/**
* @param \Helstern\Nomsky\Grammar\Symbol\SymbolSet $set
* @param NormalizedProduction $production
* @param \Helstern\Nomsky\GrammarAnalysis\ParseSets\ParseSets $followSets
* @param \Helstern\Nomsky\GrammarAnalysis\ParseSets\ParseSets $firstSets
*
* @return bool
*/
public function processProduction(SymbolSet $set, NormalizedProduction $production, ParseSets $followSets, ParseSets $firstSets)
{
$rhs = $production->getRightHandSide();
$epsilonAdded = $this->firstSetCalculator->processSymbolList($set, $rhs, $firstSets);
if ($epsilonAdded) {
$lhs = $production->getLeftHandSide();
$otherSet = $followSets->getTerminalSet($lhs);
$set->addAll($otherSet);
}
return $epsilonAdded;
}
/**
* @param SymbolSet $set
* @param NormalizedProduction $production
*
* @return bool
*/
public function processProduction(SymbolSet $set, NormalizedProduction $production)
{
$nonTerminal = $production->getLeftHandSide();
if ($set->contains($nonTerminal)) {
return false;
}
//directly generates epsilon (rhs is epsilon)
if ($this->directlyGeneratesEpsilon($production)) {
$set->add($nonTerminal);
return true;
}
//indirectly generates epsilon (all from rhs must generate epsilon)
if ($this->indirectlyGeneratesEpsilon($production, $set)) {
$set->add($nonTerminal);
return true;
}
return false;
}