add array pack

src/functions.php

@@ -118,6 +118,36 @@ function arrayFromKey(array $array, string|int ...$key): array
     return (new ArrayStandard($array))->fromKey(...$key);
 }
 
+/**
+ * Takes packing instruction and generates sub-arrays with matched keys.
+ * @param string ...$packing Named packing as `startNeedle: 'grouping',`
+ * @phpstan-ignore-next-line
+ */
+function arrayPack(array $array, string ...$packing): array
+{
+    $return = $array;
+    $trash = [];
+    $keys = array_keys($array);
+    foreach ($packing as $split => $group) {
+        $split = (string) $split;
+        $find = array_filter($keys, function ($key) use ($split) {
+            return strpos($key, $split) === 0;
+        });
+        if ($find === []) {
+            continue;
+        }
+        $return[$group] = [];
+        foreach ($find as $key) {
+            $key = (string) $key;
+            $trash[] = $key;
+            $groupedKey = (string) str_replace($split, '', $key);
+            $return[$group][$groupedKey] = $array[$key];
+        }
+    }
+
+    return arrayUnsetKey($return, ...$trash);
+}
+
 function randomString(int $length): string
 {
     // @phpstan-ignore-next-line

tests/ArrayPackTest.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of Chevere.
+ *
+ * (c) Rodolfo Berrios <rodolfo@chevere.org>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Chevere\Tests;
+
+use PHPUnit\Framework\TestCase;
+use function Chevere\Standard\arrayPack;
+
+final class ArrayPackTest extends TestCase
+{
+    public function testNoPacking(): void
+    {
+        $array = [
+            'a_id' => 1,
+            'b_num' => 2,
+            'c_val' => 3,
+        ];
+        $packed = arrayPack($array);
+        $this->assertSame($array, $packed);
+    }
+
+    public function testPacking(): void
+    {
+        $array = [
+            'a_id' => null,
+            'b_num' => 2,
+            'c_val' => 3,
+        ];
+        $expected = [
+            'a' => [
+                'id' => null,
+            ],
+            'b' => [
+                'num' => 2,
+            ],
+            'c' => [
+                'val' => 3,
+            ],
+        ];
+        $packed = arrayPack($array, a_: 'a', b_: 'b', c_: 'c');
+        $this->assertSame($expected, $packed);
+    }
+}