Array collection

Author: AydinHassan

src/Util/ArrayUtils.php

@@ -16,6 +16,13 @@ function mapWithKeys(array $array, callable $callback) : array
     return $arr;
 }
 
+function filter(array $array, callable $callback) : array
+{
+    return array_filter($array, function ($v, $k) use ($callback) {
+        return $callback($k, $v);
+    }, ARRAY_FILTER_USE_BOTH);
+}
+
 function each(array $array, callable $callback) : void
 {
     foreach ($array as $k => $v) {
@@ -27,3 +34,8 @@ function max(array $items) : int
 {
     return count($items) > 0 ? \max($items) : 0;
 }
+
+function collect(array $items) : Collection
+{
+    return new Collection($items);
+}

src/Util/Collection.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpSchool\CliMenu\Util;
+
+class Collection
+{
+    /**
+     * @var array
+     */
+    private $items;
+
+    public function __construct(array $items)
+    {
+        $this->items = $items;
+    }
+
+    public function map(callable $cb) : self
+    {
+        return new self(mapWithKeys($this->items, $cb));
+    }
+
+    public function filter(callable $cb) : self
+    {
+        return new self(filter($this->items, $cb));
+    }
+
+    public function values() : self
+    {
+        return new self(array_values($this->items));
+    }
+
+    public function each(callable $cb) : self
+    {
+        each($this->items, $cb);
+
+        return $this;
+    }
+
+    public function all() : array
+    {
+        return $this->items;
+    }
+}

test/Util/ArrayUtilTest.php

@@ -6,7 +6,9 @@
 
 use PhpSchool\CliMenu\Util\ArrayUtil;
 use PHPUnit\Framework\TestCase;
+use function PhpSchool\CliMenu\Util\collect;
 use function PhpSchool\CliMenu\Util\each;
+use function PhpSchool\CliMenu\Util\filter;
 use function PhpSchool\CliMenu\Util\mapWithKeys;
 use function PhpSchool\CliMenu\Util\max;
 
@@ -55,4 +57,18 @@ public function testMax() : void
         self::assertEquals(3, max([1, 2, 3]));
         self::assertEquals(6, max([1, 6, 3]));
     }
+
+    public function testFilter() : void
+    {
+        $cb = function (int $k, int $v) {
+            return $v > 3;
+        };
+
+        self::assertEquals([3 => 4, 4 => 5, 5 => 6], filter([1, 2, 3, 4, 5, 6], $cb));
+    }
+
+    public function testCollect() : void
+    {
+        self::assertEquals([1, 2, 3], collect([1, 2, 3])->all());
+    }
 }

test/Util/CollectionTest.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpSchool\CliMenuTest\Util;
+
+use PhpSchool\CliMenu\Util\Collection;
+use PHPUnit\Framework\TestCase;
+
+class CollectionTest extends TestCase
+{
+    public function testCollection() : void
+    {
+        $result = (new Collection([1, 2, 3, 4, 5, 6]))
+            ->filter(function ($k, $v) {
+                return $v > 3;
+            })
+            ->values()
+            ->map(function ($k, $v) {
+                return $v * 2;
+            })
+            ->all();
+
+        self::assertEquals([8, 10, 12], $result);
+    }
+}