protected internal virtual IntervalSet GetErrorRecoverySet(Parser recognizer)
{
ATN atn = recognizer.Interpreter.atn;
RuleContext ctx = recognizer._ctx;
IntervalSet recoverSet = new IntervalSet();
while (ctx != null && ctx.invokingState >= 0)
{
// compute what follows who invoked us
ATNState invokingState = atn.states[ctx.invokingState];
RuleTransition rt = (RuleTransition)invokingState.Transition(0);
IntervalSet follow = atn.NextTokens(rt.followState);
recoverSet.AddAll(follow);
ctx = ctx.parent;
}
recoverSet.Remove(TokenConstants.Epsilon);
// System.out.println("recover set "+recoverSet.toString(recognizer.getTokenNames()));
return recoverSet;
}
public virtual IntervalSet GetExpectedTokens(int stateNumber, RuleContext context)
{
if (stateNumber < 0 || stateNumber >= states.Count)
{
throw new ArgumentException("Invalid state number.");
}
RuleContext ctx = context;
ATNState s = states[stateNumber];
IntervalSet following = NextTokens(s);
if (!following.Contains(TokenConstants.Epsilon))
{
return following;
}
IntervalSet expected = new IntervalSet();
expected.AddAll(following);
expected.Remove(TokenConstants.Epsilon);
while (ctx != null && ctx.invokingState >= 0 && following.Contains(TokenConstants.Epsilon))
{
ATNState invokingState = states[ctx.invokingState];
RuleTransition rt = (RuleTransition)invokingState.Transition(0);
following = NextTokens(rt.followState);
expected.AddAll(following);
expected.Remove(TokenConstants.Epsilon);
ctx = ctx.parent;
}
if (following.Contains(TokenConstants.Epsilon))
{
expected.Add(TokenConstants.Eof);
}
return expected;
}
