Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like StringConditionTree 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 StringConditionTree, and based on these observations, apply Extract Interface, too.
| 1 | <?php declare(strict_types = 1); |
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| 13 | class StringConditionTree |
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| 14 | { |
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| 15 | /** Tree node root element identifier, needed for recursion */ |
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| 16 | const ROOT_NAME = ''; |
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| 17 | |||
| 18 | /** Final tree node branch identifier */ |
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| 19 | const SELF_NAME = '@self'; |
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| 20 | |||
| 21 | /** String parameter start marker */ |
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| 22 | const PARAMETER_START = '{'; |
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| 23 | |||
| 24 | /** String parameter end marker */ |
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| 25 | const PARAMETER_END = '}'; |
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| 26 | |||
| 27 | /** Parameter sorting length value for counting */ |
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| 28 | const PARAMETER_COF = 2000; |
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| 29 | |||
| 30 | /** @var TreeNode Resulting collection for debugging */ |
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| 31 | protected $debug; |
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| 32 | |||
| 33 | /** @var array Collection of input string => identifier */ |
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| 34 | protected $source; |
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| 35 | |||
| 36 | /** @var string Parametrized string start marker */ |
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| 37 | protected $parameterStartMarker = self::PARAMETER_START; |
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| 38 | |||
| 39 | /** @var string Parametrized string end marker */ |
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| 40 | protected $parameterEndMarker = self::PARAMETER_END; |
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| 41 | |||
| 42 | /** |
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| 43 | * StringConditionTree constructor. |
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| 44 | * |
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| 45 | * @param string $parameterStartMarker Parametrized string start marker |
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| 46 | * @param string $parameterEndMarker Parametrized string end marker |
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| 47 | */ |
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| 48 | public function __construct( |
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| 56 | |||
| 57 | /** |
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| 58 | * Build similarity strings tree. |
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| 59 | * |
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| 60 | * @param array $input Collection of strings |
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| 61 | * |
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| 62 | * @return TreeNode Resulting similarity strings tree |
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| 63 | */ |
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| 64 | public function process(array $input): TreeNode |
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| 78 | |||
| 79 | /** |
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| 80 | * Recursive string similarity tree builder. |
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| 81 | * |
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| 82 | * @param string $prefix |
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| 83 | * @param array $input |
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| 84 | * @param TreeNode $result |
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| 85 | */ |
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| 86 | protected function innerProcessor(string $prefix, array $input, TreeNode $result) |
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| 120 | |||
| 121 | /** |
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| 122 | * Get collection of grouped longest matching prefixes with strings sub-array. |
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| 123 | * |
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| 124 | * @param array $input Input strings array |
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| 125 | * |
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| 126 | * @return array Longest matching prefixes array |
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| 127 | */ |
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| 128 | protected function getLMPCollection(array $input): array |
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| 153 | |||
| 154 | /** |
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| 155 | * Find longest matching prefix between two strings. |
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| 156 | * |
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| 157 | * @param string $initialString Initial string |
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| 158 | * @param string $comparedString Compared string |
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| 159 | * |
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| 160 | * @return string Longest matching prefix |
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| 161 | */ |
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| 162 | protected function getLongestMatchingPrefix(string $initialString, string $comparedString): string |
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| 213 | |||
| 214 | /** |
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| 215 | * Add only unique value to array. |
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| 216 | * |
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| 217 | * @param mixed $value Unique value |
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| 218 | * @param array $array Array for adding unique value |
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| 219 | * @param bool $strict Strict uniqueness check |
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| 220 | * |
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| 221 | * @return bool True if unique value was added |
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| 222 | * @see in_array(); |
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| 223 | * |
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| 224 | */ |
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| 225 | protected function addUniqueToArray($value, &$array, bool $strict = true) |
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| 242 | |||
| 243 | /** |
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| 244 | * Sort strings array considering PCG and NPCG string structure. |
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| 245 | * |
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| 246 | * @param array $input Input array for sorting |
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| 247 | * |
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| 248 | * @return array Sorted array |
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| 249 | */ |
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| 250 | protected function sortArrayByKeys(array &$input) |
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| 263 | |||
| 264 | /** |
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| 265 | * Iterate LMP and remove duplicate strings in other LMPs. |
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| 266 | * |
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| 267 | * @param array $prefixes LMP collection, returning value |
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| 268 | */ |
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| 269 | protected function filterLMPStrings(array &$prefixes) |
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| 278 | |||
| 279 | /** |
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| 280 | * Find all duplication of source array values in compared array and remove them. |
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| 281 | * |
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| 282 | * @param array $source Source array |
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| 283 | * @param array $compared Compared array for filtering duplicates |
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| 284 | */ |
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| 285 | protected function removeDuplicatesInSubArray(array $source, array &$compared) |
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| 295 | |||
| 296 | /** |
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| 297 | * Remove key string from the beginning of all sub-array strings. |
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| 298 | * |
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| 299 | * @param array $array Input array of key => [keyStrings...] |
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| 300 | * |
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| 301 | * @return array Processed array with removed keys from beginning of sub arrays |
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| 302 | */ |
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| 303 | protected function removeKeyFromArrayStrings(array $array): array |
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| 325 | |||
| 326 | /** |
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| 327 | * Build string character group structure considering parametrized |
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| 328 | * and not parametrized character groups and their length(PCG, NPCG). |
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| 329 | * |
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| 330 | * @param string $prefix Prefix string |
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| 331 | * |
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| 332 | * @return array String character groups structure |
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| 333 | */ |
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| 334 | protected function getPrefixStructure(string $prefix): array |
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| 376 | |||
| 377 | /** |
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| 378 | * Compare string structures. |
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| 379 | * |
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| 380 | * @param array $initial Initial string structure |
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| 381 | * @param array $compared Compared string structure |
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| 382 | * |
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| 383 | * @return int Result of array elements comparison |
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| 384 | */ |
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| 385 | protected function compareStringStructure(array $initial, array $compared): int |
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| 460 | } |
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| 461 |