tmilos /
scim-filter-parser
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 Parser 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 Parser, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 19 | class Parser |
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| 20 | { |
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| 21 | /** @var Lexer */ |
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| 22 | private $lexer; |
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| 23 | |||
| 24 | /** @var Version */ |
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| 25 | private $version; |
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| 26 | |||
| 27 | /** @var Mode */ |
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| 28 | private $mode; |
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| 29 | |||
| 30 | /** @var bool */ |
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| 31 | private $inValuePath; |
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| 32 | |||
| 33 | /** |
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| 34 | * @param Mode $mode |
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| 35 | * @param Version $version |
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| 36 | */ |
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| 37 | public function __construct(Mode $mode = null, Version $version = null) |
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| 46 | |||
| 47 | /** |
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| 48 | * @return Mode |
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| 49 | */ |
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| 50 | public function getMode() |
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| 54 | |||
| 55 | /** |
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| 56 | * @param Mode $mode |
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| 57 | */ |
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| 58 | public function setMode(Mode $mode) |
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| 62 | |||
| 63 | /** |
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| 64 | * @return Version |
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| 65 | */ |
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| 66 | public function getVersion() |
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| 70 | |||
| 71 | /** |
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| 72 | * @param Version $version |
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| 73 | */ |
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| 74 | public function setVersion(Version $version) |
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| 78 | |||
| 79 | /** |
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| 80 | * @param string $input |
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| 81 | * |
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| 82 | * @return Ast\Node |
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| 83 | */ |
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| 84 | public function parse($input) |
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| 101 | |||
| 102 | /** |
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| 103 | * @return Ast\Path |
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| 104 | */ |
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| 105 | private function path() |
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| 120 | |||
| 121 | /** |
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| 122 | * @return Ast\Term|Ast\Disjunction |
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| 123 | */ |
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| 124 | View Code Duplication | private function disjunction() |
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| 125 | { |
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| 126 | /** @var Ast\Term[] $terms */ |
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| 127 | $terms = []; |
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| 128 | $terms[] = $this->conjunction(); |
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| 129 | |||
| 130 | if ($this->lexer->isNextToken(Tokens::T_SP)) { |
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| 131 | $nextToken = $this->lexer->glimpse(); |
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| 132 | if ($this->isName('or', $nextToken)) { |
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| 133 | $this->match(Tokens::T_SP); |
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| 134 | $this->match(Tokens::T_NAME); |
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| 135 | $this->match(Tokens::T_SP); |
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| 136 | $terms[] = $this->conjunction(); |
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| 137 | } |
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| 138 | } |
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| 139 | |||
| 140 | if (count($terms) == 1) { |
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| 141 | return $terms[0]; |
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| 142 | } |
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| 143 | |||
| 144 | return new Ast\Disjunction($terms); |
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| 145 | } |
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| 146 | |||
| 147 | /** |
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| 148 | * @return Ast\Conjunction|Ast\Factor |
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| 149 | */ |
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| 150 | View Code Duplication | private function conjunction() |
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| 151 | { |
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| 152 | $factors = []; |
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| 153 | $factors[] = $this->factor(); |
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| 154 | |||
| 155 | if ($this->lexer->isNextToken(Tokens::T_SP)) { |
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| 156 | $nextToken = $this->lexer->glimpse(); |
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| 157 | if ($this->isName('and', $nextToken)) { |
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| 158 | $this->match(Tokens::T_SP); |
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| 159 | $this->match(Tokens::T_NAME); |
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| 160 | $this->match(Tokens::T_SP); |
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| 161 | $factors[] = $this->factor(); |
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| 162 | } |
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| 163 | } |
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| 164 | |||
| 165 | if (count($factors) == 1) { |
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| 166 | return $factors[0]; |
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| 167 | } |
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| 168 | |||
| 169 | return new Ast\Conjunction($factors); |
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| 170 | } |
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| 171 | |||
| 172 | /** |
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| 173 | * @return Ast\Filter |
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| 174 | */ |
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| 175 | private function factor() |
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| 203 | |||
| 204 | /** |
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| 205 | * @return Ast\ValuePath |
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| 206 | */ |
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| 207 | private function valuePath() |
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| 218 | |||
| 219 | /** |
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| 220 | * @return Ast\ComparisonExpression |
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| 221 | */ |
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| 222 | private function comparisionExpression() |
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| 237 | |||
| 238 | /** |
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| 239 | * @return Ast\AttributePath |
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| 240 | */ |
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| 241 | private function attributePath() |
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| 270 | |||
| 271 | /** |
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| 272 | * @return string |
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| 273 | */ |
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| 274 | private function comparisonOperator() |
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| 284 | |||
| 285 | /** |
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| 286 | * @return mixed |
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| 287 | */ |
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| 288 | private function compareValue() |
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| 319 | |||
| 320 | /** |
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| 321 | * @return bool |
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| 322 | */ |
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| 323 | private function isValuePathIncoming() |
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| 330 | |||
| 331 | /** |
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| 332 | * @param string|string[] $value |
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| 333 | * @param Token|null $token |
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| 334 | * |
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| 335 | * @return bool |
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| 336 | */ |
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| 337 | private function isName($value, $token) |
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| 358 | |||
| 359 | private function match($tokenName) |
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| 373 | |||
| 374 | private function syntaxError($expected = '', Token $token = null) |
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| 393 | } |
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| 394 |
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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.