Chris@0: <?php
Chris@0: 
Chris@0: /*
Chris@0:  * This file is part of the Symfony package.
Chris@0:  *
Chris@0:  * (c) Fabien Potencier <fabien@symfony.com>
Chris@0:  *
Chris@0:  * For the full copyright and license information, please view the LICENSE
Chris@0:  * file that was distributed with this source code.
Chris@0:  */
Chris@0: 
Chris@0: namespace Symfony\Component\CssSelector\Parser;
Chris@0: 
Chris@0: use Symfony\Component\CssSelector\Exception\InternalErrorException;
Chris@0: use Symfony\Component\CssSelector\Exception\SyntaxErrorException;
Chris@0: 
Chris@0: /**
Chris@0:  * CSS selector token stream.
Chris@0:  *
Chris@0:  * This component is a port of the Python cssselect library,
Chris@0:  * which is copyright Ian Bicking, @see https://github.com/SimonSapin/cssselect.
Chris@0:  *
Chris@0:  * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
Chris@0:  *
Chris@0:  * @internal
Chris@0:  */
Chris@0: class TokenStream
Chris@0: {
Chris@0:     /**
Chris@0:      * @var Token[]
Chris@0:      */
Chris@17:     private $tokens = [];
Chris@0: 
Chris@0:     /**
Chris@0:      * @var Token[]
Chris@0:      */
Chris@17:     private $used = [];
Chris@0: 
Chris@0:     /**
Chris@0:      * @var int
Chris@0:      */
Chris@0:     private $cursor = 0;
Chris@0: 
Chris@0:     /**
Chris@0:      * @var Token|null
Chris@0:      */
Chris@14:     private $peeked;
Chris@0: 
Chris@0:     /**
Chris@0:      * @var bool
Chris@0:      */
Chris@0:     private $peeking = false;
Chris@0: 
Chris@0:     /**
Chris@0:      * Pushes a token.
Chris@0:      *
Chris@0:      * @return $this
Chris@0:      */
Chris@0:     public function push(Token $token)
Chris@0:     {
Chris@0:         $this->tokens[] = $token;
Chris@0: 
Chris@0:         return $this;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Freezes stream.
Chris@0:      *
Chris@0:      * @return $this
Chris@0:      */
Chris@0:     public function freeze()
Chris@0:     {
Chris@0:         return $this;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns next token.
Chris@0:      *
Chris@0:      * @return Token
Chris@0:      *
Chris@0:      * @throws InternalErrorException If there is no more token
Chris@0:      */
Chris@0:     public function getNext()
Chris@0:     {
Chris@0:         if ($this->peeking) {
Chris@0:             $this->peeking = false;
Chris@0:             $this->used[] = $this->peeked;
Chris@0: 
Chris@0:             return $this->peeked;
Chris@0:         }
Chris@0: 
Chris@0:         if (!isset($this->tokens[$this->cursor])) {
Chris@0:             throw new InternalErrorException('Unexpected token stream end.');
Chris@0:         }
Chris@0: 
Chris@0:         return $this->tokens[$this->cursor++];
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns peeked token.
Chris@0:      *
Chris@0:      * @return Token
Chris@0:      */
Chris@0:     public function getPeek()
Chris@0:     {
Chris@0:         if (!$this->peeking) {
Chris@0:             $this->peeked = $this->getNext();
Chris@0:             $this->peeking = true;
Chris@0:         }
Chris@0: 
Chris@0:         return $this->peeked;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns used tokens.
Chris@0:      *
Chris@0:      * @return Token[]
Chris@0:      */
Chris@0:     public function getUsed()
Chris@0:     {
Chris@0:         return $this->used;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns nex identifier token.
Chris@0:      *
Chris@0:      * @return string The identifier token value
Chris@0:      *
Chris@0:      * @throws SyntaxErrorException If next token is not an identifier
Chris@0:      */
Chris@0:     public function getNextIdentifier()
Chris@0:     {
Chris@0:         $next = $this->getNext();
Chris@0: 
Chris@0:         if (!$next->isIdentifier()) {
Chris@0:             throw SyntaxErrorException::unexpectedToken('identifier', $next);
Chris@0:         }
Chris@0: 
Chris@0:         return $next->getValue();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns nex identifier or star delimiter token.
Chris@0:      *
Chris@17:      * @return string|null The identifier token value or null if star found
Chris@0:      *
Chris@0:      * @throws SyntaxErrorException If next token is not an identifier or a star delimiter
Chris@0:      */
Chris@0:     public function getNextIdentifierOrStar()
Chris@0:     {
Chris@0:         $next = $this->getNext();
Chris@0: 
Chris@0:         if ($next->isIdentifier()) {
Chris@0:             return $next->getValue();
Chris@0:         }
Chris@0: 
Chris@17:         if ($next->isDelimiter(['*'])) {
Chris@0:             return;
Chris@0:         }
Chris@0: 
Chris@0:         throw SyntaxErrorException::unexpectedToken('identifier or "*"', $next);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Skips next whitespace if any.
Chris@0:      */
Chris@0:     public function skipWhitespace()
Chris@0:     {
Chris@0:         $peek = $this->getPeek();
Chris@0: 
Chris@0:         if ($peek->isWhitespace()) {
Chris@0:             $this->getNext();
Chris@0:         }
Chris@0:     }
Chris@0: }