PHP: parse HTML element attributes

parseAttributes.php

<?php

function parseAttributes($text) {
    $attributes = array();
    $pattern = '#(?(DEFINE)
            (?<name>[a-zA-Z][a-zA-Z0-9-:]*)
            (?<value_double>"[^"]+")
            (?<value_single>\'[^\']+\')
            (?<value_none>[^\s>]+)
            (?<value>((?&value_double)|(?&value_single)|(?&value_none)))
        )
        (?<n>(?&name))(=(?<v>(?&value)))?#xs';

    if (preg_match_all($pattern, $text, $matches, PREG_SET_ORDER)) {
        foreach ($matches as $match) {
            $attributes[$match['n']] = isset($match['v'])
                ? trim($match['v'], '\'"')
                : null;
        }
    }
    
    return $attributes;
}

//$text = '<a double="google.com" keyword single=\'google.com\' none=google.com>';
$text = 'double="double.com" keyword single=\'single.com\' none=none.com';
$res = parseAttributes($text);
var_dump($res);

@rickhellewell Try changing line 12
from: (?<n>(?&name))(=(?<v>(?&value)))?#xs';
to: (?<n>(?&name))(\s*=\s*(?<v>(?&value)))?#xs';