Complex classes like Context often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Context, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 13 | class Context implements TokenVisitorInterface { |
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| 14 | |||
| 15 | // context constants |
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| 16 | const CONTEXT_FILE = 'file'; |
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| 17 | const CONTEXT_STRUCT = 'struct'; |
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| 18 | const CONTEXT_ROUTINE = 'routine'; |
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| 19 | const CONTEXT_BLOCK = 'block'; |
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| 20 | const CONTEXT_GROUP = 'group'; |
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| 21 | |||
| 22 | // event constants |
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| 23 | const EVENT_BLOCK_ENTER = 'context.block_enter'; |
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| 24 | const EVENT_BLOCK_LEAVE = 'context.block_leave'; |
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| 25 | const EVENT_STRUCT_ENTER = 'context.struct_enter'; |
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| 26 | const EVENT_STRUCT_LEAVE = 'context.struct_leave'; |
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| 27 | const EVENT_ROUTINE_ENTER = 'context.routine_enter'; |
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| 28 | const EVENT_ROUTINE_LEAVE = 'context.routine_leave'; |
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| 29 | const EVENT_GROUP_ENTER = 'context.group_enter'; |
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| 30 | const EVENT_GROUP_LEAVE = 'context.group_leave'; |
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| 31 | |||
| 32 | // current contexts |
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| 33 | private $block; |
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| 34 | private $group; |
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| 35 | private $inStructBody = false; |
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| 36 | private $inRoutineBody = false; |
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| 37 | |||
| 38 | // stacks |
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| 39 | private $blockStack; |
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| 40 | private $groupStack; |
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| 41 | private $contextStack; |
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| 42 | private $line; |
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| 43 | |||
| 44 | // helpers |
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| 45 | private $blockDetected; |
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| 46 | private $tracker; |
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| 47 | private $dispatcher; |
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| 48 | private $parser; |
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| 49 | private $matcher; |
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| 50 | private $events = [ |
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| 51 | self::EVENT_BLOCK_ENTER, self::EVENT_BLOCK_LEAVE, |
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| 52 | self::EVENT_GROUP_ENTER, self::EVENT_GROUP_LEAVE, |
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| 53 | self::EVENT_ROUTINE_ENTER, self::EVENT_ROUTINE_LEAVE, |
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| 54 | self::EVENT_STRUCT_ENTER, self::EVENT_STRUCT_LEAVE |
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| 55 | ]; |
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| 56 | |||
| 57 | private static $PROPERTIES = [T_PRIVATE, T_PUBLIC, T_PROTECTED, T_STATIC, T_VAR]; |
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| 58 | |||
| 59 | 10 | public function __construct(Parser $parser) { |
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| 67 | |||
| 68 | 10 | public function reset() { |
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| 69 | // remove listeners |
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| 70 | 10 | foreach ($this->events as $event) { |
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| 71 | 10 | $listeners = $this->dispatcher->getListeners($event); |
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| 72 | 10 | foreach ($listeners as $listener) { |
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| 73 | 10 | $this->dispatcher->removeListener($event, $listener); |
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| 74 | } |
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| 75 | } |
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| 76 | |||
| 77 | // reset data objects |
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| 78 | 10 | $this->blockStack->clear(); |
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| 79 | 10 | $this->groupStack->clear(); |
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| 80 | 10 | $this->contextStack->clear(); |
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| 81 | 10 | } |
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| 82 | |||
| 83 | 10 | public function setTracker(TokenTracker $tracker) { |
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| 86 | |||
| 87 | 10 | public function addListener($name, $listener) { |
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| 90 | |||
| 91 | public function removeListener($name, $listener) { |
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| 94 | |||
| 95 | 10 | public function visitToken(Token $token) { |
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| 105 | |||
| 106 | 10 | private function detectBlockContext(Token $token) { |
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| 107 | 10 | if ($this->matcher->isBlock($token)) { |
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| 108 | 10 | $this->blockDetected = $token; |
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| 109 | } |
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| 110 | |||
| 111 | 10 | $this->enterBlockContext($token); |
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| 112 | 10 | $this->leaveBlockContext($token); |
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| 113 | |||
| 114 | // neglect block detection |
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| 115 | 10 | if ($this->blockDetected !== null && $token->contents == ';' |
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| 116 | 10 | && ($this->group !== null ? !($this->group->type == Group::BLOCK |
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| 117 | 10 | || $this->group->type == Group::GROUP) : true)) { |
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| 118 | 10 | $this->blockDetected = null; |
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| 119 | } |
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| 120 | 10 | } |
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| 121 | |||
| 122 | 10 | private function enterBlockContext(Token $token) { |
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| 123 | 10 | if ($token->contents == '{' && $this->blockDetected !== null) { |
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| 124 | 10 | $type = Block::getType($this->blockDetected); |
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| 125 | 10 | if ($type == Block::TYPE_FUNCTION && $this->getCurrentContext() == self::CONTEXT_STRUCT) { |
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| 126 | 5 | $type = Block::TYPE_METHOD; |
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| 127 | } |
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| 128 | 10 | $block = new Block($type); |
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| 129 | 10 | $block->start = $this->findBlockStart($this->blockDetected); |
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| 130 | 10 | $block->open = $token; |
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| 131 | 10 | $this->blockStack->push($block); |
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| 132 | 10 | $this->block = $block; |
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| 133 | 10 | $this->blockDetected = null; |
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| 134 | |||
| 135 | 10 | $event = new BlockEvent($token, $this->block); |
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| 136 | 10 | $this->dispatcher->dispatch(self::EVENT_BLOCK_ENTER, $event); |
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| 137 | |||
| 138 | // enter struct context |
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| 139 | 10 | if ($block->isStruct()) { |
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| 140 | 5 | $this->inStructBody = true; |
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| 141 | 5 | $this->dispatcher->dispatch(self::EVENT_STRUCT_ENTER, $event); |
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| 142 | 5 | $this->contextStack->push(self::CONTEXT_STRUCT); |
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| 143 | } |
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| 144 | |||
| 145 | // enter routine context |
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| 146 | 10 | else if ($block->isRoutine()) { |
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| 147 | 5 | $this->inRoutineBody = true; |
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| 148 | 5 | $this->dispatcher->dispatch(self::EVENT_ROUTINE_ENTER, $event); |
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| 149 | 5 | $this->contextStack->push(self::CONTEXT_ROUTINE); |
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| 150 | } |
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| 151 | |||
| 152 | // enter block context |
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| 153 | else { |
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| 154 | 8 | $this->contextStack->push(self::CONTEXT_BLOCK); |
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| 155 | } |
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| 156 | } |
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| 157 | 10 | } |
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| 158 | |||
| 159 | 10 | private function findBlockStart(Token $token) { |
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| 160 | 10 | $startToken = $token; |
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| 161 | 10 | $prevToken = $this->tracker->prevToken($token); |
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| 162 | |||
| 163 | 10 | while ($this->matcher->isModifier($prevToken)) { |
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| 164 | 5 | $startToken = $prevToken; |
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| 165 | 5 | $prevToken = $this->tracker->prevToken($prevToken); |
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| 166 | } |
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| 167 | |||
| 168 | 10 | return $startToken; |
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| 169 | } |
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| 170 | |||
| 171 | 10 | private function leaveBlockContext(Token $token) { |
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| 172 | 10 | if ($token->contents == '}') { |
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| 173 | 10 | $this->block = $this->blockStack->pop(); |
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| 174 | |||
| 175 | // find block end |
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| 176 | 10 | if ($this->block->type == Block::TYPE_DO) { |
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| 177 | 5 | $nextToken = $token; |
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| 178 | do { |
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| 179 | 5 | $nextToken = $this->tracker->nextToken($nextToken); |
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| 180 | 5 | } while ($nextToken->contents != ';'); |
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| 181 | 5 | $this->block->end = $nextToken; |
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| 182 | } else { |
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| 183 | 10 | $this->block->end = $token; |
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| 184 | } |
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| 185 | |||
| 186 | 10 | $event = new BlockEvent($token, $this->block); |
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| 187 | 10 | $this->dispatcher->dispatch(self::EVENT_BLOCK_LEAVE, $event); |
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| 188 | 10 | $this->contextStack->pop(); |
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| 189 | |||
| 190 | // leave struct context |
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| 191 | 10 | if ($this->inStructBody && $this->block->isStruct()) { |
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| 192 | 5 | $this->inStructBody = false; |
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| 193 | 5 | $this->dispatcher->dispatch(self::EVENT_STRUCT_LEAVE, $event); |
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| 194 | } |
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| 195 | |||
| 196 | // leave routine context |
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| 197 | 10 | else if ($this->inRoutineBody && $this->block->isRoutine()) { |
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| 198 | 5 | $this->inRoutineBody = false; |
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| 199 | 5 | $this->dispatcher->dispatch(self::EVENT_ROUTINE_LEAVE, $event); |
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| 200 | } |
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| 201 | } |
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| 202 | 10 | } |
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| 203 | |||
| 204 | public function isBlockContextDetected() { |
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| 207 | |||
| 208 | /** |
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| 209 | * Tells you, whenever being in a struct, this is also true when inside |
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| 210 | * a method or inside a function, which is inside a method |
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| 211 | * |
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| 212 | * @return bool |
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| 213 | */ |
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| 214 | public function inStructBody() { |
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| 217 | |||
| 218 | /** |
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| 219 | * Tells you, whenever being in a function or method |
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| 220 | * |
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| 221 | * @return bool |
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| 222 | */ |
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| 223 | public function inRoutineBody() { |
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| 226 | |||
| 227 | 10 | private function detectGroupContext(Token $token) { |
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| 228 | 10 | $prevToken = $this->tracker->getPrevToken(); |
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| 229 | 10 | if ($token->contents == '(') { |
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| 230 | 10 | $group = new Group(); |
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| 231 | 10 | $group->start = $token; |
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| 232 | // if (in_array($prevToken->type, Tokenizer::$BLOCKS) |
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| 233 | // || in_array($prevToken->type, Tokenizer::$OPERATORS)) { |
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| 234 | 10 | if (($this->matcher->isBlock($prevToken) || $this->matcher->isOperator($prevToken)) |
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| 235 | 10 | && !$this->group->isBlock()) { |
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| 236 | 8 | $group->type = Group::BLOCK; |
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| 237 | 8 | $group->token = $prevToken; |
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| 238 | 10 | } else if ($this->isFunctionInvocation($token)) { |
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| 239 | 10 | $group->type = Group::CALL; |
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| 240 | 10 | $group->token = $prevToken; |
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| 241 | } else { |
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| 242 | 5 | $group->type = Group::GROUP; |
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| 243 | } |
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| 244 | |||
| 245 | 10 | $this->groupStack->push($group); |
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| 246 | 10 | $this->group = $group; |
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| 247 | |||
| 248 | 10 | $event = new GroupEvent($token, $group); |
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| 249 | 10 | $this->dispatcher->dispatch(self::EVENT_GROUP_ENTER, $event); |
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| 250 | 10 | } else if ($token->contents == ')') { |
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| 251 | 10 | $this->group = $this->groupStack->pop(); |
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| 252 | 10 | $this->group->end = $token; |
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| 253 | |||
| 254 | 10 | $event = new GroupEvent($token, $this->group); |
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| 255 | 10 | $this->dispatcher->dispatch(self::EVENT_GROUP_LEAVE, $event); |
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| 256 | } |
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| 257 | 10 | } |
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| 258 | |||
| 259 | 10 | private function isFunctionInvocation($token) { |
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| 263 | |||
| 264 | 10 | private function detectLineContext(Token $token) { |
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| 265 | 10 | if ($this->matcher->isLineContext($token)) { |
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| 266 | 2 | $this->line = $token->contents; |
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| 267 | } |
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| 268 | 10 | } |
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| 269 | |||
| 270 | 2 | public function resetLineContext() { |
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| 273 | |||
| 274 | /** |
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| 275 | * Returns the line context or null if not present |
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| 276 | * |
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| 277 | * @return string|null |
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| 278 | */ |
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| 279 | 2 | public function getLineContext() { |
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| 282 | |||
| 283 | /** |
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| 284 | * Returns the current context. Context is one of the Context::CONTEXT_* constants. |
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| 285 | * |
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| 286 | * @return string |
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| 287 | */ |
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| 288 | 5 | public function getCurrentContext() { |
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| 295 | |||
| 296 | /** |
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| 297 | * Returns the current block context |
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| 298 | * |
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| 299 | * @return Block |
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| 300 | */ |
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| 301 | public function getBlockContext() { |
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| 304 | |||
| 305 | /** |
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| 306 | * Returns the current group context |
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| 307 | * |
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| 308 | * @return Group|null |
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| 309 | */ |
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| 310 | 2 | public function getGroupContext() { |
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| 313 | |||
| 314 | 10 | private function peekBlock() { |
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| 320 | |||
| 321 | 10 | private function peekGroup() { |
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| 327 | } |
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| 328 |
This check marks private properties in classes that are never used. Those properties can be removed.