如何编写与嵌套括号匹配的递归正则表达式? [英] How to write a recursive regex that matches nested parentheses?

问题描述

我正在尝试编写一个与嵌套括号匹配的正则表达式，例如:

I am trying to write a regexp which matches nested parentheses, e.g.:

"(((text(text))))(text()()text)(casual(characters(#$%^^&&#^%#@!&**&#^*!@#^**_)))"

这样的字符串应该匹配，导致所有嵌套括号都被关闭，

A string like this should be matched, cause all the nested parentheses are closed, instead:

"(((text)))(text)(casualChars*#(!&#*(!))"

应该或更不应该至少与(((text)))(text)"的第一部分匹配.

Should not, or better, should match at least the first "(((text)))(text)" part.

实际上，我的正则表达式是:

Actually, my regexp is:

 $regex = '/( (  (\() ([^[]*?)  (?R)?  (\))  ){0,}) /x';

但是它不能正常运行.如何解决?我哪里错了?谢谢！

But it does not work properly as I am expecting. How to fix that? Where am I wrong? Thanks!

推荐答案

当我找到此答案时，我无法弄清楚如何修改模式以使用我自己的分隔符，其中{和} .所以我的方法是使其更通用.

When I found this answer I wasn't able to figure out how to modify the pattern to work with my own delimiters which where { and }. So my approach was to make it more generic.

$delimiter_wrap  = '~';
$delimiter_left  = '{';/* put YOUR left delimiter here.  */
$delimiter_right = '}';/* put YOUR right delimiter here. */

$delimiter_left  = preg_quote( $delimiter_left,  $delimiter_wrap );
$delimiter_right = preg_quote( $delimiter_right, $delimiter_wrap );
$pattern         = $delimiter_wrap . $delimiter_left
                 . '((?:[^' . $delimiter_left . $delimiter_right . ']++|(?R))*)'
                 . $delimiter_right . $delimiter_wrap;

/* Now you can use the generated pattern. */
preg_match_all( $pattern, $subject, $matches );

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