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:
| 1 | <?php declare(strict_types=1); |
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| 13 | class StructureSorter |
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| 14 | { |
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| 15 | /** Variable length characters group */ |
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| 16 | const G_VARIABLE = 0; |
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| 17 | |||
| 18 | /** Fixed length characters group */ |
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| 19 | const G_FIXED = 1; |
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| 20 | |||
| 21 | /** @var string Parametrized string start marker */ |
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| 22 | protected $parameterStartMarker; |
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| 23 | |||
| 24 | /** @var string Parametrized string end marker */ |
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| 25 | protected $parameterEndMarker; |
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| 26 | |||
| 27 | /** |
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| 28 | * StructureSorter constructor. |
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| 29 | * |
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| 30 | * @param string $parameterStartMarker Parametrized string start marker |
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| 31 | * @param string $parameterEndMarker Parametrized string end marker |
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| 32 | */ |
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| 33 | public function __construct(string $parameterStartMarker, string $parameterEndMarker) |
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| 38 | |||
| 39 | /** |
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| 40 | * Sort strings array considering PCG and NPCG string structure. |
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| 41 | * |
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| 42 | * @param array $input Input array for sorting |
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| 43 | * |
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| 44 | * @return array Sorted keys array |
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| 45 | */ |
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| 46 | public function sortArrayByKeys(array $input): array |
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| 61 | |||
| 62 | /** |
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| 63 | * Build string character group structure considering parametrized |
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| 64 | * and not parametrized character groups and their length(PCG, NPCG). |
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| 65 | * |
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| 66 | * @param string $prefix Prefix string |
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| 67 | * |
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| 68 | * @return array String character groups structure |
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| 69 | */ |
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| 70 | protected function getPrefixStructure(string $prefix): array |
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| 112 | |||
| 113 | /** |
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| 114 | * Compare string structures. |
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| 115 | * |
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| 116 | * @param array $initial Initial string structure |
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| 117 | * @param array $compared Compared string structure |
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| 118 | * |
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| 119 | * @return int Result of array elements comparison |
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| 120 | */ |
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| 121 | protected function compareStringStructure(array $initial, array $compared): int |
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| 161 | |||
| 162 | /** |
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| 163 | * Make CGS equals size. |
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| 164 | * |
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| 165 | * @param array $initial Initial CGS, will be changed |
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| 166 | * @param array $compared Compared CGS, will be changed |
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| 167 | * |
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| 168 | * @return int Longest CGS size(now they are both equal) |
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| 169 | */ |
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| 170 | protected function equalizeStructures(array &$initial, array &$compared): int |
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| 182 | |||
| 183 | /** |
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| 184 | * Fill CSG with previous group value if not present. |
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| 185 | * |
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| 186 | * @param array $groups CSG for filling |
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| 187 | * @param int $index CSG index |
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| 188 | */ |
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| 189 | private function fillMissingStructureGroup(array &$groups, int $index) |
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| 195 | |||
| 196 | /** |
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| 197 | * Compare longer CGS considering that: |
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| 198 | * - Shortest fixed CGS should have higher priority |
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| 199 | * - Longest variable CGS should have higher priority |
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| 200 | * |
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| 201 | * @param array $initialGroup Initial CGS |
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| 202 | * @param array $comparedGroup Compared CGS |
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| 203 | * @param int $type Fixed/Variable CGS |
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| 204 | * @param int $dataIndex CSG data index |
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| 205 | * |
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| 206 | * @return int 0 if initial CGS is not longer than compared, |
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| 207 | * otherwise -1/1 depending on CGS type. |
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| 208 | */ |
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| 209 | private function compareCSGData(array $initialGroup, array $comparedGroup, int $type, int $dataIndex = 1) |
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| 223 | |||
| 224 | /** |
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| 225 | * Compare two character group structure(CGS) length and define |
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| 226 | * which one is longer. |
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| 227 | * |
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| 228 | * @param array $initial Initial CGS |
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| 229 | * @param array $compared Compared CGS |
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| 230 | * @param int $type CGS type (Variable|Fixed length) |
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| 231 | * |
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| 232 | * @return int -1 if initial CGS longer |
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| 233 | * 0 if initial and compared CGS are equal |
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| 234 | * 1 if compared CGS longer |
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| 235 | */ |
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| 236 | protected function compareStructureLengths(array $initial, array $compared, int $type = self::G_FIXED): int |
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| 257 | } |
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| 258 |
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVarassignment in line 1 and the$higherassignment in line 2 are dead. The first because$myVaris never used and the second because$higheris always overwritten for every possible time line.