[sc34wg3] TMCL and MAX_INT

[Lars Marius Garshol]

(I have a set of comments on TMCL which I would like to try to discuss  
before the Prague meeting, so that the simplest ones can be resolved  
without consuming time in the meetings. This is the first one.)

In the TMCL examples in the spec the MAX_INT literal is used to  
represent the biggest possible integer in order to be able to express  
unrestricted maximum cardinalities while using the templates. The  
problem is that this is not a legal integer literal according to XML  
Schema.

In other words, the following is what one has to write now:

ph:photo isa tmcl:topic-type ;
   plays-role(ph:categorized, ph:in-category, 0, MAX_INT) .

However, this does not work, because syntactically MAX_INT is a topic  
reference, not an integer. And leaving the parameter out is not  
possible in CTM.

Possible solutions:

(1) Find some way to shoehorn MAX_INT into CTM (and XTM 1.0/2.0!).

(2) Support optional arguments in CTM templates (which also requires  
some way to make parts of a template conditional).

The example above would then become

ph:photo isa tmcl:topic-type ;
   plays-role(ph:categorized, ph:in-category, 0) .

(3) Introduce topics representing cardinalities and have predefined
topics for 0-1, 1-1, 0-*, and 1-*. Omit the max-card occurrence to
make the cardinality unlimited. Pass these topics to the template
instead of the integers.

The example above would then become

ph:photo isa tmcl:topic-type ;
   plays-role(ph:categorized, ph:in-category, tmcl:unlimited) .

(4) Define extra templates (with different names) which omit the max
cardinality argument (implicitly setting it to infinity).

The example above would then become

ph:photo isa tmcl:topic-type ;
   plays-role-unlimited(ph:categorized, ph:in-category, 0) .

Thoughts on this?

--Lars M.
http://www.garshol.priv.no/blog/
http://www.garshol.priv.no/tmphoto/