public IEnumerable <GrammarRule> AncestorRules(GrammarRule rule)
{
var parents = ParentRules(rule).ToList();
return(parents.Concat(parents.SelectMany(AncestorRules)).Distinct());
}
public bool IsLeaf(GrammarRule rule)
{
return(!Rules.Any(r => r.Parents.Contains(rule.Nonterminal)));
}
public IEnumerable <GrammarRule> ParentRules(GrammarRule rule)
{
return(Rules.Where(r => rule.Parents.Contains(r.Nonterminal)));
}