elixir-lang/ecto — pull request #328 by jeregrine (2014-12-16 18:33:11+00:00)
Title: [WIP] Unique validation predicate. 

I've so far I've converted this from https://github.com/hexpm/hex_web/blob/master/lib/hex_web/validation.ex#L29 to the new format. And documented it.

I'll need to test it, which I assume I will want to have a mocked up repo for.

Any advice/feedback is welcome.