1<?php
2
3/**
4 * Hoa
5 *
6 *
7 * @license
8 *
9 * New BSD License
10 *
11 * Copyright © 2007-2017, Hoa community. All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions are met:
15 *     * Redistributions of source code must retain the above copyright
16 *       notice, this list of conditions and the following disclaimer.
17 *     * Redistributions in binary form must reproduce the above copyright
18 *       notice, this list of conditions and the following disclaimer in the
19 *       documentation and/or other materials provided with the distribution.
20 *     * Neither the name of the Hoa nor the names of its contributors may be
21 *       used to endorse or promote products derived from this software without
22 *       specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37namespace Hoa\Iterator;
38
39/**
40 * Class \Hoa\Iterator\CallbackGenerator.
41 *
42 * Yield a value based on a callback.
43 *
44 * @copyright  Copyright © 2007-2017 Hoa community
45 * @license    New BSD License
46 */
47class CallbackGenerator implements Iterator
48{
49    /**
50     * Callback.
51     *
52     * @var callable
53     */
54    protected $_callback = null;
55
56    /**
57     * Current key.
58     *
59     * @var mixed
60     */
61    protected $_key      = 0;
62
63    /**
64     * Current computed value.
65     *
66     * @var mixed
67     */
68    protected $_current  = null;
69
70
71
72    /**
73     * Constructor.
74     *
75     * @param   callable  $callback    Callback.
76     */
77    public function __construct(callable $callback)
78    {
79        $this->_callback = $callback;
80
81        return;
82    }
83
84    /**
85     * Return the current element.
86     *
87     * @return  mixed
88     */
89    public function current()
90    {
91        $handle = $this->_callback;
92
93        return $this->_current = $handle($this->_key);
94    }
95
96    /**
97     * Return the key of the current element.
98     *
99     * @return  mixed
100     */
101    public function key()
102    {
103        return $this->_key;
104    }
105
106    /**
107     * Move forward to next element.
108     *
109     * @return  void
110     */
111    public function next()
112    {
113        ++$this->_key;
114
115        return;
116    }
117
118    /**
119     * Rewind the iterator to the first element.
120     *
121     * @return  void
122     */
123    public function rewind()
124    {
125        $this->_key     = 0;
126        $this->_current = null;
127
128        return;
129    }
130
131    /**
132     * Check if current position is valid.
133     *
134     * @return  bool
135     */
136    public function valid()
137    {
138        return true;
139    }
140}
141