[topicmapmail] occurrence abuse ? Was: [geolang-comment] Firstproposals for ISO 639 and 3166 available

[Lars Marius Garshol]

* Anthony B. Coates
| 
| I guess in this view, occurrences should contain only simple data
| types, without structure.  

I haven't formally raised this issue yet, but I think we will have to
extend occurrences so that they may be typed. Obvious types include
booleans, numbers, and dates, while less obvious types are things like
XML. These things will be needed for various purposes, querying,
validation, sorting, and presentation among them.

| But what is structure?  In truth, it depends on what software
| library you are using.  If you have support for ISO dates/times in
| your software library, then a date/time is a simple type.  If you
| don't, it is a piece of structured text that you have to parse and
| process.  So, there will never be a black-and-white way of deciding
| what should be considered a "simple" datatype for use as occurrence
| data.  It will at best be a guiding principle, just as it is for XML
| attribute values.

Actually, I'm not sure we need to make that distinction. The
occurrence points to an information resource, and these can be
arbitrarily complex. Inline occurrences are just a pragmatic shorthand
for storing the string somewhere and pointing to it rather than
including it directly. So I don't really see any reason why inline
occurrences can't have structure.

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
ISO SC34/WG3, OASIS GeoLang TC        <URL: http://www.garshol.priv.no >