1: <?php
 2: /**
 3:  * PHPExcel
 4:  *
 5:  * Copyright (c) 2006 - 2014 PHPExcel
 6:  *
 7:  * This library is free software; you can redistribute it and/or
 8:  * modify it under the terms of the GNU Lesser General Public
 9:  * License as published by the Free Software Foundation; either
10:  * version 2.1 of the License, or (at your option) any later version.
11:  *
12:  * This library is distributed in the hope that it will be useful,
13:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15:  * Lesser General Public License for more details.
16:  *
17:  * You should have received a copy of the GNU Lesser General Public
18:  * License along with this library; if not, write to the Free Software
19:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
20:  *
21:  * @category   PHPExcel
22:  * @package    PHPExcel_Calculation
23:  * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
24:  * @license http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt   LGPL
25:  * @version 1.8.0, 2014-03-02
26:  */
27: 
28: 
29: /**
30:  * PHPExcel_CalcEngine_CyclicReferenceStack
31:  *
32:  * @category    PHPExcel_CalcEngine_CyclicReferenceStack
33:  * @package     PHPExcel_Calculation
34:  * @copyright   Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
35:  */
36: class PHPExcel_CalcEngine_CyclicReferenceStack {
37: 
38:     /**
39:      *  The call stack for calculated cells
40:      *
41:      *  @var mixed[]
42:      */
43:     private $_stack = array();
44: 
45: 
46:     /**
47:      * Return the number of entries on the stack
48:      *
49:      * @return  integer
50:      */
51:     public function count() {
52:         return count($this->_stack);
53:     }
54: 
55:     /**
56:      * Push a new entry onto the stack
57:      *
58:      * @param  mixed  $value
59:      */
60:     public function push($value) {
61:         $this->_stack[] = $value;
62:     }   //  function push()
63: 
64:     /**
65:      * Pop the last entry from the stack
66:      *
67:      * @return  mixed
68:      */
69:     public function pop() {
70:         return array_pop($this->_stack);
71:     }   //  function pop()
72: 
73:     /**
74:      * Test to see if a specified entry exists on the stack
75:      *
76:      * @param  mixed  $value  The value to test
77:      */
78:     public function onStack($value) {
79:         return in_array($value, $this->_stack);
80:     }
81: 
82:     /**
83:      * Clear the stack
84:      */
85:     public function clear() {
86:         $this->_stack = array();
87:     }   //  function push()
88: 
89:     /**
90:      * Return an array of all entries on the stack
91:      *
92:      * @return  mixed[]
93:      */
94:     public function showStack() {
95:         return $this->_stack;
96:     }
97: 
98: }   //  class PHPExcel_CalcEngine_CyclicReferenceStack
99: