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<?php |
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namespace WPDeveloper\BetterDocs\Dependencies\PhpParser; |
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|
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use WPDeveloper\BetterDocs\Dependencies\PhpParser\Parser\Tokens; |
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|
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class Lexer |
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{ |
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protected $code; |
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protected $tokens; |
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protected $pos; |
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protected $line; |
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protected $filePos; |
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protected $prevCloseTagHasNewline; |
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|
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protected $tokenMap; |
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protected $dropTokens; |
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|
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protected $usedAttributes; |
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|
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/** |
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* Creates a Lexer. |
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* |
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* @param array $options Options array. Currently only the 'usedAttributes' option is supported, |
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* which is an array of attributes to add to the AST nodes. Possible |
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* attributes are: 'comments', 'startLine', 'endLine', 'startTokenPos', |
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* 'endTokenPos', 'startFilePos', 'endFilePos'. The option defaults to the |
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* first three. For more info see getNextToken() docs. |
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*/ |
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public function __construct(array $options = array()) { |
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// map from internal tokens to WPDeveloper\BetterDocs\Dependencies\PhpParser tokens |
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$this->tokenMap = $this->createTokenMap(); |
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|
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// map of tokens to drop while lexing (the map is only used for isset lookup, |
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// that's why the value is simply set to 1; the value is never actually used.) |
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$this->dropTokens = array_fill_keys( |
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array(T_WHITESPACE, T_OPEN_TAG, T_COMMENT, T_DOC_COMMENT), 1 |
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); |
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|
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// the usedAttributes member is a map of the used attribute names to a dummy |
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// value (here "true") |
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$options += array( |
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'usedAttributes' => array('comments', 'startLine', 'endLine'), |
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); |
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$this->usedAttributes = array_fill_keys($options['usedAttributes'], true); |
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} |
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|
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/** |
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* Initializes the lexer for lexing the provided source code. |
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* |
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* This function does not throw if lexing errors occur. Instead, errors may be retrieved using |
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* the getErrors() method. |
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* |
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* @param string $code The source code to lex |
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* @param ErrorHandler|null $errorHandler Error handler to use for lexing errors. Defaults to |
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* ErrorHandler\Throwing |
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*/ |
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public function startLexing($code, ErrorHandler $errorHandler = null) { |
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if (null === $errorHandler) { |
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$errorHandler = new ErrorHandler\Throwing(); |
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} |
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|
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$this->code = $code; // keep the code around for __halt_compiler() handling |
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$this->pos = -1; |
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$this->line = 1; |
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$this->filePos = 0; |
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|
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// If inline HTML occurs without preceding code, treat it as if it had a leading newline. |
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// This ensures proper composability, because having a newline is the "safe" assumption. |
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$this->prevCloseTagHasNewline = true; |
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|
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$scream = ini_set('xdebug.scream', '0'); |
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|
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$this->resetErrors(); |
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$this->tokens = @token_get_all($code); |
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$this->handleErrors($errorHandler); |
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|
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if (false !== $scream) { |
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ini_set('xdebug.scream', $scream); |
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} |
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} |
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|
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protected function resetErrors() { |
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if (function_exists('error_clear_last')) { |
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error_clear_last(); |
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} else { |
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// set error_get_last() to defined state by forcing an undefined variable error |
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set_error_handler(function() { return false; }, 0); |
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@$undefinedVariable; |
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restore_error_handler(); |
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} |
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} |
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|
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private function handleInvalidCharacterRange($start, $end, $line, ErrorHandler $errorHandler) { |
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for ($i = $start; $i < $end; $i++) { |
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$chr = $this->code[$i]; |
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if ($chr === 'b' || $chr === 'B') { |
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// HHVM does not treat b" tokens correctly, so ignore these |
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continue; |
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} |
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|
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if ($chr === "\0") { |
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// PHP cuts error message after null byte, so need special case |
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$errorMsg = 'Unexpected null byte'; |
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} else { |
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$errorMsg = sprintf( |
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'Unexpected character "%s" (ASCII %d)', $chr, ord($chr) |
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); |
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} |
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|
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$errorHandler->handleError(new Error($errorMsg, [ |
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'startLine' => $line, |
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'endLine' => $line, |
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'startFilePos' => $i, |
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'endFilePos' => $i, |
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])); |
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} |
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} |
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|
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private function isUnterminatedComment($token) { |
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return ($token[0] === T_COMMENT || $token[0] === T_DOC_COMMENT) |
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&& substr($token[1], 0, 2) === '/*' |
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&& substr($token[1], -2) !== '*/'; |
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} |
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|
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private function errorMayHaveOccurred() { |
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if (defined('HHVM_VERSION')) { |
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// In HHVM token_get_all() does not throw warnings, so we need to conservatively |
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// assume that an error occurred |
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return true; |
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} |
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|
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$error = error_get_last(); |
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return null !== $error |
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&& false === strpos($error['message'], 'Undefined variable'); |
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} |
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|
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protected function handleErrors(ErrorHandler $errorHandler) { |
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if (!$this->errorMayHaveOccurred()) { |
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return; |
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} |
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|
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// PHP's error handling for token_get_all() is rather bad, so if we want detailed |
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// error information we need to compute it ourselves. Invalid character errors are |
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// detected by finding "gaps" in the token array. Unterminated comments are detected |
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// by checking if a trailing comment has a "*/" at the end. |
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|
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$filePos = 0; |
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$line = 1; |
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foreach ($this->tokens as $i => $token) { |
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$tokenValue = \is_string($token) ? $token : $token[1]; |
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$tokenLen = \strlen($tokenValue); |
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|
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if (substr($this->code, $filePos, $tokenLen) !== $tokenValue) { |
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// Something is missing, must be an invalid character |
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$nextFilePos = strpos($this->code, $tokenValue, $filePos); |
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$this->handleInvalidCharacterRange( |
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$filePos, $nextFilePos, $line, $errorHandler); |
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$filePos = $nextFilePos; |
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} |
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|
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$filePos += $tokenLen; |
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$line += substr_count($tokenValue, "\n"); |
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} |
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|
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if ($filePos !== \strlen($this->code)) { |
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if (substr($this->code, $filePos, 2) === '/*') { |
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// Unlike PHP, HHVM will drop unterminated comments entirely |
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$comment = substr($this->code, $filePos); |
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$errorHandler->handleError(new Error('Unterminated comment', [ |
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'startLine' => $line, |
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'endLine' => $line + substr_count($comment, "\n"), |
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'startFilePos' => $filePos, |
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'endFilePos' => $filePos + \strlen($comment), |
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])); |
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|
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// Emulate the PHP behavior |
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$isDocComment = isset($comment[3]) && $comment[3] === '*'; |
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$this->tokens[] = [$isDocComment ? T_DOC_COMMENT : T_COMMENT, $comment, $line]; |
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} else { |
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// Invalid characters at the end of the input |
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$this->handleInvalidCharacterRange( |
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$filePos, \strlen($this->code), $line, $errorHandler); |
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} |
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return; |
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} |
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|
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if (count($this->tokens) > 0) { |
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// Check for unterminated comment |
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$lastToken = $this->tokens[count($this->tokens) - 1]; |
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if ($this->isUnterminatedComment($lastToken)) { |
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$errorHandler->handleError(new Error('Unterminated comment', [ |
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'startLine' => $line - substr_count($lastToken[1], "\n"), |
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'endLine' => $line, |
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'startFilePos' => $filePos - \strlen($lastToken[1]), |
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'endFilePos' => $filePos, |
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])); |
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} |
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} |
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} |
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|
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/** |
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* Fetches the next token. |
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* |
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* The available attributes are determined by the 'usedAttributes' option, which can |
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* be specified in the constructor. The following attributes are supported: |
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* |
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* * 'comments' => Array of WPDeveloper\BetterDocs\Dependencies\PhpParser\Comment or WPDeveloper\BetterDocs\Dependencies\PhpParser\Comment\Doc instances, |
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* representing all comments that occurred between the previous |
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* non-discarded token and the current one. |
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* * 'startLine' => Line in which the node starts. |
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* * 'endLine' => Line in which the node ends. |
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* * 'startTokenPos' => Offset into the token array of the first token in the node. |
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* * 'endTokenPos' => Offset into the token array of the last token in the node. |
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* * 'startFilePos' => Offset into the code string of the first character that is part of the node. |
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* * 'endFilePos' => Offset into the code string of the last character that is part of the node. |
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* |
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* @param mixed $value Variable to store token content in |
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* @param mixed $startAttributes Variable to store start attributes in |
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* @param mixed $endAttributes Variable to store end attributes in |
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* |
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* @return int Token id |
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*/ |
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public function getNextToken(&$value = null, &$startAttributes = null, &$endAttributes = null) { |
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$startAttributes = array(); |
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$endAttributes = array(); |
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|
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while (1) { |
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if (isset($this->tokens[++$this->pos])) { |
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$token = $this->tokens[$this->pos]; |
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} else { |
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// EOF token with ID 0 |
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$token = "\0"; |
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} |
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|
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if (isset($this->usedAttributes['startLine'])) { |
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$startAttributes['startLine'] = $this->line; |
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} |
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if (isset($this->usedAttributes['startTokenPos'])) { |
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$startAttributes['startTokenPos'] = $this->pos; |
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} |
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if (isset($this->usedAttributes['startFilePos'])) { |
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$startAttributes['startFilePos'] = $this->filePos; |
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} |
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|
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if (\is_string($token)) { |
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$value = $token; |
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if (isset($token[1])) { |
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// bug in token_get_all |
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$this->filePos += 2; |
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$id = ord('"'); |
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} else { |
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$this->filePos += 1; |
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$id = ord($token); |
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} |
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} elseif (!isset($this->dropTokens[$token[0]])) { |
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$value = $token[1]; |
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$id = $this->tokenMap[$token[0]]; |
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if (T_CLOSE_TAG === $token[0]) { |
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$this->prevCloseTagHasNewline = false !== strpos($token[1], "\n"); |
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} else if (T_INLINE_HTML === $token[0]) { |
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$startAttributes['hasLeadingNewline'] = $this->prevCloseTagHasNewline; |
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} |
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|
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$this->line += substr_count($value, "\n"); |
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$this->filePos += \strlen($value); |
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} else { |
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if (T_COMMENT === $token[0] || T_DOC_COMMENT === $token[0]) { |
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if (isset($this->usedAttributes['comments'])) { |
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$comment = T_DOC_COMMENT === $token[0] |
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? new Comment\Doc($token[1], $this->line, $this->filePos) |
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: new Comment($token[1], $this->line, $this->filePos); |
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$startAttributes['comments'][] = $comment; |
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} |
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} |
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|
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$this->line += substr_count($token[1], "\n"); |
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$this->filePos += \strlen($token[1]); |
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continue; |
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} |
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|
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if (isset($this->usedAttributes['endLine'])) { |
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$endAttributes['endLine'] = $this->line; |
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} |
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if (isset($this->usedAttributes['endTokenPos'])) { |
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$endAttributes['endTokenPos'] = $this->pos; |
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} |
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if (isset($this->usedAttributes['endFilePos'])) { |
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$endAttributes['endFilePos'] = $this->filePos - 1; |
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} |
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|
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return $id; |
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} |
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|
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throw new \RuntimeException('Reached end of lexer loop'); |
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} |
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|
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/** |
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* Returns the token array for current code. |
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* |
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* The token array is in the same format as provided by the |
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* token_get_all() function and does not discard tokens (i.e. |
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* whitespace and comments are included). The token position |
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* attributes are against this token array. |
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* |
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* @return array Array of tokens in token_get_all() format |
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*/ |
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public function getTokens() { |
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return $this->tokens; |
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} |
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|
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/** |
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* Handles __halt_compiler() by returning the text after it. |
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* |
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* @return string Remaining text |
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*/ |
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public function handleHaltCompiler() { |
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// text after T_HALT_COMPILER, still including (); |
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$textAfter = substr($this->code, $this->filePos); |
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|
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// ensure that it is followed by (); |
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// this simplifies the situation, by not allowing any comments |
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// in between of the tokens. |
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if (!preg_match('~^\s*\(\s*\)\s*(?:;|\?>\r?\n?)~', $textAfter, $matches)) { |
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throw new Error('__HALT_COMPILER must be followed by "();"'); |
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} |
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|
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// prevent the lexer from returning any further tokens |
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$this->pos = count($this->tokens); |
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|
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// return with (); removed |
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return (string) substr($textAfter, strlen($matches[0])); // (string) converts false to '' |
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} |
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|
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/** |
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* Creates the token map. |
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* |
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* The token map maps the PHP internal token identifiers |
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* to the identifiers used by the Parser. Additionally it |
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* maps T_OPEN_TAG_WITH_ECHO to T_ECHO and T_CLOSE_TAG to ';'. |
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* |
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* @return array The token map |
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*/ |
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protected function createTokenMap() { |
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$tokenMap = array(); |
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|
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// 256 is the minimum possible token number, as everything below |
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// it is an ASCII value |
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for ($i = 256; $i < 1000; ++$i) { |
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if (T_DOUBLE_COLON === $i) { |
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// T_DOUBLE_COLON is equivalent to T_PAAMAYIM_NEKUDOTAYIM |
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$tokenMap[$i] = Tokens::T_PAAMAYIM_NEKUDOTAYIM; |
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} elseif(T_OPEN_TAG_WITH_ECHO === $i) { |
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// T_OPEN_TAG_WITH_ECHO with dropped T_OPEN_TAG results in T_ECHO |
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$tokenMap[$i] = Tokens::T_ECHO; |
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} elseif(T_CLOSE_TAG === $i) { |
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// T_CLOSE_TAG is equivalent to ';' |
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$tokenMap[$i] = ord(';'); |
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} elseif ('UNKNOWN' !== $name = token_name($i)) { |
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if ('T_HASHBANG' === $name) { |
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// HHVM uses a special token for #! hashbang lines |
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$tokenMap[$i] = Tokens::T_INLINE_HTML; |
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} else if (defined($name = Tokens::class . '::' . $name)) { |
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// Other tokens can be mapped directly |
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$tokenMap[$i] = constant($name); |
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} |
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} |
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} |
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|
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// HHVM uses a special token for numbers that overflow to double |
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if (defined('T_ONUMBER')) { |
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$tokenMap[T_ONUMBER] = Tokens::T_DNUMBER; |
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} |
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// HHVM also has a separate token for the __COMPILER_HALT_OFFSET__ constant |
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if (defined('T_COMPILER_HALT_OFFSET')) { |
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$tokenMap[T_COMPILER_HALT_OFFSET] = Tokens::T_STRING; |
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} |
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|
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return $tokenMap; |
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} |
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} |
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|
