private static ReduceAction CreateReduceAction(ActionSubRecord record, SymbolCollection symbols,
RuleCollection rules)
{
SymbolTerminal symbol = symbols[record.SymbolIndex] as SymbolTerminal;
Rule rule = rules[record.Target];
return new ReduceAction(symbol, rule);
}
private static GotoAction CreateGotoAction(ActionSubRecord record, SymbolCollection symbols,
StateCollection states)
{
SymbolNonterminal symbol = symbols[record.SymbolIndex] as SymbolNonterminal;
State state = states[record.Target];
return new GotoAction(symbol, state);
}
private static ShiftAction CreateShiftAction(ActionSubRecord record, SymbolCollection symbols,
StateCollection states)
{
State state = states[record.Target];
SymbolTerminal symbol = symbols[record.SymbolIndex] as SymbolTerminal;
//todo: exception symbol type
return new ShiftAction(symbol, state);
}
public ActionSubRecordCollection(Record record, int start)
{
list = new ArrayList();
if ((record.Entries.Count - start) % 4 != 0)
throw new CGTContentException("Invalid number of entries for actions in LALR state");
for (int i = start; i < record.Entries.Count; i = i + 4)
{
ActionSubRecord actionRecord =
new ActionSubRecord(record.Entries[i], record.Entries[i + 1], record.Entries[i + 2]);
list.Add(actionRecord);
}
}
public ActionSubRecordCollection(Record record, int start)
{
list = new ArrayList();
if ((record.Entries.Count - start) % 4 != 0)
{
throw new CGTContentException("Invalid number of entries for actions in LALR state");
}
for (int i = start; i < record.Entries.Count; i = i + 4)
{
ActionSubRecord actionRecord =
new ActionSubRecord(record.Entries[i], record.Entries[i + 1], record.Entries[i + 2]);
list.Add(actionRecord);
}
}
/// <summary>
/// Creates a new action by specifying the needed information.
/// </summary>
/// <param name="record">A part of the LALR record from the file content.</param>
/// <param name="states">The LALR states.</param>
/// <param name="symbols">The symbols.</param>
/// <param name="rules">The rules.</param>
/// <returns>A new action object.</returns>
public static Action CreateAction(ActionSubRecord record,
StateCollection states,
SymbolCollection symbols,
RuleCollection rules)
{
Action action;
switch (record.Action)
{
case 1: action = CreateShiftAction(record,symbols,states); break;
case 2: action = CreateReduceAction(record,symbols,rules); break;
case 3: action = CreateGotoAction(record,symbols,states); break;
case 4: action = CreateAcceptAction(record,symbols); break;
default: return null; //todo: make exception
}
return action;
}
private static AcceptAction CreateAcceptAction(ActionSubRecord record,
SymbolCollection symbols)
{
SymbolTerminal symbol = symbols[record.SymbolIndex] as SymbolTerminal;
return new AcceptAction(symbol);
}
