A convenient conditional that excludes empty objects (Enumerables, in general).

Emptor is a hack. It's merely a shorter expression for those who want to consider empty collections to be falsy. Calling

$ this._or_ that

Returns the first object that's either a non-empty collection (collections are assumed if the operand responds_to :empty?) or a non-collection that's truthy (in the Colbertian sense). So:

$ []._or_ [1,2,3]
# => [1,2,3]

$ "yep"._or_ [1,2,3]
# => "yep"

$ []._or_ []
# => nil

One example of usage would be while performing an ActiveRecord find with scoping, where you'd like to return an unscoped set if the first set turns out empty.

This:

$ User.all.with_photos.present? ? User.all.with_photos : User.all

Becomes:

$ Person.all.with_photos._or_ Person.all

That's all, folks.