public int Compare(Object x, Object y)
{
Nfa a = (Nfa)x;
Nfa b = (Nfa)y;
return(a.GetLabel() - b.GetLabel());
}
/*
* Function: sort_states
*/
public void sort_states()
{
nfa_set.Sort(0, nfa_set.Count, null);
//nfa_set.Sort(0, nfa_set.Count, new NfaComp());
#if OLD_DEBUG
Console.Write("NFA vector indices: ");
for (int index = 0; index < nfa_set.Count; index++)
{
Nfa elem = (Nfa)nfa_set[index];
Console.Write(Int32.ToString(elem.GetLabel()) + " ");
}
Console.Write("\n");
#endif
return;
}
/*
* function: Print_Set
*/
public static void Print_Set(ArrayList nfa_set)
{
int size;
int elem;
size = nfa_set.Count;
if (size == 0)
{
Console.Write("empty ");
}
for (elem = 0; elem < size; ++elem)
{
Nfa nfa = (Nfa)nfa_set[elem];
Console.Write(Int32.ToString(nfa.GetLabel()) + " ");
}
}
/*
* Function: e_closure
* Description: Alters input set.
*/
public void e_closure()
{
Nfa state = null;
/*
* Debug checks
*/
#if DEBUG
Utility.assert(null != nfa_set);
Utility.assert(null != nfa_bit);
#endif
accept = null;
anchor = Spec.NONE;
accept_index = Utility.INT_MAX;
/*
* Create initial stack.
*/
Stack nfa_stack = new Stack();
int size = nfa_set.Count;
for (int i = 0; i < size; i++)
{
state = (Nfa)nfa_set[i];
#if DEBUG
Utility.assert(nfa_bit.Get(state.GetLabel()));
#endif
nfa_stack.Push(state);
}
/*
* Main loop.
*/
while (nfa_stack.Count > 0)
{
Object o = nfa_stack.Pop();
if (o == null)
{
break;
}
state = (Nfa)o;
#if OLD_DUMP_DEBUG
if (null != state.GetAccept())
{
Console.WriteLine("Looking at accepting state "
+ Int32.ToString(state.GetLabel())
+ " with <"
+ state.GetAccept().action
+ ">");
}
#endif
if (null != state.GetAccept() && state.GetLabel() < accept_index)
{
accept_index = state.GetLabel();
accept = state.GetAccept();
anchor = state.GetAnchor();
#if OLD_DUMP_DEBUG
Console.WriteLine("Found accepting state "
+ Int32.ToString(state.GetLabel())
+ " with <"
+ state.GetAccept().action
+ ">");
#endif
#if DEBUG
Utility.assert(null != accept);
Utility.assert(Spec.NONE == anchor ||
0 != (anchor & Spec.END) ||
0 != (anchor & Spec.START));
#endif
}
if (Nfa.EPSILON == state.GetEdge())
{
if (state.GetNext() != null)
{
if (false == nfa_set.Contains(state.GetNext()))
{
#if DEBUG
Utility.assert(false == nfa_bit.Get(state.GetNext().GetLabel()));
#endif
nfa_bit.Set(state.GetNext().GetLabel(), true);
nfa_set.Add(state.GetNext());
nfa_stack.Push(state.GetNext());
}
}
if (null != state.GetSib())
{
if (false == nfa_set.Contains(state.GetSib()))
{
#if DEBUG
Utility.assert(false == nfa_bit.Get(state.GetSib().GetLabel()));
#endif
nfa_bit.Set(state.GetSib().GetLabel(), true);
nfa_set.Add(state.GetSib());
nfa_stack.Push(state.GetSib());
}
}
}
}
if (null != nfa_set)
{
sort_states();
}
}