How explode string to array elements via regex? - php

Question

I want to convert nested brackets to array with keywords. Here is pattern:
preg_match_all('/(?=\{((?:[^{}]++|\{(?0)\})++)\})/', $string, $res);
And data which need to parse:
employee {
cashier { salary = 100; }
technician { age = 44; }
}
Result, that I need:
Array
(
[employee] => Array (
[0] => Array
(
[cashier] => Array
(
[salary] => 100
)
)
[1] => Array
(
[technician] => Array
(
[age] => 44
)
)
)
)
But cant iterate within nested brackets. Stucked here. Thanks in advance for your help

Answer 1

You'll need a recursive approach here.
First, analyze the outer structure with { and } on both sides.
See, if we can find another nested structure
If not, look for key = value pairs and return them
A regex demo for the outer structure can be found on regex101.com, a complete PHP demo would look as follows:
<?php
$string = <<<DATA
employee {
cashier { salary = 100; }
technician { age = 44; }
}
DATA;
// regular expressions
$outer = '~(?P<key>\w+)\s*(?P<value>\{(?:[^{}]*|(?R))*\})~';
// inner, key = value
$inner = '~(?P<key>\w+)\s*=\s*(?P<value>\w+)~';
function parse($string) {
global $outer, $inner;
$result = array();
// outer
preg_match_all($outer, $string, $matches, PREG_SET_ORDER);
foreach ($matches as $match) {
$result[$match["key"]] = parse(
substr($match["value"], 1, -1)
);
}
// if not found, inner structure
if (!$matches) {
preg_match_all($inner, $string, $matches, PREG_SET_ORDER);
foreach ($matches as $match) {
$result[$match["key"]] = $match["value"];
}
return $result;
}
return $result;
}
$result = parse($string);
print_r($result);
?>
This yields:
Array
(
[employee] => Array
(
[cashier] => Array
(
[salary] => 100
)
[technician] => Array
(
[age] => 44
)
)
)