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148 lars 1
<?php
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declare(strict_types=1);
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/*
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 * This file is part of the league/commonmark package.
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 *
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 * (c) Colin O'Dell <colinodell@gmail.com>
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 *
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 * Original code based on the CommonMark JS reference parser (https://bitly.com/commonmark-js)
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 *  - (c) John MacFarlane
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 *
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 * Additional code based on commonmark-java (https://github.com/commonmark/commonmark-java)
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 *  - (c) Atlassian Pty Ltd
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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 League\CommonMark\Parser;
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use League\CommonMark\Environment\EnvironmentInterface;
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use League\CommonMark\Event\DocumentParsedEvent;
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use League\CommonMark\Event\DocumentPreParsedEvent;
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use League\CommonMark\Input\MarkdownInput;
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use League\CommonMark\Node\Block\Document;
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use League\CommonMark\Node\Block\Paragraph;
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use League\CommonMark\Parser\Block\BlockContinueParserInterface;
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use League\CommonMark\Parser\Block\BlockContinueParserWithInlinesInterface;
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use League\CommonMark\Parser\Block\BlockStart;
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use League\CommonMark\Parser\Block\BlockStartParserInterface;
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use League\CommonMark\Parser\Block\DocumentBlockParser;
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use League\CommonMark\Parser\Block\ParagraphParser;
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use League\CommonMark\Reference\ReferenceInterface;
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use League\CommonMark\Reference\ReferenceMap;
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final class MarkdownParser implements MarkdownParserInterface
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{
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    /** @psalm-readonly */
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    private EnvironmentInterface $environment;
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    /** @psalm-readonly-allow-private-mutation */
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    private int $maxNestingLevel;
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    /** @psalm-readonly-allow-private-mutation */
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    private ReferenceMap $referenceMap;
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    /** @psalm-readonly-allow-private-mutation */
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    private int $lineNumber = 0;
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    /** @psalm-readonly-allow-private-mutation */
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    private Cursor $cursor;
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    /**
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     * @var array<int, BlockContinueParserInterface>
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     *
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     * @psalm-readonly-allow-private-mutation
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     */
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    private array $activeBlockParsers = [];
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    /**
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     * @var array<int, BlockContinueParserWithInlinesInterface>
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     *
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     * @psalm-readonly-allow-private-mutation
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     */
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    private array $closedBlockParsers = [];
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    public function __construct(EnvironmentInterface $environment)
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    {
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        $this->environment = $environment;
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    }
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    private function initialize(): void
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    {
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        $this->referenceMap       = new ReferenceMap();
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        $this->lineNumber         = 0;
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        $this->activeBlockParsers = [];
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        $this->closedBlockParsers = [];
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        $this->maxNestingLevel = $this->environment->getConfiguration()->get('max_nesting_level');
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    }
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    /**
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     * @throws \RuntimeException
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     */
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    public function parse(string $input): Document
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    {
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        $this->initialize();
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        $documentParser = new DocumentBlockParser($this->referenceMap);
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        $this->activateBlockParser($documentParser);
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        $preParsedEvent = new DocumentPreParsedEvent($documentParser->getBlock(), new MarkdownInput($input));
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        $this->environment->dispatch($preParsedEvent);
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        $markdownInput = $preParsedEvent->getMarkdown();
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        foreach ($markdownInput->getLines() as $lineNumber => $line) {
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            $this->lineNumber = $lineNumber;
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            $this->parseLine($line);
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        }
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        // finalizeAndProcess
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        $this->closeBlockParsers(\count($this->activeBlockParsers), $this->lineNumber);
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        $this->processInlines();
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        $this->environment->dispatch(new DocumentParsedEvent($documentParser->getBlock()));
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        return $documentParser->getBlock();
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    }
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    /**
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     * Analyze a line of text and update the document appropriately. We parse markdown text by calling this on each
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     * line of input, then finalizing the document.
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     */
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    private function parseLine(string $line): void
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    {
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        $this->cursor = new Cursor($line);
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        $matches = $this->parseBlockContinuation();
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        if ($matches === null) {
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            return;
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        }
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        $unmatchedBlocks = \count($this->activeBlockParsers) - $matches;
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        $blockParser     = $this->activeBlockParsers[$matches - 1];
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        $startedNewBlock = false;
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        // Unless last matched container is a code block, try new container starts,
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        // adding children to the last matched container:
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        $tryBlockStarts = $blockParser->getBlock() instanceof Paragraph || $blockParser->isContainer();
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        while ($tryBlockStarts) {
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            // this is a little performance optimization
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            if ($this->cursor->isBlank()) {
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                $this->cursor->advanceToEnd();
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                break;
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            }
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            if ($blockParser->getBlock()->getDepth() >= $this->maxNestingLevel) {
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                break;
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            }
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            $blockStart = $this->findBlockStart($blockParser);
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            if ($blockStart === null || $blockStart->isAborting()) {
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                $this->cursor->advanceToNextNonSpaceOrTab();
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                break;
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            }
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            if (($state = $blockStart->getCursorState()) !== null) {
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                $this->cursor->restoreState($state);
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            }
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            $startedNewBlock = true;
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            // We're starting a new block. If we have any previous blocks that need to be closed, we need to do it now.
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            if ($unmatchedBlocks > 0) {
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                $this->closeBlockParsers($unmatchedBlocks, $this->lineNumber - 1);
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                $unmatchedBlocks = 0;
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            }
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            if ($blockStart->isReplaceActiveBlockParser()) {
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                $this->prepareActiveBlockParserForReplacement();
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            }
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            foreach ($blockStart->getBlockParsers() as $newBlockParser) {
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                $blockParser    = $this->addChild($newBlockParser);
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                $tryBlockStarts = $newBlockParser->isContainer();
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            }
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        }
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        // What remains at the offset is a text line. Add the text to the appropriate block.
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        // First check for a lazy paragraph continuation:
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        if (! $startedNewBlock && ! $this->cursor->isBlank() && $this->getActiveBlockParser()->canHaveLazyContinuationLines()) {
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            $this->getActiveBlockParser()->addLine($this->cursor->getRemainder());
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        } else {
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            // finalize any blocks not matched
177
            if ($unmatchedBlocks > 0) {
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                $this->closeBlockParsers($unmatchedBlocks, $this->lineNumber);
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            }
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            if (! $blockParser->isContainer()) {
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                $this->getActiveBlockParser()->addLine($this->cursor->getRemainder());
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            } elseif (! $this->cursor->isBlank()) {
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                $this->addChild(new ParagraphParser());
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                $this->getActiveBlockParser()->addLine($this->cursor->getRemainder());
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            }
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        }
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    }
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    private function parseBlockContinuation(): ?int
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    {
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        // For each containing block, try to parse the associated line start.
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        // The document will always match, so we can skip the first block parser and start at 1 matches
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        $matches = 1;
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        for ($i = 1; $i < \count($this->activeBlockParsers); $i++) {
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            $blockParser   = $this->activeBlockParsers[$i];
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            $blockContinue = $blockParser->tryContinue(clone $this->cursor, $this->getActiveBlockParser());
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            if ($blockContinue === null) {
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                break;
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            }
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            if ($blockContinue->isFinalize()) {
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                $this->closeBlockParsers(\count($this->activeBlockParsers) - $i, $this->lineNumber);
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205
                return null;
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            }
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208
            if (($state = $blockContinue->getCursorState()) !== null) {
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                $this->cursor->restoreState($state);
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            }
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212
            $matches++;
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        }
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        return $matches;
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    }
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    private function findBlockStart(BlockContinueParserInterface $lastMatchedBlockParser): ?BlockStart
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    {
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        $matchedBlockParser = new MarkdownParserState($this->getActiveBlockParser(), $lastMatchedBlockParser);
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        foreach ($this->environment->getBlockStartParsers() as $blockStartParser) {
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            \assert($blockStartParser instanceof BlockStartParserInterface);
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            if (($result = $blockStartParser->tryStart(clone $this->cursor, $matchedBlockParser)) !== null) {
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                return $result;
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            }
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        }
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        return null;
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    }
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    private function closeBlockParsers(int $count, int $endLineNumber): void
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    {
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        for ($i = 0; $i < $count; $i++) {
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            $blockParser = $this->deactivateBlockParser();
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            $this->finalize($blockParser, $endLineNumber);
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            // phpcs:disable SlevomatCodingStandard.ControlStructures.EarlyExit.EarlyExitNotUsed
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            if ($blockParser instanceof BlockContinueParserWithInlinesInterface) {
240
                // Remember for inline parsing
241
                $this->closedBlockParsers[] = $blockParser;
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            }
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        }
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    }
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    /**
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     * Finalize a block. Close it and do any necessary postprocessing, e.g. creating string_content from strings,
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     * setting the 'tight' or 'loose' status of a list, and parsing the beginnings of paragraphs for reference
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     * definitions.
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     */
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    private function finalize(BlockContinueParserInterface $blockParser, int $endLineNumber): void
252
    {
253
        if ($blockParser instanceof ParagraphParser) {
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            $this->updateReferenceMap($blockParser->getReferences());
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        }
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        $blockParser->getBlock()->setEndLine($endLineNumber);
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        $blockParser->closeBlock();
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    }
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    /**
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     * Walk through a block & children recursively, parsing string content into inline content where appropriate.
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     */
264
    private function processInlines(): void
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    {
266
        $p = new InlineParserEngine($this->environment, $this->referenceMap);
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        foreach ($this->closedBlockParsers as $blockParser) {
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            $blockParser->parseInlines($p);
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        }
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    }
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    /**
274
     * Add block of type tag as a child of the tip. If the tip can't accept children, close and finalize it and try
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     * its parent, and so on til we find a block that can accept children.
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     */
277
    private function addChild(BlockContinueParserInterface $blockParser): BlockContinueParserInterface
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    {
279
        $blockParser->getBlock()->setStartLine($this->lineNumber);
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281
        while (! $this->getActiveBlockParser()->canContain($blockParser->getBlock())) {
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            $this->closeBlockParsers(1, $this->lineNumber - 1);
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        }
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285
        $this->getActiveBlockParser()->getBlock()->appendChild($blockParser->getBlock());
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        $this->activateBlockParser($blockParser);
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288
        return $blockParser;
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    }
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291
    private function activateBlockParser(BlockContinueParserInterface $blockParser): void
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    {
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        $this->activeBlockParsers[] = $blockParser;
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    }
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    private function deactivateBlockParser(): BlockContinueParserInterface
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    {
298
        $popped = \array_pop($this->activeBlockParsers);
299
        if ($popped === null) {
300
            throw new \RuntimeException('The last block parser should not be deactivated');
301
        }
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        return $popped;
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    }
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    private function prepareActiveBlockParserForReplacement(): void
307
    {
308
        // Note that we don't want to parse inlines or finalize this block, as it's getting replaced.
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        $old = $this->deactivateBlockParser();
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311
        if ($old instanceof ParagraphParser) {
312
            $this->updateReferenceMap($old->getReferences());
313
        }
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315
        $old->getBlock()->detach();
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    }
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    /**
319
     * @param ReferenceInterface[] $references
320
     */
321
    private function updateReferenceMap(iterable $references): void
322
    {
323
        foreach ($references as $reference) {
324
            if (! $this->referenceMap->contains($reference->getLabel())) {
325
                $this->referenceMap->add($reference);
326
            }
327
        }
328
    }
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330
    public function getActiveBlockParser(): BlockContinueParserInterface
331
    {
332
        $active = \end($this->activeBlockParsers);
333
        if ($active === false) {
334
            throw new \RuntimeException('No active block parsers are available');
335
        }
336
 
337
        return $active;
338
    }
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}