1: <?php
 2: 
 3: namespace BN\Compiler\Postfix\Token;
 4: 
 5: use BN\Compiler\Token\Token;
 6: use BN\Compiler\Token\TokenType;
 7: use BN\Compiler\Postfix\Operands\Operands;
 8: use BN\Compiler\Postfix\Operands\OperandsSummary;
 9: use BN\Compiler\Postfix\Variables;
10: 
11: class ProcessKeyword
12: {
13:     private $variables;
14:     private $strategy;
15:     private $accumulator;
16: 
17:     public function __construct($accumulator, Variables $variables, ProcessKeywordStrategy $strategy)
18:     {
19:         $this->accumulator = $accumulator;
20:         $this->variables = $variables;
21:         $this->strategy = $strategy;
22:     }
23: 
24:     public function process(Token $token)
25:     {
26:         $operands = $this->strategy->getOperands();
27:         $operandsSummary = $this->getOperands($operands);
28: 
29:         if ($this->accumulator->continueInCalculation()) {
30:             if ($operandsSummary->areOperandsValid) {
31:                 $result = $this->evaluate($operandsSummary);
32:                 $this->accumulator->pushNumber($result);
33:             } else {
34:                 $this->accumulator->stopCalculation('invalidOperands', $token->value, $operandsSummary);
35:             }
36:         }
37:     }
38: 
39:     private function getOperands(Operands $operands)
40:     {
41:         $summary = $operands->getOperands($this->accumulator->getStack());
42:         foreach ($summary->operands as $i => $token) {
43:             if ($token->type == TokenType::VARIABLE) {
44:                 if ($i == 0 && $this->strategy->isFirstOperandVariable()) {
45:                     continue;
46:                 } elseif ($this->variables->exists($token)) {
47:                     $token->value = $this->variables->get($token);
48:                     $summary->operands[$i] = $token;
49:                 } else {
50:                     $this->accumulator->stopCalculation('undefinedVariable', $token->value);
51:                 }
52:             }
53:         }
54:         return $summary;
55:     }
56: 
57:     private function evaluate(OperandsSummary $summary)
58:     {
59:         $evaluator = $this->strategy->getEvaluator();
60:         $operands = $this->strategy->tokensToOperands($summary->operands);
61:         return $evaluator($operands);
62:     }
63: }
64: