code: func (l *Lexer) emitString(delimiter rune) {
  	str := l.input[l.start:l.pos]
  
  	// replace escaped delimiters
  	str = strings.Replace(str, "\\"+string(delimiter), string(delimiter), -1)
  
  	l.produce(TokenString, str)
  }
docs: // emitString emits a scanned string