正则表达式匹配多维字符串中的顶级定界符 [英] Regex to match top level delimiters in a multi dimensional string

问题描述

我有一个类似于json的大型多维结构文件，但是距离我不够远，无法使用json库.

I have a file that is structured in a large multidimensional structure, similar to json, but not close enough for me to use a json library.

数据看起来像这样:

alpha {
    beta {
        charlie;
    }
    delta;
}

echo;
foxtrot {
    golf;
    hotel;
}

我要构建的正则表达式(对于preg_match_all)应与每个顶级父级(由{}大括号分隔)匹配，以便我可以遍历匹配项，从而建立表示数据的多维php数组.

The regex I am trying to build (for a preg_match_all) should match each top level parent (delimited by {} braces) so that I can recurse through the matches, building up a multidimensional php array that represents the data.

我尝试的第一个正则表达式是/(?<=\{).*(?=\})/s，它与括号内的内容贪婪地匹配，但是这并不正确，因为在顶层有多个同级时，匹配太贪婪了.下面的示例:

The first regex I tried is /(?<=\{).*(?=\})/s which greedily matches content inside braces, however this isn't quite right as when there is more than one sibling in the top level the match is too greedy. Example below:

使用正则表达式/(?<=\{).*(?=\})/s匹配表示为:

Using regex /(?<=\{).*(?=\})/s match is given as:

匹配1:

    beta {
        charlie;
    }
    delta;
}

echo;
foxtrot {
    golf;
    hotel;

相反，结果应为: 比赛1:

Instead the result should be: Match 1:

    beta {
        charlie;
    }
    delta;

匹配2:

    golf;
    hotel;

所以正则表达式向导，我在这里缺少什么功能，或者我需要以某种方式用php解决这个问题?任何提示都非常欢迎:)

So regex wizards, what function am I missing here or do I need to solve this with php somehow? Any tips very welcome :)

推荐答案

您不能 ¹ 使用正则表达式来做到这一点.

You can't ¹ do this with regular expressions.

或者，如果要匹配深浅块，则可以使用\{[^\{\}]*?\}和preg_replace_callback()存储值，然后返回null从字符串中删除它.回调将需要相应地嵌套值.

Alternatively, if you want to match deep-to-shallow blocks, you can use \{[^\{\}]*?\} and preg_replace_callback() to store the value, and return null to erase it from the string. The callback will need to take care of nesting the value accordingly.

$heirarchalStorage = ...;
do {
    $string = \preg_replace_callback('#\{[^\{\}]*?\}#', function($block)
    use(&$heirarchalStorage) {
        // do your magic with $heirarchalStorage
        // in here
        return null;
    }, $string);
} while (!empty($string));

_{不完整，未经测试，也不提供保修.}

此方法还要求将字符串也包裹在{}中，否则最终匹配将不会发生，并且您将永远循环.

This approach requires that the string be wrapped in {} as well, otherwise the final match won't happen and you'll loop forever.

这是一项糟糕的工作(效率低下)，这些工作可以通过众所周知的交换/存储格式(例如JSON)轻松解决.

This is an awful lot of (inefficient) work for something that can just as easily be solved with a well known exchange/storage format such as JSON.

¹ 我要输入"您可以，但是... "，但是我再说一遍，" 您不能 " ²

¹ I was going to put "you can, but...", however I'll just say once again, "You can't" ²

² 不要

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