> The Validator provides validation methods for datatypes (and parameter
> definitions etc.) and WD certainly needs similar methods
The main things that Validator provides is a declarative parameter handling system. So far we do not need this anywhere in the WikiData software itself (next to the API, but this has it's own parameter definition mechanism). If we run into a place where we need this kind of parameter handling, we'll definitely look at Validator.
> is it planned that those methods (or part of it) are being moved into the core?
There are no plans to move this into core right now. If we do end up using it in Wikidata, that'll increase the incentive to at least have it in the default MediaWiki distribution tarball. I am however working on a rewrite of the extension making it better suited to do what's actually being done with it. Will have more news on this in a few weeks.
Jeroen De Dauw
Don't panic. Don't be evil.