public RandomAcceptedStrings(Automaton a)
{
this.a = a;
if (a.IsSingleton)
{
leadsToAccept = null;
return;
}
// must use IdentityHashmap because two Transitions w/
// different start nodes can be considered the same
leadsToAccept = new JCG.Dictionary <Transition, bool?>(IdentityEqualityComparer <Transition> .Default);
IDictionary <State, IList <ArrivingTransition> > allArriving = new Dictionary <State, IList <ArrivingTransition> >();
Queue <State> q = new Queue <State>();
ISet <State> seen = new JCG.HashSet <State>();
// reverse map the transitions, so we can quickly look
// up all arriving transitions to a given state
foreach (State s in a.GetNumberedStates())
{
for (int i = 0; i < s.numTransitions; i++)
{
Transition t = s.TransitionsArray[i];
if (!allArriving.TryGetValue(t.to, out IList <ArrivingTransition> tl) || tl == null)
{
tl = new List <ArrivingTransition>();
allArriving[t.to] = tl;
}
tl.Add(new ArrivingTransition(s, t));
}
if (s.Accept)
{
q.Enqueue(s);
seen.Add(s);
}
}
// Breadth-first search, from accept states,
// backwards:
while (q.Count > 0)
{
State s = q.Dequeue();
if (allArriving.TryGetValue(s, out IList <ArrivingTransition> arriving) && arriving != null)
{
foreach (ArrivingTransition at in arriving)
{
State from = at.from;
if (!seen.Contains(from))
{
q.Enqueue(from);
seen.Add(from);
leadsToAccept[at.t] = true;
}
}
}
}
}
/// <summary>
/// Converts an incoming utf32 <see cref="Automaton"/> to an equivalent
/// utf8 one. The incoming automaton need not be
/// deterministic. Note that the returned automaton will
/// not in general be deterministic, so you must
/// determinize it if that's needed.
/// </summary>
public Automaton Convert(Automaton utf32)
{
if (utf32.IsSingleton)
{
utf32 = utf32.CloneExpanded();
}
State[] map = new State[utf32.GetNumberedStates().Length];
JCG.List <State> pending = new JCG.List <State>();
State utf32State = utf32.GetInitialState();
pending.Add(utf32State);
Automaton utf8 = new Automaton();
utf8.IsDeterministic = false;
State utf8State = utf8.GetInitialState();
utf8States = new State[5];
utf8StateCount = 0;
utf8State.number = utf8StateCount;
utf8States[utf8StateCount] = utf8State;
utf8StateCount++;
utf8State.Accept = utf32State.Accept;
map[utf32State.number] = utf8State;
while (pending.Count != 0)
{
utf32State = pending[pending.Count - 1];
pending.RemoveAt(pending.Count - 1);
utf8State = map[utf32State.number];
for (int i = 0; i < utf32State.numTransitions; i++)
{
Transition t = utf32State.TransitionsArray[i];
State destUTF32 = t.to;
State destUTF8 = map[destUTF32.number];
if (destUTF8 == null)
{
destUTF8 = NewUTF8State();
destUTF8.accept = destUTF32.accept;
map[destUTF32.number] = destUTF8;
pending.Add(destUTF32);
}
ConvertOneEdge(utf8State, destUTF8, t.min, t.max);
}
}
utf8.SetNumberedStates(utf8States, utf8StateCount);
return(utf8);
}
/// <summary>
/// Returns a (deterministic) automaton that accepts the complement of the
/// language of the given automaton.
/// <para/>
/// Complexity: linear in number of states (if already deterministic).
/// </summary>
public static Automaton Complement(Automaton a)
{
a = a.CloneExpandedIfRequired();
a.Determinize();
a.Totalize();
foreach (State p in a.GetNumberedStates())
{
p.accept = !p.accept;
}
a.RemoveDeadTransitions();
return(a);
}
/// <summary>
/// Constructs a new <code>RunAutomaton</code> from a deterministic
/// <code>Automaton</code>.
/// </summary>
/// <param name="a"> an automaton </param>
/// <param name="maxInterval"></param>
/// <param name="tableize"></param>
public RunAutomaton(Automaton a, int maxInterval, bool tableize)
{
this._maxInterval = maxInterval;
a.Determinize();
_points = a.GetStartPoints();
State[] states = a.GetNumberedStates();
m_initial = a.initial.Number;
_size = states.Length;
m_accept = new bool[_size];
m_transitions = new int[_size * _points.Length];
for (int n = 0; n < _size * _points.Length; n++)
{
m_transitions[n] = -1;
}
foreach (State s in states)
{
int n = s.number;
m_accept[n] = s.accept;
for (int c = 0; c < _points.Length; c++)
{
State q = s.Step(_points[c]);
if (q != null)
{
m_transitions[n * _points.Length + c] = q.number;
}
}
}
/*
* Set alphabet table for optimal run performance.
*/
if (tableize)
{
_classmap = new int[maxInterval + 1];
int i = 0;
for (int j = 0; j <= maxInterval; j++)
{
if (i + 1 < _points.Length && j == _points[i + 1])
{
i++;
}
_classmap[j] = i;
}
}
else
{
_classmap = null;
}
}
/// <summary>
/// Reverses the language of the given (non-singleton) automaton while returning
/// the set of new initial states.
/// </summary>
public static ISet <State> Reverse(Automaton a)
{
a.ExpandSingleton();
// reverse all edges
Dictionary <State, ISet <Transition> > m = new Dictionary <State, ISet <Transition> >();
State[] states = a.GetNumberedStates();
ISet <State> accept = new JCG.HashSet <State>();
foreach (State s in states)
{
if (s.Accept)
{
accept.Add(s);
}
}
foreach (State r in states)
{
m[r] = new JCG.HashSet <Transition>();
r.accept = false;
}
foreach (State r in states)
{
foreach (Transition t in r.GetTransitions())
{
m[t.to].Add(new Transition(t.min, t.max, r));
}
}
foreach (State r in states)
{
ISet <Transition> tr = m[r];
r.SetTransitions(tr.ToArray(/*new Transition[tr.Count]*/));
}
// make new initial+final states
a.initial.accept = true;
a.initial = new State();
foreach (State r in accept)
{
a.initial.AddEpsilon(r); // ensures that all initial states are reachable
}
a.deterministic = false;
a.ClearNumberedStates();
return(accept);
}
/// <summary>
/// Minimizes the given automaton using Hopcroft's algorithm.
/// </summary>
public static void MinimizeHopcroft(Automaton a)
{
a.Determinize();
if (a.initial.numTransitions == 1)
{
Transition t = a.initial.TransitionsArray[0];
if (t.to == a.initial && t.min == Character.MIN_CODE_POINT && t.max == Character.MAX_CODE_POINT)
{
return;
}
}
a.Totalize();
// initialize data structures
int[] sigma = a.GetStartPoints();
State[] states = a.GetNumberedStates();
int sigmaLen = sigma.Length, statesLen = states.Length;
List <State>[,] reverse = new List <State> [statesLen, sigmaLen];
ISet <State>[] partition = new EquatableSet <State> [statesLen];
List <State>[] splitblock = new List <State> [statesLen];
int[] block = new int[statesLen];
StateList[,] active = new StateList[statesLen, sigmaLen];
StateListNode[,] active2 = new StateListNode[statesLen, sigmaLen];
LinkedList <Int32Pair> pending = new LinkedList <Int32Pair>();
OpenBitSet pending2 = new OpenBitSet(sigmaLen * statesLen);
OpenBitSet split = new OpenBitSet(statesLen),
refine = new OpenBitSet(statesLen), refine2 = new OpenBitSet(statesLen);
for (int q = 0; q < statesLen; q++)
{
splitblock[q] = new List <State>();
partition[q] = new EquatableSet <State>();
for (int x = 0; x < sigmaLen; x++)
{
active[q, x] = new StateList();
}
}
// find initial partition and reverse edges
for (int q = 0; q < statesLen; q++)
{
State qq = states[q];
int j = qq.accept ? 0 : 1;
partition[j].Add(qq);
block[q] = j;
for (int x = 0; x < sigmaLen; x++)
{
//List<State>[] r = reverse[qq.Step(sigma[x]).number];
var r = qq.Step(sigma[x]).number;
if (reverse[r, x] == null)
{
reverse[r, x] = new List <State>();
}
reverse[r, x].Add(qq);
}
}
// initialize active sets
for (int j = 0; j <= 1; j++)
{
for (int x = 0; x < sigmaLen; x++)
{
foreach (State qq in partition[j])
{
if (reverse[qq.number, x] != null)
{
active2[qq.number, x] = active[j, x].Add(qq);
}
}
}
}
// initialize pending
for (int x = 0; x < sigmaLen; x++)
{
int j = (active[0, x].Count <= active[1, x].Count) ? 0 : 1;
pending.AddLast(new Int32Pair(j, x));
pending2.Set(x * statesLen + j);
}
// process pending until fixed point
int k = 2;
while (pending.Count > 0)
{
Int32Pair ip = pending.First.Value;
pending.Remove(ip);
int p = ip.N1;
int x = ip.N2;
pending2.Clear(x * statesLen + p);
// find states that need to be split off their blocks
for (StateListNode m = active[p, x].First; m != null; m = m.Next)
{
List <State> r = reverse[m.Q.number, x];
if (r != null)
{
foreach (State s in r)
{
int i = s.number;
if (!split.Get(i))
{
split.Set(i);
int j = block[i];
splitblock[j].Add(s);
if (!refine2.Get(j))
{
refine2.Set(j);
refine.Set(j);
}
}
}
}
}
// refine blocks
for (int j = refine.NextSetBit(0); j >= 0; j = refine.NextSetBit(j + 1))
{
List <State> sb = splitblock[j];
if (sb.Count < partition[j].Count)
{
ISet <State> b1 = partition[j];
ISet <State> b2 = partition[k];
foreach (State s in sb)
{
b1.Remove(s);
b2.Add(s);
block[s.number] = k;
for (int c = 0; c < sigmaLen; c++)
{
StateListNode sn = active2[s.number, c];
if (sn != null && sn.Sl == active[j, c])
{
sn.Remove();
active2[s.number, c] = active[k, c].Add(s);
}
}
}
// update pending
for (int c = 0; c < sigmaLen; c++)
{
int aj = active[j, c].Count, ak = active[k, c].Count, ofs = c * statesLen;
if (!pending2.Get(ofs + j) && 0 < aj && aj <= ak)
{
pending2.Set(ofs + j);
pending.AddLast(new Int32Pair(j, c));
}
else
{
pending2.Set(ofs + k);
pending.AddLast(new Int32Pair(k, c));
}
}
k++;
}
refine2.Clear(j);
foreach (State s in sb)
{
split.Clear(s.number);
}
sb.Clear();
}
refine.Clear(0, refine.Length - 1);
}
// make a new state for each equivalence class, set initial state
State[] newstates = new State[k];
for (int n = 0; n < newstates.Length; n++)
{
State s = new State();
newstates[n] = s;
foreach (State q in partition[n])
{
if (q == a.initial)
{
a.initial = s;
}
s.accept = q.accept;
s.number = q.number; // select representative
q.number = n;
}
}
// build transitions and set acceptance
for (int n = 0; n < newstates.Length; n++)
{
State s = newstates[n];
s.accept = states[s.number].accept;
foreach (Transition t in states[s.number].GetTransitions())
{
s.AddTransition(new Transition(t.min, t.max, newstates[t.to.number]));
}
}
a.ClearNumberedStates();
a.RemoveDeadTransitions();
}
/// <summary>
/// Determinizes the given automaton.
/// <para/>
/// Worst case complexity: exponential in number of states.
/// </summary>
public static void Determinize(Automaton a)
{
if (a.IsDeterministic || a.IsSingleton)
{
return;
}
State[] allStates = a.GetNumberedStates();
// subset construction
bool initAccept = a.initial.accept;
int initNumber = a.initial.number;
a.initial = new State();
SortedInt32Set.FrozenInt32Set initialset = new SortedInt32Set.FrozenInt32Set(initNumber, a.initial);
LinkedList <SortedInt32Set.FrozenInt32Set> worklist = new LinkedList <SortedInt32Set.FrozenInt32Set>();
IDictionary <SortedInt32Set.FrozenInt32Set, State> newstate = new Dictionary <SortedInt32Set.FrozenInt32Set, State>();
worklist.AddLast(initialset);
a.initial.accept = initAccept;
newstate[initialset] = a.initial;
int newStateUpto = 0;
State[] newStatesArray = new State[5];
newStatesArray[newStateUpto] = a.initial;
a.initial.number = newStateUpto;
newStateUpto++;
// like Set<Integer,PointTransitions>
PointTransitionSet points = new PointTransitionSet();
// like SortedMap<Integer,Integer>
SortedInt32Set statesSet = new SortedInt32Set(5);
// LUCENENET NOTE: The problem here is almost certainly
// due to the conversion to FrozenIntSet along with its
// differing equality checking.
while (worklist.Count > 0)
{
SortedInt32Set.FrozenInt32Set s = worklist.First.Value;
worklist.Remove(s);
// Collate all outgoing transitions by min/1+max:
for (int i = 0; i < s.values.Length; i++)
{
State s0 = allStates[s.values[i]];
for (int j = 0; j < s0.numTransitions; j++)
{
points.Add(s0.TransitionsArray[j]);
}
}
if (points.count == 0)
{
// No outgoing transitions -- skip it
continue;
}
points.Sort();
int lastPoint = -1;
int accCount = 0;
State r = s.state;
for (int i = 0; i < points.count; i++)
{
int point = points.points[i].point;
if (statesSet.upto > 0)
{
Debug.Assert(lastPoint != -1);
statesSet.ComputeHash();
State q;
if (!newstate.TryGetValue(statesSet.ToFrozenInt32Set(), out q) || q == null)
{
q = new State();
SortedInt32Set.FrozenInt32Set p = statesSet.Freeze(q);
worklist.AddLast(p);
if (newStateUpto == newStatesArray.Length)
{
State[] newArray = new State[ArrayUtil.Oversize(1 + newStateUpto, RamUsageEstimator.NUM_BYTES_OBJECT_REF)];
Array.Copy(newStatesArray, 0, newArray, 0, newStateUpto);
newStatesArray = newArray;
}
newStatesArray[newStateUpto] = q;
q.number = newStateUpto;
newStateUpto++;
q.accept = accCount > 0;
newstate[p] = q;
}
else
{
Debug.Assert((accCount > 0) == q.accept, "accCount=" + accCount + " vs existing accept=" + q.accept + " states=" + statesSet);
}
r.AddTransition(new Transition(lastPoint, point - 1, q));
}
// process transitions that end on this point
// (closes an overlapping interval)
Transition[] transitions = points.points[i].ends.transitions;
int limit = points.points[i].ends.count;
for (int j = 0; j < limit; j++)
{
Transition t = transitions[j];
int num = t.to.number;
statesSet.Decr(num);
accCount -= t.to.accept ? 1 : 0;
}
points.points[i].ends.count = 0;
// process transitions that start on this point
// (opens a new interval)
transitions = points.points[i].starts.transitions;
limit = points.points[i].starts.count;
for (int j = 0; j < limit; j++)
{
Transition t = transitions[j];
int num = t.to.number;
statesSet.Incr(num);
accCount += t.to.accept ? 1 : 0;
}
lastPoint = point;
points.points[i].starts.count = 0;
}
points.Reset();
Debug.Assert(statesSet.upto == 0, "upto=" + statesSet.upto);
}
a.deterministic = true;
a.SetNumberedStates(newStatesArray, newStateUpto);
}
/// <summary>
/// Returns <c>true</c> if the given string is accepted by the automaton.
/// <para/>
/// Complexity: linear in the length of the string.
/// <para/>
/// <b>Note:</b> for full performance, use the <see cref="RunAutomaton"/> class.
/// </summary>
public static bool Run(Automaton a, string s)
{
if (a.IsSingleton)
{
return(s.Equals(a.singleton, StringComparison.Ordinal));
}
if (a.deterministic)
{
State p = a.initial;
for (int i = 0, cp = 0; i < s.Length; i += Character.CharCount(cp))
{
State q = p.Step(cp = Character.CodePointAt(s, i));
if (q == null)
{
return(false);
}
p = q;
}
return(p.accept);
}
else
{
State[] states = a.GetNumberedStates();
LinkedList <State> pp = new LinkedList <State>();
LinkedList <State> pp_other = new LinkedList <State>();
OpenBitSet bb = new OpenBitSet(states.Length);
OpenBitSet bb_other = new OpenBitSet(states.Length);
pp.AddLast(a.initial);
List <State> dest = new List <State>();
bool accept = a.initial.accept;
for (int i = 0, c = 0; i < s.Length; i += Character.CharCount(c))
{
c = Character.CodePointAt(s, i);
accept = false;
pp_other.Clear();
bb_other.Clear(0, bb_other.Length - 1);
foreach (State p in pp)
{
dest.Clear();
p.Step(c, dest);
foreach (State q in dest)
{
if (q.accept)
{
accept = true;
}
if (!bb_other.Get(q.number))
{
bb_other.Set(q.number);
pp_other.AddLast(q);
}
}
}
LinkedList <State> tp = pp;
pp = pp_other;
pp_other = tp;
OpenBitSet tb = bb;
bb = bb_other;
bb_other = tb;
}
return(accept);
}
}
/// <summary>
/// Determinizes the given automaton.
/// <para/>
/// Worst case complexity: exponential in number of states.
/// </summary>
public static void Determinize(Automaton a)
{
if (a.IsDeterministic || a.IsSingleton)
{
return;
}
State[] allStates = a.GetNumberedStates();
// subset construction
bool initAccept = a.initial.accept;
int initNumber = a.initial.number;
a.initial = new State();
SortedInt32Set.FrozenInt32Set initialset = new SortedInt32Set.FrozenInt32Set(initNumber, a.initial);
Queue <SortedInt32Set.FrozenInt32Set> worklist = new Queue <SortedInt32Set.FrozenInt32Set>(); // LUCENENET specific - Queue is much more performant than LinkedList
IDictionary <SortedInt32Set.FrozenInt32Set, State> newstate = new Dictionary <SortedInt32Set.FrozenInt32Set, State>();
worklist.Enqueue(initialset);
a.initial.accept = initAccept;
newstate[initialset] = a.initial;
int newStateUpto = 0;
State[] newStatesArray = new State[5];
newStatesArray[newStateUpto] = a.initial;
a.initial.number = newStateUpto;
newStateUpto++;
// like Set<Integer,PointTransitions>
PointTransitionSet points = new PointTransitionSet();
// like SortedMap<Integer,Integer>
SortedInt32Set statesSet = new SortedInt32Set(5);
while (worklist.Count > 0)
{
SortedInt32Set.FrozenInt32Set s = worklist.Dequeue();
//worklist.Remove(s);
// Collate all outgoing transitions by min/1+max:
for (int i = 0; i < s.values.Length; i++)
{
State s0 = allStates[s.values[i]];
for (int j = 0; j < s0.numTransitions; j++)
{
points.Add(s0.TransitionsArray[j]);
}
}
if (points.count == 0)
{
// No outgoing transitions -- skip it
continue;
}
points.Sort();
int lastPoint = -1;
int accCount = 0;
State r = s.state;
for (int i = 0; i < points.count; i++)
{
int point = points.points[i].point;
if (statesSet.upto > 0)
{
if (Debugging.AssertsEnabled)
{
Debugging.Assert(lastPoint != -1);
}
statesSet.ComputeHash();
if (!newstate.TryGetValue(statesSet.ToFrozenInt32Set(), out State q) || q == null)
{
q = new State();
SortedInt32Set.FrozenInt32Set p = statesSet.Freeze(q);
worklist.Enqueue(p);
if (newStateUpto == newStatesArray.Length)
{
// LUCENENET: Resize rather than copy
Array.Resize(ref newStatesArray, ArrayUtil.Oversize(1 + newStateUpto, RamUsageEstimator.NUM_BYTES_OBJECT_REF));
}
newStatesArray[newStateUpto] = q;
q.number = newStateUpto;
newStateUpto++;
q.accept = accCount > 0;
newstate[p] = q;
}
else
{
if (Debugging.AssertsEnabled)
{
Debugging.Assert((accCount > 0) == q.accept, "accCount={0} vs existing accept={1} states={2}", accCount, q.accept, statesSet);
}
}
r.AddTransition(new Transition(lastPoint, point - 1, q));
}
// process transitions that end on this point
// (closes an overlapping interval)
Transition[] transitions = points.points[i].ends.transitions;
int limit = points.points[i].ends.count;
for (int j = 0; j < limit; j++)
{
Transition t = transitions[j];
int num = t.to.number;
statesSet.Decr(num);
accCount -= t.to.accept ? 1 : 0;
}
points.points[i].ends.count = 0;
// process transitions that start on this point
// (opens a new interval)
transitions = points.points[i].starts.transitions;
limit = points.points[i].starts.count;
for (int j = 0; j < limit; j++)
{
Transition t = transitions[j];
int num = t.to.number;
statesSet.Incr(num);
accCount += t.to.accept ? 1 : 0;
}
lastPoint = point;
points.points[i].starts.count = 0;
}
points.Reset();
if (Debugging.AssertsEnabled)
{
Debugging.Assert(statesSet.upto == 0, "upto={0}", statesSet.upto);
}
}
a.deterministic = true;
a.SetNumberedStates(newStatesArray, newStateUpto);
}