change CartesianProduct to be associative

Author: chx

Combinatorics/Combination/CartesianProduct.php

@@ -9,6 +9,7 @@
  * New BSD License
  *
  * Copyright © 2007-2015, Ivan Enderlin. All rights reserved.
+ * Copyright © 2007-2015, Karoly Negyesi. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -70,6 +71,13 @@ class CartesianProduct implements Iterator {
      */
     protected $_max     = 0;
 
+    /**
+     * array_keys() of the input array.
+     *
+     * @var array
+     */
+    protected $_keys = [];
+
     /**
      * Key.
      *
@@ -97,13 +105,13 @@ class CartesianProduct implements Iterator {
      * Constructor.
      *
      * @access  public
-     * @param   \Traversable  $set    Set.
-     * @param   …             …       …
+     * @param   \Traversable  $sets    Sets.
      * @return  void
      */
-    public function __construct ( $set ) {
+    public function __construct ( $sets ) {
 
-        foreach(func_get_args() as $s) {
+        $this->_keys = array_keys($sets);
+        foreach($sets as $s) {
 
             if(is_array($s))
                 $s = new Iterator\Map($s);
@@ -140,8 +148,8 @@ protected function _current ( ) {
 
         $this->_current = [];
 
-        foreach($this->_sets as $set)
-            $this->_current[] = $set->current();
+        foreach($this->_sets as $i => $set)
+            $this->_current[$this->_keys[$i]] = $set->current();
 
         return;
     }

Test/Unit/Combinatorics/Combination/CartesianProduct.php

@@ -64,7 +64,7 @@ public function case_empty ( ) {
     public function case_X ( ) {
 
         $this
-            ->given($iterator = new CUT([1, 2, 3]))
+            ->given($iterator = new CUT([[1], [2], [3]]))
             ->when($result = iterator_to_array($iterator))
             ->then
                 ->array($result)
@@ -78,62 +78,59 @@ public function case_X ( ) {
     public function case_X_Y ( ) {
 
         $this
-            ->given($iterator = new CUT([1, 2, 3], [4, 5, 6]))
+            ->given($iterator = new CUT(['X' => [1, 2, 3], 'Y' => [4, 5, 6]]))
             ->when($result = iterator_to_array($iterator))
             ->then
                 ->array($result)
                     ->isEqualTo([
-                        [1, 4],
-                        [2, 4],
-                        [3, 4],
-
-                        [1, 5],
-                        [2, 5],
-                        [3, 5],
-
-                        [1, 6],
-                        [2, 6],
-                        [3, 6]
+                        ['X' => 1, 'Y' => 4],
+                        ['X' => 2, 'Y' => 4],
+                        ['X' => 3, 'Y' => 4],
+                        ['X' => 1, 'Y' => 5],
+                        ['X' => 2, 'Y' => 5],
+                        ['X' => 3, 'Y' => 5],
+                        ['X' => 1, 'Y' => 6],
+                        ['X' => 2, 'Y' => 6],
+                        ['X' => 3, 'Y' => 6]
                     ]);
     }
 
-    public function case_X_Y_Z ( ) {
 
+    public function case_X_Y_Z ( ) {
         $this
-            ->given($iterator = new CUT([1, 2, 3], [4, 5, 6], [7, 8, 9]))
+            ->given($iterator = new CUT(['X' => [1, 2, 3], 'Y' => [4, 5, 6], 'Z' => [7, 8, 9]]))
             ->when($result = iterator_to_array($iterator))
             ->then
                 ->array($result)
                     ->isEqualTo([
-                        [1, 4, 7],
-                        [2, 4, 7],
-                        [3, 4, 7],
-                        [1, 5, 7],
-                        [2, 5, 7],
-                        [3, 5, 7],
-                        [1, 6, 7],
-                        [2, 6, 7],
-                        [3, 6, 7],
-
-                        [1, 4, 8],
-                        [2, 4, 8],
-                        [3, 4, 8],
-                        [1, 5, 8],
-                        [2, 5, 8],
-                        [3, 5, 8],
-                        [1, 6, 8],
-                        [2, 6, 8],
-                        [3, 6, 8],
-
-                        [1, 4, 9],
-                        [2, 4, 9],
-                        [3, 4, 9],
-                        [1, 5, 9],
-                        [2, 5, 9],
-                        [3, 5, 9],
-                        [1, 6, 9],
-                        [2, 6, 9],
-                        [3, 6, 9]
+                        ['X' => 1, 'Y' => 4, 'Z' => 7],
+                        ['X' => 2, 'Y' => 4, 'Z' => 7],
+                        ['X' => 3, 'Y' => 4, 'Z' => 7],
+                        ['X' => 1, 'Y' => 5, 'Z' => 7],
+                        ['X' => 2, 'Y' => 5, 'Z' => 7],
+                        ['X' => 3, 'Y' => 5, 'Z' => 7],
+                        ['X' => 1, 'Y' => 6, 'Z' => 7],
+                        ['X' => 2, 'Y' => 6, 'Z' => 7],
+                        ['X' => 3, 'Y' => 6, 'Z' => 7],
+                        ['X' => 1, 'Y' => 4, 'Z' => 8],
+                        ['X' => 2, 'Y' => 4, 'Z' => 8],
+                        ['X' => 3, 'Y' => 4, 'Z' => 8],
+                        ['X' => 1, 'Y' => 5, 'Z' => 8],
+                        ['X' => 2, 'Y' => 5, 'Z' => 8],
+                        ['X' => 3, 'Y' => 5, 'Z' => 8],
+                        ['X' => 1, 'Y' => 6, 'Z' => 8],
+                        ['X' => 2, 'Y' => 6, 'Z' => 8],
+                        ['X' => 3, 'Y' => 6, 'Z' => 8],
+                        ['X' => 1, 'Y' => 4, 'Z' => 9],
+                        ['X' => 2, 'Y' => 4, 'Z' => 9],
+                        ['X' => 3, 'Y' => 4, 'Z' => 9],
+                        ['X' => 1, 'Y' => 5, 'Z' => 9],
+                        ['X' => 2, 'Y' => 5, 'Z' => 9],
+                        ['X' => 3, 'Y' => 5, 'Z' => 9],
+                        ['X' => 1, 'Y' => 6, 'Z' => 9],
+                        ['X' => 2, 'Y' => 6, 'Z' => 9],
+                        ['X' => 3, 'Y' => 6, 'Z' => 9]
                     ]);
     }
+
 }