public void DoNotBacktrack(int xi_token_type)
{
if (!NoBacktrackingTokens.Contains(xi_token_type))
{
NoBacktrackingTokens.Add(xi_token_type, xi_token_type);
}
}
private void GenerateStateCodeWalker(ail.net.parser.Fsa xi_fsa, ail.net.parser.FsaState xi_state, int xi_token_type, StringBuilder xio_code)
{
ail.net.framework.Assert.NonNullReference(xi_state, "xi_state");
if (xi_state.Id != xi_fsa.StartState.Id) // start state was generated earley with switch/case code
{
xi_state.Marked = true;
xio_code.Append(Environment.NewLine);
xio_code.Append(@"_q");
xio_code.Append(xi_state.Id.ToString());
xio_code.Append(@":");
bool finalstate = xi_state.Papa.FinalStates.Contains(xi_state.Id);
if (finalstate && xi_state.Token != (object)null)
{
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"PushState((int)");
xio_code.Append(Token.GetClassName());
xio_code.Append(@".EType.");
xio_code.Append(Token.GetTokenName(xi_state.Token.Type));
xio_code.Append(@"); // save accepted state for backtracking");
xio_code.Append(Environment.NewLine);
}
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"Next();");
xio_code.Append(Environment.NewLine);
for (int rank = 0, i = 0; ; rank++) // fix point
{
int length = xio_code.Length;
foreach (ail.net.parser.FsaTransition transition in xi_state.Transitions.Values)
{
ail.net.framework.Assert.NonNullReference(transition, "transition");
if (transition.Predicate.Rank == rank)
{
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
if (i > 0)
{
xio_code.Append(@"else ");
}
else
{
i++;
}
xio_code.Append(@"if(");
if (transition.Predicate.Context.Length != 0)
{
xio_code.Append("xi_context == ");
xio_code.Append(transition.Predicate.Context);
xio_code.Append(" && ");
}
xio_code.Append(transition.Predicate.Text);
xio_code.Append(@"(Current))");
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"{");
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab4);
xio_code.Append(@"goto _q");
xio_code.Append(transition.End.ToString());
xio_code.Append(@";");
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"}");
}
}
if (xio_code.Length == length && rank > ail.net.parser.FsaTransition.kMaxRankValue)
{
break;
}
}
if (!finalstate && HasBacktracking && !NoBacktrackingTokens.Contains(xi_token_type))
{
if (xi_state.Transitions.Values.Count > 0)
{
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"else");
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"{");
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab4);
}
else
{
xio_code.Append(kTab3);
}
xio_code.Append(@"PopState(); // restore the last accepted state, backtracking");
if (xi_state.Transitions.Values.Count > 0)
{
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"}");
}
}
xio_code.Append(Environment.NewLine);
xio_code.Append(kTab3);
xio_code.Append(@"goto _exit;");
}
int token_type = xi_token_type;
if (xi_state.Token != (object)null)
{
token_type = xi_state.Token.Type;
}
foreach (ail.net.parser.FsaTransition transition in xi_state.Transitions.Values)
{
ail.net.framework.Assert.NonNullReference(transition, "transition");
ail.net.parser.FsaState state = (ail.net.parser.FsaState)xi_fsa.States[transition.End];
ail.net.framework.Assert.NonNullReference(state, "state");
if (!state.Marked)
{
GenerateStateCodeWalker(xi_fsa, state, token_type, xio_code);
}
}
}
