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 Collection 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 Collection, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 4 | class Collection implements \IteratorAggregate  | 
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| 5 | { | 
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| 6 | use Traits\SortTrait;  | 
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| 7 | use Traits\SetsTrait;  | 
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| 8 | use Traits\TerminateTrait;  | 
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| 9 | use Traits\LimitTrait;  | 
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| 10 | |||
| 11 | const TYPE_FOR = 'for';  | 
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| 12 | const TYPE_FOREACH = 'foreach';  | 
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| 13 | |||
| 14 | private $type = self::TYPE_FOREACH;  | 
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| 15 | private $debug = false;  | 
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| 16 | |||
| 17 | private $ops = [];  | 
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| 18 | private $seed;  | 
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| 19 | private $is_array;  | 
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| 20 | private $vars = [];  | 
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| 21 | private $fn_cnt = 0;  | 
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| 22 | |||
| 23 | /**  | 
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| 24 | * @return \Spindle\Collection  | 
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| 25 | */  | 
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| 26 | 7 | public static function from($iterable, $debug = null)  | 
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| 30 | |||
| 31 | /**  | 
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| 32 | * Generator-based range()  | 
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| 33 | * @param int|string $start  | 
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| 34 | * @param int|string $end  | 
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| 35 | * @param int $step  | 
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| 36 | * @param bool $debug  | 
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| 37 | * @return \Spindle\Collection  | 
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| 38 | */  | 
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| 39 | 13 | public static function range($start, $end, $step = 1, $debug = null)  | 
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| 59 | |||
| 60 | /**  | 
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| 61 | * Generator-based repeat()  | 
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| 62 | * @param mixed $elem  | 
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| 63 | * @param int $count  | 
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| 64 | * @param bool $debug  | 
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| 65 | */  | 
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| 66 | 2 | public static function repeat($elem, $count, $debug = null)  | 
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| 80 | |||
| 81 | /**  | 
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| 82 | * @param iterable $seed  | 
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| 83 | */  | 
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| 84 | 21 | public function __construct($seed, $debug = null, $type = null)  | 
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| 100 | |||
| 101 | 8 | private function step()  | 
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| 109 | |||
| 110 | /**  | 
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| 111 | * @param string|callable $fn '$_ * 2'  | 
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| 112 | * @return $this  | 
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| 113 | */  | 
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| 114 | 4 | View Code Duplication | public function map($fn)  | 
            
| 126 | |||
| 127 | /**  | 
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| 128 | * @param string|string[] columns  | 
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| 129 | * @return $this  | 
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| 130 | */  | 
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| 131 | 1 | public function column($columns)  | 
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| 147 | |||
| 148 | /**  | 
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| 149 | * @return \Spindle\Collection (new instance)  | 
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| 150 | */  | 
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| 151 | 1 | public function flip()  | 
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| 157 | |||
| 158 | /**  | 
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| 159 | * @return \Generator|\ArrayIterator  | 
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| 160 | */  | 
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| 161 | 1 | public function getIterator()  | 
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| 177 | |||
| 178 | /**  | 
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| 179 | * @return array  | 
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| 180 | */  | 
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| 181 | 12 | public function toArray()  | 
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| 203 | |||
| 204 | /**  | 
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| 205 | * @return $this  | 
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| 206 | */  | 
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| 207 | 1 | public function dump()  | 
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| 212 | |||
| 213 | /**  | 
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| 214 | * @return $this  | 
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| 215 | */  | 
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| 216 | 1 | public function assignTo(&$var = null)  | 
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| 221 | |||
| 222 | /**  | 
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| 223 | * @return $this  | 
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| 224 | */  | 
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| 225 | 1 | public function assignArrayTo(&$var = null)  | 
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| 230 | |||
| 231 | /**  | 
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| 232 | * @return string  | 
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| 233 | */  | 
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| 234 | 1 | public function __toString()  | 
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| 242 | |||
| 243 | /**  | 
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| 244 | * @return array  | 
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| 245 | */  | 
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| 246 | 1 | public function __debugInfo()  | 
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| 264 | |||
| 265 | private static function evaluate($_seed, $_vars, $_code, $_before, $_after)  | 
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| 281 | |||
| 282 | 15 | private function compile($ops)  | 
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| 290 | |||
| 291 | 12 | private static function compileFor($ops, $seed)  | 
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| 305 | |||
| 306 | 3 | private static function compileForeach($ops)  | 
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| 318 | }  | 
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| 319 | 
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: