DoublyLinkedList::contains() - Code Metrics - Inspection of "Improved return in contains of doubly linked list" - SiroDiaz/DataStructures - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( f77e5d...e03d70 )

by Siro Díaz

created 2017-07-20 10:13 UTC

DoublyLinkedList::contains() A

↳ Parent: DoublyLinkedList

Complexity

Conditions	4
Paths	4

Size

Total Lines	17
Code Lines	11

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	17
rs	9.2
c	0
b	0
f	0
cc	4
eloc	11
nc	4
nop	1

<?php
/**
 * DataStructures for PHP
 *
 * @link      https://github.com/SiroDiaz/DataStructures
 * @copyright Copyright (c) 2017 Siro Díaz Palazón
 * @license   https://github.com/SiroDiaz/DataStructures/blob/master/README.md (MIT License)
 */
namespace DataStructures\Lists;

use DataStructures\Lists\Traits\{CountTrait, ArrayAccessTrait};
use DataStructures\Lists\Nodes\DoublyLinkedListNode;
use DataStructures\Lists\ListAbstract;
use OutOfBoundsException;

/**
 * DoublyLinkedList
 *
 * DoublyLinkedList is a double linked list that has
 * a pointer to the next and the previous node.
 *
 * @author Siro Diaz Palazon <[email protected]>
 */
class DoublyLinkedList extends ListAbstract {
    use ArrayAccessTrait;

    protected $head;
    private $tail;
    private $position;
    private $current;

    public function __construct() {

        $this->head = null;
        $this->tail = &$this->head;
        $this->size = 0;
        $this->position = 0;
        $this->current = &$this->head;
    }
    
    /**
     * Gets the data stored in the position especified.
     *
     * @param integer $index Index that must be greater than 0
     *  and lower than the list size.
     * @return mixed The data stored in the given index
     * @throws OutOfBoundsException if index is out bounds.
     */
    public function get($index) {

        $node = $this->search($index);
        if($node === null) {
            return null;
        }

        return $node->data;
    }

    /**
     * Gets the node stored in the position especified.
     * If index is 0 or (size - 1) the method is O(1) else O(n).
     *
     * @param integer $index the position.
     * @throws OutOfBoundsException if it is out of limits (< 0 or > size - 1)
     * @return DataStructures\Lists\Nodes\DoublyLinkedListNode|null the node stored in $index.
     */
    protected function search($index) {
        if($index < 0 || $index > $this->size - 1) {
            throw new OutOfBoundsException();
        }

        if($index === 0) {
            return $this->head;

        }

        if($index === $this->size - 1) {
            return $this->tail;

        }

        $current = &$this->head;
        if($index < (int) ceil($this->size / 2)) {
            $i = 0;
            while($i < $index) {
                $current = &$current->next;
                $i++;
            }    
        } else {
            $i = $this->size;
            while($i > $index) {
                $current = &$current->prev;
                $i--;
            }
        }

        return $current;
    }

    /**
     * Returns the data in the last node with O(1).
     *
     * @return mixed null if the list is empty.
     */
    public function getLast() {
        if($this->head === null) {
            return null;
        }
        return $this->tail->data;
    }

    /**
     * Returns the last node with O(1).
     *
     * @return DataStructures\Lists\Nodes\DoublyLinkedListNode|null if the list is empty.
     */
    public function searchLast() {
        if($this->head === null) {
            return null;
        }
        return $this->tail;
    }

    /**
     * {@inheritDoc}
     */
    public function contains($data) : bool {
        if($this->empty()) {
            return false;
        }

        $current = $this->head->next;
        $prev = $this->head;
        while($current !== $this->head) {
            if($prev->data === $data) {
                return true;
            }
            $prev = $current;
            $current = $current->next;
        }

        return $prev->data === $data;
    }

    /**
     * {@inheritDoc}
     */
    public function indexOf($data) {

        if($this->head === null) {
            return false;
        }
        
        $current = $this->head;
        $i = 0;
        
        while($i < $this->size) {
            if($current->data === $data) {
                return $i;
            }

            $current = $current->next;
            $i++;
        }

        return false;
    }

    /**
     * {@inheritDoc}
     */
    public function lastIndexOf($data) {

        if($this->head === null) {
            return false;
        }
        
        $current = $this->head;
        $i = 0;
        $pos = false;
        while($i < $this->size) {
            if($current->data == $data) {
                $pos = $i;
            }

            $current = $current->next;
            $i++;
        }

        return $pos;
    }

    /**
     * {@inheritDoc}
     */
    public function remove($data) {
        $current = &$this->head;
        $i = 0;
        
        if($this->head === null) {
            return null;
        }

        if($this->head->data === $data) {
            $this->head = &$this->head->next;
            $this->head->prev = &$this->tail;
            $this->size--;
            
            return $data;
        }

        while($i < $this->size) {

            if($current->data === $data) {
                $current->prev = &$current->next;
                $current = null;
                $this->size--;
                return $data;
            }

            $current = $current->next;
        }

        return null;
    }
    
    /**
     * Generator for retrieve all nodes stored.
     * 
     * @return null if the head is null (or list is empty)
     */
    public function getAll() {

        if($this->head === null) {
            return;
        }

        if($this->head === $this->tail) {
            yield $this->head->data;
        } else {
            $current = $this->head;
            $i = 0;
            while($i < $this->size) {
                yield $current->data;
                $current = $current->next;
                $i++;
            }
        }
    }

    /**
     * {@inheritDoc}
     */
    protected function insertBeginning($data) {
        $newNode = new DoublyLinkedListNode($data);
        if($this->head === null) {
            $newNode->next = &$this->head;
            $newNode->prev = &$this->head;
            $this->head = &$newNode;
            $this->tail = &$newNode;
        } else {
            $this->tail->next = &$newNode;
            $newNode->next = &$this->head;
            $newNode->prev = &$this->tail;
            $this->head = &$newNode;
        }
    }

    protected function insertEnd($data) {
        $newNode = new DoublyLinkedListNode($data);
        $this->tail->next = &$newNode;
        $newNode->next = &$this->head;
        $newNode->prev = &$this->tail;
        $this->tail = &$newNode;
        $this->head->prev = &$newNode;
    }

    /**
     * Add a new node in the specified index.
     *
     * @param integer $index the position.
     * @param mixed $data the data to be stored.
     */
    protected function insertAt($index, $data) {
        $newNode = new DoublyLinkedListNode($data);
        $current = $this->head;
        $prev = null;
        $i = 0;
        while($i < $index) {
            $prev = $current;
            $current = $current->next;
            $i++;
        }
        
        $prev->next = &$newNode;
        $newNode->prev = &$prev;
        $newNode->next = &$current;
        $current->prev = &$newNode;
    }

    /**
     * Deletes at the beginnig of the list and returns the data stored.
     *
     * @return mixed the data stored in the node.
     */
    protected function deleteBeginning() {

        // if only there is an element
        if($this->head->next === $this->head) {
            $temp = $this->head;
            $this->head = null;
        } else {
            $temp = $this->head;
            $this->head = &$this->head->next;
            $this->tail->next = &$this->head;
            
        }
        return $temp->data;
    }

    /**
     * Deletes at the specified position and returns the data stored.
     *
     * @param integer $index the position.
     * @return mixed the data stored in the node.
     */
    protected function deleteAt($index) {
        $i = 0;
        $prev = $this->head;
        $current = $this->head;
        
        while($i < $index) {
            $prev = $current;
            $current = $current->next;
            $i++;
        }

        $temp = $current;
        $prev->next = &$current->next;
        $current->next->prev = &$pre;

        $current = null;
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}

        return $temp->data;
    }

    /**
     * Deletes at the end of the list and returns the data stored.
     *
     * @return mixed the data stored in the node.
     */
    protected function deleteEnd() {

        $prev = $this->head;
        $current = $this->head;
        
        while($current !== $this->tail) {
            $prev = $current;
            $current = $current->next;
        }
        
        $temp = $current;
        $prev->next = &$this->head;
        $this->head->prev = &$prev;
        $this->tail = &$prev;
        $current = null;
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}

        return $temp->data;
    }

    /**
     * Reset the cursor position.
     */
    public function rewind() {
        $this->position = 0;
        $this->current = &$this->head;
    }

    /**
     * Returns the current node data.
     *
     * @return mixed
     */
    public function current() {
        return $this->current->data;
    }

    /**
     * Key or index that indicates the cursor position.
     *
     * @return integer The current position.
     */
    public function key() {
        return $this->position;
    }

    /**
     * Move the cursor to the next node and increments the
     * position counter.
     */
    public function next() {
        ++$this->position;
        $this->current = $this->current->next;
    }

    /**
     * Returns if the current pointer position is valid.
     *
     * @return boolean true if pointer is not last, else false.
     */
    public function valid() {
        return $this->position < $this->size;
    }
}

1		<?php
2		/**
3		* DataStructures for PHP
4		*
5		* @link https://github.com/SiroDiaz/DataStructures
6		* @copyright Copyright (c) 2017 Siro Díaz Palazón
7		* @license https://github.com/SiroDiaz/DataStructures/blob/master/README.md (MIT License)
8		*/
9		namespace DataStructures\Lists;
10
11		use DataStructures\Lists\Traits\{CountTrait, ArrayAccessTrait};
12		use DataStructures\Lists\Nodes\DoublyLinkedListNode;
13		use DataStructures\Lists\ListAbstract;
14		use OutOfBoundsException;
15
16		/**
17		* DoublyLinkedList
18		*
19		* DoublyLinkedList is a double linked list that has
20		* a pointer to the next and the previous node.
21		*
22		* @author Siro Diaz Palazon <[email protected]>
23		*/
24		class DoublyLinkedList extends ListAbstract {
25		use ArrayAccessTrait;
26
27		protected $head;
28		private $tail;
29		private $position;
30		private $current;
31
32	View Code Duplication	public function __construct() {
		0 ignored issues – show Duplication introduced 2017-06-05 14:14 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
33		$this->head = null;
34		$this->tail = &$this->head;
35		$this->size = 0;
36		$this->position = 0;
37		$this->current = &$this->head;
38		}
39
40		/**
41		* Gets the data stored in the position especified.
42		*
43		* @param integer $index Index that must be greater than 0
44		* and lower than the list size.
45		* @return mixed The data stored in the given index
46		* @throws OutOfBoundsException if index is out bounds.
47		*/
48	View Code Duplication	public function get($index) {
		0 ignored issues – show Duplication introduced 2017-06-24 20:15 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
49		$node = $this->search($index);
50		if($node === null) {
51		return null;
52		}
53
54		return $node->data;
55		}
56
57		/**
58		* Gets the node stored in the position especified.
59		* If index is 0 or (size - 1) the method is O(1) else O(n).
60		*
61		* @param integer $index the position.
62		* @throws OutOfBoundsException if it is out of limits (< 0 or > size - 1)
63		* @return DataStructures\Lists\Nodes\DoublyLinkedListNode\|null the node stored in $index.
64		*/
65		protected function search($index) {
66		if($index < 0 \|\| $index > $this->size - 1) {
67		throw new OutOfBoundsException();
68		}
69
70		if($index === 0) {
71		return $this->head;
		0 ignored issues – show Bug Compatibility introduced 2017-06-24 14:29 UTC by Report Bug Copy Issue Report The expression `$this->head;` of type `null\|DataStructures\List...es\DoublyLinkedListNode` adds the type `DataStructures\Lists\Nodes\DoublyLinkedListNode` to the return on line 71 which is incompatible with the return type documented by `DataStructures\Lists\DoublyLinkedList::search` of type `DataStructures\Lists\Dat...ublyLinkedListNode\|null`. Loading history...
72		}
73
74		if($index === $this->size - 1) {
75		return $this->tail;
		0 ignored issues – show Bug Compatibility introduced 2017-06-24 14:29 UTC by Report Bug Copy Issue Report The expression `$this->tail;` of type `null\|DataStructures\List...es\DoublyLinkedListNode` adds the type `DataStructures\Lists\Nodes\DoublyLinkedListNode` to the return on line 75 which is incompatible with the return type documented by `DataStructures\Lists\DoublyLinkedList::search` of type `DataStructures\Lists\Dat...ublyLinkedListNode\|null`. Loading history...
76		}
77
78		$current = &$this->head;
79		if($index < (int) ceil($this->size / 2)) {
80		$i = 0;
81		while($i < $index) {
82		$current = &$current->next;
83		$i++;
84		}
85		} else {
86		$i = $this->size;
87		while($i > $index) {
88		$current = &$current->prev;
89		$i--;
90		}
91		}
92
93		return $current;
94		}
95
96		/**
97		* Returns the data in the last node with O(1).
98		*
99		* @return mixed null if the list is empty.
100		*/
101		public function getLast() {
102		if($this->head === null) {
103		return null;
104		}
105		return $this->tail->data;
106		}
107
108		/**
109		* Returns the last node with O(1).
110		*
111		* @return DataStructures\Lists\Nodes\DoublyLinkedListNode\|null if the list is empty.
112		*/
113		public function searchLast() {
114		if($this->head === null) {
115		return null;
116		}
117		return $this->tail;
118		}
119
120		/**
121		* {@inheritDoc}
122		*/
123		public function contains($data) : bool {
124		if($this->empty()) {
125		return false;
126		}
127
128		$current = $this->head->next;
129		$prev = $this->head;
130		while($current !== $this->head) {
131		if($prev->data === $data) {
132		return true;
133		}
134		$prev = $current;
135		$current = $current->next;
136		}
137
138		return $prev->data === $data;
139		}
140
141		/**
142		* {@inheritDoc}
143		*/
144	View Code Duplication	public function indexOf($data) {
		0 ignored issues – show Duplication introduced 2017-07-08 23:51 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
145		if($this->head === null) {
146		return false;
147		}
148
149		$current = $this->head;
150		$i = 0;
151
152		while($i < $this->size) {
153		if($current->data === $data) {
154		return $i;
155		}
156
157		$current = $current->next;
158		$i++;
159		}
160
161		return false;
162		}
163
164		/**
165		* {@inheritDoc}
166		*/
167	View Code Duplication	public function lastIndexOf($data) {
		0 ignored issues – show Duplication introduced 2017-07-09 14:20 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
168		if($this->head === null) {
169		return false;
170		}
171
172		$current = $this->head;
173		$i = 0;
174		$pos = false;
175		while($i < $this->size) {
176		if($current->data == $data) {
177		$pos = $i;
178		}
179
180		$current = $current->next;
181		$i++;
182		}
183
184		return $pos;
185		}
186
187		/**
188		* {@inheritDoc}
189		*/
190		public function remove($data) {
191		$current = &$this->head;
192		$i = 0;
193
194		if($this->head === null) {
195		return null;
196		}
197
198		if($this->head->data === $data) {
199		$this->head = &$this->head->next;
200		$this->head->prev = &$this->tail;
201		$this->size--;
202
203		return $data;
204		}
205
206	View Code Duplication	while($i < $this->size) {
		0 ignored issues – show Duplication introduced 2017-07-13 14:42 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
207		if($current->data === $data) {
208		$current->prev = &$current->next;
209		$current = null;
210		$this->size--;
211		return $data;
212		}
213
214		$current = $current->next;
215		}
216
217		return null;
218		}
219
220		/**
221		* Generator for retrieve all nodes stored.
222		*
223		* @return null if the head is null (or list is empty)
224		*/
225	View Code Duplication	public function getAll() {
		0 ignored issues – show Duplication introduced 2017-06-05 14:14 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
226		if($this->head === null) {
227		return;
228		}
229
230		if($this->head === $this->tail) {
231		yield $this->head->data;
232		} else {
233		$current = $this->head;
234		$i = 0;
235		while($i < $this->size) {
236		yield $current->data;
237		$current = $current->next;
238		$i++;
239		}
240		}
241		}
242
243		/**
244		* {@inheritDoc}
245		*/
246		protected function insertBeginning($data) {
247		$newNode = new DoublyLinkedListNode($data);
248		if($this->head === null) {
249		$newNode->next = &$this->head;
250		$newNode->prev = &$this->head;
251		$this->head = &$newNode;
252		$this->tail = &$newNode;
253		} else {
254		$this->tail->next = &$newNode;
255		$newNode->next = &$this->head;
256		$newNode->prev = &$this->tail;
257		$this->head = &$newNode;
258		}
259		}
260
261		protected function insertEnd($data) {
262		$newNode = new DoublyLinkedListNode($data);
263		$this->tail->next = &$newNode;
264		$newNode->next = &$this->head;
265		$newNode->prev = &$this->tail;
266		$this->tail = &$newNode;
267		$this->head->prev = &$newNode;
268		}
269
270		/**
271		* Add a new node in the specified index.
272		*
273		* @param integer $index the position.
274		* @param mixed $data the data to be stored.
275		*/
276		protected function insertAt($index, $data) {
277		$newNode = new DoublyLinkedListNode($data);
278		$current = $this->head;
279		$prev = null;
280		$i = 0;
281		while($i < $index) {
282		$prev = $current;
283		$current = $current->next;
284		$i++;
285		}
286
287		$prev->next = &$newNode;
288		$newNode->prev = &$prev;
289		$newNode->next = &$current;
290		$current->prev = &$newNode;
291		}
292
293		/**
294		* Deletes at the beginnig of the list and returns the data stored.
295		*
296		* @return mixed the data stored in the node.
297		*/
298	View Code Duplication	protected function deleteBeginning() {
		0 ignored issues – show Duplication introduced 2017-06-05 14:14 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
299		// if only there is an element
300		if($this->head->next === $this->head) {
301		$temp = $this->head;
302		$this->head = null;
303		} else {
304		$temp = $this->head;
305		$this->head = &$this->head->next;
306		$this->tail->next = &$this->head;
307
308		}
309		return $temp->data;
310		}
311
312		/**
313		* Deletes at the specified position and returns the data stored.
314		*
315		* @param integer $index the position.
316		* @return mixed the data stored in the node.
317		*/
318		protected function deleteAt($index) {
319		$i = 0;
320		$prev = $this->head;
321		$current = $this->head;
322
323		while($i < $index) {
324		$prev = $current;
325		$current = $current->next;
326		$i++;
327		}
328
329		$temp = $current;
330		$prev->next = &$current->next;
331		$current->next->prev = &$pre;
		0 ignored issues – show Bug introduced 2017-06-05 14:14 UTC by Report Bug Copy Issue Report The variable `$pre` does not exist. Did you forget to declare it? This check marks access to variables or properties that have not been declared yet. While PHP has no explicit notion of declaring a variable, accessing it before a value is assigned to it is most likely a bug. Loading history...
332		$current = null;
		0 ignored issues – show Unused Code introduced 2017-06-05 14:14 UTC by Report Bug Copy Issue Report `$current` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history...
333
334		return $temp->data;
335		}
336
337		/**
338		* Deletes at the end of the list and returns the data stored.
339		*
340		* @return mixed the data stored in the node.
341		*/
342	View Code Duplication	protected function deleteEnd() {
		0 ignored issues – show Duplication introduced 2017-06-05 14:14 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
343		$prev = $this->head;
344		$current = $this->head;
345
346		while($current !== $this->tail) {
347		$prev = $current;
348		$current = $current->next;
349		}
350
351		$temp = $current;
352		$prev->next = &$this->head;
353		$this->head->prev = &$prev;
354		$this->tail = &$prev;
355		$current = null;
		0 ignored issues – show Unused Code introduced 2017-06-05 14:14 UTC by Report Bug Copy Issue Report `$current` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history...
356
357		return $temp->data;
358		}
359
360		/**
361		* Reset the cursor position.
362		*/
363		public function rewind() {
364		$this->position = 0;
365		$this->current = &$this->head;
366		}
367
368		/**
369		* Returns the current node data.
370		*
371		* @return mixed
372		*/
373		public function current() {
374		return $this->current->data;
375		}
376
377		/**
378		* Key or index that indicates the cursor position.
379		*
380		* @return integer The current position.
381		*/
382		public function key() {
383		return $this->position;
384		}
385
386		/**
387		* Move the cursor to the next node and increments the
388		* position counter.
389		*/
390		public function next() {
391		++$this->position;
392		$this->current = $this->current->next;
393		}
394
395		/**
396		* Returns if the current pointer position is valid.
397		*
398		* @return boolean true if pointer is not last, else false.
399		*/
400		public function valid() {
401		return $this->position < $this->size;
402		}
403		}

SiroDiaz / DataStructures

Push — master ( f77e5d...e03d70 )

DoublyLinkedList::contains() A

Complexity

Size

Duplication

Importance

Duplication Side-by-Side

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