\\\\[*]|[^*]|[*][^*]*[*])+?)[*]{2}/s',
$markdown,
$matches
)
|| $marker === '_'
&& preg_match(
'/^__((?>\\\\_|[^_]|_[^_]*_)+?)__\b/us',
$markdown,
$matches
)
) {
$content = $matches[1];
// If nothing is contained in a strong,
// do not consider it valid.
if ($content === '') {
return [['text', $markdown[0]], 2];
}
// First and last chars of the strong text
// cannot be whitespace.
if (
strspn($content, " \t\n", 0, 1) === 0
&& strspn($content, " \t\n", -1) === 0
) {
return [
[
'strong',
$this->parseInline($content),
],
strlen($matches[0])
];
}
}
} else {
// Emphasis
// Avoid excessive regex backtracking if there is no closing marker.
if (strpos($markdown, $marker, 1) === false) {
return [['text', $markdown[0]], 1];
}
if (
$marker === '*'
&& preg_match(
'/^[*]((?>\\\\[*]|[^*]|[*][*][^*]+?[*][*])+?)[*](?![*][^*])/s',
$markdown,
$matches
)
|| $marker === '_'
&& preg_match(
'/^_((?>\\\\_|[^_]|__[^_]*__)+?)_(?!_[^_])\b/us',
$markdown,
$matches
)
) {
$content = $matches[1];
// If nothing is contained in an emphasis,
// do not consider it valid.
if ($content === '') {
return [['text', $markdown[0]], 2];
}
// First and last chars of the emphasised text
// cannot be whitespace.
if (
strspn($content, " \t\n", 0, 1) === 0
&& strspn($content, " \t\n", -1) === 0
) {
return [
[
'emph',
$this->parseInline($content),
],
strlen($matches[0])
];
}
}
}
return [['text', $markdown[0]], 1];
}
protected function renderStrong($block): string
{
return ''
. $this->renderAbsy($block[1])
. '';
}
protected function renderEmph($block): string
{
return ''
. $this->renderAbsy($block[1])
. '';
}
abstract protected function parseInline($text);
abstract protected function renderAbsy($blocks);
}