/**
* @param Symbol $nonTerminal
* @return ArraySet|null
*/
public function getTerminalSet(Symbol $nonTerminal)
{
$key = $nonTerminal->toString();
if (array_key_exists($key, $this->terminalSets)) {
return $this->terminalSets[$key];
}
return null;
}
public function add(Symbol $terminal)
{
$key = $terminal->toString();
if (array_key_exists($key, $this->terminals)) {
return false;
}
$this->terminals[$key] = $terminal;
return true;
}
public function matchSymbol(Symbol $symbol)
{
if ($symbol instanceof EpsilonSymbol) {
return true;
}
if (EpsilonSymbol::singletonInstance()->getType() == $symbol->getType()) {
return EpsilonSymbol::singletonInstance()->toString() == $symbol->toString();
}
return false;
}
/**
* @param Symbol $symbol
* @return array|NormalizedProduction[]
*/
public function getAllEntriesFor(Symbol $symbol)
{
$set = new ArraySet($this->productionHash);
foreach ($this->uniqueEntries as $entry) {
if ($entry->getNonTerminal()->toString() == $symbol->toString() || $entry->getTerminal()->toString() == $symbol->toString()) {
$otherSet = $entry->getProductionSet();
$set->addAll($otherSet);
}
}
return $set->toList();
}
/**
* @return string
*/
public function toHash()
{
$string = $this->nonTerminal->toString() . $this->terminal->toString();
$hash = md5($string);
return $hash;
}
/**
* @param Symbol $symbol
* @return bool
*/
public function matchSymbol(Symbol $symbol)
{
return $symbol->getType() === $this->type;
}
public function compare(Symbol $leftSymbol, Symbol $rightSymbol)
{
$leftString = $leftSymbol->toString();
$rightString = $rightSymbol->toString();
return strcmp($leftString, $rightString);
}
public function contains(Symbol $symbol)
{
return array_key_exists($symbol->toString(), $this->symbols);
}
/**
* @param Symbol $symbol
* @return bool
*/
public function match(Symbol $symbol)
{
$match = $symbol->getType() === Symbol::TYPE_TERMINAL;
$this->matchedOne |= $match;
return $match;
}
/**
* @param Symbol $symbol
* @return ExpressionSymbol
*/
public static function createAdapterForSymbol(Symbol $symbol)
{
$expression = new self($symbol->getType(), $symbol->toString());
return $expression;
}