internal override TokenParseResult Execute <T>(IParser <T> parser, T token)
{
bool trim = reduceRule.ContainsOneNonterminal && parser.CanTrim(reduceRule);
T head = trim ? parser.PopToken() : parser.CreateReduction(reduceRule);
LalrActionGoto gotoAction = parser.TopState.GetActionBySymbol(reduceRule.RuleSymbol) as LalrActionGoto;
if (gotoAction == null)
{
Debug.Fail("Internal table error.");
return(TokenParseResult.InternalError);
}
parser.PushTokenAndState(head, gotoAction.State);
return(trim ? TokenParseResult.ReduceEliminated : TokenParseResult.ReduceNormal);
}
/// <summary>
/// Read LR state information.
/// </summary>
/// <param name="context"></param>
private void ReadLRState(LoadContext context)
{
int index = context.ReadIntegerEntry();
context.ReadEmptyEntry();
LalrAction[] table = new LalrAction[context.EntryCount / 4];
for (int i = 0; i < table.Length; i++)
{
Symbol symbol = symbolTable[context.ReadIntegerEntry()];
LalrActionType actionType = (LalrActionType)context.ReadIntegerEntry();
int targetIndex = context.ReadIntegerEntry();
context.ReadEmptyEntry();
LalrAction action;
switch (actionType)
{
case LalrActionType.Accept:
action = new LalrActionAccept(i, symbol);
break;
case LalrActionType.Goto:
action = new LalrActionGoto(i, symbol, GetLalrState(targetIndex));
break;
case LalrActionType.Reduce:
action = new LalrActionReduce(i, symbol, GetRule(targetIndex));
break;
case LalrActionType.Shift:
action = new LalrActionShift(i, symbol, GetLalrState(targetIndex));
break;
default:
throw new InvalidOperationException("Invalid table action data");
}
table[i] = action;
}
// Create the transition vector
LalrAction[] transitionVector = new LalrAction[symbolTable.Length];
for (int i = 0; i < transitionVector.Length; i++)
{
transitionVector[i] = null;
}
for (int i = 0; i < table.Length; i++)
{
transitionVector[table[i].Symbol.Index] = table[i];
}
GetLalrState(index).Initialize(table, transitionVector);
}
