Initial commit

Author: benvilliere

README.md

@@ -8,6 +8,30 @@ Linked List implementation in PHP.
 composer require angle/linked
 ```
 
+## Usage
+
+Creating an empty list and appending items.
+```php
+$list = new Angle\Linked\Linked;
+$list->append('PHP');
+$list->append('Ruby');
+$list->append('Javascript');
+
+print $list->head->next->next->data; // Javascript
+```
+
+Prepend elements to the list:
+```php
+$list->prepend('Golang');
+
+print $list->head->data; // Golang
+```
+
+Print the list:
+```php
+print $list; // Golang, PHP, Ruby, Javascript
+```
+
 ## Contributing
 
 Improvements are welcome! Feel free to submit pull requests.

composer.json

@@ -1,6 +1,6 @@
 {
     "name": "angle/linked",
-    "description": "Composer Package Template",
+    "description": "Linked List implementation in PHP.",
     "type": "library",
     "license": "MIT",
     "authors": [

src/Linked.php

@@ -0,0 +1,98 @@
+<?php
+
+namespace Angle\Linked;
+
+use Angle\Linked\Node;
+
+class Linked
+{
+    /** @var Node */
+    public $head = null;
+
+    /**
+     * Creates a list with a give set of nodes.
+     * @param array $nodes
+     */
+    public function __construct(...$nodes)
+    {
+        foreach ($nodes as $node) {
+            $this->append($node);
+        }
+    }
+
+    /**
+     * Appends a node to the linked list.
+     * @param mixed $data
+     */
+    public function append($data): void
+    {
+        if ($this->head == null) {
+            $this->head = new Node($data);
+            return;
+        }
+
+        $current = $this->head;
+
+        while ($current->next != null) {
+            $current = $current->next;
+        }
+
+        $current->next = new Node($data);
+    }
+
+    /**
+     * Prepends a node to the head of the list.
+     * @param mixed $data
+     */
+    public function prepend($data): void
+    {
+        $newHead = new Node($data);
+        $newHead->next = $this->head;
+        $this->head = $newHead;
+    }
+
+    /**
+     * Deletes a node matching the given data.
+     * @param mixed $data
+     */
+    public function delete($data): void
+    {
+        if ($this->head == null) {
+            return;
+        }
+
+        if ($this->head->data == $data) {
+            $this->head = $this->head->next;
+            return;
+        }
+
+        $current = $this->head;
+
+        while ($current->next != null) {
+            if ($current->next->data == $data) {
+                $current->next = $current->next->next;
+                return;
+            }
+
+            $current = $current->next;
+        }
+    }
+
+    public function __toString()
+    {
+        $current = $this->head;
+        $string = '';
+
+        while ($current != null) {
+            $string .= $current->data;
+
+            if ($current->next != null) {
+                $string .= ', ';
+            }
+
+            $current = $current->next;
+        }
+
+        return $string;
+    }
+}

src/Node.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Angle\Linked;
+
+class Node
+{
+    /** @var Node */
+    public $next;
+
+    /** @var mixed */
+    public $data;
+
+    /** @param mixed $data */
+    public function __construct($data)
+    {
+        $this->data = $data;
+    }
+}

src/Package.php

@@ -0,0 +1,72 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+use Angle\Linked\Linked;
+use Angle\Linked\Node;
+
+class LinkedTest extends TestCase
+{
+    /** @var Linked */
+    public $list;
+
+    public function setUp() : void
+    {
+        $this->list = new Linked;
+        $this->list->append('PHP');
+        $this->list->append('Ruby');
+        $this->list->append('Javascript');
+    }
+
+    /** @test */
+    public function canCreateSingleNode()
+    {
+        $item = new Node('I <3 programming.');
+
+        $this->assertTrue($item->data === 'I <3 programming.');
+    }
+
+    /** @test */
+    public function nodesWereAppended()
+    {
+        $this->assertTrue($this->list->head->next->next->data == 'Javascript');
+    }
+
+    /** @test */
+    public function nodesCanBePrepended()
+    {
+        $this->list->prepend('Golang');
+
+        $this->assertTrue($this->list->head->data == 'Golang');
+    }
+
+    /** @test */
+    public function listCanBeConvertedToString()
+    {
+        $expected = 'Golang, PHP, Ruby, Javascript';
+
+        $this->list->prepend('Golang');
+
+        print $this->list;
+
+        $this->expectOutputString($expected);
+
+        $this->assertTrue($expected == (string) $this->list);
+    }
+
+    /** @test */
+    public function listCanBeCreatedWithNodes()
+    {
+        $list = new Linked('Laravel', 'Symfony', 'Rails');
+
+        $this->assertTrue($list->head->next->next->data == 'Rails');
+    }
+
+    /** @test */
+    public function aListCanContainAnything()
+    {
+        $list = new Linked(['some' => 'array'], 42, new stdClass);
+
+        $this->assertTrue($list->head->next->data == 42);
+    }
+}