code: func (l *Lexer) nextUntilEOF(s string) bool {
  	for r := l.next(); r != eof && strings.IndexRune(s, r) < 0; r = l.next() {
  		// l.next()
  		l.accept()
  	}
  	if l.r == eof {
  		return true
  	}
  	return false
  }
docs: // nextUntilEOF will loop until it finds the matching string OR EOF