/// <summary>
/// Attempts to traverse the specified transition, given the current match state.
/// </summary>
/// <param name="input">The string input</param>
/// <param name="t">The transition to probe</param>
/// <param name="mode">The match mode</param>
/// <returns>The new match state or null if the transition cannot be traversed</returns>
public MatchState Traverse(string input, FSTTransition t, Matcher.MatchMode mode, bool ignoreCase)
{
#if false
bool consumed;
Label output;
if (t.CanTraverse(mode, input, _InputPosition, ignoreCase, out output, out consumed))
{
MatchState result = new MatchState(this);
result._State = t.Target;
result.AppendOutput(output);
if (consumed)
{
++result._ConsumedSymbols;
++result._InputPosition;
}
return(result);
}
else
{
return(null);
}
#else
Label matchLabel;
Label outputLabel;
switch (mode)
{
case Matcher.MatchMode.Analyse:
matchLabel = t.Input;
outputLabel = t.Output;
break;
case Matcher.MatchMode.Generate:
matchLabel = t.Output;
outputLabel = t.Input;
break;
default:
throw new Exception("Illegal case constant");
}
if (matchLabel.Matches(input, _InputPosition, ignoreCase))
{
MatchState result = new MatchState(this);
result._State = t.Target;
if (outputLabel.IsConsuming)
{
result._Output.Add(outputLabel);
}
if (matchLabel.IsConsuming)
{
++result._ConsumedSymbols;
++result._InputPosition;
}
return(result);
}
return(null);
#endif
}
public void Match(string input, bool matchWholeInput, MatchMode mode, int startOffset,
bool ignoreCase,
MatchFoundCallback matchFoundCallback,
ContinueIterationCallback continueIterationCallback)
{
if (startOffset < 0)
{
throw new ArgumentOutOfRangeException("startOffset");
}
if (matchFoundCallback == null)
{
throw new ArgumentNullException("callback");
}
int inputLength = String.IsNullOrEmpty(input) ? 0 : input.Length;
if (startOffset > inputLength)
{
return;
}
int start = _FST.GetStartState();
if (start < 0)
{
return;
}
#if DEBUG
bool dumpAutomaton = false;
if (dumpAutomaton)
{
_FST.Dump("D:/temp/fst.txt");
}
#endif
// TODO make sure the FST is not modified during transition
// NOTE the match callbacks throw each found match, not just the longest one. The
// caller needs to make sure that longer matches are scanned.
List <MatchState> states = new List <MatchState>();
bool continueMatchProcess = true;
MatchState startState = new MatchState(start);
startState.InputPosition = startOffset;
states.Add(startState);
if (_FST.IsFinal(startState.State))
{
if (!matchWholeInput || startState.InputPosition >= inputLength)
{
continueMatchProcess = matchFoundCallback(startState);
}
}
// remember the number of attempted/tested transitions to send caller a keep-alive signal
int ticks = 0;
bool logTransitions = false;
while (states.Count > 0 && continueMatchProcess)
{
/* we put the transition target states into a new list so that we don't mess
* around with the current one.
*/
List <MatchState> newStates = new List <MatchState>();
for (int s = states.Count - 1; s >= 0; --s)
{
MatchState ms = states[s];
State state = _FST.GetState(ms.State);
foreach (FSTTransition trans in state.Transitions)
{
/*
* if (state.TransitionsSorted
* && !ignoreCase
* && (mode == MatchMode.Analyse)
* && trans.Input.IsCharLabel
* && ms.InputPosition < input.Length
* && input[ms.InputPosition] > trans.Input.Symbol)
* {
* break;
* }
*/
++ticks;
MatchState next;
if ((next = ms.Traverse(input, trans, mode, ignoreCase)) != null)
{
if (logTransitions)
{
System.Diagnostics.Debug.WriteLine(String.Format("\tTraversing from ({0}, {1}/{2}) to ({3}, {4}/{5}) on {6}",
ms.State, ms.InputPosition, ms.ConsumedSymbols,
next.State, next.InputPosition, next.ConsumedSymbols,
ms.InputPosition < input.Length ? input[ms.InputPosition] : '#'));
}
newStates.Add(next);
if (_FST.IsFinal(next.State))
{
if (!matchWholeInput || next.InputPosition >= inputLength)
{
continueMatchProcess = matchFoundCallback(next);
}
}
}
}
}
states = null;
states = newStates;
if ((ticks % 1000) == 0 && continueMatchProcess && continueIterationCallback != null)
{
continueMatchProcess = continueIterationCallback(ticks);
}
}
}