name : ReferenceParser.php <?php declare(strict_types=1); /* * This file is part of the league/commonmark package. * * (c) Colin O'Dell <colinodell@gmail.com> * * Original code based on the CommonMark JS reference parser (https://bitly.com/commonmark-js) * - (c) John MacFarlane * * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace League\CommonMark\Reference; use League\CommonMark\Parser\Cursor; use League\CommonMark\Util\LinkParserHelper; final class ReferenceParser { // Looking for the start of a definition, i.e. `[` private const START_DEFINITION = 0; // Looking for and parsing the label, i.e. `[foo]` within `[foo]` private const LABEL = 1; // Parsing the destination, i.e. `/url` in `[foo]: /url` private const DESTINATION = 2; // Looking for the start of a title, i.e. the first `"` in `[foo]: /url "title"` private const START_TITLE = 3; // Parsing the content of the title, i.e. `title` in `[foo]: /url "title"` private const TITLE = 4; // End state, no matter what kind of lines we add, they won't be references private const PARAGRAPH = 5; /** @psalm-readonly-allow-private-mutation */ private string $paragraph = ''; /** * @var array<int, ReferenceInterface> * * @psalm-readonly-allow-private-mutation */ private array $references = []; /** @psalm-readonly-allow-private-mutation */ private int $state = self::START_DEFINITION; /** @psalm-readonly-allow-private-mutation */ private ?string $label = null; /** @psalm-readonly-allow-private-mutation */ private ?string $destination = null; /** * @var string string * * @psalm-readonly-allow-private-mutation */ private string $title = ''; /** @psalm-readonly-allow-private-mutation */ private ?string $titleDelimiter = null; /** @psalm-readonly-allow-private-mutation */ private bool $referenceValid = false; public function getParagraphContent(): string { return $this->paragraph; } /** * @return ReferenceInterface[] */ public function getReferences(): iterable { $this->finishReference(); return $this->references; } public function hasReferences(): bool { return $this->references !== []; } public function parse(string $line): void { if ($this->paragraph !== '') { $this->paragraph .= "\n"; } $this->paragraph .= $line; $cursor = new Cursor($line); while (! $cursor->isAtEnd()) { $result = false; switch ($this->state) { case self::PARAGRAPH: // We're in a paragraph now. Link reference definitions can only appear at the beginning, so once // we're in a paragraph, there's no going back. return; case self::START_DEFINITION: $result = $this->parseStartDefinition($cursor); break; case self::LABEL: $result = $this->parseLabel($cursor); break; case self::DESTINATION: $result = $this->parseDestination($cursor); break; case self::START_TITLE: $result = $this->parseStartTitle($cursor); break; case self::TITLE: $result = $this->parseTitle($cursor); break; default: // this should never happen break; } if (! $result) { $this->state = self::PARAGRAPH; return; } } } private function parseStartDefinition(Cursor $cursor): bool { $cursor->advanceToNextNonSpaceOrTab(); if ($cursor->isAtEnd() || $cursor->getCurrentCharacter() !== '[') { return false; } $this->state = self::LABEL; $this->label = ''; $cursor->advance(); if ($cursor->isAtEnd()) { $this->label .= "\n"; } return true; } private function parseLabel(Cursor $cursor): bool { $cursor->advanceToNextNonSpaceOrTab(); $partialLabel = LinkParserHelper::parsePartialLinkLabel($cursor); if ($partialLabel === null) { return false; } \assert($this->label !== null); $this->label .= $partialLabel; if ($cursor->isAtEnd()) { // label might continue on next line $this->label .= "\n"; return true; } if ($cursor->getCurrentCharacter() !== ']') { return false; } $cursor->advance(); // end of label if ($cursor->getCurrentCharacter() !== ':') { return false; } $cursor->advance(); // spec: A link label can have at most 999 characters inside the square brackets if (\mb_strlen($this->label, 'UTF-8') > 999) { return false; } // spec: A link label must contain at least one non-whitespace character if (\trim($this->label) === '') { return false; } $cursor->advanceToNextNonSpaceOrTab(); $this->state = self::DESTINATION; return true; } private function parseDestination(Cursor $cursor): bool { $cursor->advanceToNextNonSpaceOrTab(); $destination = LinkParserHelper::parseLinkDestination($cursor); if ($destination === null) { return false; } $this->destination = $destination; $advanced = $cursor->advanceToNextNonSpaceOrTab(); if ($cursor->isAtEnd()) { // Destination was at end of line, so this is a valid reference for sure (and maybe a title). // If not at end of line, wait for title to be valid first. $this->referenceValid = true; $this->paragraph = ''; } elseif ($advanced === 0) { // spec: The title must be separated from the link destination by whitespace return false; } $this->state = self::START_TITLE; return true; } private function parseStartTitle(Cursor $cursor): bool { $cursor->advanceToNextNonSpaceOrTab(); if ($cursor->isAtEnd()) { $this->state = self::START_DEFINITION; return true; } $this->titleDelimiter = null; switch ($c = $cursor->getCurrentCharacter()) { case '"': case "'": $this->titleDelimiter = $c; break; case '(': $this->titleDelimiter = ')'; break; default: // no title delimter found break; } if ($this->titleDelimiter !== null) { $this->state = self::TITLE; $cursor->advance(); if ($cursor->isAtEnd()) { $this->title .= "\n"; } } else { $this->finishReference(); // There might be another reference instead, try that for the same character. $this->state = self::START_DEFINITION; } return true; } private function parseTitle(Cursor $cursor): bool { \assert($this->titleDelimiter !== null); $title = LinkParserHelper::parsePartialLinkTitle($cursor, $this->titleDelimiter); if ($title === null) { // Invalid title, stop return false; } // Did we find the end delimiter? $endDelimiterFound = false; if (\substr($title, -1) === $this->titleDelimiter) { $endDelimiterFound = true; // Chop it off $title = \substr($title, 0, -1); } $this->title .= $title; if (! $endDelimiterFound && $cursor->isAtEnd()) { // Title still going, continue on next line $this->title .= "\n"; return true; } // We either hit the end delimiter or some extra whitespace $cursor->advanceToNextNonSpaceOrTab(); if (! $cursor->isAtEnd()) { // spec: No further non-whitespace characters may occur on the line. return false; } $this->referenceValid = true; $this->finishReference(); $this->paragraph = ''; // See if there's another definition $this->state = self::START_DEFINITION; return true; } private function finishReference(): void { if (! $this->referenceValid) { return; } /** @psalm-suppress PossiblyNullArgument -- these can't possibly be null if we're in this state */ $this->references[] = new Reference($this->label, $this->destination, $this->title); $this->label = null; $this->referenceValid = false; $this->destination = null; $this->title = ''; $this->titleDelimiter = null; } }