[sc34wg3] TMQL: Item reference vs. IRI

[Lars Heuer]

Hi all,

Comments against TMQL draft dtd. 2007-07-13.

Maybe this is too micrological, but anyway ... ;)

Acc. to section 4.3.:

     """
     [...]
     an absolute IRI or a QName is interpreted as subject identifier
     [...]
     """

And it seems that "music:ec" in

    %prefix music http://psi.example.org/music/

    member-of(member: music:ec, group: $g)

is interpreted as a reference to the topic with the subject identifier
http://psi.example.org/music/ec, there is *no need* to append a "~" or
"<< indicators" to "music:ec" since the interpretation as topic is
implicit.

Acc. to section 4.4: "indicators"
     """
     If the value is a topic item, in forward direction
     this step retrieves all subject indicators of this item.
     If the value is an IRI, in backward direction this step produces
     the topic which has this IRI as subject indicator.
     """

Hmm... isn't that a bit unlogical? If every IRI is already interpreted
as reference to a topic with that subject identifier, the 'value' can
never be an IRI, since it is already a topic, so the 'backward
direction' seems to be useless.

And if an IRI is already a reference to a topic with that subject
identifier, the "locators" section in 4.4. seems to be invalid, since
in the expression:

   http://www.example.org/ << locators

'http://www.example.org/' *may* be interpreted as reference to a topic
with a subject identifier eq. to 'http://www.example.org/'. So, there
is no IRI in front of '<<' but a topic, right?


If TMQL introduces a notation of subject locators, i.e. the '=' in
front of the IRI TMQL could drop the backward directions for
"indicators" and "locators". Would we loose something?
     
Best regards,
Lars
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Semagia 
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