function inject(self $ts)
{
if ($ts->isEmpty()) {
return;
}
if ($this->current instanceof NodeEnd) {
$this->jump($this->last->previous);
}
$a = $this->isEmpty() ? $this->first : $this->current;
$b = $ts->first->next;
$e = $ts->last->previous;
$f = $this->isEmpty() ? $this->last : $this->current->next;
self::link($a, $b);
self::link($e, $f);
}
protected final function error(TokenStream $ts)
{
if ($this->errorLevel === Error::ENABLED) {
return new Error($this->expected(), $ts->current(), $ts->last());
}
}
