private static bool TryDerive([NotNull, ItemNotNull] List <Symbol> tape, int start, [NotNull] GrammarRule1 rule, ITracker tracker, [CanBeNull] Dictionary <GrammarRule1, bool> used) { if (tape.Count < start + rule.LeftHandSide.Count) { return(false); } var sublist = tape.GetRange(start, rule.LeftHandSide.Count); if (!sublist.SequenceEqual(rule.LeftHandSide)) { return(false); } if (used != null) { used[rule] = true; } tape.RemoveRange(start, rule.LeftHandSide.Count); tape.InsertRange(start, rule.RightHandSide); tracker.Track(tape, rule); return(true); }
public static bool TryDerive([NotNull, ItemNotNull] this List <Symbol> tape, [NotNull] GrammarRule1 rule, ITracker tracker, [CanBeNull] Dictionary <GrammarRule1, bool> used) => tape.Where((t, index) => TryDerive(tape, index, rule, tracker, used)).Any();
public void Track(IList <Symbol> track, GrammarRule1 rule) => Rules.Add(rule);