3.0.0 release about datavalues

[JeroenDeDauw]

@lucaswerkmeister @addshore what about killing these interfaces? https://github.com/DataValues/DataValues/tree/master/src/interfaces

They where added for some stuff in Wikibase but I would not be surprised (and hope) that they are no longer used.

[JeroenDeDauw]

One reason is removal of dead code

Another is that these classes are not namespaced and have general names, making them a possible source of future conflicts. At which point we'd need another major release of this library, which might well be more hassle than removing the interfaces.

[JeroenDeDauw]

Searched for usages in codebase with Wikibase loaded, plus Lexeme, MediaInfo, QualityConstraints etc

• Hashable: implemented by 2 or 3 DataModel classes, not used as type - trivial migration
• Comparable: implemented by many DM classes, not used as type - easy migration
• Immutable: implemented by Snak and Reference, not used as type - trivial migration

My impression is that basically all of this is dead code. Bit surprised by no code using Comparable as type. Maybe I missed something. Would just drop Hashable and Immutable and not create a replacement. Unsure about Comparable.

[lucaswerkmeister]

Alright, we’ll try to remove the interfaces and see if that works out.

[lucaswerkmeister]

They’re still implemented in our data model classes as far as I can tell. It would probably be possible to get rid of them with more or less effort, but I don’t really see a reason to, at the moment.

[JeroenDeDauw]

(Reply to #62 (comment))

What about Comparable?

It seemed from the comment on #58 that there were still doubts about that particular interface, also from a quick code search it didn't seems so clear cut like the other ones (more repos affected).

Presumably you could just have the Comparable interface in Wikibase DataModel if you do not wish to get rid of it. Or if you want to do so slowly.