private void Shift(int stateIndex)
{
#if TRACE_ACTIONS
Console.Error.Write("Shifting token {0}, ", TerminalToString(NextToken));
#endif
FsaState = states[stateIndex];
valueStack.Push(scanner.yylval);
StateStack.Push(FsaState);
LocationStack.Push(scanner.yylloc);
if (recovering)
{
if (NextToken != errorToken)
{
tokensSinceLastError++;
}
if (tokensSinceLastError > 5)
{
recovering = false;
}
}
if (NextToken != endOfFileToken)
{
NextToken = 0;
}
}
/// <summary>
/// Shift.
/// </summary>
/// <param name="stateIndex">state index.</param>
private void Shift(int stateIndex)
{
FsaState = states[stateIndex];
ValueStack.Push(Scanner.yylval);
StateStack.Push(FsaState);
LocationStack.Push(Scanner.yylloc);
if (recovering)
{
if (NextToken != errorToken)
{
tokensSinceLastError++;
}
if (tokensSinceLastError > 5)
{
recovering = false;
}
}
if (NextToken != endOfFileToken)
{
NextToken = 0;
}
}
private void Reduce(int ruleNumber)
{
#if TRACE_ACTIONS
DisplayRule(ruleNumber);
#endif
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 = 0; i < rule.RightHandSide.Length; i++)
{
StateStack.Pop();
valueStack.Pop();
LocationStack.Pop();
}
FsaState = StateStack.TopElement();
if (FsaState.Goto.ContainsKey(rule.LeftHandSide))
{
FsaState = states[FsaState.Goto[rule.LeftHandSide]];
}
StateStack.Push(FsaState);
valueStack.Push(CurrentSemanticValue);
LocationStack.Push(CurrentLocationSpan);
}
private void Reduce(int ruleNumber)
{
#if TRACE_ACTIONS
DisplayRule(ruleNumber);
#endif
Rule rule = rules[ruleNumber];
if (rule.RightHandSide.Length == 1)
{
CurrentSemanticValue = valueStack.TopElement();
CurrentLocationSpan = LocationStack.TopElement();
}
else
{
if (rule.RightHandSide.Length == 0)
{
CurrentSemanticValue = default(TValue);
CurrentLocationSpan = (scanner.yylloc != null && LastSpan != null ?
scanner.yylloc.Merge(LastSpan) :
default(TSpan));
}
else
{
CurrentSemanticValue = valueStack.TopElement();
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 = 0; i < rule.RightHandSide.Length; i++)
{
StateStack.Pop();
valueStack.Pop();
LocationStack.Pop();
}
#if TRACE_ACTIONS
DisplayStack();
#endif
FsaState = StateStack.TopElement();
if (FsaState.Goto.ContainsKey(rule.LeftHandSide))
{
FsaState = states[FsaState.Goto[rule.LeftHandSide]];
}
StateStack.Push(FsaState);
valueStack.Push(CurrentSemanticValue);
LocationStack.Push(CurrentLocationSpan);
}
/// <summary>
/// Main entry point of the Shift-Reduce Parser.
/// </summary>
/// <returns>True if parse succeeds, else false for
/// unrecoverable errors</returns>
public bool Parse()
{
Initialize(); // allow derived classes to instantiate rules, states and nonTerminals
NextToken = 0;
FsaState = states[0];
StateStack.Push(FsaState);
valueStack.Push(CurrentSemanticValue);
LocationStack.Push(CurrentLocationSpan);
while (true)
{
#if TRACE_ACTIONS
Console.Error.WriteLine("Entering state {0} ", FsaState.number);
DisplayStack();
#endif
int action = FsaState.defaultAction;
if (FsaState.ParserTable != null)
{
if (NextToken == 0)
{
// We save the last token span, so that the location span
// of production right hand sides that begin or end with a
// nullable production will be correct.
LastSpan = scanner.yylloc;
NextToken = scanner.yylex();
#if TRACE_ACTIONS
Console.Error.WriteLine("Reading: Next token is {0}", TerminalToString(NextToken));
#endif
}
#if TRACE_ACTIONS
else
{
Console.Error.WriteLine("Next token is still {0}", TerminalToString(NextToken));
}
#endif
if (FsaState.ParserTable.ContainsKey(NextToken))
{
action = FsaState.ParserTable[NextToken];
}
}
if (action > 0) // shift
{
Shift(action);
}
else if (action < 0) // reduce
{
try {
Reduce(-action);
if (action == -1) // accept
{
return(true);
}
}
catch (AbortException) {
return(false);
}
catch (AcceptException) {
return(true);
}
catch (ErrorException) {
if (!ErrorRecovery())
{
return(false);
}
else
{
throw; // Rethrow x, preserving information.
}
}
}
else if (action == 0 && !ErrorRecovery()) // error
{
return(false);
}
}
}
/// <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);
}
/// <summary>
/// Main entry point of the Shift-Reduce Parser.
/// </summary>
/// <returns>True if parse succeeds, else false for
/// unrecoverable errors</returns>
public bool Parse()
{
_valueParameterList = new TValue[15]; // added Nate Wallace
_errorOccured = false;
Initialize(); // allow derived classes to instantiate rules, states and nonTerminals
NextToken = 0;
FsaState = states[0];
StateStack.Push(FsaState);
ValueStack.Push(CurrentSemanticValue);
LocationStack.Push(CurrentLocationSpan);
while (true)
{
int action = FsaState.defaultAction;
if (FsaState.ParserTable != null)
{
if (NextToken == 0)
{
// We save the last token span, so that the location span
// of production right hand sides that begin or end with a
// nullable production will be correct.
LastSpan = Scanner.yylloc;
NextToken = Scanner.yylex();
}
if (FsaState.ParserTable.ContainsKey(NextToken))
{
action = FsaState.ParserTable[NextToken];
}
}
if (action > 0) // shift
{
Shift(action);
}
else if (action < 0) // reduce
{
try
{
Reduce(-action);
if (action == -1) // accept
{
return(true);
}
}
catch (Exception x)
{
if (x is AbortException)
{
return(false);
}
else if (x is AcceptException)
{
return(true);
}
else if (x is ErrorException && !ErrorRecovery())
{
return(false);
}
else
{
throw; // Rethrow x, preserving information.
}
}
}
else if (action == 0) // error
{
_tokenOnError = NextToken;
_locationOnError = Scanner.yylloc;
if (!ErrorRecovery())
{
return(false);
}
}
}
}
public bool Parse()
{
Initialize();
NextToken = 0;
FsaState = states[0];
StateStack.Push(FsaState);
valueStack.Push(CurrentSemanticValue);
LocationStack.Push(CurrentLocationSpan);
while (true)
{
#if TRACE_ACTIONS
Console.Error.WriteLine("Entering state {0} ", FsaState.number);
#endif
int action = FsaState.defaultAction;
if (FsaState.ParserTable != null)
{
if (NextToken == 0)
{
#if TRACE_ACTIONS
Console.Error.Write("Reading a token: ");
#endif
LastSpan = scanner.yylloc;
NextToken = scanner.yylex();
}
#if TRACE_ACTIONS
Console.Error.WriteLine("Next token is {0}", TerminalToString(NextToken));
#endif
if (FsaState.ParserTable.ContainsKey(NextToken))
{
action = FsaState.ParserTable[NextToken];
}
}
if (action > 0)
{
Shift(action);
}
else if (action < 0)
{
try
{
Reduce(-action);
if (action == -1)
{
return(true);
}
}
catch (Exception x)
{
if (x is AbortException)
{
return(false);
}
else if (x is AcceptException)
{
return(true);
}
else if (x is ErrorException && !ErrorRecovery())
{
return(false);
}
else
{
throw;
}
}
}
else if (action == 0)
{
if (!ErrorRecovery())
{
return(false);
}
}
}
}
