执行及描述任务访问者模式

php
//visitor.php 访问者模式abstract class Unit{protected $depth;function accept(ArmyVisitor $visitor){$method &＃61; "visit".get_class($this);$visitor->$method($this);}protected function setDepth($depth){$this->depth &＃61; $depth;}function getDepth(){return $this->depth;}function getComposite(){return null;}abstract function bombardStrengrg();
}abstract class CompositeUnit extends Unit{protected $unit &＃61; array();function getComposite(){return $this;}function removeUnit(Unit $unit){$this->unit &＃61; array_udiff($this->unit,array($unit),function($a,$b){return ($a&＃61;&＃61;&＃61;$b)?0:1;});}function addUnit(Unit $unit){if(in_array($unit,$this->unit,true)){return;}$unit->setDepth($this->depth&＃43;1);$this->unit[] &＃61; $unit;}function accept(ArmyVisitor $visitor){parent::accept($visitor);foreach ($this->unit as $thisunit) {$thisunit->accept($visitor);}}
}class Army extends CompositeUnit{function bombardStrengrg(){$ret &＃61; 0;foreach ($this->unit as $unit) {$ret&＃43;&＃61;$unit->bombardStrengrg();}return $ret;}
}class Archer extends Unit{function bombardStrengrg(){return 4;}
}class LaserCannon extends Unit{function bombardStrengrg(){return 5;}
}abstract class ArmyVisitor{abstract function visit(Unit $node);function visitArcher(Archer $node){$this->visit($node);}function visitLaserCannon(LaserCannon $node){$this->visit($node);}function visitTroopCarrierUnit(TroopCarrierUnit $node){$this->visit($node);}function visitArmy(Army $node){$this->visit($node);}
}class TextDumpArmyVisitor extends ArmyVisitor{private $text&＃61;&＃39;&＃39;;function visit(Unit $node){$ret &＃61; &＃39;&＃39;;$pad &＃61; 4*$node->getDepth();$ret.&＃61;sprintf("%{$pad}s",&＃39;&＃39;);$ret.&＃61;get_class($node).": ";$ret.&＃61;"bombard: ".$node->bombardStrengrg()."
";$this->text.&＃61;$ret;}function getText(){return $this->text;}
}class TaxCollectionVisitor extends ArmyVisitor{private $due&＃61;0;private $report&＃61;0;function visit(Unit $node){$this->levy($node,1);}function visitArcher(Archer $node){$this->levy($node,2);}function visitTroopCarrierUnit(TroopCarrierUnit $node){$this->levy($node,2);}function visitLaserCannon(LaserCannon $node){$this->levy($node,2);}function levy(Unit $unit,$amout){$this->report.&＃61;"Tax levied for ".get_class($unit);$this->report.&＃61;": $amout
";$this->due&＃43;&＃61;$amout;}function getRepost(){return $this->report;}function getTax(){return $this->due;}
}$main_army &＃61; new Army();
$main_army->addUnit(new Archer());
$main_army->addUnit(new LaserCannon());//$textdump &＃61; new TextDumpArmyVisitor();
$taxcollector &＃61; new TaxCollectionVisitor();
$main_army->accept($taxcollector);
//echo $textdump->getText();
echo "TOTAL: ";
echo $taxcollector->getTax()."
";
echo $taxcollector->getRepost();
?>