/// <summary>
/// Reduz a regra.
/// </summary>
/// <param name="rule"></param>
/// <returns></returns>
private ParseResult Reduce(Rule rule)
{
ParseResult reduceEliminated;
Token token;
if (this._trimReductions && rule.ContainsOneNonTerminal)
{
token = _tempStack.PopToken();
token.SetParent(rule.RuleNonTerminal);
reduceEliminated = ParseResult.ReduceEliminated;
}
else
{
Reduction reduction = new Reduction();
reduction.ParentRule = rule;
_tempStack.PopTokensInto(reduction, rule.SymbolCount);
token = new Token();
token.Data = reduction;
token.SetParent(rule.RuleNonTerminal);
this._haveReduction = true;
reduceEliminated = ParseResult.ReduceNormal;
}
int state = _tempStack.PeekToken().State;
LRAction actionForSymbol = _LalrTables[state].GetActionForSymbol(rule.RuleNonTerminal.TableIndex);
if (actionForSymbol == null)
{
throw new ParserException("Action for LALR state is null");
}
token.State = _LalrState = actionForSymbol.Value;
this._tempStack.PushToken(token);
return(reduceEliminated);
}
/// <summary>
/// Remove os tokens que estão no topo da pilha e adiciona
/// a quantidade informada para a redução.
/// </summary>
/// <param name="reduction"></param>
/// <param name="count">Quantidade de itens que serão recuperados,</param>
public void PopTokensInto(Reduction reduction, int count)
{
int index = _items.Count - count;
int count2 = _items.Count;
for (int i = index; i < count2; i++)
{
reduction.AddToken(_items[i]);
}
_items.RemoveRange(index, count);
}