_parse (RParsec::StringCaseInsensitiveParser)

    # File rparsec/parsers.rb, line 380
      def _parse ctxt
        if @str.length > ctxt.available
          return ctxt.expecting(@msg)
        end
        cur = 0
        for cur in (0...@str.length)
          if downcase(@str[cur]) != downcase(ctxt.peek(cur))
            return ctxt.expecting(@msg)
          end
        end
        result = ctxt.src[ctxt.index, @str.length]
        ctxt.advance(@str.length)
        ctxt.retn result
      end