Drupal investigation

TokenStream.php 3.6KB

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  1. <?php
  2. /*
  3. * This file is part of the Symfony package.
  4. *
  5. * (c) Fabien Potencier <fabien@symfony.com>
  6. *
  7. * For the full copyright and license information, please view the LICENSE
  8. * file that was distributed with this source code.
  9. */
  10. namespace Symfony\Component\CssSelector\Parser;
  11. use Symfony\Component\CssSelector\Exception\InternalErrorException;
  12. use Symfony\Component\CssSelector\Exception\SyntaxErrorException;
  13. /**
  14. * CSS selector token stream.
  15. *
  16. * This component is a port of the Python cssselect library,
  17. * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
  18. *
  19. * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
  20. *
  21. * @internal
  22. */
  23. class TokenStream
  24. {
  25. /**
  26. * @var Token[]
  27. */
  28. private $tokens = array();
  29. /**
  30. * @var bool
  31. */
  32. private $frozen = false;
  33. /**
  34. * @var Token[]
  35. */
  36. private $used = array();
  37. /**
  38. * @var int
  39. */
  40. private $cursor = 0;
  41. /**
  42. * @var Token|null
  43. */
  44. private $peeked = null;
  45. /**
  46. * @var bool
  47. */
  48. private $peeking = false;
  49. /**
  50. * Pushes a token.
  51. *
  52. * @param Token $token
  53. *
  54. * @return $this
  55. */
  56. public function push(Token $token)
  57. {
  58. $this->tokens[] = $token;
  59. return $this;
  60. }
  61. /**
  62. * Freezes stream.
  63. *
  64. * @return $this
  65. */
  66. public function freeze()
  67. {
  68. $this->frozen = true;
  69. return $this;
  70. }
  71. /**
  72. * Returns next token.
  73. *
  74. * @return Token
  75. *
  76. * @throws InternalErrorException If there is no more token
  77. */
  78. public function getNext()
  79. {
  80. if ($this->peeking) {
  81. $this->peeking = false;
  82. $this->used[] = $this->peeked;
  83. return $this->peeked;
  84. }
  85. if (!isset($this->tokens[$this->cursor])) {
  86. throw new InternalErrorException('Unexpected token stream end.');
  87. }
  88. return $this->tokens[$this->cursor++];
  89. }
  90. /**
  91. * Returns peeked token.
  92. *
  93. * @return Token
  94. */
  95. public function getPeek()
  96. {
  97. if (!$this->peeking) {
  98. $this->peeked = $this->getNext();
  99. $this->peeking = true;
  100. }
  101. return $this->peeked;
  102. }
  103. /**
  104. * Returns used tokens.
  105. *
  106. * @return Token[]
  107. */
  108. public function getUsed()
  109. {
  110. return $this->used;
  111. }
  112. /**
  113. * Returns nex identifier token.
  114. *
  115. * @return string The identifier token value
  116. *
  117. * @throws SyntaxErrorException If next token is not an identifier
  118. */
  119. public function getNextIdentifier()
  120. {
  121. $next = $this->getNext();
  122. if (!$next->isIdentifier()) {
  123. throw SyntaxErrorException::unexpectedToken('identifier', $next);
  124. }
  125. return $next->getValue();
  126. }
  127. /**
  128. * Returns nex identifier or star delimiter token.
  129. *
  130. * @return null|string The identifier token value or null if star found
  131. *
  132. * @throws SyntaxErrorException If next token is not an identifier or a star delimiter
  133. */
  134. public function getNextIdentifierOrStar()
  135. {
  136. $next = $this->getNext();
  137. if ($next->isIdentifier()) {
  138. return $next->getValue();
  139. }
  140. if ($next->isDelimiter(array('*'))) {
  141. return;
  142. }
  143. throw SyntaxErrorException::unexpectedToken('identifier or "*"', $next);
  144. }
  145. /**
  146. * Skips next whitespace if any.
  147. */
  148. public function skipWhitespace()
  149. {
  150. $peek = $this->getPeek();
  151. if ($peek->isWhitespace()) {
  152. $this->getNext();
  153. }
  154. }
  155. }