| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  |  * This file is part of Railt package. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  |  * For the full copyright and license information, please view the LICENSE | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  |  * file that was distributed with this source code. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  | declare(strict_types=1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | namespace Railt\Compiler\Grammar; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  | use Railt\Compiler\Exception\GrammarException; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  | use Railt\Compiler\Grammar\Builder\AbstractBuilder; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  | use Railt\Compiler\Grammar\Builder\Alternation; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  | use Railt\Compiler\Grammar\Builder\Concatenation; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  | use Railt\Compiler\Grammar\Builder\Repetition; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  | use Railt\Compiler\Grammar\Builder\Terminal; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  | use Railt\Compiler\Grammar\Delegate\RuleDelegate; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  | use Railt\Lexer\Result\Eoi; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  | use Railt\Parser\Rule\Rule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |  * Analyze rules and transform them into atomic rules operations. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  | class Analyzer | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |      * @var array|RuleDelegate[] | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |     protected $rules = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |      * Parsed rules. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 |  |  |      * @var array|AbstractBuilder[] | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |     protected $parsedRules; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 |  |  |      * Counter to auto-name transitional rules. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 40 |  |  |      * @var int | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |     protected $transitionalRuleCounter = 0; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 |  |  |      * Rule name being analyzed. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |      * @var string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |     private $ruleName; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |      * @param RuleDelegate $delegate | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 |  |  |     public function addRuleDelegate(RuleDelegate $delegate): void | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |         $this->rules[$delegate->getRuleName()] = $delegate; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |      * Build the analyzer of the rules (does not analyze the rules). | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |      * @return Rule[]|\Traversable | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |     public function analyze(): iterable | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 |  |  |         if (\count($this->rules) === 0) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 |  |  |             throw new GrammarException('No rules specified'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 |  |  |         $this->parsedRules = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 |  |  |         foreach ($this->rules as $delegate) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 |  |  |             $this->ruleName = $delegate->getRuleName(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 |  |  |             $nodeId         = $delegate->isKept() ? $delegate->getRuleName() : null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 75 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 76 |  |  |             $pNodeId = $nodeId; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 77 |  |  |             $rule    = $this->rule($delegate->getInnerTokens(), $pNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 78 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 79 |  |  |             if ($rule === null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 80 |  |  |                 $error = \sprintf('Error while parsing rule %s.', $delegate->getRuleName()); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 81 |  |  |                 throw new GrammarException($error, 1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 82 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 83 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 |  |  |             $zeRule = $this->parsedRules[$rule]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 |  |  |             $zeRule->setName($delegate->getRuleName()); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 |  |  |             if ($nodeId !== null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 |  |  |                 $zeRule->setDefaultId($nodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 |  |  |             unset($this->parsedRules[$rule]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 |  |  |             $this->parsedRules[$delegate->getRuleName()] = $zeRule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 93 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 94 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 |  |  |         foreach ($this->parsedRules as $builder) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 |  |  |             yield $builder->build(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 98 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 99 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 100 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 101 |  |  |      * Implementation of “rule”. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 102 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 103 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 104 |  |  |      * @param string|null $pNodeId | 
            
                                                                                                            
                            
            
                                    
            
            
                | 105 |  |  |      * @return string|int|null | 
            
                                                                                                            
                            
            
                                    
            
            
                | 106 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 107 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 108 |  |  |     protected function rule(LookaheadIterator $tokens, &$pNodeId) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 109 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 110 |  |  |         return $this->choice($tokens, $pNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 111 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 112 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 113 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 114 |  |  |      * Implementation of “choice”. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 115 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 116 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 117 |  |  |      * @param string|null $pNodeId | 
            
                                                                                                            
                            
            
                                    
            
            
                | 118 |  |  |      * @return string|int|null | 
            
                                                                                                            
                            
            
                                    
            
            
                | 119 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 120 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 121 |  |  |     protected function choice(LookaheadIterator $tokens, &$pNodeId) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 122 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 123 |  |  |         $children = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 124 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 125 |  |  |         // concatenation() … | 
            
                                                                                                            
                            
            
                                    
            
            
                | 126 |  |  |         $nNodeId = $pNodeId; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 127 |  |  |         $rule    = $this->concatenation($tokens, $nNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 128 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 129 |  |  |         if ($rule === null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 130 |  |  |             return null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 131 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 132 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 133 |  |  |         if ($nNodeId !== null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 134 |  |  |             $this->parsedRules[$rule]->setNodeId($nNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 135 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 136 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 137 |  |  |         $children[] = $rule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 138 |  |  |         $others     = false; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 139 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 140 |  |  |         // … ( ::or:: concatenation() )* | 
                            
                    |  |  |  | 
                                                                                        
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                | 141 |  |  |         while ($tokens->current()->getName() === Parser::T_OR) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 142 |  |  |             $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 143 |  |  |             $others  = true; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 144 |  |  |             $nNodeId = $pNodeId; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 145 |  |  |             $rule    = $this->concatenation($tokens, $nNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 146 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 147 |  |  |             if ($rule === null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 148 |  |  |                 return null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 149 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 150 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 151 |  |  |             if ($nNodeId !== null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 152 |  |  |                 $this->parsedRules[$rule]->setNodeId($nNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 153 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 154 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 155 |  |  |             $children[] = $rule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 156 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 157 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 158 |  |  |         $pNodeId = null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 159 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 160 |  |  |         if ($others === false) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 161 |  |  |             return $rule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 162 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 163 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 164 |  |  |         $name = $this->transitionalRuleCounter++; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 165 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 166 |  |  |         $this->parsedRules[$name] = new Alternation($name, $children); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 167 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 168 |  |  |         return $name; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 169 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 170 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 171 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 172 |  |  |      * Implementation of “concatenation”. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 173 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 174 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 175 |  |  |      * @param string|null $pNodeId | 
            
                                                                                                            
                            
            
                                    
            
            
                | 176 |  |  |      * @return string|int|null | 
            
                                                                                                            
                            
            
                                    
            
            
                | 177 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 178 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 179 |  |  |     protected function concatenation(LookaheadIterator $tokens, &$pNodeId) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 180 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 181 |  |  |         $children = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 182 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 183 |  |  |         // repetition() … | 
            
                                                                                                            
                            
            
                                    
            
            
                | 184 |  |  |         $rule = $this->repetition($tokens, $pNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 185 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 186 |  |  |         if ($rule === null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 187 |  |  |             return null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 188 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 189 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 190 |  |  |         $children[] = $rule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 191 |  |  |         $others     = false; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 192 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 193 |  |  |         // … repetition()* | 
            
                                                                                                            
                            
            
                                    
            
            
                | 194 |  |  |         while (null !== $r1 = $this->repetition($tokens, $pNodeId)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 195 |  |  |             $children[] = $r1; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 196 |  |  |             $others     = true; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 197 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 198 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 199 |  |  |         if ($others === false && $pNodeId === null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 200 |  |  |             return $rule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 201 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 202 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 203 |  |  |         $name = $this->transitionalRuleCounter++; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 204 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 205 |  |  |         $this->parsedRules[$name] = new Concatenation($name, $children); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 206 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 207 |  |  |         return $name; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 208 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 209 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 210 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 211 |  |  |      * Implementation of “repetition”. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 212 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 213 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 214 |  |  |      * @param string|null $pNodeId | 
            
                                                                                                            
                            
            
                                    
            
            
                | 215 |  |  |      * @return string|int|null | 
            
                                                                                                            
                            
            
                                    
            
            
                | 216 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 217 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 218 |  |  |     protected function repetition(LookaheadIterator $tokens, &$pNodeId) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 219 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 220 |  |  |         [$min, $max] = [null, null]; | 
                            
                    |  |  |  | 
                                                                                        
                                                                                            
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 221 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 222 |  |  |         // simple() … | 
            
                                                                                                            
                            
            
                                    
            
            
                | 223 |  |  |         $children = $this->simple($tokens, $pNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 224 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 225 |  |  |         if ($children === null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 226 |  |  |             return null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 227 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 228 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 229 |  |  |         // … quantifier()? | 
                            
                    |  |  |  | 
                                                                                        
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 230 |  |  |         switch ($tokens->current()->getName()) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 231 |  |  |             case Parser::T_REPEAT_ZERO_OR_ONE: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 232 |  |  |                 [$min, $max] = [0, 1]; | 
                            
                    |  |  |  | 
                                                                                        
                                                                                            
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 233 |  |  |                 $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 234 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 235 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 236 |  |  |             case Parser::T_REPEAT_ONE_OR_MORE: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 237 |  |  |                 [$min, $max] = [1, -1]; | 
                            
                    |  |  |  | 
                                                                                        
                                                                                            
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 238 |  |  |                 $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 239 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 240 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 241 |  |  |             case Parser::T_REPEAT_ZERO_OR_MORE: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 242 |  |  |                 [$min, $max] = [0, -1]; | 
                            
                    |  |  |  | 
                                                                                        
                                                                                            
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 243 |  |  |                 $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 244 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 245 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 246 |  |  |             case Parser::T_REPEAT_N_TO_M: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 247 |  |  |                 $min = (int)$tokens->current()->getValue(1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 248 |  |  |                 $max = (int)$tokens->current()->getValue(2); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 249 |  |  |                 $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 250 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 251 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 252 |  |  |             case Parser::T_REPEAT_ZERO_TO_M: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 253 |  |  |                 [$min, $max] = [0, (int)$tokens->current()->getValue(1)]; | 
                            
                    |  |  |  | 
                                                                                        
                                                                                            
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 254 |  |  |                 $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 255 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 256 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 257 |  |  |             case Parser::T_REPEAT_N_OR_MORE: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 258 |  |  |                 [$min, $max] = [(int)$tokens->current()->getValue(1), -1]; | 
                            
                    |  |  |  | 
                                                                                        
                                                                                            
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 259 |  |  |                 $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 260 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 261 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 262 |  |  |             case Parser::T_REPEAT_EXACTLY_N: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 263 |  |  |                 $min = $max = (int)$tokens->current()->getValue(1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 264 |  |  |                 $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 265 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 266 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 267 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 268 |  |  |         // … <node>? | 
            
                                                                                                            
                            
            
                                    
            
            
                | 269 |  |  |         if ($tokens->current()->getName() === Parser::T_KEPT_NAME) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 270 |  |  |             $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 271 |  |  |             $pNodeId = $tokens->current()->getValue(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 272 |  |  |             $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 273 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 274 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 275 |  |  |         if ($min === null) { | 
                            
                    |  |  |  | 
                                                                                        
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 276 |  |  |             return $children; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 277 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 278 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 279 |  |  |         if ($max !== -1 && $max < $min) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 280 |  |  |             $error = 'Upper bound %d must be greater or equal to lower bound %d in rule %s.'; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 281 |  |  |             $error = \sprintf($error, $max, $min, $this->ruleName); | 
                            
                    |  |  |  | 
                                                                                        
                                                                                     | 
            
                                                                                                            
                            
            
                                    
            
            
                | 282 |  |  |             throw new GrammarException($error, 2); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 283 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 284 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 285 |  |  |         $name = $this->transitionalRuleCounter++; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 286 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 287 |  |  |         $this->parsedRules[$name] = new Repetition($name, $min, $max, $children); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 288 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 289 |  |  |         return $name; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 290 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 291 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 292 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 293 |  |  |      * Implementation of “simple”. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 294 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 295 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 296 |  |  |      * @param int|string|null $pNodeId | 
            
                                                                                                            
                            
            
                                    
            
            
                | 297 |  |  |      * @return string|int|null | 
            
                                                                                                            
                            
            
                                    
            
            
                | 298 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 299 |  |  |      */ | 
            
                                                                        
                            
            
                                    
            
            
                | 300 |  |  |     protected function simple(LookaheadIterator $tokens, &$pNodeId) | 
            
                                                                        
                            
            
                                    
            
            
                | 301 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 302 |  |  |         switch ($tokens->current()->getName()) { | 
            
                                                                        
                            
            
                                    
            
            
                | 303 |  |  |             case Parser::T_GROUP_OPEN: | 
            
                                                                        
                            
            
                                    
            
            
                | 304 |  |  |                 return $this->group($tokens, $pNodeId); | 
            
                                                                        
                            
            
                                    
            
            
                | 305 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 306 |  |  |             case Parser::T_TOKEN_SKIPPED: | 
            
                                                                        
                            
            
                                    
            
            
                | 307 |  |  |                 return $this->token($tokens, false); | 
            
                                                                        
                            
            
                                    
            
            
                | 308 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 309 |  |  |             case Parser::T_TOKEN_KEPT: | 
            
                                                                        
                            
            
                                    
            
            
                | 310 |  |  |                 return $this->token($tokens, true); | 
            
                                                                        
                            
            
                                    
            
            
                | 311 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 312 |  |  |             case Parser::T_INVOKE: | 
            
                                                                        
                            
            
                                    
            
            
                | 313 |  |  |                 return $this->invoke($tokens); | 
            
                                                                        
                            
            
                                    
            
            
                | 314 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 315 |  |  |             default: | 
            
                                                                        
                            
            
                                    
            
            
                | 316 |  |  |                 return null; | 
            
                                                                        
                            
            
                                    
            
            
                | 317 |  |  |         } | 
            
                                                                        
                            
            
                                    
            
            
                | 318 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 319 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 320 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 321 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 322 |  |  |      * @param int|string|null $pNodeId | 
            
                                                                                                            
                            
            
                                    
            
            
                | 323 |  |  |      * @return int|null|string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 324 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 325 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 326 |  |  |     protected function group(LookaheadIterator $tokens, &$pNodeId) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 327 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 328 |  |  |         $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 329 |  |  |         $rule = $this->choice($tokens, $pNodeId); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 330 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 331 |  |  |         if ($rule === null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 332 |  |  |             return null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 333 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 334 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 335 |  |  |         if ($tokens->current()->getName() !== Parser::T_GROUP_CLOSE) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 336 |  |  |             return null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 337 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 338 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 339 |  |  |         $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 340 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 341 |  |  |         return $rule; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 342 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 343 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 344 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 345 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 346 |  |  |      * @param bool $kept | 
            
                                                                                                            
                            
            
                                    
            
            
                | 347 |  |  |      * @return int|string|null | 
            
                                                                                                            
                            
            
                                    
            
            
                | 348 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 349 |  |  |     protected function token(LookaheadIterator $tokens, bool $kept = true) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 350 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 351 |  |  |         $tokenName = $tokens->current()->getValue(1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 352 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 353 |  |  |         $name = $this->transitionalRuleCounter++; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 354 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 355 |  |  |         $this->parsedRules[$name] = new Terminal($name, $tokenName, $kept); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 356 |  |  |         $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 357 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 358 |  |  |         return $name; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 359 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 360 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 361 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 362 |  |  |      * @param LookaheadIterator $tokens | 
            
                                                                                                            
                            
            
                                    
            
            
                | 363 |  |  |      * @return int|string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 364 |  |  |      * @throws GrammarException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 365 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 366 |  |  |     protected function invoke(LookaheadIterator $tokens) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 367 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 368 |  |  |         $tokenName = $tokens->current()->getValue(1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 369 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 370 |  |  |         if (! \array_key_exists($tokenName, $this->rules)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 371 |  |  |             $error = \vsprintf('Cannot call rule %s() in rule %s because it does not exist.', [ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 372 |  |  |                 $tokenName, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 373 |  |  |                 $this->ruleName, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 374 |  |  |             ]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 375 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 376 |  |  |             throw new GrammarException($error, 5); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 377 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 378 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 379 |  |  |         if ($tokens->getNext()->getName() === Eoi::T_NAME) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 380 |  |  |             $name                     = $this->transitionalRuleCounter++; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 381 |  |  |             $this->parsedRules[$name] = new Concatenation($name, [$tokenName]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 382 |  |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 383 |  |  |             $name = $tokenName; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 384 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 385 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 386 |  |  |         $tokens->next(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 387 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 388 |  |  |         return $name; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 389 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 390 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 391 |  |  |  | 
            
                        
Sometimes obsolete code just ends up commented out instead of removed. In this case it is better to remove the code once you have checked you do not need it.
The code might also have been commented out for debugging purposes. In this case it is vital that someone uncomments it again or your project may behave in very unexpected ways in production.
This check looks for comments that seem to be mostly valid code and reports them.