/**
* @return Symbol[]
*/
public function getNonTerminals()
{
$productions = $this->getProductions();
$collected = array();
foreach ($productions as $production) {
$collected[] = $production->getNonTerminal();
}
$nonTerminals = HashCodeComparator::singletonInstance()->unique($collected);
return $nonTerminals;
}
/**
* @return array|Symbol[]
*/
public function getCollected()
{
if (count($this->collectedSymbols) == 0) {
return array();
}
$unique = HashCodeComparator::singletonInstance()->unique($this->collectedSymbols);
return $unique;
}