/**
* Initializes grammar G = (N, T, P, S)
* @param PaccSet<PaccNonterminal>
* @param PaccSet<PaccTerminal>
* @param PaccSet<PaccProduction>
* @param PaccNonterminal
*/
public function __construct(PaccSet $nonterminals, PaccSet $terminals, PaccSet $productions, PaccNonterminal $start)
{
// check
if ($nonterminals->getType() !== 'PaccNonterminal') {
throw new InvalidArgumentException('PaccSet<PaccNonterminal> expected, PaccSet<' . $nonterminals->getType() . '> given.');
}
if ($terminals->getType() !== 'PaccTerminal') {
throw new InvalidArgumentException('PaccSet<PaccTerminal> expected, PaccSet<' . $terminals->getType() . '> given.');
}
if ($productions->getType() !== 'PaccProduction') {
throw new InvalidArgumentException('PaccSet<PaccProduction> expected, PaccSet<' . $productions->getType() . '> given.');
}
// initialize
$this->nonterminals = $nonterminals;
$this->terminals = $terminals;
$this->productions = $productions;
$this->start = $start;
}
/**
* @param PaccSet<PaccLRItem>
* @param PaccSymbol
* @return PaccSet<PaccLRItem>
*/
private function jump(PaccSet $items, PaccSymbol $symbol)
{
if ($items->getType() !== 'PaccLRItem') {
throw new InvalidArgumentException('Bad type - expected PaccSet<LRItem>, given PaccSet<' . $items->getType() . '>.');
}
$ret = new PaccSet('PaccLRItem');
foreach ($items as $item) {
if (!(current($item->afterDot()) !== FALSE && current($item->afterDot())->__eq($symbol))) {
continue;
}
$ret->add(new PaccLRItem($item->production, $item->dot + 1, $item->terminalindex));
}
return $this->closure($ret);
}
