<?php

class Prototype
{
	protected static $prototype_methods = array();
	protected static $prototype_properties = array();
	
	protected $prototype_obj_properties = array();
	
	public static function add_method()
	{
		$args = func_get_args();
		$method = array_shift( $args );
		$callback = str_replace( '$this', '$self', array_pop( $args ) );
		array_push( $args, '$self' );
		$args = implode( ',', $args);
		
		self::$prototype_methods[$method] = create_function( $args, $callback );
	}
	
	public static function add_property( $name )
	{
		self::$prototype_properties[] = $name;
	}
	
	public function __construct()
	{
		if ( self::$prototype_properties ) {
			$this->prototype_obj_properties = array_combine(
				self::$prototype_properties,
				array_fill( 0, count(self::$prototype_properties), null )
				);
		}
	} 
	
	public function __call( $method, $args = array() )
	{
		if ( isset( self::$prototype_methods[$method] ) ) {
			array_push( $args, $this );
			return call_user_func_array( self::$prototype_methods[$method], $args );
		}
	}
	
	public function __get( $name )
	{
		if ( in_array( $name, self::$prototype_properties ) ) {
			return isset( $this->prototype_obj_properties[$name] ) ? $this->prototype_obj_properties[$name] : null;
		}
		else {
			return null;
		}
	}
	
	public function __set( $name, $value )
	{
		if ( in_array( $name, self::$prototype_properties ) ) {
			return $this->prototype_obj_properties[$name] = $value;
		}
		else {
			return null;
		}
	}
	
	public function __isset( $name )
	{
		return isset( $this->prototype_obj_properties[$name] );
	}
	
	public function __unset( $name )
	{
		unset( $this->prototype_obj_properties[$name] );
	}
}

class Person extends Prototype
{
    public $name;
    public $gender;
   
    function gender()
    {
        echo "$this->name is $this->gender\n";
    }
}
?>