/// <summary>
/// Find error recovery state.
/// </summary>
/// <returns>result.</returns>
private bool FindErrorRecoveryState()
{
while (true) // pop states until one found that accepts error token
{
if (FsaState.ParserTable != null &&
FsaState.ParserTable.ContainsKey(errorToken) &&
FsaState.ParserTable[errorToken] > 0) // shift
{
return(true);
}
StateStack.Pop();
ValueStack.Pop();
LocationStack.Pop();
if (StateStack.IsEmpty())
{
return(false);
}
else
{
FsaState = StateStack.TopElement();
}
}
}
/// <summary>
/// Reduce.
/// </summary>
/// <param name="ruleNumber">The rule to reduce by.</param>
private void Reduce(int ruleNumber)
{
Rule rule = rules[ruleNumber];
//
// Default actions for unit productions.
//
if (rule.RightHandSide.Length == 1)
{
CurrentSemanticValue = ValueStack.TopElement(); // Default action: $$ = $1;
CurrentLocationSpan = LocationStack.TopElement(); // Default action "@$ = @1;
}
else
{
if (rule.RightHandSide.Length == 0)
{
// Create a new blank value.
// Explicit semantic action may mutate this value
CurrentSemanticValue = default(TValue);
// The location span for an empty production will start with the
// beginning of the next lexeme, and end with the finish of the
// previous lexeme. This gives the correct behaviour when this
// nonsense value is used in later Merge operations.
CurrentLocationSpan = (Scanner.yylloc != null && LastSpan != null ?
Scanner.yylloc.Merge(LastSpan) :
default(TSpan));
}
else
{
// Default action: $$ = $1;
CurrentSemanticValue = ValueStack.TopElement();
// Default action "@$ = @1.Merge(@N)" for location info.
TSpan at1 = LocationStack[LocationStack.Depth - rule.RightHandSide.Length];
TSpan atN = LocationStack[LocationStack.Depth - 1];
CurrentLocationSpan =
((at1 != null && atN != null) ? at1.Merge(atN) : default(TSpan));
}
}
DoAction(ruleNumber);
for (int i = rule.RightHandSide.Length - 1; i >= 0; i--)
{
_valueParameterList[i] = ValueStack.Pop(); // capture the values - added by Nate Wallace
StateStack.Pop();
LocationStack.Pop();
}
if (!_errorOccured)
{
ProcessReduce(rule.LeftHandSide, _valueParameterList, rule.RightHandSide.Length); // process the reduce action - added by Nate Wallace
}
else
{
_errorOccured = false;
}
FsaState = StateStack.TopElement();
if (FsaState.Goto.ContainsKey(rule.LeftHandSide))
{
FsaState = states[FsaState.Goto[rule.LeftHandSide]];
}
StateStack.Push(FsaState);
ValueStack.Push(CurrentSemanticValue);
LocationStack.Push(CurrentLocationSpan);
}