javascript - 正则表达式:立即捕获某些文本与左括号和右括号之间的单词

Question

我并不是正则表达式方面的专家，尤其是困难的正则表达式。我想要位于括号之间和单词“index”之后的字符串。

"(NO3)  index(doc.id(), doc.description)  index (doc.id)" 

会返回

"[ 'doc.id(), doc.description' ,  'doc.id' ]"

到目前为止我做了什么 https://jsfiddle.net/asjbcvve/

Answer 1

匹配字符串内的括号会使这变得困难。递归正则表达式将匹配它，但并非所有正则表达式引擎都实现它。例如，JS 不会(PCRE 会)

带递归的正则表达式

这在 JS 和许多其他正则表达式引擎中不起作用

index\s*\((([^\(\)]*(\([^\(\)]*\g<2>\))?)*)

不带递归且带 1 个嵌套括号的正则表达式

index\s*\((([^\(\)]*(\([^\(\)]*\))?)*)

他们都在第一组中捕获了你想要的东西。

示例:

var rx = /index\s*\((([^\(\)]*(\([^\(\)]*\))?)*)/g;			//works with 1 nested parentheses
var rx_recursion = /index\s*\((([^\(\)]*(\([^\(\)]*\g<2>\))?)*)/g; //works with any number of nested parentheses, but JS regex engine doesn't suppoorts recursion
var res = [], m;
var s = "(NO3)  index(doc.id(s)(), doc.description)  index (doc.id) index(nestet.doesnt.work((())))";
while ((m=rx.exec(s)) !== null) {
  res.push(m[1]);
}
document.body.innerHTML = "<pre>" + JSON.stringify(res, 0, 4) + "</pre>";

正则表达式说明

index\s*         - Match literal 'index' followed by any number of white characters
\(               - Match literal openning parenthesis character
(                - Group 1
  (              - Group 2
    [^\(\)]*     - Match anything that is not parentheses
    (            - Group 3
      \(         - Match literal opening parenthesis
      [^\(\)]*   - Match anything that is not parentheses
      \g<1>      - Recursively match group 1
      \)         - Match literal closing parenthesis
    )?           - End group 3, match it one or more times
   )*            - End group 2, match it zero or more times
)                - End group 1

如果您需要匹配多个嵌套括号，但您选择的引擎不支持递归，只需将\g<1> 替换为整个组 2 的文字即可。重复您期望在字符串中出现的嵌套括号的次数.