[sc34wg3] TMCL: 4.4.8 Subject Identifier Constraint

[Robert Barta]

On Fri, Feb 15, 2008 at 11:43:58AM -0000, Graham Moore wrote:
> 
> All we need to say is that on evaluation $this is the constraint being
> evaluated. 

Yes.

What does NOT work, btw, is that the TMCL structure is introspected
inside the TMQL query. At least not on all positions. For instance

  ... at least $$cardmin ...   

If $$cardmin is replaced before the query is analyzed, everything is
fine. But

  ... at least $this / cardmin ...

is not valid TMQL. There was never a use case for that.

\rho

> --------------------------------------------
> Graham Moore, Director, Networked Planet Limited
> Editor XTM 1.0, ISO13250 (TopicMaps) -2,-3, TMCL
> e: graham.moore at networkedplanet.com
> w: www.networkedplanet.com
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> m: +47 45271713   (Norway)
> 
> Networked Planet Limited is registered in England and Wales, no. 5273377
>  
> 
> -----Original Message-----
> From: sc34wg3-bounces at isotopicmaps.org
> [mailto:sc34wg3-bounces at isotopicmaps.org] On Behalf Of Robert Barta
> Sent: 15 February 2008 09:48
> To: Graham Moore
> Cc: Discussion of ISO/IEC 13250 Topic Maps
> Subject: Re: [sc34wg3] TMCL: 4.4.8 Subject Identifier Constraint
> 
> On Fri, Feb 15, 2008 at 07:06:07AM -0000, Graham Moore wrote:
> > One key point:
> 
> > >>every $t in // $$topictype
> > >> satisfies
> > >>     at least $$cardmin $si in $t ~
> > >>        satisfies $si =~ $$regexp
> > >>   & at least $$cardmax $si in $t ~
> > >>        satisfies $si =~ $$regexp
> > 
> > >> I am using $$ to prefix the Meta-variables. They become constants
> in
> > the >> TMQL query after inserting.
> > 
> > This $$ stuff isn't necessary and kind of breaks the intent. These
> > variables are in the constraint structure, so they should be located
> via
> > the tmcl expression. 
> 
> The TMQL expression you mean.
> 
> Ah, I did not get this idea. Scary at first, but it should work!
> 
> > If $this is the constraint being evaluated then the cardmin is found
> via
> >
> > $this >> occurrences [cardmin]
> 
> Or just
> 
>    $this / cardmin
> 
> But you will have to say something about $this.
> 
> \rho
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