WordPress Version: 5.5
/**
* Returns the regexp for common whitespace characters.
*
* By default, spaces include new lines, tabs, nbsp entities, and the UTF-8 nbsp.
* This is designed to replace the PCRE \s sequence. In ticket #22692, that
* sequence was found to be unreliable due to random inclusion of the A0 byte.
*
* @since 4.0.0
*
* @return string The spaces regexp.
*/
function wp_spaces_regexp()
{
static $spaces = '';
if (empty($spaces)) {
/**
* Filters the regexp for common whitespace characters.
*
* This string is substituted for the \s sequence as needed in regular
* expressions. For websites not written in English, different characters
* may represent whitespace. For websites not encoded in UTF-8, the 0xC2 0xA0
* sequence may not be in use.
*
* @since 4.0.0
*
* @param string $spaces Regexp pattern for matching common whitespace characters.
*/
$spaces = apply_filters('wp_spaces_regexp', '[\r\n\t ]|\xC2\xA0| ');
}
return $spaces;
}