Question

正则表达的粉丝，嗨。在下面的代码中，有两个父标签（T1-4和T5-6）和一个子标签（T2-3）。

你如何匹配T1-4？或者一般来说，你如何匹配父标签？

<?php
$subject = '

{{poo}}             # T1
    Hello

    {{poo}}         # T2
        Nested 1
    {{/poo}}        # T3

{{/poo}}            # T4


{{poo}}             # T5
    Bye
{{/poo}}            # T6



';

$p = '!{{(\w+)}}(.*){{/\1}}!s';     // matches T1-6, too greedy
$p = '!{{(\w+)}}(.*?){{/\1}}!s';    // matches T1-3, not what I want

$p = '`(?xs) # xtended

{{(\w+)}}

.*?
(?R)?       # currently working on this one...

{{/\1}}


`';



preg_replace_callback($p, function($match){
    var_dump($match);
}, $subject);

Answer 1

这可能就是你要找的东西：

$p = '`(?x)
{{(\w+)}}
# ( # you need probably this capture group later
(?>
    [^{]++
  |
    { (?!{)
  |
    {{ (?! /? \1 \b) # if needed you can add }} in the lookahead
  |
    (?R)
)*
# )
{{/\1}}
`';

Answer 2

答案略有不同：

~                       # Delimiter
{{(.*?)}}               # Match opening tag and put the name in group 1
(?:                     # Non-capturing group
   (?:(?!{{/?\1}}).)++  # Match anything that's not an opening/closing tag one or more times, no backtracking
   |                    # Or
   (?0)                 # Recurse the whole pattern, same as (?R)
)*                      # Repeat zero or more times
{{/\1}}                 # Match closing tag
~xs

我添加了以下修饰符：

x：自由间隔模式，我们的正则表达式中也有精彩的评论。
s：将换行符与点匹配。

Online demo

正则表达式：匹配打开/关闭标记，它接受另一个具有相同名称的打开/关闭标记

2 个答案: