Named backreferences with preg_replace

Question

Pretty straightforward; I can\'t seem to find anything definitive regarding PHP\'s preg_replace() supporting named backreferences:

// should mat         


        

Answer 1

you can use this :

class oreg_replace_helper {
    const REGEXP = '~
(?\d++)
    )
    |
    (?:
        \$\+?{(?P\w++)}
    )
    |
    (?:
        \x5Cg\<(?P\w++)\>
    )
)?
~xs';

    protected $replace;
    protected $matches;

    public function __construct($replace) {
        $this->replace = $replace;
    }

    public function replace($matches) {
        var_dump($matches);
        $this->matches = $matches;
        return preg_replace_callback(self::REGEXP, array($this, 'map'), $this->replace);
    }

    public function map($matches) {
        foreach (array('num', 'name1', 'name2') as $name) {
            if (isset($this->matches[$matches[$name]])) {
                return stripslashes($matches[1]) . $this->matches[$matches[$name]];
            }
        }
        return stripslashes($matches[1]);
    }
}

function oreg_replace($pattern, $replace, $subject) {
    return preg_replace_callback($pattern, array(new oreg_replace_helper($replace), 'replace'), $subject);
}

then you can use either \g ${name} or $+{name} as reference in your replace statement.

cf (http://www.rexegg.com/regex-disambiguation.html#namedcapture)