如何在正则表达式中匹配字符串后跟重复模式？

Question

I'm looking for a regex to match the following pattern:

--header-- any text -pre- any text -/pre- -pre- any text -/pre-

For example: the following text

--comment--
list of comments
-pre-
comment 1
-/pre-

-pre-
comment 2
-/pre-

--Answers--
list of Answers
-pre-
Answer 1
-/pre-

-pre-
Answer 2
-/pre-

should be returned as following when apply the regex:

Array
(
    [comments] => Array
        (
            [0] => comment 1
            [1] => comment 2
        )

    [answers] => Array
        (
            [0] => answer 1
            [1] => answer 2
        )

)

I tried the following regex --(.*?)--.*?(-pre-(.*?)-\/pre-)+ but it only match comment 1 and answer 1

Example Code: https://regex101.com/r/59OKzs/1

Answer 1

Regex:

(?:--([^-]+)--(?:(?!-pre-).)+|(?!\A)\G)\s*-pre-\s*((?:(?!-/pre-).)*)-/pre-\K

Live demo

PHP:

preg_match_all('~(?:--([^-]+)--(?:(?!-pre-).)+|(?!\A)\G)\s*-pre-\s*((?:(?!-/pre-).)*)-/pre-\K~s', $str, $matches, PREG_SET_ORDER);

To integrate appropriate keys and values:

// Filter empty values
$matches = array_map(function($v) {
    return array_values(array_filter($v));
}, $matches);

// Initialize two variables which we use them soon
$index = null; $finalArray = [];

// Iterate over recent matches in order to apply keys
array_map(function($array) use (&$index, &$finalArray) {
    count($array) == 2 ? ($index = $array[0]) && ($finalArray[$index][] = $array[1]) : $finalArray[$index][] = $array[0];
}, $matches);

// Print out
print_r($finalArray);

PHP live demo