<?php
/*
* This file is part of the league/commonmark package.
*
* (c) Colin O'Dell <[email protected]>
*
* Original code based on the CommonMark JS reference parser (https://bitly.com/commonmark-js)
* - (c) John MacFarlane
*
* Additional emphasis processing code based on commonmark-java (https://github.com/atlassian/commonmark-java)
* - (c) Atlassian Pty Ltd
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace League\CommonMark\Delimiter;
use League\CommonMark\Delimiter\Processor\DelimiterProcessorCollection;
use League\CommonMark\Inline\AdjacentTextMerger;
final class DelimiterStack
{
/**
* @var DelimiterInterface|null
*/
private $top;
/**
* @param DelimiterInterface $newDelimiter
*
* @return void
*/
public function push(DelimiterInterface $newDelimiter)
{
$newDelimiter->setPrevious($this->top);
if ($this->top !== null) {
$this->top->setNext($newDelimiter);
}
$this->top = $newDelimiter;
}
private function findEarliest(DelimiterInterface $stackBottom = null): ?DelimiterInterface
{
$delimiter = $this->top;
while ($delimiter !== null && $delimiter->getPrevious() !== $stackBottom) {
$delimiter = $delimiter->getPrevious();
}
return $delimiter;
}
/**
* @param DelimiterInterface $delimiter
*
* @return void
*/
public function removeDelimiter(DelimiterInterface $delimiter)
{
if ($delimiter->getPrevious() !== null) {
$delimiter->getPrevious()->setNext($delimiter->getNext());
}
if ($delimiter->getNext() === null) {
// top of stack
$this->top = $delimiter->getPrevious();
} else {
$delimiter->getNext()->setPrevious($delimiter->getPrevious());
}
}
private function removeDelimiterAndNode(DelimiterInterface $delimiter): void
{
$delimiter->getInlineNode()->detach();
$this->removeDelimiter($delimiter);
}
private function removeDelimitersBetween(DelimiterInterface $opener, DelimiterInterface $closer): void
{
$delimiter = $closer->getPrevious();
while ($delimiter !== null && $delimiter !== $opener) {
$previous = $delimiter->getPrevious();
$this->removeDelimiter($delimiter);
$delimiter = $previous;
}
}
/**
* @param DelimiterInterface|null $stackBottom
*
* @return void
*/
public function removeAll(DelimiterInterface $stackBottom = null)
{
while ($this->top && $this->top !== $stackBottom) {
$this->removeDelimiter($this->top);
}
}
/**
* @param string $character
*
* @return void
*/
public function removeEarlierMatches(string $character)
{
$opener = $this->top;
while ($opener !== null) {
if ($opener->getChar() === $character) {
$opener->setActive(false);
}
$opener = $opener->getPrevious();
}
}
/**
* @param string|string[] $characters
*
* @return DelimiterInterface|null
*/
public function searchByCharacter($characters): ?DelimiterInterface
{
if (!\is_array($characters)) {
$characters = [$characters];
}
$opener = $this->top;
while ($opener !== null) {
if (\in_array($opener->getChar(), $characters)) {
break;
}
$opener = $opener->getPrevious();
}
return $opener;
}
/**
* @param DelimiterInterface|null $stackBottom
* @param DelimiterProcessorCollection $processors
*
* @return void
*/
public function processDelimiters(?DelimiterInterface $stackBottom, DelimiterProcessorCollection $processors)
{
$openersBottom = [];
// Find first closer above stackBottom
$closer = $this->findEarliest($stackBottom);
// Move forward, looking for closers, and handling each
while ($closer !== null) {
$delimiterChar = $closer->getChar();
$delimiterProcessor = $processors->getDelimiterProcessor($delimiterChar);
if (!$closer->canClose() || $delimiterProcessor === null) {
$closer = $closer->getNext();
continue;
}
$openingDelimiterChar = $delimiterProcessor->getOpeningCharacter();
$useDelims = 0;
$openerFound = false;
$potentialOpenerFound = false;
$opener = $closer->getPrevious();
while ($opener !== null && $opener !== $stackBottom && $opener !== ($openersBottom[$delimiterChar] ?? null)) {
if ($opener->canOpen() && $opener->getChar() === $openingDelimiterChar) {
$potentialOpenerFound = true;
$useDelims = $delimiterProcessor->getDelimiterUse($opener, $closer);
if ($useDelims > 0) {
$openerFound = true;
break;
}
}
$opener = $opener->getPrevious();
}
if (!$openerFound) {
if (!$potentialOpenerFound) {
// Only do this when we didn't even have a potential
// opener (one that matches the character and can open).
// If an opener was rejected because of the number of
// delimiters (e.g. because of the "multiple of 3"
// Set lower bound for future searches for openersrule),
// we want to consider it next time because the number
// of delimiters can change as we continue processing.
$openersBottom[$delimiterChar] = $closer->getPrevious();
if (!$closer->canOpen()) {
// We can remove a closer that can't be an opener,
// once we've seen there's no matching opener.
$this->removeDelimiter($closer);
}
}
$closer = $closer->getNext();
continue;
}
$openerNode = $opener->getInlineNode();
$closerNode = $closer->getInlineNode();
// Remove number of used delimiters from stack and inline nodes.
$opener->setLength($opener->getLength() - $useDelims);
$closer->setLength($closer->getLength() - $useDelims);
$openerNode->setContent(\substr($openerNode->getContent(), 0, -$useDelims));
$closerNode->setContent(\substr($closerNode->getContent(), 0, -$useDelims));
$this->removeDelimitersBetween($opener, $closer);
// The delimiter processor can re-parent the nodes between opener and closer,
// so make sure they're contiguous already. Exclusive because we want to keep opener/closer themselves.
AdjacentTextMerger::mergeTextNodesBetweenExclusive($openerNode, $closerNode);
$delimiterProcessor->process($openerNode, $closerNode, $useDelims);
// No delimiter characters left to process, so we can remove delimiter and the now empty node.
if ($opener->getLength() === 0) {
$this->removeDelimiterAndNode($opener);
}
if ($closer->getLength() === 0) {
$next = $closer->getNext();
$this->removeDelimiterAndNode($closer);
$closer = $next;
}
}
// Remove all delimiters
$this->removeAll($stackBottom);
}
}