Complex classes like TokenStream 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 TokenStream, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 13 | class TokenStream { |
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| 14 | private $current = null; |
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| 15 | /** |
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| 16 | * @var InputStream |
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| 17 | */ |
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| 18 | private $input; |
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| 19 | |||
| 20 | /** |
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| 21 | * TokenStream constructor. |
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| 22 | * |
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| 23 | * @param InputStream $input |
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| 24 | */ |
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| 25 | 24 | public function __construct(InputStream $input) { |
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| 28 | |||
| 29 | /** |
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| 30 | * @return Token |
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| 31 | */ |
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| 32 | 24 | public function next() { |
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| 33 | 24 | $token = $this->current; |
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| 34 | 24 | $this->current = null; |
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| 35 | 24 | if ($token) { |
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| 36 | 16 | return $token; |
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| 37 | } |
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| 38 | 8 | return $this->readNext(); |
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| 39 | } |
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| 40 | |||
| 41 | /** |
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| 42 | * @return bool |
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| 43 | */ |
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| 44 | 6 | public function eof() { |
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| 47 | |||
| 48 | /** |
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| 49 | * @return Token |
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| 50 | */ |
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| 51 | 16 | public function peek() { |
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| 58 | |||
| 59 | /** |
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| 60 | * @param string $msg |
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| 61 | * |
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| 62 | * @throws ParseException |
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| 63 | */ |
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| 64 | 1 | public function error($msg) { |
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| 67 | |||
| 68 | /** |
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| 69 | * @return Token |
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| 70 | * @throws ParseException |
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| 71 | */ |
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| 72 | 24 | protected function readNext() { |
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| 102 | |||
| 103 | protected function skipComment() { |
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| 111 | |||
| 112 | /** |
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| 113 | * @return Token |
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| 114 | */ |
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| 115 | 9 | protected function readDoubleQuotedString() { |
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| 118 | |||
| 119 | /** |
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| 120 | * @return Token |
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| 121 | */ |
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| 122 | 1 | protected function readSingleQuotedString() { |
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| 125 | |||
| 126 | /** |
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| 127 | * @return Token |
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| 128 | */ |
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| 129 | 2 | protected function readDoubleBracketString() { |
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| 155 | |||
| 156 | /** |
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| 157 | * @param string $end |
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| 158 | * |
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| 159 | * @return string |
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| 160 | */ |
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| 161 | 10 | protected function readEscaped($end) { |
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| 184 | |||
| 185 | /** |
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| 186 | * @return Token |
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| 187 | */ |
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| 188 | 6 | protected function readNumber() { |
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| 204 | |||
| 205 | /** |
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| 206 | * @return Token |
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| 207 | */ |
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| 208 | 9 | protected function readIdentifier() { |
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| 224 | |||
| 225 | /** |
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| 226 | * @return Token |
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| 227 | */ |
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| 228 | 8 | protected function readPunctuation() { |
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| 231 | |||
| 232 | /** |
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| 233 | * @param callable $predicate |
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| 234 | * |
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| 235 | * @return string |
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| 236 | */ |
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| 237 | 24 | protected function readWhile(callable $predicate) { |
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| 244 | |||
| 245 | /** |
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| 246 | * @param string $char |
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| 247 | * |
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| 248 | * @return bool |
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| 249 | */ |
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| 250 | 24 | protected function isWhitespace($char) { |
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| 253 | |||
| 254 | /** |
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| 255 | * @param string $char |
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| 256 | * |
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| 257 | * @return bool |
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| 258 | */ |
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| 259 | 17 | protected function isDigit($char) { |
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| 262 | |||
| 263 | /** |
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| 264 | * @return bool |
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| 265 | */ |
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| 266 | 19 | protected function isDoubleBracketString() { |
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| 269 | |||
| 270 | /** |
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| 271 | * @param string $char |
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| 272 | * |
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| 273 | * @return bool |
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| 274 | */ |
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| 275 | 13 | protected function isStartIdentifierCharacter($char) { |
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| 278 | |||
| 279 | /** |
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| 280 | * @param string $char |
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| 281 | * |
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| 282 | * @return bool |
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| 283 | */ |
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| 284 | 9 | protected function isIdentifierCharacter($char) { |
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| 287 | |||
| 288 | /** |
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| 289 | * @param string $char |
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| 290 | * |
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| 291 | * @return bool |
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| 292 | */ |
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| 293 | 9 | protected function isPunctuation($char) { |
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| 296 | |||
| 297 | /** |
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| 298 | * @param string $text |
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| 299 | * |
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| 300 | * @return bool |
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| 301 | */ |
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| 302 | 9 | protected function isKeyword($text) { |
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| 305 | } |
This check compares the return type specified in the
@returnannotation of a function or method doc comment with the types returned by the function and raises an issue if they mismatch.