Question

我是regex的新手。我有这个字符串

new.TITLE['kinds.of'].food

或

new.TITLE['deep thought'].food

我想要检索这些令牌：

new, TITLE, kinds.of, food.

或（第二个例子）

new, TITLE, deep thought, food.

我不能简单地拆分与'.'我需要正则表达式匹配来获取值。怎么做？

Answer 1

使用令牌时 解析器（在这种情况下， FST - 有限状态机）应该：

private static IEnumerable<string> ParseIt(string value) {
  int lastIndex = 0;

  bool inApostroph = false;

  for (int i = 0; i < value.Length; ++i) {
    char ch = value[i];

    if (ch == '\'') {
      inApostroph = !inApostroph;

      continue;
    }

    if (inApostroph)
      continue;

    if (ch == '.' || ch == ']' || ch == '[') {
      if (i - lastIndex > 0) {
        if (value[lastIndex] != '\'')
          yield return value.Substring(lastIndex, i - lastIndex);
        else {
          string result = value.Substring(lastIndex, i - lastIndex).Replace("''", "'");

          yield return result.Substring(1, result.Length - 2);
        }
      }

      lastIndex = i + 1;
    }
  }

  if (lastIndex < value.Length)
    yield return value.Substring(lastIndex);
}

试验：

string test1 = @"new.TITLE['kinds.of'].food";
string test2 = @"new.TITLE['deep thought'].food";

string[] result1 = ParseIt(test1).ToArray(); 
string[] result2 = ParseIt(test2).ToArray();

Console.WriteLine(string.Join(Environment.NewLine, result1));
Console.WriteLine(string.Join(Environment.NewLine, result2));

结果：

new
TITLE
kinds.of
food

new
TITLE
deep thought
food

我怎样才能获得值new.TITLE ['kinds.of']。食物

1 个答案: