/// <summary>
/// Creates an automaton that repeats the sub-automaton a number of times in the given range [min, max]
/// </summary>
/// <param name="sub">The sub-automaton</param>
/// <param name="min">The minimum (included) number of time to repeat</param>
/// <param name="max">The maximum (included) number of time to repeat</param>
/// <returns>The new automaton</returns>
// TODO: should get rid of static methods
public static NFA NewRepeatRange(NFA sub, int min, int max)
{
NFA final = NewMinimal();
NFAState last = final.StateEntry;
for (int i = 0; i != min; i++)
{
NFA inner = sub.Clone();
final.states.AddRange(inner.states);
last.AddTransition(NFA.EPSILON, inner.StateEntry);
last = inner.StateExit;
}
for (int i = min; i != max; i++)
{
NFA inner = NewOptional(sub, true);
final.states.AddRange(inner.states);
last.AddTransition(NFA.EPSILON, inner.StateEntry);
last = inner.StateExit;
}
last.AddTransition(NFA.EPSILON, final.StateExit);
if (min == 0)
{
final.StateEntry.AddTransition(NFA.EPSILON, final.StateExit);
}
return(final);
}
/// <summary>
/// Creates an automaton that repeats the sub-automaton one or more times
/// </summary>
/// <param name="sub">The sub-automaton</param>
/// <param name="useClones">True to completely clone the sub-automaton</param>
/// <returns>The new automaton</returns>
// TODO: should get rid of static methods
public static NFA NewRepeatOneOrMore(NFA sub, bool useClones)
{
NFA final = NewMinimal();
if (useClones)
{
sub = sub.Clone();
}
final.states.AddRange(sub.states);
final.StateEntry.AddTransition(NFA.EPSILON, sub.StateEntry);
sub.StateExit.AddTransition(NFA.EPSILON, final.StateExit);
final.StateExit.AddTransition(NFA.EPSILON, sub.StateEntry);
return(final);
}
/// <summary>
/// Creates an automaton that concatenates the two sub-automaton
/// </summary>
/// <param name="left">The left automaton</param>
/// <param name="right">The right automaton</param>
/// <param name="useClones">True to completely clone the sub-automata</param>
/// <returns>The new automaton</returns>
// TODO: should get rid of static methods
public static NFA NewConcatenation(NFA left, NFA right, bool useClones)
{
NFA final = new NFA();
if (useClones)
{
left = left.Clone(true);
right = right.Clone(true);
}
final.states.AddRange(left.states);
final.states.AddRange(right.states);
final.StateEntry = left.StateEntry;
final.StateExit = right.StateExit;
left.StateExit.AddTransition(NFA.EPSILON, right.StateEntry);
return(final);
}
/// <summary>
/// Creates an automaton that is the union of the two sub-automaton
/// </summary>
/// <param name="left">The left automaton</param>
/// <param name="right">The right automaton</param>
/// <param name="useClones">True to completely clone the sub-automata</param>
/// <returns>The new automaton</returns>
// TODO: should get rid of static methods
public static NFA NewUnion(NFA left, NFA right, bool useClones)
{
NFA final = NewMinimal();
if (useClones)
{
left = left.Clone(true);
right = right.Clone(true);
}
final.states.AddRange(left.states);
final.states.AddRange(right.states);
final.StateEntry.AddTransition(NFA.EPSILON, left.StateEntry);
final.StateEntry.AddTransition(NFA.EPSILON, right.StateEntry);
left.StateExit.AddTransition(NFA.EPSILON, final.StateExit);
right.StateExit.AddTransition(NFA.EPSILON, final.StateExit);
return(final);
}
/// <summary>
/// Creates an automaton that is the difference between the left and right sub-automata
/// </summary>
/// <param name="left">The left automaton</param>
/// <param name="right">The right automaton</param>
/// <param name="useClones">True to completely clone the sub-automata</param>
/// <returns>The new automaton</returns>
// TODO: should get rid of static methods
public static NFA NewDifference(NFA left, NFA right, bool useClones)
{
NFA final = NewMinimal();
NFAState statePositive = final.AddNewState();
NFAState stateNegative = final.AddNewState();
statePositive.Mark = 1;
stateNegative.Mark = -1;
if (useClones)
{
left = left.Clone(true);
right = right.Clone(true);
}
final.states.AddRange(left.states);
final.states.AddRange(right.states);
final.StateEntry.AddTransition(NFA.EPSILON, left.StateEntry);
final.StateEntry.AddTransition(NFA.EPSILON, right.StateEntry);
left.StateExit.AddTransition(NFA.EPSILON, statePositive);
right.StateExit.AddTransition(NFA.EPSILON, stateNegative);
statePositive.AddTransition(NFA.EPSILON, final.StateExit);
final.StateExit.AddItem(DummyItem.Instance);
DFA equivalent = new DFA(final);
equivalent.Prune();
final = new NFA(equivalent);
final.StateExit = final.AddNewState();
foreach (NFAState state in final.states)
{
if (state.Items.Contains(DummyItem.Instance))
{
state.ClearItems();
state.AddTransition(NFA.EPSILON, final.StateExit);
}
}
return(final);
}