php实现组合模式

 将一组对象组合为可以像单个对象一样被使用的结构

units;
	}
	function removeUnit(Unit $unit){
		$units=array();
		foreach ($this->units as $thisunit){
			if(!unit!==$thisunit){
				$units[]=$thisunit;
			}
		}
		$this->units=$units;
	}
	function addUnit(Unit $unit){
		if(in_array($unit, $this->units,true)){
			return;
		}
		$this->units[]=$unit;
	}
}

//弓箭手类
/* class Archer extends Unit{
	//实现父类的抽象方法 攻击强度
	function bombardStrength(){
		return 4;
	}
} */


//弓箭手
class Archer extends Unit{
	function addUnit(Unit $unit){
		throw new UnitException(get_class($this)."is a leaf");
	}
	function removeUnit(Unit $unit){
		throw new UnitException(get_class($this)."is a leaf");
	}
	function bombardStrength(){
		return 4;
	}
}



//激光炮单位
class LaserCanonUnit extends Unit{
	function bombardStrength(){
		return 44;
	}
	function addUnit(Unit $unit){
		
	}
	function removeUnit(Unit $unit){
		
	}
}
//陆军类
/* class Army{
	private $units=array();
	private $armies=array();
	//添加单位
	function addUnit(Unit $unit){
		array_push($this->units, $unit);
	}
	
	//攻击强度	
	function bombardStrength(){
		$ret=0;
		foreach ($this->units as $unit){
			$ret+=$unit->bombardStrength();
		}
		foreach ($this->armies as $army){
			$ret+=$army->bombardStrength();
		}
		return $ret;
	}
	
	//添加陆军
	function addArmy(Army $army){
		array_push($this->armies, $army);
	}	
} */

class Army extends Unit{
	public  $units=array();
	//添加单位
	function addUnit(Unit $unit){
		if(in_array($unit, $this->units,true)){
			return;
		}
		$this->units[]=$unit;
	}
	
	//移除单位
	function removeUnit(Unit $unit){
		$units=array();
		foreach ($this->units as $thisunit){
			if($unit!==$thisunit){
				$units[]=$thisunit;
			}
		}
		$this->units=$thisunit;
	}

	//攻击强度
	function bombardStrength(){
		$ret=0;
		foreach ($this->units as $unit){
			$ret+=$unit->bombardStrength();
		}
		
		return $ret;
	}

	//添加陆军
	function addArmy(Army $army){
		array_push($this->armies, $army);
	}
}

//运兵船
class TroopCarrier{
	function addUnit(Unit $unit){
		if($unit instanceof Cavalry){//骑兵对象
			throw new UnitException("Can't get a horse on the vehicle");
		}
		super::addUnit($unit);
	}
	function bombardStrength(){
		return 0;
	}
}

//骑兵对象
class Cavalry extends CompositeUnit{
	function addUnit(Unit $unit){
		
	}
	function removeUnit(Unit $unit){
		
	}
	function bombardStrength(){
		
	}	
}
class UnitException extends Exception{
}

class UnitScript{
	static function joinExisting(Unit $newUnit,Unit $occupyingUnit){
		$comp;
		if(!is_null($comp=$occupyingUnit->getComposite())){
			$comp->addUnit($newUnit);
		}else {
			$comp=new Army();
			$comp->addUnit($occupyingUnit);
			$comp->addUnit($newUnit);
		}
		return $comp;
	}
}



$main_army=new Army();
$main_army->addUnit(new Archer());
$main_army->addUnit(new LaserCanonUnit());

$sub_army=new Army();
$sub_army->addUnit(new Archer());

$sub_army->addUnit(new Archer());
$sub_army->addUnit(new Archer());

$main_army->addUnit($sub_army);

// print_r($main_army->units);
// print "攻击强度：{$main_army->bombardStrength()}
"; 

UnitScript::joinExisting($main_army, $sub_army);