code: func htmlEscapeString(w io.Writer, str string) {
  	last := 0
  	for i := 0; i < len(str); i++ {
  		var html []byte
  		switch str[i] {
  		case '"':
  			html = htmlQuot
  		case '\'':
  			html = htmlApos
  		case '&':
  			html = htmlAmp
  		case '<':
  			html = htmlLt
  		case '>':
  			html = htmlGt
  		default:
  			continue
  		}
  		io.WriteString(w, str[last:i])
  		w.Write(html)
  		last = i + 1
  	}
  	io.WriteString(w, str[last:])
  }
docs: // htmlEscapeString is a modified veresion of the stdlib HTMLEscape routine
  // escapes a string without making copies.