# File lib/rcov/file_statistics.rb, line 79
    def code_coverage
      indices = (0...@lines.size).select{|i| is_code? i }
      return 0 if indices.size == 0
      count = 0
      indices.each {|i| count += 1 if @coverage[i] }
      1.0 * count / indices.size
    end