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ExpressionParser.php
001 <?php
002
003 /*
004 * This file is part of Twig.
005 *
006 * (c) 2009 Fabien Potencier
007 * (c) 2009 Armin Ronacher
008 *
009 * For the full copyright and license information, please view the LICENSE
010 * file that was distributed with this source code.
011 */
012
013 /**
014 * Parses expressions.
015 *
016 * This parser implements a "Precedence climbing" algorithm.
017 *
018 * @see http://www.engr.mun.ca/~theo/Misc/exp_parsing.htm
019 * @see http://en.wikipedia.org/wiki/Operator-precedence_parser
020 *
021 * @author Fabien Potencier <fabien@symfony.com>
022 */
023 class Twig_ExpressionParser
024 {
025 const OPERATOR_LEFT = 1;
026 const OPERATOR_RIGHT = 2;
027
028 protected $parser;
029 protected $unaryOperators;
030 protected $binaryOperators;
031
032 public function __construct(Twig_Parser $parser, array $unaryOperators, array $binaryOperators)
033 {
034 $this->parser = $parser;
035 $this->unaryOperators = $unaryOperators;
036 $this->binaryOperators = $binaryOperators;
037 }
038
039 public function parseExpression($precedence = 0)
040 {
041 $expr = $this->getPrimary();
042 $token = $this->parser->getCurrentToken();
043 while ($this->isBinary($token) && $this->binaryOperators[$token->getValue()]['precedence'] >= $precedence) {
044 $op = $this->binaryOperators[$token->getValue()];
045 $this->parser->getStream()->next();
046
047 if (isset($op['callable'])) {
048 $expr = call_user_func($op['callable'], $this->parser, $expr);
049 } else {
050 $expr1 = $this->parseExpression(self::OPERATOR_LEFT === $op['associativity'] ? $op['precedence'] + 1 : $op['precedence']);
051 $class = $op['class'];
052 $expr = new $class($expr, $expr1, $token->getLine());
053 }
054
055 $token = $this->parser->getCurrentToken();
056 }
057
058 if (0 === $precedence) {
059 return $this->parseConditionalExpression($expr);
060 }
061
062 return $expr;
063 }
064
065 protected function getPrimary()
066 {
067 $token = $this->parser->getCurrentToken();
068
069 if ($this->isUnary($token)) {
070 $operator = $this->unaryOperators[$token->getValue()];
071 $this->parser->getStream()->next();
072 $expr = $this->parseExpression($operator['precedence']);
073 $class = $operator['class'];
074
075 return $this->parsePostfixExpression(new $class($expr, $token->getLine()));
076 } elseif ($token->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
077 $this->parser->getStream()->next();
078 $expr = $this->parseExpression();
079 $this->parser->getStream()->expect(Twig_Token::PUNCTUATION_TYPE, ')', 'An opened parenthesis is not properly closed');
080
081 return $this->parsePostfixExpression($expr);
082 }
083
084 return $this->parsePrimaryExpression();
085 }
086
087 protected function parseConditionalExpression($expr)
088 {
089 while ($this->parser->getStream()->nextIf(Twig_Token::PUNCTUATION_TYPE, '?')) {
090 if (!$this->parser->getStream()->nextIf(Twig_Token::PUNCTUATION_TYPE, ':')) {
091 $expr2 = $this->parseExpression();
092 if ($this->parser->getStream()->nextIf(Twig_Token::PUNCTUATION_TYPE, ':')) {
093 $expr3 = $this->parseExpression();
094 } else {
095 $expr3 = new Twig_Node_Expression_Constant('', $this->parser->getCurrentToken()->getLine());
096 }
097 } else {
098 $expr2 = $expr;
099 $expr3 = $this->parseExpression();
100 }
101
102 $expr = new Twig_Node_Expression_Conditional($expr, $expr2, $expr3, $this->parser->getCurrentToken()->getLine());
103 }
104
105 return $expr;
106 }
107
108 protected function isUnary(Twig_Token $token)
109 {
110 return $token->test(Twig_Token::OPERATOR_TYPE) && isset($this->unaryOperators[$token->getValue()]);
111 }
112
113 protected function isBinary(Twig_Token $token)
114 {
115 return $token->test(Twig_Token::OPERATOR_TYPE) && isset($this->binaryOperators[$token->getValue()]);
116 }
117
118 public function parsePrimaryExpression()
119 {
120 $token = $this->parser->getCurrentToken();
121 switch ($token->getType()) {
122 case Twig_Token::NAME_TYPE:
123 $this->parser->getStream()->next();
124 switch ($token->getValue()) {
125 case 'true':
126 case 'TRUE':
127 $node = new Twig_Node_Expression_Constant(true, $token->getLine());
128 break;
129
130 case 'false':
131 case 'FALSE':
132 $node = new Twig_Node_Expression_Constant(false, $token->getLine());
133 break;
134
135 case 'none':
136 case 'NONE':
137 case 'null':
138 case 'NULL':
139 $node = new Twig_Node_Expression_Constant(null, $token->getLine());
140 break;
141
142 default:
143 if ('(' === $this->parser->getCurrentToken()->getValue()) {
144 $node = $this->getFunctionNode($token->getValue(), $token->getLine());
145 } else {
146 $node = new Twig_Node_Expression_Name($token->getValue(), $token->getLine());
147 }
148 }
149 break;
150
151 case Twig_Token::NUMBER_TYPE:
152 $this->parser->getStream()->next();
153 $node = new Twig_Node_Expression_Constant($token->getValue(), $token->getLine());
154 break;
155
156 case Twig_Token::STRING_TYPE:
157 case Twig_Token::INTERPOLATION_START_TYPE:
158 $node = $this->parseStringExpression();
159 break;
160
161 case Twig_Token::OPERATOR_TYPE:
162 if (preg_match(Twig_Lexer::REGEX_NAME, $token->getValue(), $matches) && $matches[0] == $token->getValue()) {
163 // in this context, string operators are variable names
164 $this->parser->getStream()->next();
165 $node = new Twig_Node_Expression_Name($token->getValue(), $token->getLine());
166 break;
167 } elseif (isset($this->unaryOperators[$token->getValue()])) {
168 $class = $this->unaryOperators[$token->getValue()]['class'];
169
170 $ref = new ReflectionClass($class);
171 $negClass = 'Twig_Node_Expression_Unary_Neg';
172 $posClass = 'Twig_Node_Expression_Unary_Pos';
173 if (!(in_array($ref->getName(), array($negClass, $posClass)) || $ref->isSubclassOf($negClass) || $ref->isSubclassOf($posClass))) {
174 throw new Twig_Error_Syntax(sprintf('Unexpected unary operator "%s".', $token->getValue()), $token->getLine(), $this->parser->getFilename());
175 }
176
177 $this->parser->getStream()->next();
178 $expr = $this->parsePrimaryExpression();
179
180 $node = new $class($expr, $token->getLine());
181 break;
182 }
183
184 default:
185 if ($token->test(Twig_Token::PUNCTUATION_TYPE, '[')) {
186 $node = $this->parseArrayExpression();
187 } elseif ($token->test(Twig_Token::PUNCTUATION_TYPE, '{')) {
188 $node = $this->parseHashExpression();
189 } else {
190 throw new Twig_Error_Syntax(sprintf('Unexpected token "%s" of value "%s".', Twig_Token::typeToEnglish($token->getType()), $token->getValue()), $token->getLine(), $this->parser->getFilename());
191 }
192 }
193
194 return $this->parsePostfixExpression($node);
195 }
196
197 public function parseStringExpression()
198 {
199 $stream = $this->parser->getStream();
200
201 $nodes = array();
202 // a string cannot be followed by another string in a single expression
203 $nextCanBeString = true;
204 while (true) {
205 if ($nextCanBeString && $token = $stream->nextIf(Twig_Token::STRING_TYPE)) {
206 $nodes[] = new Twig_Node_Expression_Constant($token->getValue(), $token->getLine());
207 $nextCanBeString = false;
208 } elseif ($stream->nextIf(Twig_Token::INTERPOLATION_START_TYPE)) {
209 $nodes[] = $this->parseExpression();
210 $stream->expect(Twig_Token::INTERPOLATION_END_TYPE);
211 $nextCanBeString = true;
212 } else {
213 break;
214 }
215 }
216
217 $expr = array_shift($nodes);
218 foreach ($nodes as $node) {
219 $expr = new Twig_Node_Expression_Binary_Concat($expr, $node, $node->getLine());
220 }
221
222 return $expr;
223 }
224
225 public function parseArrayExpression()
226 {
227 $stream = $this->parser->getStream();
228 $stream->expect(Twig_Token::PUNCTUATION_TYPE, '[', 'An array element was expected');
229
230 $node = new Twig_Node_Expression_Array(array(), $stream->getCurrent()->getLine());
231 $first = true;
232 while (!$stream->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
233 if (!$first) {
234 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'An array element must be followed by a comma');
235
236 // trailing ,?
237 if ($stream->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
238 break;
239 }
240 }
241 $first = false;
242
243 $node->addElement($this->parseExpression());
244 }
245 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ']', 'An opened array is not properly closed');
246
247 return $node;
248 }
249
250 public function parseHashExpression()
251 {
252 $stream = $this->parser->getStream();
253 $stream->expect(Twig_Token::PUNCTUATION_TYPE, '{', 'A hash element was expected');
254
255 $node = new Twig_Node_Expression_Array(array(), $stream->getCurrent()->getLine());
256 $first = true;
257 while (!$stream->test(Twig_Token::PUNCTUATION_TYPE, '}')) {
258 if (!$first) {
259 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'A hash value must be followed by a comma');
260
261 // trailing ,?
262 if ($stream->test(Twig_Token::PUNCTUATION_TYPE, '}')) {
263 break;
264 }
265 }
266 $first = false;
267
268 // a hash key can be:
269 //
270 // * a number -- 12
271 // * a string -- 'a'
272 // * a name, which is equivalent to a string -- a
273 // * an expression, which must be enclosed in parentheses -- (1 + 2)
274 if (($token = $stream->nextIf(Twig_Token::STRING_TYPE)) || ($token = $stream->nextIf(Twig_Token::NAME_TYPE)) || $token = $stream->nextIf(Twig_Token::NUMBER_TYPE)) {
275 $key = new Twig_Node_Expression_Constant($token->getValue(), $token->getLine());
276 } elseif ($stream->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
277 $key = $this->parseExpression();
278 } else {
279 $current = $stream->getCurrent();
280
281 throw new Twig_Error_Syntax(sprintf('A hash key must be a quoted string, a number, a name, or an expression enclosed in parentheses (unexpected token "%s" of value "%s".', Twig_Token::typeToEnglish($current->getType()), $current->getValue()), $current->getLine(), $this->parser->getFilename());
282 }
283
284 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ':', 'A hash key must be followed by a colon (:)');
285 $value = $this->parseExpression();
286
287 $node->addElement($value, $key);
288 }
289 $stream->expect(Twig_Token::PUNCTUATION_TYPE, '}', 'An opened hash is not properly closed');
290
291 return $node;
292 }
293
294 public function parsePostfixExpression($node)
295 {
296 while (true) {
297 $token = $this->parser->getCurrentToken();
298 if ($token->getType() == Twig_Token::PUNCTUATION_TYPE) {
299 if ('.' == $token->getValue() || '[' == $token->getValue()) {
300 $node = $this->parseSubscriptExpression($node);
301 } elseif ('|' == $token->getValue()) {
302 $node = $this->parseFilterExpression($node);
303 } else {
304 break;
305 }
306 } else {
307 break;
308 }
309 }
310
311 return $node;
312 }
313
314 public function getFunctionNode($name, $line)
315 {
316 switch ($name) {
317 case 'parent':
318 $this->parseArguments();
319 if (!count($this->parser->getBlockStack())) {
320 throw new Twig_Error_Syntax('Calling "parent" outside a block is forbidden.', $line, $this->parser->getFilename());
321 }
322
323 if (!$this->parser->getParent() && !$this->parser->hasTraits()) {
324 throw new Twig_Error_Syntax('Calling "parent" on a template that does not extend nor "use" another template is forbidden.', $line, $this->parser->getFilename());
325 }
326
327 return new Twig_Node_Expression_Parent($this->parser->peekBlockStack(), $line);
328 case 'block':
329 return new Twig_Node_Expression_BlockReference($this->parseArguments()->getNode(0), false, $line);
330 case 'attribute':
331 $args = $this->parseArguments();
332 if (count($args) < 2) {
333 throw new Twig_Error_Syntax('The "attribute" function takes at least two arguments (the variable and the attributes).', $line, $this->parser->getFilename());
334 }
335
336 return new Twig_Node_Expression_GetAttr($args->getNode(0), $args->getNode(1), count($args) > 2 ? $args->getNode(2) : null, Twig_Template::ANY_CALL, $line);
337 default:
338 if (null !== $alias = $this->parser->getImportedSymbol('function', $name)) {
339 $arguments = new Twig_Node_Expression_Array(array(), $line);
340 foreach ($this->parseArguments() as $n) {
341 $arguments->addElement($n);
342 }
343
344 $node = new Twig_Node_Expression_MethodCall($alias['node'], $alias['name'], $arguments, $line);
345 $node->setAttribute('safe', true);
346
347 return $node;
348 }
349
350 $args = $this->parseArguments(true);
351 $class = $this->getFunctionNodeClass($name, $line);
352
353 return new $class($name, $args, $line);
354 }
355 }
356
357 public function parseSubscriptExpression($node)
358 {
359 $stream = $this->parser->getStream();
360 $token = $stream->next();
361 $lineno = $token->getLine();
362 $arguments = new Twig_Node_Expression_Array(array(), $lineno);
363 $type = Twig_Template::ANY_CALL;
364 if ($token->getValue() == '.') {
365 $token = $stream->next();
366 if (
367 $token->getType() == Twig_Token::NAME_TYPE
368 ||
369 $token->getType() == Twig_Token::NUMBER_TYPE
370 ||
371 ($token->getType() == Twig_Token::OPERATOR_TYPE && preg_match(Twig_Lexer::REGEX_NAME, $token->getValue()))
372 ) {
373 $arg = new Twig_Node_Expression_Constant($token->getValue(), $lineno);
374
375 if ($stream->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
376 $type = Twig_Template::METHOD_CALL;
377 foreach ($this->parseArguments() as $n) {
378 $arguments->addElement($n);
379 }
380 }
381 } else {
382 throw new Twig_Error_Syntax('Expected name or number', $lineno, $this->parser->getFilename());
383 }
384
385 if ($node instanceof Twig_Node_Expression_Name && null !== $this->parser->getImportedSymbol('template', $node->getAttribute('name'))) {
386 if (!$arg instanceof Twig_Node_Expression_Constant) {
387 throw new Twig_Error_Syntax(sprintf('Dynamic macro names are not supported (called on "%s").', $node->getAttribute('name')), $token->getLine(), $this->parser->getFilename());
388 }
389
390 $name = $arg->getAttribute('value');
391
392 if ($this->parser->isReservedMacroName($name)) {
393 throw new Twig_Error_Syntax(sprintf('"%s" cannot be called as macro as it is a reserved keyword.', $name), $token->getLine(), $this->parser->getFilename());
394 }
395
396 $node = new Twig_Node_Expression_MethodCall($node, 'get'.$name, $arguments, $lineno);
397 $node->setAttribute('safe', true);
398
399 return $node;
400 }
401 } else {
402 $type = Twig_Template::ARRAY_CALL;
403
404 // slice?
405 $slice = false;
406 if ($stream->test(Twig_Token::PUNCTUATION_TYPE, ':')) {
407 $slice = true;
408 $arg = new Twig_Node_Expression_Constant(0, $token->getLine());
409 } else {
410 $arg = $this->parseExpression();
411 }
412
413 if ($stream->nextIf(Twig_Token::PUNCTUATION_TYPE, ':')) {
414 $slice = true;
415 }
416
417 if ($slice) {
418 if ($stream->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
419 $length = new Twig_Node_Expression_Constant(null, $token->getLine());
420 } else {
421 $length = $this->parseExpression();
422 }
423
424 $class = $this->getFilterNodeClass('slice', $token->getLine());
425 $arguments = new Twig_Node(array($arg, $length));
426 $filter = new $class($node, new Twig_Node_Expression_Constant('slice', $token->getLine()), $arguments, $token->getLine());
427
428 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ']');
429
430 return $filter;
431 }
432
433 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ']');
434 }
435
436 return new Twig_Node_Expression_GetAttr($node, $arg, $arguments, $type, $lineno);
437 }
438
439 public function parseFilterExpression($node)
440 {
441 $this->parser->getStream()->next();
442
443 return $this->parseFilterExpressionRaw($node);
444 }
445
446 public function parseFilterExpressionRaw($node, $tag = null)
447 {
448 while (true) {
449 $token = $this->parser->getStream()->expect(Twig_Token::NAME_TYPE);
450
451 $name = new Twig_Node_Expression_Constant($token->getValue(), $token->getLine());
452 if (!$this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
453 $arguments = new Twig_Node();
454 } else {
455 $arguments = $this->parseArguments(true);
456 }
457
458 $class = $this->getFilterNodeClass($name->getAttribute('value'), $token->getLine());
459
460 $node = new $class($node, $name, $arguments, $token->getLine(), $tag);
461
462 if (!$this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, '|')) {
463 break;
464 }
465
466 $this->parser->getStream()->next();
467 }
468
469 return $node;
470 }
471
472 /**
473 * Parses arguments.
474 *
475 * @param bool $namedArguments Whether to allow named arguments or not
476 * @param bool $definition Whether we are parsing arguments for a function definition
477 *
478 * @return Twig_Node
479 *
480 * @throws Twig_Error_Syntax
481 */
482 public function parseArguments($namedArguments = false, $definition = false)
483 {
484 $args = array();
485 $stream = $this->parser->getStream();
486
487 $stream->expect(Twig_Token::PUNCTUATION_TYPE, '(', 'A list of arguments must begin with an opening parenthesis');
488 while (!$stream->test(Twig_Token::PUNCTUATION_TYPE, ')')) {
489 if (!empty($args)) {
490 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'Arguments must be separated by a comma');
491 }
492
493 if ($definition) {
494 $token = $stream->expect(Twig_Token::NAME_TYPE, null, 'An argument must be a name');
495 $value = new Twig_Node_Expression_Name($token->getValue(), $this->parser->getCurrentToken()->getLine());
496 } else {
497 $value = $this->parseExpression();
498 }
499
500 $name = null;
501 if ($namedArguments && $token = $stream->nextIf(Twig_Token::OPERATOR_TYPE, '=')) {
502 if (!$value instanceof Twig_Node_Expression_Name) {
503 throw new Twig_Error_Syntax(sprintf('A parameter name must be a string, "%s" given.', get_class($value)), $token->getLine(), $this->parser->getFilename());
504 }
505 $name = $value->getAttribute('name');
506
507 if ($definition) {
508 $value = $this->parsePrimaryExpression();
509
510 if (!$this->checkConstantExpression($value)) {
511 throw new Twig_Error_Syntax(sprintf('A default value for an argument must be a constant (a boolean, a string, a number, or an array).'), $token->getLine(), $this->parser->getFilename());
512 }
513 } else {
514 $value = $this->parseExpression();
515 }
516 }
517
518 if ($definition) {
519 if (null === $name) {
520 $name = $value->getAttribute('name');
521 $value = new Twig_Node_Expression_Constant(null, $this->parser->getCurrentToken()->getLine());
522 }
523 $args[$name] = $value;
524 } else {
525 if (null === $name) {
526 $args[] = $value;
527 } else {
528 $args[$name] = $value;
529 }
530 }
531 }
532 $stream->expect(Twig_Token::PUNCTUATION_TYPE, ')', 'A list of arguments must be closed by a parenthesis');
533
534 return new Twig_Node($args);
535 }
536
537 public function parseAssignmentExpression()
538 {
539 $targets = array();
540 while (true) {
541 $token = $this->parser->getStream()->expect(Twig_Token::NAME_TYPE, null, 'Only variables can be assigned to');
542 $value = $token->getValue();
543 if (in_array(strtolower($value), array('true', 'false', 'none', 'null'))) {
544 throw new Twig_Error_Syntax(sprintf('You cannot assign a value to "%s"', $value), $token->getLine(), $this->parser->getFilename());
545 }
546 $targets[] = new Twig_Node_Expression_AssignName($value, $token->getLine());
547
548 if (!$this->parser->getStream()->nextIf(Twig_Token::PUNCTUATION_TYPE, ',')) {
549 break;
550 }
551 }
552
553 return new Twig_Node($targets);
554 }
555
556 public function parseMultitargetExpression()
557 {
558 $targets = array();
559 while (true) {
560 $targets[] = $this->parseExpression();
561 if (!$this->parser->getStream()->nextIf(Twig_Token::PUNCTUATION_TYPE, ',')) {
562 break;
563 }
564 }
565
566 return new Twig_Node($targets);
567 }
568
569 protected function getFunctionNodeClass($name, $line)
570 {
571 $env = $this->parser->getEnvironment();
572
573 if (false === $function = $env->getFunction($name)) {
574 $e = new Twig_Error_Syntax(sprintf('Unknown "%s" function.', $name), $line, $this->parser->getFilename());
575 $e->addSuggestions($name, array_keys($env->getFunctions()));
576
577 throw $e;
578 }
579
580 if ($function instanceof Twig_SimpleFunction && $function->isDeprecated()) {
581 $message = sprintf('Twig Function "%s" is deprecated', $function->getName());
582 if (!is_bool($function->getDeprecatedVersion())) {
583 $message .= sprintf(' since version %s', $function->getDeprecatedVersion());
584 }
585 if ($function->getAlternative()) {
586 $message .= sprintf('. Use "%s" instead', $function->getAlternative());
587 }
588 $message .= sprintf(' in %s at line %d.', $this->parser->getFilename(), $line);
589
590 @trigger_error($message, E_USER_DEPRECATED);
591 }
592
593 if ($function instanceof Twig_SimpleFunction) {
594 return $function->getNodeClass();
595 }
596
597 return $function instanceof Twig_Function_Node ? $function->getClass() : 'Twig_Node_Expression_Function';
598 }
599
600 protected function getFilterNodeClass($name, $line)
601 {
602 $env = $this->parser->getEnvironment();
603
604 if (false === $filter = $env->getFilter($name)) {
605 $e = new Twig_Error_Syntax(sprintf('Unknown "%s" filter.', $name), $line, $this->parser->getFilename());
606 $e->addSuggestions($name, array_keys($env->getFilters()));
607
608 throw $e;
609 }
610
611 if ($filter instanceof Twig_SimpleFilter && $filter->isDeprecated()) {
612 $message = sprintf('Twig Filter "%s" is deprecated', $filter->getName());
613 if (!is_bool($filter->getDeprecatedVersion())) {
614 $message .= sprintf(' since version %s', $filter->getDeprecatedVersion());
615 }
616 if ($filter->getAlternative()) {
617 $message .= sprintf('. Use "%s" instead', $filter->getAlternative());
618 }
619 $message .= sprintf(' in %s at line %d.', $this->parser->getFilename(), $line);
620
621 @trigger_error($message, E_USER_DEPRECATED);
622 }
623
624 if ($filter instanceof Twig_SimpleFilter) {
625 return $filter->getNodeClass();
626 }
627
628 return $filter instanceof Twig_Filter_Node ? $filter->getClass() : 'Twig_Node_Expression_Filter';
629 }
630
631 // checks that the node only contains "constant" elements
632 protected function checkConstantExpression(Twig_NodeInterface $node)
633 {
634 if (!($node instanceof Twig_Node_Expression_Constant || $node instanceof Twig_Node_Expression_Array
635 || $node instanceof Twig_Node_Expression_Unary_Neg || $node instanceof Twig_Node_Expression_Unary_Pos
636 )) {
637 return false;
638 }
639
640 foreach ($node as $n) {
641 if (!$this->checkConstantExpression($n)) {
642 return false;
643 }
644 }
645
646 return true;
647 }
648 }
649