[tmql-wg] Result set requirements
Mon, 23 Feb 2004 21:26:21 -0500
> Introducing all TMDM data structures would probably add another
> type dimension into TMQL.
> One option we have is to treat this as "language pragma"
> pragma INTERFACE_MODEL (TMDM)
> return $t/bn # returns basename item
> pragma INTERFACE_MODEL (simple)
> return $t/bn # return string
> pragma INTERFACE_MODEL (maplet)
> return $t # returns topic as part of a maplet
> only allowed on the outest level so that it does not affect language
> semantics, but only interface semantics.
> Or, to choose a reasonable default and use 'ATTRIBUTE'
> (meta-information on data):
> return $t/bn'TMDM # returns basename as item
> return $t/bn # default is stringification
> return $t/bn'VALUE # same
I am not sure about Toma and AsTMa but in TMPath I have special
'shortcuts' which help to get and return values.
If I need base name node I use:
$topic/bn[<name type>] or just $topic/bn
If I need value I use $topic/bn::<name type> or $topic/bn::*
TMPath provides access and allow to return TMDM constructs.
For example, long path:
goes by all TMDM nodes.
But there are also 'shortcuts' which help to move in 'hyper space'.
or (with binary projection bornIn for association born-in)
Detailed paths are used typically in questions with introspection.
Shortcuts are used when I know types of names, occurrences, roles and
associations and I am interested in "values".
I think that "full" result sets such as XML, TopicMaps/fragments and
tables can be reasonably easy integrated with host environment.
XML->DOM or SAX
Topicmap -> TMAPI based set of classes
tuple streams -> lists or streams or cursors
I am not so sure about partial results such as list of base names.
Partial results are useful between TMQL layers (TOLOG->TMTL)
But I do not see "standard" way of integration of partial results with