Lookahead.php 4.2 KB

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  1. <?php
  2. /**
  3. * Hoa
  4. *
  5. *
  6. * @license
  7. *
  8. * New BSD License
  9. *
  10. * Copyright © 2007-2017, Hoa community. All rights reserved.
  11. *
  12. * Redistribution and use in source and binary forms, with or without
  13. * modification, are permitted provided that the following conditions are met:
  14. * * Redistributions of source code must retain the above copyright
  15. * notice, this list of conditions and the following disclaimer.
  16. * * Redistributions in binary form must reproduce the above copyright
  17. * notice, this list of conditions and the following disclaimer in the
  18. * documentation and/or other materials provided with the distribution.
  19. * * Neither the name of the Hoa nor the names of its contributors may be
  20. * used to endorse or promote products derived from this software without
  21. * specific prior written permission.
  22. *
  23. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  24. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26. * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE
  27. * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  28. * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  29. * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  30. * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  31. * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  32. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33. * POSSIBILITY OF SUCH DAMAGE.
  34. */
  35. namespace Hoa\Iterator;
  36. /**
  37. * Class \Hoa\Iterator\Lookahead.
  38. *
  39. * Look ahead iterator.
  40. *
  41. * @copyright Copyright © 2007-2017 Hoa community
  42. * @license New BSD License
  43. */
  44. class Lookahead extends IteratorIterator implements Outer
  45. {
  46. /**
  47. * Current iterator.
  48. *
  49. * @var \Iterator
  50. */
  51. protected $_iterator = null;
  52. /**
  53. * Current key.
  54. *
  55. * @var mixed
  56. */
  57. protected $_key = 0;
  58. /**
  59. * Current value.
  60. *
  61. * @var mixed
  62. */
  63. protected $_current = null;
  64. /**
  65. * Whether the current element is valid or not.
  66. *
  67. * @var bool
  68. */
  69. protected $_valid = false;
  70. /**
  71. * Construct.
  72. *
  73. * @param \Iterator $iterator Iterator.
  74. */
  75. public function __construct(\Iterator $iterator)
  76. {
  77. $this->_iterator = $iterator;
  78. return;
  79. }
  80. /**
  81. * Get inner iterator.
  82. *
  83. * @return \Iterator
  84. */
  85. public function getInnerIterator()
  86. {
  87. return $this->_iterator;
  88. }
  89. /**
  90. * Return the current element.
  91. *
  92. * @return mixed
  93. */
  94. public function current()
  95. {
  96. return $this->_current;
  97. }
  98. /**
  99. * Return the key of the current element.
  100. *
  101. * @return mixed
  102. */
  103. public function key()
  104. {
  105. return $this->_key;
  106. }
  107. /**
  108. * Move forward to next element.
  109. *
  110. * @return void
  111. */
  112. public function next()
  113. {
  114. $innerIterator = $this->getInnerIterator();
  115. $this->_valid = $innerIterator->valid();
  116. if (false === $this->_valid) {
  117. return;
  118. }
  119. $this->_key = $innerIterator->key();
  120. $this->_current = $innerIterator->current();
  121. return $innerIterator->next();
  122. }
  123. /**
  124. * Rewind the iterator to the first element.
  125. *
  126. * @return void
  127. */
  128. public function rewind()
  129. {
  130. $out = $this->getInnerIterator()->rewind();
  131. $this->next();
  132. return $out;
  133. }
  134. /**
  135. * Check if current position is valid.
  136. *
  137. * @return bool
  138. */
  139. public function valid()
  140. {
  141. return $this->_valid;
  142. }
  143. /**
  144. * Check whether there is a next element.
  145. *
  146. * @return bool
  147. */
  148. public function hasNext()
  149. {
  150. return $this->getInnerIterator()->valid();
  151. }
  152. /**
  153. * Get next value.
  154. *
  155. * @return mixed
  156. */
  157. public function getNext()
  158. {
  159. return $this->getInnerIterator()->current();
  160. }
  161. /**
  162. * Get next key.
  163. *
  164. * @return mixed
  165. */
  166. public function getNextKey()
  167. {
  168. return $this->getInnerIterator()->key();
  169. }
  170. }