private function extractLineNumbers($buffer)
{
$this->sourcePositions = [0 => 0];
$prev = 0;
while (($pos = strpos($buffer, "\n", $prev)) !== false) {
$this->sourcePositions[] = $pos;
$prev = $pos + 1;
}
$this->sourcePositions[] = strlen($buffer);
if (substr($buffer, -1) !== "\n") {
$this->sourcePositions[] = strlen($buffer) + 1;
}
}