/// <summary>
/// Gets the new dfa states produced by this partition
/// </summary>
/// <returns>The dfa states produced by this partition</returns>
public List <DFAState> GetDFAStates()
{
// For each group in the partition
foreach (DFAStateGroup group in groups)
{
bool found = false;
foreach (DFAState state in group.States)
{
if (state.ID == 0)
{
groups.Remove(group);
groups.Insert(0, group);
found = true;
break;
}
}
if (found)
{
break;
}
}
List <DFAState> states = new List <DFAState>();
// For each group in the partition
// Create the coresponding state and add the finals
foreach (DFAStateGroup group in groups)
{
// Create a new state
DFAState newState = new DFAState(states.Count);
// Add the terminal from the group to the new state
newState.AddItems(group.Representative.Items);
states.Add(newState);
}
// Do linkage
for (int i = 0; i != groups.Count; i++)
{
foreach (CharSpan Key in groups[i].Representative.Transitions)
{
states[i].AddTransition(Key, states[GetDFAStates_GetGroupIndexOf(groups[i].Representative.GetChildBy(Key))]);
}
}
return(states);
}
/// <summary>
/// Extracts the sub-DFA that leads to any of the specified states
/// </summary>
/// <param name="targets">States in this DFA</param>
/// <returns>The sub-DFA for the specified states</returns>
public DFA ExtractSubTo(IEnumerable <DFAState> targets)
{
if (targets == null)
{
throw new System.ArgumentException("The specified collection must not be null");
}
// build a list of all the required states
DFAInverse inverse = new DFAInverse(this);
List <DFAState> originals = inverse.CloseByAntecedents(targets);
// setup the list
int index = originals.IndexOf(states[0]);
if (index == -1)
{
throw new System.ArgumentException("The specified states are not reachable from the starting state");
}
originals[index] = originals[0];
originals[0] = states[0];
// copies the states
List <DFAState> copy = new List <DFAState>();
for (int i = 0; i != originals.Count; i++)
{
copy.Add(new DFAState(i));
}
for (int i = 0; i != originals.Count; i++)
{
DFAState original = originals[i];
DFAState clone = copy[i];
clone.AddItems(original.Items);
foreach (CharSpan key in original.Transitions)
{
index = originals.IndexOf(original.GetChildBy(key));
if (index != -1)
{
clone.AddTransition(key, copy[index]);
}
}
}
return(new DFA(copy));
}
