Hi!
while you are at it, some things would be very useful to be search-able (maybe some are already by now):
- "primary" (not references/qualifiers) years, for birth/death/flourit etc.
- "primary" string/monolingual values (title, taxon name, etc.)
- "primary" IDs, e.g. VIAF (might cause confusion with years, so maybe
only add numerical IDs if 5+ digits?)
We have the code to index statements already, and we're already indexing P31 and P279. We could index more properties. We don't have syntax or any other way though to actually use those in search - yet, except for boosting (see https://gerrit.wikimedia.org/r/#/c/384632/).
We're looking at which properties to add (nominations welcome, probably in the form of phab ticket?) - since adding them requires full reindex of wikidata (couple of days) we probably don't want to add them one by one but want to collect a set and then do it in one hit.
We also do not have syntax for searching (as in match, instead of boost) by statement values, but it should not be hard - we just need to design proper syntax and implement it (syntaxes are now pluggable, so should not be too big of a problem).