collapse

# File activerecord/lib/arel/select_manager.rb, line 258
      def collapse(exprs)
        exprs = exprs.compact
        exprs.map! { |expr|
          if String === expr
            # FIXME: Don't do this automatically
            Arel.sql(expr)
          else
            expr
          end
        }

        if exprs.length == 1
          exprs.first
        else
          create_and exprs
        end
      end