/** * @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; }