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