private static AcceptAction CreateAcceptAction(ActionSubRecord record,
SymbolCollection symbols)
{
SymbolTerminal symbol = symbols[record.SymbolIndex] as SymbolTerminal;
return(new AcceptAction(symbol));
}
/// <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 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 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 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));
}