public static Automaton Optional(Automaton a) { a = a.CloneExpandedIfRequired(); var s = new State(); s.AddEpsilon(a.Initial); s.Accept = true; a.Initial = s; a.IsDeterministic = false; a.ClearHashCode(); a.CheckMinimizeAlways(); return(a); }
public static Automaton MakeInterval(int min, int max, int digits) { var a = new Automaton(); var x = Convert.ToString(min); var y = Convert.ToString(max); if (min > max || (digits > 0 && y.Length > digits)) { throw new ArgumentException(); } var d = digits > 0 ? digits : y.Length; var sb1 = new StringBuilder(); for (var i = x.Length; i < d; i++) { _ = sb1.Append('0'); } _ = sb1.Append(x); x = sb1.ToString(); var sb2 = new StringBuilder(); for (var i = y.Length; i < d; i++) { _ = sb2.Append('0'); } _ = sb2.Append(y); y = sb2.ToString(); ICollection <State> initials = new List <State>(); a.Initial = Between(x, y, 0, initials, digits <= 0); if (digits <= 0) { var pairs = (from p in initials where a.Initial != p select new StatePair(a.Initial, p)).ToList(); a.AddEpsilons(pairs); a.Initial.AddTransition(new Transition('0', a.Initial)); a.IsDeterministic = false; } else { a.IsDeterministic = true; } a.CheckMinimizeAlways(); return(a); }
public static Automaton Repeat(Automaton a) { a = a.CloneExpanded(); var s = new State { Accept = true, }; s.AddEpsilon(a.Initial); foreach (var p in a.GetAcceptStates()) { p.AddEpsilon(s); } a.Initial = s; a.IsDeterministic = false; a.ClearHashCode(); a.CheckMinimizeAlways(); return(a); }
public static Automaton Concatenate(Automaton a1, Automaton a2) { if (a1.IsSingleton && a2.IsSingleton) { return(BasicAutomata.MakeString(a1.Singleton + a2.Singleton)); } if (IsEmpty(a1) || IsEmpty(a2)) { return(BasicAutomata.MakeEmpty()); } var deterministic = a1.IsSingleton && a2.IsDeterministic; if (a1 == a2) { a1 = a1.CloneExpanded(); a2 = a2.CloneExpanded(); } else { a1 = a1.CloneExpandedIfRequired(); a2 = a2.CloneExpandedIfRequired(); } foreach (var s in a1.GetAcceptStates()) { s.Accept = false; s.AddEpsilon(a2.Initial); } a1.IsDeterministic = deterministic; a1.ClearHashCode(); a1.CheckMinimizeAlways(); return(a1); }
public static void AddEpsilons(Automaton a, ICollection <StatePair> pairs) { a.ExpandSingleton(); var forward = new Dictionary <State, HashSet <State> >(); var back = new Dictionary <State, HashSet <State> >(); foreach (var p in pairs) { var to = forward[p.FirstState]; if (to == null) { to = new HashSet <State>(); forward.Add(p.FirstState, to); } _ = to.Add(p.SecondState); var from = back[p.SecondState]; if (from == null) { from = new HashSet <State>(); back.Add(p.SecondState, from); } _ = from.Add(p.FirstState); } var worklist = new LinkedList <StatePair>(pairs); var workset = new HashSet <StatePair>(pairs); while (worklist.Count != 0) { var p = worklist.RemoveAndReturnFirst(); _ = workset.Remove(p); var to = forward[p.SecondState]; var from = back[p.FirstState]; if (to != null) { foreach (var s in to) { var pp = new StatePair(p.FirstState, s); if (!pairs.Contains(pp)) { pairs.Add(pp); _ = forward[p.FirstState].Add(s); _ = back[s].Add(p.FirstState); _ = worklist.AddLast(pp); _ = workset.Add(pp); if (from != null) { foreach (var q in from) { var qq = new StatePair(q, p.FirstState); if (!workset.Contains(qq)) { _ = worklist.AddLast(qq); _ = workset.Add(qq); } } } } } } } foreach (var p in pairs) { p.FirstState.AddEpsilon(p.SecondState); } a.IsDeterministic = false; a.ClearHashCode(); a.CheckMinimizeAlways(); }
public static Automaton Intersection(Automaton a1, Automaton a2) { if (a1.IsSingleton) { return(a2.Run(a1.Singleton) ? a1.CloneIfRequired() : BasicAutomata.MakeEmpty()); } if (a2.IsSingleton) { return(a1.Run(a2.Singleton) ? a2.CloneIfRequired() : BasicAutomata.MakeEmpty()); } if (a1 == a2) { return(a1.CloneIfRequired()); } var transitions1 = Automaton.GetSortedTransitions(a1.GetStates()); var transitions2 = Automaton.GetSortedTransitions(a2.GetStates()); var c = new Automaton(); var worklist = new LinkedList <StatePair>(); var newstates = new Dictionary <StatePair, StatePair>(); var p = new StatePair(c.Initial, a1.Initial, a2.Initial); _ = worklist.AddLast(p); newstates.Add(p, p); while (worklist.Count > 0) { p = worklist.RemoveAndReturnFirst(); p.S.Accept = p.FirstState.Accept && p.SecondState.Accept; var t1 = transitions1[p.FirstState.Number]; var t2 = transitions2[p.SecondState.Number]; for (int n1 = 0, b2 = 0; n1 < t1.Length; n1++) { while (b2 < t2.Length && t2[b2].Max < t1[n1].Min) { b2++; } for (var n2 = b2; n2 < t2.Length && t1[n1].Max >= t2[n2].Min; n2++) { if (t2[n2].Max >= t1[n1].Min) { var q = new StatePair(t1[n1].To, t2[n2].To); _ = newstates.TryGetValue(q, out var r); if (r == null) { q.S = new State(); _ = worklist.AddLast(q); newstates.Add(q, q); r = q; } var min = t1[n1].Min > t2[n2].Min ? t1[n1].Min : t2[n2].Min; var max = t1[n1].Max < t2[n2].Max ? t1[n1].Max : t2[n2].Max; p.S.Transitions.Add(new Transition(min, max, r.S)); } } } } c.IsDeterministic = a1.IsDeterministic && a2.IsDeterministic; c.RemoveDeadTransitions(); c.CheckMinimizeAlways(); return(c); }