gistfile1.rbx

      @offset = 0

      @active_branches   = [0] 
      @inactive_branches = {}
      @max_stack = 0

      stream.each {|inst|
        case inst
        when git, gif
          @active_branches.each {|n| @inactive_branches[label.ip] = n}
        when goto
          unless label.ip < @offset
            @active_branches.each {|n| @inactive_branches[label.ip] = n }
            @active_branches = {}
          end
        when ret
          @max = @active_branches.max if @active_branches.max > @max
          @active_branches = []
        else
          inst.do_stuff
          @active_branches.map {|n| n += inst.stack_change }
        end

        @inactive_branches.delete_if {|k,v| @active_branches << v if k == @offset }
      }