[topicmapmail] Requirements for serializing LTM

[Steve Pepper]

Ontopia has decided to introduce support for serializing topic
maps as LTM and I have volunteered to start the discussion on
requirements.

As you probably know, LTM (the Linear Topic Maps notation[1]) is
a simple text-based notation for writing topic maps. It was
defined as an alternative to XTM for use in situations where
XTM's verbosity rendered the standard syntax suboptimal.

Typical use cases for LTM are:

(1) Manual topic map maintenance using a text editor.

(2) Fast prototyping using a text editor, for example when
    teaching Topic Maps.

(3) Presentation of code examples in email discussions and
    other documents.

LTM was inspired by the linear notation for conceptual graphs
(see the work of John Sowa) and was designed to be the opposite
of XTM in the following respects:

(1) Compact
(2) Quick to type
(3) Easy to read
(4) Amenable to regexp processing

As of today, LTM is an unofficial syntax designed, documented
and maintained by Ontopia and implemented in the OKS (Ontopia
Knowledge Suite) and the Omnigator. It is however also
implemented in a number of other tools, including TM4J, and
there are plans afoot for a TMAPI implementation. Those tools
that support LTM *import* also support XTM export and thus provide
a guarantee that topic maps maintained in LTM will not become
unreadable in the future.

Ontopia originally shied away from implementing LTM *export*
because we felt it would be functionality that in some ways
contradicted the whole point of LTM:

A major use case for LTM was to allow topic map authors to create
and maintain topic maps using an ordinary text editor. This meant
they would have full control over the formatting (including
comments and the use of white space). We didn't want to have to
retain knowledge of that formatting when importing LTM in order
to recreate it on export; as a result, any export would probably
be such that authors would not want to use it anyway...

In retrospect there turns out to be a need for LTM export after
all. Some typical use cases are:

(1) TMs generated automatically and thereafter maintained by
    hand.

(2) TMs generated automatically (as with test cases) which then
    need to be inspected manually and/or included as examples
    in email or other documents (and should be as readable as
    possible).

Ontopia has therefore decided to implement support for LTM
export... And this is YOUR CHANCE to influence the design of
that implementation!

Please post your use cases here, along with any ideas you might
about the order in which topics, associations, and occurrences
should be output, and any (white-space) formatting that you
would like to see applied.

Best regards,

Steve

[1] http://www.ontopia.net/download/ltm.html


--
Steve Pepper <pepper@ontopia.net>
Chief Strategy Officer, Ontopia
Convenor, ISO/IEC JTC 1/SC 34/WG 3
Editor, XTM (XML Topic Maps 1.0)