Re: TMQL - Proposal: Removal of reifier axis

Hi Andrew,

[...]
> The main problem I see is that your proposal makes subject proxies
> in the general sense first-class citizens in the TMDM. Once this
> happens, there's no longer a need for the distinction of constructs
> that can only have terminal property values (TMDM topics) and
> constructs that can only have non-terminal property values - what I
> call links (TMDM associations).  This would therefore invalidate a
> number of fundamental assumptions baked into TMDM systems, and I
> think that makes it a non-runner (in addition to rather unpopular). ;)

I know what you mean but I don't want to make constructs != topic
first-class citizens in TMDM (not yet ;)). TMDM wouldn't change, we'd
just define that TMQL supports a more truthful model and supports
reification directly. I don't know if that works or is accepted (I am
afraid it won't). TMDM, XTM, TMCL and CTM would stay as they are (an
explicit reifier property) but TMQL would interpret reification
correctly.

TMDM systems (like TMAPI) wouldn't break, I think. If a TMDM system
sees a query like

     $name/role[. isa foo]

it would check if the name is reified and iterate through the played
roles of the reifier. If the name is not reified, the sequence would
be empty.

Maybe TMDM addicts would be surprised if

    $name/type

returns a sequence with more than one item iff $name is reified and
the reifier is an instance of another topic, but TMQL wouldn't unhinge
TMDM. TMQL would just provide a more truthful interpretation of TMDM. ;)

Best regards,
Lars
-- 
Semagia 
<http://www.semagia.com/>

<https://twitter.com/larsheuer/> Twitter
<http://www.topicmaps.de/mailinglist/> German Topic Maps mailing list
<http://tinytim.sourceforge.net/> Open Source Topic Maps engine
<http://mappa.semagia.com/> Mappa - Python Topic Maps engine