class CallEcho
{
 
  protected $callable = null;
 
  public function __construct()
  {  
    //callable 初始化
    $this->seed();
  }
 
  protected function seed(){
    $this->callable = $this;
  }
 
  public function __invoke($obj)
  {
    return $obj;
  }
 
  public function __call($name, $arguments)
  {
    $current = $this->callable;
    /**
     * 每产生__call，就往callable上面裹一层
     */
    $this->callable = function($obj) use($name, $arguments, $current){
      return call_user_func_array($current, [$obj])->{$name}(...$arguments);
    };
    return $this;
  }
   
  //作用于真正的对象上面
  public function invoke($obj){
    return call_user_func_array($this->callable, [$obj]);
  }
}
 

class TestCallEcho{
  protected $called = [];
 
  public function __call($name, $arguments)
  {
    $this->called[] = [$name, $arguments];
    return $this;
  }
 
  public function end(){
    $this->called[] = "end";
    return $this;
  }
 
  public function getCalled(){
    return $this->called;
  }
}
 
function testArrayEq($array1, $array2){
  if(count($array1) !== count($array2)){
    return false;
  }
 
  foreach ($array1 as $index => $value1){
    if(!isset($array2[$index])){
      return false;
    }
    $value2 = $array2[$index];
 
    if(is_array($value1) && is_array($value2)){
      if(!testArrayEq($value1, $value2)){
        return false;
      }else{
        //继续判断
      }
    }else{
      if($value1 !== $value2){
        return false;
      }
    }
  }
  return true;
}
 
function testTestArrayEq(){
  $array1 = [1, 2];
  $array2 = [1, 3];
  $array3 = [1, 2, 3];
 
  assert(testArrayEq($array1, $array2) == false);
  assert(testArrayEq($array1, $array3) == false);
  assert(testArrayEq($array1, $array1) == true);
}
testTestArrayEq();
 
$obj = new \stdClass();
$callEcho = new CallEcho();
 
/*************重点开始****************/
/** @var CallEcho $callEcho */
$callEcho = $callEcho->testNumber(1)->testString("myname")->testObj($obj)->testMulti(1, "myname")->testMulti2("1", $obj)->end();
 
/** @var TestCallEcho $testCallEcho */
$testCallEcho = $callEcho->invoke(new TestCallEcho());
/************重点结束****************/
 
//基本上和这个作用一样
$a = function($obj){
  $obj->testNumber(1)->testString("myname")->testObj($obj)->testMulti(1, "myname")->testMulti2("1", $obj)->end();
};
 
 
$called = $testCallEcho->getCalled();
 
$eq = testArrayEq($called, [
  ["testNumber", [1]],
  ["testString", ["myname"]],
  ["testObj", [$obj]],
  ["testMulti", [1, "myname"]],
  ["testMulti2", ["1", $obj]],
  "end"
]);
assert($eq);