Consider LINDT for adding Units of Measure

[VladimirAlexiev]

@kenwenzel The README says

Planned: support quantities and units (QUDT and others)

Please first consider w3c/sparql-dev#129

[kenwenzel]

Hey @VladimirAlexiev,

LINDT looks interesting and maybe it is not hard to support.
How are plain units expressed in LINDT? It seems that there is only a mechanism to express quantity values.

[VladimirAlexiev]

@kenwenzel in LINDT, units are not expressed as resources. They are strings whose meaning and processing is defined by UCUM and implemented in java (and other languages).
If you read the related issue, there's a fair amount of "hate" for LINDT exactly because of this. But I think we need a "belt and suspenders" aporoach:

• QUDT has 2 fields for "UCUM code". We use that for the rich semantic description of units: qk, discipline, etc
• we use LINDT for the convenient operations, and the countably infinite set of units that it supports
• whenever a new unit is used often, we make a PR for QUDT to keep the mapping more complete

[kenwenzel]

OK, sounds reasonable. Do you have a concrete example that uses units? Maybe we can use it to test the integration.