Currently, the mw.wikibase.lexeme module has the following methods:
- getLemmas( id )
- getLanguage( id )
- getLexicalCategory( id )
- splitLexemeId( id )
The first three are equivalent to calling the method of the same name, without arguments, on the result of mw.wikibase.getEntity( id ). I propose we remove them, to reduce duplication in the interface; I don’t think it’s useful to have them. (splitLexemeId is useful and can be kept, it’s not a method that can be called on an individual lexeme entity.)
In Wikibase, for items and properties, there’s similar duplication in some methods (related to labels and descriptions). However, Wikibase can actually look up item/property labels/descriptions more efficiently in this case, by getting them from the term store, without loading the full entity. For lexemes, there’s no such secondary storage, and getLemmas/getLanguage/getLexicalCategory are implemented in PHP by loading the full entity and getting the information from it, which is only marginally more efficient than loading the full entity into Lua and then getting the information from it there. In this way, I think the mw.wikibase.lexeme functions are not only redundant, but arguably confusing, since users familiar with the Wikibase lua interface might expect those functions to not count against the entity limit, whereas they actually do count against it. And I don’t think we’ll have a secondary storage comparable to the terms store for lexemes in the foreseeable future; if we add it at some point, we can still add those functions then, when they actually have the potential to be more efficient.
