1: <?php
 2: 
 3: namespace BN\Compiler\Postfix\Operands;
 4: 
 5: use BN\Collections\Stack;
 6: 
 7: abstract class Operands
 8: {
 9:     protected $operandsCount;
10: 
11:     public function __construct($operandsCount)
12:     {
13:         $this->operandsCount = $operandsCount;
14:     }
15: 
16:     public function getOperands(Stack $stack)
17:     {
18:         $r = new OperandsSummary();
19:         $r->operands = $this->getOperandsInInfixOrder($stack);
20:         $r->areOperandsValid = $this->isOperandsCountValid($r->countOperands());
21:         $r->expectedCount = $this->operandsCount;
22:         return $r;
23:     }
24: 
25:     private function getOperandsInInfixOrder(Stack $stack)
26:     {
27:         $operands = $this->popOperands($stack);
28:         return array_reverse($operands);
29:     }
30: 
31:     abstract protected function popOperands(Stack $stack);
32: 
33:     abstract protected function isOperandsCountValid($operandsCount);
34: }
35: