# File erubis/enhancer.rb, line 342
    def convert(input)
      src = ""
      add_preamble(src)
      #regexp = pattern_regexp(@pattern)
      pos = 0
      input.scan(SIMPLE_REGEXP) do |indicator, code|
        match = Regexp.last_match
        index = match.begin(0)
        text  = input[pos, index - pos]
        pos   = match.end(0)
        add_text(src, text)
        if !indicator              # <% %>
          add_stmt(src, code)
        elsif indicator[0] == ?\#  # <%# %>
          n = code.count("\n")
          add_stmt(src, "\n" * n)
        else                       # <%= %>
          add_expr(src, code, indicator)
        end
      end
      #rest = $' || input                      # ruby1.8
      rest = pos == 0 ? input : input[pos..-1]  # ruby1.9
      add_text(src, rest)
      add_postamble(src)
      return src
    end