public function push(CollectionInterface $set)
{
if ($set->count() > 0 && !$this->exists($set)) {
$this->_items[] = $set;
return true;
}
return false;
}
/**
* Calculates the closure set for the given set of rules
*
* @param \Phparser\Rule\RulesCollection $set Set of rules
* @return array
*/
protected function _closure(CollectionInterface $set)
{
$regex = implode('|', $this->variables());
$hasChanged = true;
while ($hasChanged) {
$hasChanged = false;
foreach ($set as $rule) {
$result = preg_match('/\\.\\b(' . $regex . ')\\b/', $rule->rhs(), $matches);
if ($result) {
$variable = str_replace('.', '', $matches[1]);
foreach ($this->_rules as $r) {
$lhs = $r->lhs();
if ($lhs == $variable) {
$newRHS = '.' . $r->rhs();
$newPro = new Rule("{$variable} -> {$newRHS}");
if ($set->push($newPro)) {
$hasChanged = true;
}
}
}
}
}
}
return $set;
}
/**
* Constructor.
*
* @param \Phparser\Rule\CollectionInterface $rules Rules of the grammar, used to
* extract all valid symbols (variables and terminals) which are the columns
* of this table.
*/
public function __construct(CollectionInterface $rules)
{
$this->_columns = array_merge($rules->terminals(), ['$'], $rules->variables());
}
