/// <summary>Transverse the tree and create the follows table</summary>
/// <param name="node">The current node</param>
private void CreateFollowsTable(Node node)
{
if (node != null)
{
CreateFollowsTable(node.LeftChild);
CreateFollowsTable(node.RightChild);
if (node.LeftChild != null || node.RightChild != null)
{
if (node.Value.Equals("ยท"))
{
Tuple <int, string> key = new Tuple <int, string>(node.LeftChild.Identifier,
node.LeftChild.Value);
Tuple <List <int>[], bool> c1 = FirstLastTable[key];
key = new Tuple <int, string>(node.RightChild.Identifier, node.RightChild.Value);
Tuple <List <int>[], bool> c2 = FirstLastTable[key];
foreach (int last in c1.Item1[1])
{
Tuple <int, string> insert = FollowsTable.FirstOrDefault(x => x.Key.Item1 == last).Key;
FollowsTable[insert].AddRange(c2.Item1[0]);
}
}
else if (node.Value.Equals("*") || node.Value.Equals("+"))
{
Tuple <int, string> key = new Tuple <int, string>(node.LeftChild.Identifier,
node.LeftChild.Value);
Tuple <List <int>[], bool> c1 = FirstLastTable[key];
foreach (int last in c1.Item1[1])
{
Tuple <int, string> insert = FollowsTable.FirstOrDefault(x => x.Key.Item1 == last).Key;
FollowsTable[insert].AddRange(c1.Item1[0]);
}
}
}
}
}
/// <summary>Create the transitions</summary>
private void CreateTransitions()
{
int cont = 0;
List <int> initialStateValue = FirstLastTable.FirstOrDefault(x => x.Key.Item1 == Tree.Identifier).Value
.Item1[0];
Tuple <string, List <int> > initialState = new Tuple <string, List <int> >("State 0", initialStateValue);
Queue <Tuple <string, List <int> > > pendingStates = new Queue <Tuple <string, List <int> > >();
pendingStates.Enqueue(initialState);
while (pendingStates.Count > 0)
{
Dictionary <string, List <int> > values = new Dictionary <string, List <int> >();
Tuple <string, List <int> > state = pendingStates.Peek();
foreach (int number in state.Item2)
{
Tuple <int, string> followKey = FollowsTable.FirstOrDefault(x => x.Key.Item1 == number).Key;
string transitionWith = followKey.Item2;
List <int> transitionValues = new List <int>(FollowsTable[followKey]);
if (transitionValues.Count > 0)
{
if (values.ContainsKey(transitionWith))
{
foreach (int element in transitionValues)
{
if (!values[transitionWith].Contains(element))
{
values[transitionWith].Add(element);
}
}
}
else
{
values.Add(transitionWith, transitionValues);
}
values[transitionWith].Sort();
}
}
foreach (KeyValuePair <string, List <int> > value in values)
{
if (!Transitions.Any(x => x.Key.Item2.SequenceEqual(value.Value)) &&
!pendingStates.Any(x => x.Item2.SequenceEqual(value.Value)))
{
cont++;
Tuple <string, List <int> > newState = new Tuple <string, List <int> >("State " + cont, value.Value);
pendingStates.Enqueue(newState);
}
}
Tuple <string, List <int>, bool> key;
if (state.Item2.Contains(Tree.RightChild.Identifier))
{
key = new Tuple <string, List <int>, bool>(state.Item1, state.Item2, true);
}
else
{
key = new Tuple <string, List <int>, bool>(state.Item1, state.Item2, false);
}
pendingStates.Dequeue();
Transitions.Add(key, values);
}
}