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\Lookahead.
41 *
42 * Look ahead iterator.
43 *
44 * @copyright  Copyright © 2007-2017 Hoa community
45 * @license    New BSD License
46 */
47class Lookahead extends IteratorIterator implements Outer
48{
49    /**
50     * Current iterator.
51     *
52     * @var \Iterator
53     */
54    protected $_iterator = null;
55
56    /**
57     * Current key.
58     *
59     * @var mixed
60     */
61    protected $_key      = 0;
62
63    /**
64     * Current value.
65     *
66     * @var mixed
67     */
68    protected $_current  = null;
69
70    /**
71     * Whether the current element is valid or not.
72     *
73     * @var bool
74     */
75    protected $_valid    = false;
76
77
78
79    /**
80     * Construct.
81     *
82     * @param   \Iterator  $iterator    Iterator.
83     */
84    public function __construct(\Iterator $iterator)
85    {
86        $this->_iterator = $iterator;
87
88        return;
89    }
90
91    /**
92     * Get inner iterator.
93     *
94     * @return  \Iterator
95     */
96    public function getInnerIterator()
97    {
98        return $this->_iterator;
99    }
100
101    /**
102     * Return the current element.
103     *
104     * @return  mixed
105     */
106    public function current()
107    {
108        return $this->_current;
109    }
110
111    /**
112     * Return the key of the current element.
113     *
114     * @return  mixed
115     */
116    public function key()
117    {
118        return $this->_key;
119    }
120
121    /**
122     * Move forward to next element.
123     *
124     * @return  void
125     */
126    public function next()
127    {
128        $innerIterator = $this->getInnerIterator();
129        $this->_valid  = $innerIterator->valid();
130
131        if (false === $this->_valid) {
132            return;
133        }
134
135        $this->_key     = $innerIterator->key();
136        $this->_current = $innerIterator->current();
137
138        return $innerIterator->next();
139    }
140
141    /**
142     * Rewind the iterator to the first element.
143     *
144     * @return  void
145     */
146    public function rewind()
147    {
148        $out = $this->getInnerIterator()->rewind();
149        $this->next();
150
151        return $out;
152    }
153
154    /**
155     * Check if current position is valid.
156     *
157     * @return  bool
158     */
159    public function valid()
160    {
161        return $this->_valid;
162    }
163
164    /**
165     * Check whether there is a next element.
166     *
167     * @return  bool
168     */
169    public function hasNext()
170    {
171        return $this->getInnerIterator()->valid();
172    }
173
174    /**
175     * Get next value.
176     *
177     * @return  mixed
178     */
179    public function getNext()
180    {
181        return $this->getInnerIterator()->current();
182    }
183
184    /**
185     * Get next key.
186     *
187     * @return  mixed
188     */
189    public function getNextKey()
190    {
191        return $this->getInnerIterator()->key();
192    }
193}
194