Chris@0: <?php
Chris@0: 
Chris@0: namespace PhpParser\Lexer;
Chris@0: 
Chris@0: use PhpParser\ErrorHandler;
Chris@0: use PhpParser\Parser\Tokens;
Chris@0: 
Chris@0: class Emulative extends \PhpParser\Lexer
Chris@0: {
Chris@0:     protected $newKeywords;
Chris@0:     protected $inObjectAccess;
Chris@0: 
Chris@0:     const T_ELLIPSIS   = 1001;
Chris@0:     const T_POW        = 1002;
Chris@0:     const T_POW_EQUAL  = 1003;
Chris@0:     const T_COALESCE   = 1004;
Chris@0:     const T_SPACESHIP  = 1005;
Chris@0:     const T_YIELD_FROM = 1006;
Chris@0: 
Chris@0:     const PHP_7_0 = '7.0.0dev';
Chris@0:     const PHP_5_6 = '5.6.0rc1';
Chris@0: 
Chris@0:     public function __construct(array $options = array()) {
Chris@0:         parent::__construct($options);
Chris@0: 
Chris@0:         $newKeywordsPerVersion = array(
Chris@0:             // No new keywords since PHP 5.5
Chris@0:         );
Chris@0: 
Chris@0:         $this->newKeywords = array();
Chris@0:         foreach ($newKeywordsPerVersion as $version => $newKeywords) {
Chris@0:             if (version_compare(PHP_VERSION, $version, '>=')) {
Chris@0:                 break;
Chris@0:             }
Chris@0: 
Chris@0:             $this->newKeywords += $newKeywords;
Chris@0:         }
Chris@0: 
Chris@0:         if (version_compare(PHP_VERSION, self::PHP_7_0, '>=')) {
Chris@0:             return;
Chris@0:         }
Chris@0:         $this->tokenMap[self::T_COALESCE]   = Tokens::T_COALESCE;
Chris@0:         $this->tokenMap[self::T_SPACESHIP]  = Tokens::T_SPACESHIP;
Chris@0:         $this->tokenMap[self::T_YIELD_FROM] = Tokens::T_YIELD_FROM;
Chris@0: 
Chris@0:         if (version_compare(PHP_VERSION, self::PHP_5_6, '>=')) {
Chris@0:             return;
Chris@0:         }
Chris@0:         $this->tokenMap[self::T_ELLIPSIS]  = Tokens::T_ELLIPSIS;
Chris@0:         $this->tokenMap[self::T_POW]       = Tokens::T_POW;
Chris@0:         $this->tokenMap[self::T_POW_EQUAL] = Tokens::T_POW_EQUAL;
Chris@0:     }
Chris@0: 
Chris@0:     public function startLexing($code, ErrorHandler $errorHandler = null) {
Chris@0:         $this->inObjectAccess = false;
Chris@0: 
Chris@0:         parent::startLexing($code, $errorHandler);
Chris@0:         if ($this->requiresEmulation($code)) {
Chris@0:             $this->emulateTokens();
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /*
Chris@0:      * Checks if the code is potentially using features that require emulation.
Chris@0:      */
Chris@0:     protected function requiresEmulation($code) {
Chris@0:         if (version_compare(PHP_VERSION, self::PHP_7_0, '>=')) {
Chris@0:             return false;
Chris@0:         }
Chris@0: 
Chris@0:         if (preg_match('(\?\?|<=>|yield[ \n\r\t]+from)', $code)) {
Chris@0:             return true;
Chris@0:         }
Chris@0: 
Chris@0:         if (version_compare(PHP_VERSION, self::PHP_5_6, '>=')) {
Chris@0:             return false;
Chris@0:         }
Chris@0: 
Chris@0:         return preg_match('(\.\.\.|(?<!/)\*\*(?!/))', $code);
Chris@0:     }
Chris@0: 
Chris@0:     /*
Chris@0:      * Emulates tokens for newer PHP versions.
Chris@0:      */
Chris@0:     protected function emulateTokens() {
Chris@0:         // We need to manually iterate and manage a count because we'll change
Chris@0:         // the tokens array on the way
Chris@0:         $line = 1;
Chris@0:         for ($i = 0, $c = count($this->tokens); $i < $c; ++$i) {
Chris@0:             $replace = null;
Chris@0:             if (isset($this->tokens[$i + 1])) {
Chris@0:                 if ($this->tokens[$i] === '?' && $this->tokens[$i + 1] === '?') {
Chris@0:                     array_splice($this->tokens, $i, 2, array(
Chris@0:                         array(self::T_COALESCE, '??', $line)
Chris@0:                     ));
Chris@0:                     $c--;
Chris@0:                     continue;
Chris@0:                 }
Chris@0:                 if ($this->tokens[$i][0] === T_IS_SMALLER_OR_EQUAL
Chris@0:                     && $this->tokens[$i + 1] === '>'
Chris@0:                 ) {
Chris@0:                     array_splice($this->tokens, $i, 2, array(
Chris@0:                         array(self::T_SPACESHIP, '<=>', $line)
Chris@0:                     ));
Chris@0:                     $c--;
Chris@0:                     continue;
Chris@0:                 }
Chris@0:                 if ($this->tokens[$i] === '*' && $this->tokens[$i + 1] === '*') {
Chris@0:                     array_splice($this->tokens, $i, 2, array(
Chris@0:                         array(self::T_POW, '**', $line)
Chris@0:                     ));
Chris@0:                     $c--;
Chris@0:                     continue;
Chris@0:                 }
Chris@0:                 if ($this->tokens[$i] === '*' && $this->tokens[$i + 1][0] === T_MUL_EQUAL) {
Chris@0:                     array_splice($this->tokens, $i, 2, array(
Chris@0:                         array(self::T_POW_EQUAL, '**=', $line)
Chris@0:                     ));
Chris@0:                     $c--;
Chris@0:                     continue;
Chris@0:                 }
Chris@0:             }
Chris@0: 
Chris@0:             if (isset($this->tokens[$i + 2])) {
Chris@0:                 if ($this->tokens[$i][0] === T_YIELD && $this->tokens[$i + 1][0] === T_WHITESPACE
Chris@0:                     && $this->tokens[$i + 2][0] === T_STRING
Chris@0:                     && !strcasecmp($this->tokens[$i + 2][1], 'from')
Chris@0:                 ) {
Chris@0:                     array_splice($this->tokens, $i, 3, array(
Chris@0:                         array(
Chris@0:                             self::T_YIELD_FROM,
Chris@0:                             $this->tokens[$i][1] . $this->tokens[$i + 1][1] . $this->tokens[$i + 2][1],
Chris@0:                             $line
Chris@0:                         )
Chris@0:                     ));
Chris@0:                     $c -= 2;
Chris@0:                     $line += substr_count($this->tokens[$i][1], "\n");
Chris@0:                     continue;
Chris@0:                 }
Chris@0:                 if ($this->tokens[$i] === '.' && $this->tokens[$i + 1] === '.'
Chris@0:                     && $this->tokens[$i + 2] === '.'
Chris@0:                 ) {
Chris@0:                     array_splice($this->tokens, $i, 3, array(
Chris@0:                         array(self::T_ELLIPSIS, '...', $line)
Chris@0:                     ));
Chris@0:                     $c -= 2;
Chris@0:                     continue;
Chris@0:                 }
Chris@0:             }
Chris@0: 
Chris@0:             if (\is_array($this->tokens[$i])) {
Chris@0:                 $line += substr_count($this->tokens[$i][1], "\n");
Chris@0:             }
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     public function getNextToken(&$value = null, &$startAttributes = null, &$endAttributes = null) {
Chris@0:         $token = parent::getNextToken($value, $startAttributes, $endAttributes);
Chris@0: 
Chris@0:         // replace new keywords by their respective tokens. This is not done
Chris@0:         // if we currently are in an object access (e.g. in $obj->namespace
Chris@0:         // "namespace" stays a T_STRING tokens and isn't converted to T_NAMESPACE)
Chris@0:         if (Tokens::T_STRING === $token && !$this->inObjectAccess) {
Chris@0:             if (isset($this->newKeywords[strtolower($value)])) {
Chris@0:                 return $this->newKeywords[strtolower($value)];
Chris@0:             }
Chris@0:         } else {
Chris@0:             // keep track of whether we currently are in an object access (after ->)
Chris@0:             $this->inObjectAccess = Tokens::T_OBJECT_OPERATOR === $token;
Chris@0:         }
Chris@0: 
Chris@0:         return $token;
Chris@0:     }
Chris@0: }