Is there a way to combine named scopes into a new named scope?

I have

class Foo < ActiveRecord::Base
  named_scope :a, lambda { |a| :conditions => { :a => a } }
  named_scope :b, lambda { |b| :conditions => { :b => b } }
end

I'd like

class Foo < ActiveRecord::Base
  named_scope :ab, lambda { |a,b| :conditions => { :a => a, :b => b } }
end

but I'd prefer to do it in a DRY fashion. I can get the same effect by using

 Foo.a(something).b(something_else)

but it's not particularly lovely.

Well I'm still new to rails and I'm not sure exactly what you're going for here, but if you're just going for code reuse why not use a regular class method?

        def self.ab(a, b)
            a(a).b(b)
        end
    

You could make that more flexible by taking *args instead of a and b, and then possibly make one or the other optional. If you're stuck on named_scope, can't you extend it to do much the same thing?

Let me know if I'm totally off base with what you're wanting to do.