private StateNode _NodeNextState(TransitionKey tk, StateNode state)
{
StateNode stateNew = state.NextState(tk, false);
if (stateNew == null)
{
stateNew = _stateRoot.NextState(tk, false);
}
return(stateNew != null ? stateNew : _stateRoot);
}
// Adds a new object to a given sequence of transition keys in the
// graph. Traverses existing transitions and adds new states and
// transitions as necessary.
public void Add(IEnumerable <TransitionKey> rgtkTerminal, Terminal obj)
{
StateNode state = _stateRoot;
foreach (TransitionKey tk in rgtkTerminal)
{
state = state.NextState(tk, true);
}
state.AddTerminalObj(obj);
}
// Removes a terminal object associated with a given sequence of
// transition keys from the graph. This will also remove any state
// nodes that as a result wind up without any useful information
// in them (either a transition to a new state, or a list of objects
// associated with a terminal state).
private StateNode _StateRemove(TransitionKey[] rgtkTerminal, int itk, Terminal obj, StateNode stateCur)
{
if (itk < rgtkTerminal.Length)
{
TransitionKey tk = rgtkTerminal[itk];
StateNode stateNext = stateCur.NextState(tk, false);
if (stateNext == null)
{
throw new ArgumentException("String not found in graph", "rgtkTerminal");
}
stateNext = _StateRemove(rgtkTerminal, itk + 1, obj,
stateNext);
if (stateNext == null)
{
stateCur.RemoveLink(tk);
if (stateCur.Clink == 0)
{
stateCur = null;
}
}
}
else
{
if (stateCur.CobjTerminal == 0)
{
throw new ArgumentException("String not found in graph", "rgtkTerminal");
}
stateCur.RemoveTerminalObj(obj);
if (stateCur.CobjTerminal == 0)
{
stateCur = null;
}
}
return(stateCur);
}