can hardly follow the argument to omit everything that is not TMDM. The terms 'direct' and 'indirect' can be defined with just TMDM terms. It is a little bit like a propositional logic that only allows XOR (that's possible if i remember correctly :). Why not define meaningful derivates? I agree with you that they should be kept to a minimum. But i am still for a distinction between direct and all instances. I don't care about the names. Maybe there is an established terminology in graph theory which can be taken over. +1 Cheers, Benjamin > > Kind regards, > > Robert > _______________________________________________ > topicmapmail mailing list > topicmapmail-Zo64W7twoUFWk0Htik3J/[email protected] > http://www.infoloom.com/mailman/listinfo/topicmapmail >