Added two factory methods.

Author: Six

README.md

@@ -23,9 +23,17 @@ use Blibio\Combinatorics\Combinatorics;
 
 $elements = ['A', 'B', 'C', 'D'];
 $k = 3;
-$it = Combinatorics::combinationsWithoutRepetition($elements, $k);
+
+// Using the boolean parameter:
+$it = Combinatorics::combinations($elements, $k, withRepetition: false);
 
 // or:
+// $it = Combinatorics::combinations($elements, $k, withRepetition: true);
+// $it = Combinatorics::permutations($elements, $k, withRepetition: false);
+// $it = Combinatorics::permutations($elements, $k, withRepetition: true);
+
+// Using the explicit method names:
+// $it = Combinatorics::combinationsWithoutRepetition($elements, $k);
 // $it = Combinatorics::combinationsWithRepetition($elements, $k);
 // $it = Combinatorics::permutationsWithoutRepetition($elements, $k);
 // $it = Combinatorics::permutationsWithRepetition($elements, $k);

src/Combinatorics.php

@@ -6,6 +6,23 @@
 
 final readonly class Combinatorics
 {
+    /**
+     * @template U
+     *
+     * @param array<array-key, U> $elements
+     * @param int<1, max>         $k
+     *
+     * @return ($withRepetition is true ? Combination\WithRepetition<U> : Combination\WithoutRepetition<U>)
+     *
+     * @throws \InvalidArgumentException
+     */
+    public static function combinations(array $elements, int $k, bool $withRepetition): Combination\WithRepetition|Combination\WithoutRepetition
+    {
+        return $withRepetition
+            ? new Combination\WithRepetition($elements, $k)
+            : new Combination\WithoutRepetition($elements, $k);
+    }
+
     /**
      * @template U
      *
@@ -36,6 +53,23 @@ public static function combinationsWithoutRepetition(array $elements, int $k): C
         return new Combination\WithoutRepetition($elements, $k);
     }
 
+    /**
+     * @template U
+     *
+     * @param array<array-key, U> $elements
+     * @param int<1, max>         $k
+     *
+     * @return ($withRepetition is true ? Permutation\WithRepetition<U> : Permutation\WithoutRepetition<U>)
+     *
+     * @throws \InvalidArgumentException
+     */
+    public static function permutations(array $elements, int $k, bool $withRepetition): Permutation\WithRepetition|Permutation\WithoutRepetition
+    {
+        return $withRepetition
+            ? new Permutation\WithRepetition($elements, $k)
+            : new Permutation\WithoutRepetition($elements, $k);
+    }
+
     /**
      * @template U
      *

tests/CombinatoricsTest.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Blibio\Combinatorics\Test;
+
+use Blibio\Combinatorics\Combination;
+use Blibio\Combinatorics\Combinatorics;
+use Blibio\Combinatorics\Permutation;
+use PHPUnit\Framework\TestCase;
+
+final class CombinatoricsTest extends TestCase
+{
+    public function testCombinationsWithRepetitionFromFlag(): void
+    {
+        $elements = ['A', 'B'];
+        $k = 2;
+
+        $result = Combinatorics::combinations($elements, $k, withRepetition: true);
+        $expected = Combinatorics::combinationsWithRepetition($elements, $k);
+
+        self::assertEquals(iterator_to_array($expected), iterator_to_array($result));
+        self::assertInstanceOf(Combination\WithRepetition::class, $result);
+    }
+
+    public function testCombinationsWithoutRepetitionFromFlag(): void
+    {
+        $elements = ['A', 'B', 'C'];
+        $k = 2;
+
+        $result = Combinatorics::combinations($elements, $k, withRepetition: false);
+        $expected = Combinatorics::combinationsWithoutRepetition($elements, $k);
+
+        self::assertEquals(iterator_to_array($expected), iterator_to_array($result));
+        self::assertInstanceOf(Combination\WithoutRepetition::class, $result);
+    }
+
+    public function testPermutationsWithRepetitionFromFlag(): void
+    {
+        $elements = ['A', 'B'];
+        $k = 2;
+
+        $result = Combinatorics::permutations($elements, $k, withRepetition: true);
+        $expected = Combinatorics::permutationsWithRepetition($elements, $k);
+
+        self::assertEquals(iterator_to_array($expected), iterator_to_array($result));
+        self::assertInstanceOf(Permutation\WithRepetition::class, $result);
+    }
+
+    public function testPermutationsWithoutRepetitionFromFlag(): void
+    {
+        $elements = ['A', 'B', 'C'];
+        $k = 2;
+
+        $result = Combinatorics::permutations($elements, $k, withRepetition: false);
+        $expected = Combinatorics::permutationsWithoutRepetition($elements, $k);
+
+        self::assertEquals(iterator_to_array($expected), iterator_to_array($result));
+        self::assertInstanceOf(Permutation\WithoutRepetition::class, $result);
+    }
+}