private bool TryResolveShiftReduce(int actionX, int actionY, int incomingToken, out int output)
{
output = 0;
int shiftAction, reduceAction;
if (ParserAction.IsShift(actionX) &&
ParserAction.GetKind(actionY) == ParserActionKind.Reduce)
{
shiftAction = actionX;
reduceAction = actionY;
}
else if (ParserAction.IsShift(actionY) &&
ParserAction.GetKind(actionX) == ParserActionKind.Reduce)
{
shiftAction = actionY;
reduceAction = actionX;
}
else
{
// Unsupported conflict type. Use first action
output = actionX;
return(false);
}
var shiftTokenPrecedence = grammar.GetTermPrecedence(incomingToken);
var reduceRulePrecedence = grammar.GetProductionPrecedence(ParserAction.GetId(reduceAction));
if (shiftTokenPrecedence == null && reduceRulePrecedence == null)
{
// In case of conflict prefer shift over reduce
output = shiftAction;
return(false);
}
else if (shiftTokenPrecedence == null)
{
output = reduceAction;
}
else if (reduceRulePrecedence == null)
{
output = shiftAction;
}
else if (Precedence.IsReduce(reduceRulePrecedence, shiftTokenPrecedence))
{
output = reduceAction;
}
else
{
output = shiftAction;
}
return(true);
}