<?php
class A
{
    public $a = NULL;

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

    public function make($s)
    {
        return new self($s);
    }

    public function dump($obj)
    {
        if ($obj instanceof self) {
            var_dump($this, $obj);
        }
    }
}

$obj = new A('Obj-1');
$obj->dump($obj->make('Obj-2'));

/public/index.php:19:
object(A)[1]
  public 'a' => string 'Obj-1' (length=5)
/public/index.php:19:
object(A)[2]
  public 'a' => string 'Obj-2' (length=5)

abstract class RuleAbstraction
{
    // 匹配模式
    private $pattern = null;
    // 校验对象
    private $subject = null;

    public function setSubject($subject) {
        $this->subject = $subject;
    }
}

class Email extends RuleAbstraction
{
    // E-mail正则匹配模式
    private $pattern = '/^(?!_|-)(?>[\w\.-]+)@(?!-)(?>((?>[a-zA-Z0-9-]+)\.)+)[a-zA-Z]{2,46}$/';

    /**
     * 校验EMail地址
     *
     * @return false|int
     */
    public function check()
    {
        var_dump($this);
        return preg_match($this->pattern, $this->subject);
    }
}

$obj = new Email();
$obj->setSubject('shuznhi.chen@anlaa.com');
$obj->check();//0

object(RuleEngine\Rules\Email)#9 (3) {
  ["pattern":"RuleEngine\Rules\Email":private]=>
  string(69) "/^(?!_|-)(?>[\w\.-]+)@(?!-)(?>((?>[a-zA-Z0-9-]+)\.)+)[a-zA-Z]{2,46}$/"
  ["subject":"RuleEngine\Rules\RuleAbstraction":private]=>
  string(22) "w12.a/qe_@124afasf.com"
  ["pattern":"RuleEngine\Rules\RuleAbstraction":private]=>
  NULL
}
object(RuleEngine\Rules\Email)#14 (3) {
  ["pattern":"RuleEngine\Rules\Email":private]=>
  string(69) "/^(?!_|-)(?>[\w\.-]+)@(?!-)(?>((?>[a-zA-Z0-9-]+)\.)+)[a-zA-Z]{2,46}$/"
  ["subject":"RuleEngine\Rules\RuleAbstraction":private]=>
  string(22) "shunzhi.chen@anlaa.com"
  ["pattern":"RuleEngine\Rules\RuleAbstraction":private]=>
  NULL
}

$x = 5.7;
$y = 1.3;
$r = fmod($x, $y);
// $r equals 0.5, because 4 * 1.3 + 0.5 = 5.7

$mod = gmp_mod("8", "3");
echo gmp_strval($mod) . "\n";// 2