read_escape

# File lib/rdoc/parser/ruby.rb, line 1279
  def read_escape
    res = ""
    case ch = getc
    when /[0-7]/
      ungetc ch
      3.times do
        case ch = getc
        when /[0-7]/
        when nil
          break
        else
          ungetc
          break
        end
        res << ch
      end

    when "x"
      res << ch
      2.times do
        case ch = getc
        when /[0-9a-fA-F]/
        when nil
          break
        else
          ungetc
          break
        end
        res << ch
      end

    when "M"
      res << ch
      if (ch = getc) != '-'
        ungetc
      else
        res << ch
        if (ch = getc) == "\\" #"
          res << ch
          res << read_escape
        else
          res << ch
        end
      end

    when "C", "c" #, "^"
      res << ch
      if ch == "C" and (ch = getc) != "-"
        ungetc
      else
        res << ch
        if (ch = getc) == "\\" #"
          res << ch
          res << read_escape
        else
          res << ch
        end
      end
    else
      res << ch
    end
    res
  end