如何拆分复杂的句子字符串，保留分隔符，但不将分隔符放在不应该放的地方

function splitComplexSentence(sentence) {
  const pattern = /(\w+|[^\w\s]+)/g;
  const matches = sentence.match(pattern);
  let result = '';

  for (let i = 0; i < matches.length; i++) {
    const word = matches[i];
    const nextWord = matches[i + 1];

    result += word;

    if (nextWord && isSeparator(nextWord)) {
      result += nextWord;
      i++;
    }
  }

  return result;
}

function isSeparator(word) {
  // 判断是否为分隔符，可以根据具体需求进行定义
  const separators = ['.', ',', ';', ':'];
  return separators.includes(word);
}

const sentence = 'This is a complex sentence, with separators; that need to be preserved.';
const result = splitComplexSentence(sentence);
console.log(result);