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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60 | 10 | $this->parser = $parser; |
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61 | 10 | $this->matcher = $parser->getMatcher(); |
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62 | 10 | $this->blockStack = new Stack(); |
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63 | 10 | $this->groupStack = new Stack(); |
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64 | 10 | $this->contextStack = new Stack(); |
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65 | 10 | $this->dispatcher = new EventDispatcher(); |
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66 | 10 | } |
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67 | |||
68 | 10 | public function reset() { |
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69 | // remove listeners |
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70 | 10 | foreach ($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 | 10 | } |
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75 | 10 | } |
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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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88 | 10 | $this->dispatcher->addListener($name, $listener); |
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89 | 10 | } |
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90 | |||
91 | public function removeListener($name, $listener) { |
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92 | $this->dispatcher->removeListener($name, $listener); |
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93 | } |
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94 | |||
95 | 10 | public function visitToken(Token $token) { |
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96 | // load current contexts |
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97 | 10 | $this->block = $this->peekBlock(); |
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98 | 10 | $this->group = $this->peekGroup(); |
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99 | |||
100 | // detect new contexts |
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101 | 10 | $this->detectBlockContext($token); |
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102 | 10 | $this->detectGroupContext($token); |
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103 | 10 | $this->detectLineContext($token); |
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104 | 10 | } |
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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 | 10 | } |
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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 | 10 | } |
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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 | 5 | } |
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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 | $this->contextStack->push(self::CONTEXT_STRUCT); |
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143 | 5 | } |
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144 | |||
145 | // enter routine context |
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146 | 10 | else if ($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 | 5 | } |
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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 | 10 | } |
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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 | 5 | } |
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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 | 5 | } 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, $event); |
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194 | 5 | } |
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195 | |||
196 | // leave routine context |
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197 | 10 | else if ($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 | 5 | } |
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201 | 10 | } |
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202 | 10 | } |
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203 | |||
204 | public function isBlockContextDetected() { |
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205 | return $this->blockDetected !== null; |
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206 | } |
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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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215 | return $this->inStructBody; |
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216 | } |
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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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224 | return $this->inRoutineBody; |
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225 | } |
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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 | 10 | } 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, $event); |
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256 | 10 | } |
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257 | 10 | } |
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258 | |||
259 | 10 | private function isFunctionInvocation($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 | 2 | } |
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268 | 10 | } |
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269 | |||
270 | 2 | public function resetLineContext() { |
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271 | 2 | $this->line = null; |
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272 | 2 | } |
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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.