php 迭代器使用

 /**
     * 执行入口
     * @author tianyunchong
     * Time:   4:48 pm
     * @return null
     */
    public function run()
    {
        /** 遍历下所有的意向用户 */
        foreach ($this->xrangePurpose() as $value) {
            $purposeArr = json_decode($value, true);
            $this->buildInqBuy($purposeArr);
        }
    }

    /**
     * 意向用户处理迭代器
     * @author tianyunchong
     * Time:   4:49 pm
     * @return string
     */
    private function xrangePurpose()
    {
        $id = 0;
        while (1) {
            $purposeModel = InqPurposeuser::findFirst(array(
                "conditions" => "id > ?1",
                "bind"       => array(1 => $id),
                "order"      => "id asc",
                "limit"      => 1,
            ));
            if (empty($purposeModel)) {
                break;
            }
            $id = $purposeModel->id;
            yield json_encode($purposeModel->toArray());
        }
    }