// looks for an edit at depth "depth"
// returns false and null in bestScript if no edit is found at depth "depth"
// returns false and not null in bestScript if found
// returns true if timeout
internal bool GetNFAEditScriptTimeout(
int depth, long lastEditHash,
Automaton <BDD> currentNfa2,
List <NFAEdit> editList, int scriptCost,
NFAEditScript bestScript)
{
// if timeout return true
if (sw.ElapsedMilliseconds > timeout)
{
return(true);
}
//Stop if no more moves left
if (depth == 0)
{
if (DFAUtilities.ApproximateMNEquivalent(tests, nfa1density, currentNfa2, al, solver) && currentNfa2.IsEquivalentWith(nfa1, solver))
{
//check if totalCost < finalScript cost and replace if needed
if (bestScript.script == null || scriptCost < bestScript.GetCost())
{
bestScript.script = ObjectCopier.Clone <List <NFAEdit> >(editList);
}
}
return(false);
}
NFAEdit edit = null;
long thisEditHash = 0;
#region Flip one state from fin to non fin
foreach (var state in currentNfa2.States)
{
thisEditHash = state;
if (CanAdd(thisEditHash, lastEditHash))
{
//flip its final non final status
var newFinalStates = new HashSet <int>(currentNfa2.GetFinalStates());
Automaton <BDD> nfa2new = null;
if (currentNfa2.GetFinalStates().Contains(state))
{
edit = new NFAEditState(state, false);
editList.Insert(0, edit);
newFinalStates.Remove(state);
nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, newFinalStates, currentNfa2.GetMoves());
}
else
{
edit = new NFAEditState(state, true);
editList.Insert(0, edit);
newFinalStates.Add(state);
nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, newFinalStates, currentNfa2.GetMoves());
}
if (GetNFAEditScriptTimeout(depth - 1, thisEditHash, nfa2new, editList, scriptCost + edit.GetCost(), bestScript))
{
return(true);
}
editList.RemoveAt(0);
}
}
#endregion
#region Change transition from source state
currentNfa2 = NFAUtilities.normalizeMoves(currentNfa2, solver);
foreach (var sourceState in currentNfa2.States)
{
HashSet <int> unreachedStates = new HashSet <int>(currentNfa2.States);
foreach (var moveFromSource in currentNfa2.GetMovesFrom(sourceState))
{
// take all chars in alphabet
foreach (var c in al)
{
long moveHash = currentNfa2.StateCount + IntegerUtil.TripleToInt(sourceState, moveFromSource.TargetState, alphabetMap[c]);
thisEditHash = currentNfa2.StateCount + moveHash;
if (CanAdd(thisEditHash, lastEditHash))
{
BDD cCond = solver.False;
BDD newCond = solver.False;
//skip epsilon moves
if (moveFromSource.Label != null)
{
// if c in move, remove it and recursion
if (solver.Contains(moveFromSource.Label, c))
{
cCond = solver.MkNot(solver.MkCharConstraint(false, c));
newCond = solver.MkAnd(moveFromSource.Label, cCond);
}
else // if c not in move, add it and recursion
{
cCond = solver.MkCharConstraint(false, c);
newCond = solver.MkOr(moveFromSource.Label, cCond);
}
var newMoves = new List <Move <BDD> >(currentNfa2.GetMoves());
newMoves.Remove(moveFromSource);
newMoves.Add(new Move <BDD>(sourceState, moveFromSource.TargetState, newCond));
var nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, currentNfa2.GetFinalStates(), newMoves);
edit = new NFAEditMove(sourceState, moveFromSource.TargetState, c);
editList.Insert(0, edit);
if (GetNFAEditScriptTimeout(depth - 1, thisEditHash, nfa2new, editList, scriptCost + edit.GetCost(), bestScript))
{
return(true);
}
editList.RemoveAt(0);
}
}
}
unreachedStates.Remove(moveFromSource.TargetState);
}
foreach (var targetState in unreachedStates)
{
//try adding a symbol not in transition
foreach (var c in al)
{
long moveHash = IntegerUtil.TripleToInt(sourceState, targetState, alphabetMap[c]);
thisEditHash = currentNfa2.StateCount + moveHash;
var moveCond = solver.MkCharConstraint(false, c);
var newMoves = new List <Move <BDD> >(currentNfa2.GetMoves());
newMoves.Add(new Move <BDD>(sourceState, targetState, moveCond));
var nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, currentNfa2.GetFinalStates(), newMoves);
edit = new NFAEditMove(sourceState, targetState, c);
editList.Insert(0, edit);
//TODO put correct hash
if (GetNFAEditScriptTimeout(depth - 1, thisEditHash, nfa2new, editList, scriptCost + edit.GetCost(), bestScript))
{
return(true);
}
editList.RemoveAt(0);
}
}
}
#endregion
return(false);
}
