Online PHP editor | output for Y0eoL

@ 2017-01-12T20:32:50Z

<?php


final class DbConnection
{
    private $dsn;
    private $initializer;
    public function __construct(string $dsn)
    {
        $this->dsn = $dsn;
        // socket stuff happens here, much like with PDO
    }

    public function query(string $queryString) : array
    {
        ($this->initializer)();
        // irrelevant from here on
        return ['query' => $queryString, 'dsn' => $this->dsn];
    }

    public static function lazyInstance(string $dsn) : self
    {
        $instance = (new ReflectionClass(self::class))->newInstanceWithoutConstructor();
        $instance->initializer = function () use ($dsn, $instance) {
            $instance->__construct($dsn);
            $instance->initializer = function () {
            };
        };
        return $instance;
    }
}

$instance = DbConnection::lazyInstance('mysql://something');

var_dump($instance);

var_dump($instance->query('SELECT * FROM foo'));
var_dump($instance->query('SELECT * FROM bar'));

Output for 8.4.1: object(DbConnection)#2 (2) { ["dsn":"DbConnection":private]=> NULL ["initializer":"DbConnection":private]=> object(Closure)#1 (4) { ["name"]=> string(41) "{closure:DbConnection::lazyInstance():24}" ["file"]=> string(9) "/in/Y0eoL" ["line"]=> int(24) ["static"]=> array(2) { ["dsn"]=> string(17) "mysql://something" ["instance"]=> *RECURSION* } } } array(2) { ["query"]=> string(17) "SELECT * FROM foo" ["dsn"]=> string(17) "mysql://something" } array(2) { ["query"]=> string(17) "SELECT * FROM bar" ["dsn"]=> string(17) "mysql://something" }
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.26, 8.3.0 - 8.3.14: object(DbConnection)#2 (2) { ["dsn":"DbConnection":private]=> NULL ["initializer":"DbConnection":private]=> object(Closure)#1 (1) { ["static"]=> array(2) { ["dsn"]=> string(17) "mysql://something" ["instance"]=> *RECURSION* } } } array(2) { ["query"]=> string(17) "SELECT * FROM foo" ["dsn"]=> string(17) "mysql://something" } array(2) { ["query"]=> string(17) "SELECT * FROM bar" ["dsn"]=> string(17) "mysql://something" }
Output for 5.6.0 - 5.6.29: Parse error: syntax error, unexpected ':', expecting ';' or '{' in /in/Y0eoL on line 14
Process exited with code 255.

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