php原型模式的研究

<?php

class Sea{}
class EarthSea extends Sea{}
class MarsSea extends Sea{}

class Plains{}
class EarthPlains{}
class MarsPlains{}

class Forest{}
class EarthForest{}
class MarsForest{}



class TerrainFactory{
    private $sea;
    private $forest;
    private $plains;
    
    function __construct(Sea $sea,Plains $plains,Forest $forest){
        $this->sea = $sea;
        $this->plains = $plains;
        $this->forest = $forest;
    }
    
    function getSea(){
        return clone $this->sea;
    }
    function getPlains(){
        return clone $this->plains;
    }
    function getForest(){
        return clone $this->forest;
    }
}


$factory = new TerrainFactory(new EarthSea,new EarthPlains, new EarthForest);
print_r($factory->getSea());
print_r($factory->getPlains());
print_r($factory->getForest());

$mars_factory = new TerrainFactory(new MarsSea,new MarsPlains, new MarsForest);
print_r($mars_factory->getSea());
print_r($mars_factory->getPlains());
print_r($mars_factory->getForest());