public static bool Scan(this ITdfaSimulation automaton, int[] input, out State action)
{
State state = automaton.Start;
State?acceptingState = null;
foreach (var item in input)
{
State nextState;
if (automaton.TryNext(state, item, out nextState))
{
state = nextState;
}
else if (automaton.Tunnel(state, out nextState))
{
state = nextState;
}
else
{
break;
}
if (automaton.IsAccepting(state))
{
acceptingState = state;
}
}
if (!acceptingState.HasValue)
{
action = -1;
return(false);
}
var optAction = automaton.GetAction(acceptingState.Value);
action = optAction.GetValueOrDefault(-1);
return(true);
}
public IReceiver <Msg> Accept(IReceiver <Msg> visitor)
{
int start = 0, pos = 0;
int length = text.Length;
while (pos != length)
{
int state = tdfa.Start;
int?acceptingState = null;
// Find longest token
for (; pos != length;)
{
int item = text[pos];
int next;
if (tdfa.TryNext(state, item, out next))
{
state = next;
if (tdfa.IsAccepting(state))
{
acceptingState = state;
}
++pos;
}
else if (tdfa.Tunnel(state, out next))
{
state = next;
}
else
{
break;
}
}
// Fail
if (!acceptingState.HasValue)
{
throw new Exception("Unexpected character at pos " + pos);
}
int ruleIndex = tdfa.GetAction(acceptingState.Value) ?? -1;
int tokenLength = pos - start;
TokenFactoryDelegate tokenFactory = tokenFactories[ruleIndex];
if (tokenFactory != null)
{
var prod = descriptor.Matchers[ruleIndex];
// Emit next token
visitor = visitor.Next(
new Msg(
prod.Outcome.Index,
tokenFactory(text.Substring(start, tokenLength)),
new Loc(Loc.MemoryString, start, pos)));
}
start = pos;
}
return(visitor.Done());
}