static void testEvaluaExpresion()
{
string cad = "21.8+3-5/3.11*(10+6+2)+4";
cad = TextUtils.DelEmptyString(cad);
Console.WriteLine("Evalua la expresion --> " + cad);
try {
Expression expr = new Expression(new TokenStream(cad.Trim()));
double d = expr.EvaluaExpression();
Console.WriteLine(d);
} catch (Exception ex) {
Console.WriteLine(ex.Message);
}
}