Update fromArrays() to return Iterator

README.md

@@ -12,6 +12,7 @@
 - create all combinations `of N` elements
 - create all combinations `of A 2 B` elements
 - create all combinations between multiple arrays
+- be used in data provider of PHPUnit
 
 ## 2. Contents
 - [1. Features](#1-features)
@@ -119,16 +120,15 @@ It will never exceeds the memory limit, and certainly complete the task.
 - `pairs()`: returns all pairs of the param
 - `ofN()`: returns all combinations of N elements of the param
 - `ofA2B()`: returns all combinations of A to B elements of the param
-- `fromArrays()`: returns all combinations of multiple arrays
-
-  `fromArrays()` is only implemented in `Combination` class.
+- `fromArrays()`: returns all combinations of multiple arrays as an instance of `Iterator`.
 
 ### 6.2. Macocci7\PhpCombination\CombinationGenenrator
 
 - `all()`: returns all combinations of the param
 - `pairs()`: returns all pairs of the param
 - `ofN()`: returns all combinations of N elements of the param
 - `ofA2B()`: returns all combinations of A to B elements of the param
+- `fromArrays()`: returns all combinations of multiple arrays as an instance of `Iterator`.
 
 ## 7. Limit on the Number of Array Elements
 
@@ -290,8 +290,9 @@ The max index number of array in PHP equals to `PHP_INT_MAX`.
     echo sprintf("\tArray3: (%s)\n", implode(', ', $a3));
 
     $r = $c->fromArrays([$a1, $a2, $a3, ]);
-    $n = strlen((string) count($r));
-    echo sprintf("\tThere're %d patterns:\n", count($r));
+    $count = count($a1) * count($a2) * count($a3);
+    $n = strlen((string) $count);
+    echo sprintf("\tThere're %d patterns:\n", $count);
     foreach ($r as $i => $e) {
         echo sprintf("\t%" . $n . "d: (%s)\n", $i + 1, implode(', ', $e));
     }
@@ -475,8 +476,9 @@ The max index number of array in PHP equals to `PHP_INT_MAX`.
     echo sprintf("\tArray3: (%s)\n", implode(', ', $a3));
 
     $r = $c->fromArrays([$a1, $a2, $a3, ]);
-    $n = strlen((string) count($r));
-    echo sprintf("\tThere're %d patterns:\n", count($r));
+    $count = count($a1) * count($a2) * count($a3);
+    $n = strlen((string) $count);
+    echo sprintf("\tThere're %d patterns:\n", $count);
     foreach ($r as $i => $e) {
         echo sprintf("\t%" . $n . "d: (%s)\n", $i + 1, implode(', ', $e));
     }
@@ -648,6 +650,24 @@ The max index number of array in PHP equals to `PHP_INT_MAX`.
         echo sprintf($fmt, implode(', ', $e));
     }
     echo "\n";
+
+    // All Combinations of $a1, $a2 and $a3
+    $a1 = [ 'A1', 'A2', ];
+    $a2 = [ 'B1', 'B2', 'B3', ];
+    $a3 = [ 'C1', 'C2', 'C3', 'C4', ];
+
+    echo "All Combinations of multiple arrays:\n";
+    echo sprintf("\tArray1: (%s)\n", implode(', ', $a1));
+    echo sprintf("\tArray2: (%s)\n", implode(', ', $a2));
+    echo sprintf("\tArray3: (%s)\n", implode(', ', $a3));
+
+    $r = $c->fromArrays([$a1, $a2, $a3, ]);
+    $count = count($a1) * count($a2) * count($a3);
+    $n = strlen((string) $count);
+    echo sprintf("\tThere're %d patterns:\n", $count);
+    foreach ($r as $i => $e) {
+        echo sprintf("\t%" . $n . "d: (%s)\n", $i + 1, implode(', ', $e));
+    }
     ```
 
 - Result:
@@ -730,6 +750,35 @@ The max index number of array in PHP equals to `PHP_INT_MAX`.
         (B, D, E)
         (C, D, E)
 
+    All Combinations of multiple arrays:
+        Array1: (A1, A2)
+        Array2: (B1, B2, B3)
+        Array3: (C1, C2, C3, C4)
+        There're 24 patterns:
+        1: (A1, B1, C1)
+        2: (A1, B1, C2)
+        3: (A1, B1, C3)
+        4: (A1, B1, C4)
+        5: (A1, B2, C1)
+        6: (A1, B2, C2)
+        7: (A1, B2, C3)
+        8: (A1, B2, C4)
+        9: (A1, B3, C1)
+        10: (A1, B3, C2)
+        11: (A1, B3, C3)
+        12: (A1, B3, C4)
+        13: (A2, B1, C1)
+        14: (A2, B1, C2)
+        15: (A2, B1, C3)
+        16: (A2, B1, C4)
+        17: (A2, B2, C1)
+        18: (A2, B2, C2)
+        19: (A2, B2, C3)
+        20: (A2, B2, C4)
+        21: (A2, B3, C1)
+        22: (A2, B3, C2)
+        23: (A2, B3, C3)
+        24: (A2, B3, C4)
     ```
 
 ### 8.5. Using In PHPUnit
@@ -931,6 +980,6 @@ with patterns of `size`, `color` and `amount`.
 
 *Document Created: 2023/11/11*
 
-*Document Updated: 2024/04/17*
+*Document Updated: 2024/05/15*
 
 Copyright 2023 - 2024 macocci7

composer.json

@@ -1,6 +1,6 @@
 {
     "name": "macocci7/php-combination",
-    "version": "1.0.5",
+    "version": "1.1.0",
     "description": "a simple PHP library to make combinations",
     "type": "library",
     "license": "MIT",

examples/UseCombination.php

@@ -57,8 +57,9 @@
 echo sprintf("\tArray3: (%s)\n", implode(', ', $a3));
 
 $r = $c->fromArrays([$a1, $a2, $a3, ]);
-$n = strlen((string) count($r));
-echo sprintf("\tThere're %d patterns:\n", count($r));
+$count = count($a1) * count($a2) * count($a3);
+$n = strlen((string) $count);
+echo sprintf("\tThere're %d patterns:\n", $count);
 foreach ($r as $i => $e) {
     echo sprintf("\t%" . $n . "d: (%s)\n", $i + 1, implode(', ', $e));
 }

examples/UseCombinationGenerator.php

@@ -48,3 +48,21 @@
     echo sprintf($fmt, implode(', ', $e));
 }
 echo "\n";
+
+// All Combinations of $a1, $a2 and $a3
+$a1 = [ 'A1', 'A2', ];
+$a2 = [ 'B1', 'B2', 'B3', ];
+$a3 = [ 'C1', 'C2', 'C3', 'C4', ];
+
+echo "All Combinations of multiple arrays:\n";
+echo sprintf("\tArray1: (%s)\n", implode(', ', $a1));
+echo sprintf("\tArray2: (%s)\n", implode(', ', $a2));
+echo sprintf("\tArray3: (%s)\n", implode(', ', $a3));
+
+$r = $c->fromArrays([$a1, $a2, $a3, ]);
+$count = count($a1) * count($a2) * count($a3);
+$n = strlen((string) $count);
+echo sprintf("\tThere're %d patterns:\n", $count);
+foreach ($r as $i => $e) {
+    echo sprintf("\t%" . $n . "d: (%s)\n", $i + 1, implode(', ', $e));
+}

examples/UseCombinationGenerator.txt

@@ -75,3 +75,32 @@ All Combinations of 3 to 4 elements:
 	(B, D, E)
 	(C, D, E)
 
+All Combinations of multiple arrays:
+	Array1: (A1, A2)
+	Array2: (B1, B2, B3)
+	Array3: (C1, C2, C3, C4)
+	There're 24 patterns:
+	 1: (A1, B1, C1)
+	 2: (A1, B1, C2)
+	 3: (A1, B1, C3)
+	 4: (A1, B1, C4)
+	 5: (A1, B2, C1)
+	 6: (A1, B2, C2)
+	 7: (A1, B2, C3)
+	 8: (A1, B2, C4)
+	 9: (A1, B3, C1)
+	10: (A1, B3, C2)
+	11: (A1, B3, C3)
+	12: (A1, B3, C4)
+	13: (A2, B1, C1)
+	14: (A2, B1, C2)
+	15: (A2, B1, C3)
+	16: (A2, B1, C4)
+	17: (A2, B2, C1)
+	18: (A2, B2, C2)
+	19: (A2, B2, C3)
+	20: (A2, B2, C4)
+	21: (A2, B3, C1)
+	22: (A2, B3, C2)
+	23: (A2, B3, C3)
+	24: (A2, B3, C4)

examples/UseCombinationSort.php

@@ -60,8 +60,9 @@
 echo sprintf("\tArray3: (%s)\n", implode(', ', $a3));
 
 $r = $c->fromArrays([$a1, $a2, $a3, ]);
-$n = strlen((string) count($r));
-echo sprintf("\tThere're %d patterns:\n", count($r));
+$count = count($a1) * count($a2) * count($a3);
+$n = strlen((string) $count);
+echo sprintf("\tThere're %d patterns:\n", $count);
 foreach ($r as $i => $e) {
     echo sprintf("\t%" . $n . "d: (%s)\n", $i + 1, implode(', ', $e));
 }

src/Combination.php

@@ -3,6 +3,7 @@
 namespace Macocci7\PhpCombination;
 
 use Macocci7\PhpCombination\Util;
+use Macocci7\PhpCombination\CombinationTrait;
 
 /**
  * Class for generating combinations.
@@ -11,6 +12,8 @@
  */
 class Combination
 {
+    use CombinationTrait;
+
     /**
      * returns all combinations from single array.
      * returns sorted array when the second param is set as true.
@@ -124,44 +127,4 @@ public function ofA2B(array $items, int $a, int $b, bool $sort = false)
         }
         return $combinations;
     }
-
-    /**
-     * returns all combinations from arrays
-     * @param   list<array<int, int|float|string>>  $arrays     each elements must be array.
-     * @return  array<int, array<int, int|float|string>>
-     * @thrown  \Exception
-     */
-    public function fromArrays(array $arrays): array
-    {
-        // validate
-        Util::validateArrays($arrays);
-        // initialize
-        $combinations = [];
-        // make combinations
-        foreach ($arrays[0] as $a) {
-            $this->makeCombinationsRecursive([$a], $arrays, $combinations);
-        }
-        return $combinations;
-    }
-
-    /**
-     * makes combinations recusively
-     * @param   array<int, int|float|string>        $a
-     * @param   list<array<int, int|float|string>>  &$arrays
-     * @param   array<int, int|float|string>        &$combinations
-     * @return  void
-     */
-    private function makeCombinationsRecursive($a, &$arrays, &$combinations)
-    {
-        $countA = count($a);
-        if ($countA < count($arrays)) {
-            foreach ($arrays[$countA] as $b) {
-                $c = $a;
-                $c[] = $b;
-                $this->makeCombinationsRecursive($c, $arrays, $combinations);
-            }
-        } else {
-            $combinations[] = $a;
-        }
-    }
 }

src/CombinationGenerator.php

@@ -3,6 +3,7 @@
 namespace Macocci7\PhpCombination;
 
 use Macocci7\PhpCombination\Util;
+use Macocci7\PhpCombination\CombinationTrait;
 
 /**
  * Class for generating combinations with Generator.
@@ -11,6 +12,8 @@
  */
 class CombinationGenerator
 {
+    use CombinationTrait;
+
     /**
      * returns all combinations
      * @param   array<int, int|float|string>    $items

src/CombinationIterator.php

@@ -0,0 +1,107 @@
+<?php
+
+namespace Macocci7\PhpCombination;
+
+/**
+ * Class for generating combinations with Iterator.
+ *
+ * @implements \Iterator<int, mixed>
+ * @author  macocci7 <[email protected]>
+ * @license MIT
+ */
+class CombinationIterator implements \Iterator
+{
+    /**
+     * @var mixed[] $arrays
+     */
+    private array $arrays;
+
+    /**
+     * @var int[]|null  $pointers
+     */
+    private array|null $pointers = null;
+
+    /**
+     * @var int $key
+     */
+    private int $key;
+
+    /**
+     * constructor
+     *
+     * @param   array<array<int, mixed[]>>  $arrays
+     */
+    public function __construct(array $arrays)
+    {
+        $this->arrays = $arrays;
+        $this->pointers = array_fill(0, count($arrays), 0);
+        $this->key = 0;
+    }
+
+    /**
+     * returns current element
+     *
+     * @return  mixed
+     */
+    public function current(): mixed
+    {
+        $result = [];
+        foreach ($this->pointers as $arrayIndex => $elementIndex) {
+            $result[] = $this->arrays[$arrayIndex][$elementIndex] ?? null;
+        }
+        return $result;
+    }
+
+    /**
+     * returns current key.
+     *
+     * @return  int
+     */
+    public function key(): int
+    {
+        return $this->key;
+    }
+
+    /**
+     * advances the pointer one step.
+     */
+    public function next(): void
+    {
+        for ($i = count($this->pointers) - 1; $i >= 0; $i--) {
+            if ($this->pointers[$i] < count($this->arrays[$i]) - 1) {
+                $this->pointers[$i]++;
+                // 繰り上げた位より下位の位をゼロにセット
+                // 1199 + 1 = 1200
+                //  ^           ^^
+                $count = count($this->pointers);
+                for ($j = $i + 1; $j < $count; $j++) {
+                    $this->pointers[$j] = 0;
+                }
+                $this->key++;
+                return;
+            }
+        }
+        $this->pointers = null;
+    }
+
+    /**
+     * rewinds the pointers and the key.
+     *
+     * @return  void
+     */
+    public function rewind(): void
+    {
+        $this->pointers = array_fill(0, count($this->arrays), 0);
+        $this->key = 0;
+    }
+
+    /**
+     * returns if the pointers are valid.
+     *
+     * @return  bool
+     */
+    public function valid(): bool
+    {
+        return $this->pointers !== null;
+    }
+}