next_current (REXML::Validation::Interleave)

    # File temp/validation/relaxng.rb, line 458
          def next_current( event )
            # Expand references
            c = 0 ; max = @choices.size
            while c < max
              if @choices[c][0].class == Ref
                expand_ref_in( @choices[c], 0 )
                @choices += @choices[c]
                @choices.delete( @choices[c] )
                max -= 1
              else
                c += 1
              end
            end
            @events = @choices[@choice..-1].find { |evt| evt[0].matches? event }
            @current = 0
            if @events
              # reorder the choices
              old = @choices[@choice]
              idx = @choices.index( @events )
              @choices[@choice] = @events
              @choices[idx] = old
              @choice += 1
            end

           #puts "In next with #{event.inspect}."
           #puts "events is #{@events.inspect}"
            @events = [] unless @events
          end