1: <?php
 2: 
 3: /**
 4:  * Jyxo PHP Library
 5:  *
 6:  * LICENSE
 7:  *
 8:  * This source file is subject to the new BSD license that is bundled
 9:  * with this package in the file license.txt.
10:  * It is also available through the world-wide-web at this URL:
11:  * https://github.com/jyxo/php/blob/master/license.txt
12:  */
13: 
14: namespace Jyxo\Spl;
15: 
16: /**
17:  * Utilities for working with arrays.
18:  *
19:  * @category Jyxo
20:  * @package Jyxo\Spl
21:  * @copyright Copyright (c) 2005-2011 Jyxo, s.r.o.
22:  * @license https://github.com/jyxo/php/blob/master/license.txt
23:  * @author Jakub Tománek
24:  */
25: class ArrayUtil
26: {
27:     /**
28:      * Creates an array containing item range. Similar to range() but with closures.
29:      * Params $low and $high are inclusive. If $low > $high, resulting array will be in descending order.
30:      *
31:      * @param mixed $low Minimal value
32:      * @param mixed $high Maximal value
33:      * @param \Closure $step Closure which creates next value from current
34:      * @param \Closure $compare comparing closure for detecting if we're at the end of the range (Optional)
35:      * @return array
36:      */
37:     public static function range($low, $high, \Closure $step, \Closure $compare = null)
38:     {
39:         $data = array($low);
40:         $stepDown = $low > $high;
41:         $compare = $compare ?: function ($a, $b) use ($stepDown) {
42:             return $stepDown ? $a > $b : $a < $b;
43:         };
44: 
45:         $current = $low;
46:         while ($compare($current, $high)) {
47:             $data[] = $current = $step($current);
48:         }
49:         return $data;
50:     }
51: 
52:     /**
53:      * Creates an associative array from iterator which doesn't return proper keys.
54:      * Keys are generated by applying callback $key to the current value.
55:      * It is also possible to apply another callback directly to the value.
56:      * Key callback is called BEFORE value callback.
57:      *
58:      * Example:
59:      * <code>
60:      * $data = \Jyxo\Spl\ArrayUtil::keymap($iterator, function(Object $object) {
61:      *   return $object->getId();
62:      * });
63:      * </code>
64:      *
65:      * @param \Traversable $traversable Iterator
66:      * @param \Closure $key Closure for generating keys
67:      * @param \Closure $value Closure for modifying data (Optional)
68:      * @return array
69:      */
70:     public static function keymap(\Traversable $traversable, \Closure $key, \Closure $value = null)
71:     {
72:         $data = array();
73:         foreach ($traversable as $item) {
74:             $data[$key($item)] = $value ? $value($item) : $item;
75:         }
76:         return $data;
77:     }
78: }
79: