str.replace(/(?<=\S)(?=[А-ЯЁ])/g, ' ')
str.replace(/(\S)([А-ЯЁ])/g, '$1 $2')
$doc = new DOMDocument();
$doc->loadHTML($html);
$a = $doc->getElementsByTagName('a');
$result = array_map([ $doc, 'saveHTML' ], iterator_to_array($a));
const lines = data.split('\n').map(n => n.replace(/X\S+/, 'hello, world!!'));