NAME¶
TM::PSI - Topic Maps, PSI (published subject identifiers)
DESCRIPTION¶
This package provides predefined subjects, all of which will be preloaded in
every map which is instantiated with the TM package hierarchy. When the
subjects are defined also their relationship are kept here (example:
isa is
an instance of an assertion).
Every such subject is defined by its
- item identifier
- The internal identifier, which does not really mean much.
- subject identifier
- The subject indicator(s), which is ultimately the one which
identifies any of the subjects here.
NOTE: For none of the subjects declared here a subject address exists.
All concepts are TM-related concepts.
The subjects are sorted:
- TMRM-related
- These are the minimal subjects which make a map what it is. Examples are
"isa" and its related role (type) "class" and
"instance", and "is-subclass-of" and its related
roles.
- TMDM-related (XTM things)
- These are the additional concepts which are mandated by TMDM.
- AsTMa-related
- Here are more concepts which are needed by the AsTMa= language(s), such as
"template" or "ontology".
- TMQL-related
- Here are more concepts which are needed by TMQL.
To learn about these predefined concepts, you can do one of the following
use TM::PSI;
warn Dumper ($TM::PSI::core, $TM::PSI::topicmaps_inc, $TM::PSI::astma_inc, $TM::PSI::tmql_inc);
Taxonometry¶
Two association types are predefined by the standard(s):
"is-subclass-of" and "isa". Together with these roles are
defined "subclass", "superclass" and "instance",
"class", respectively.
The TM::* suite of packages has these not only built in, but also works under
the assumption that these association types and also the roles
CANNOT
be subclassed themselves. This means that no map is allowed to use, say,
"is-specialization-of" as a subclass of "is-subclass-of".
The costs of this constraint is quite small compared to the performance
benefits.
Infrastructure Concepts¶
To make the whole machinery work, every topic map must contain infrastructure
topics such as "name", "occurrence" etc. They are topics
like the topics a user may put into the map. While this is the right thing to
do, in practical situation you often will want to filter out these
infrastructure topics. You can always get a list of these via
@@@ fix docu @@@@@
$tm->mids (keys %{$TM::PSI::topicmaps->{mid2iid}});
SEE ALSO¶
TM
Copyright 200[1-68], Robert Barta <drrho@cpan.org>, All rights reserved.
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
http://www.perl.com/perl/misc/Artistic.html