/// <summary>
/// Same as Rule just with observation
/// </summary>
/// <param name="list"> list of atomic expressions </param>
/// <returns>
/// Packed observation object, and a list containing all the
/// ConcreteObservations in the packed object
/// </returns>
public static Tuple <Observation, List <ConcreteObservation> > ObservationConversion(List <AtomicExpression> list)
{
var stack = new Stack <object>();
var concreteObservations = new List <ConcreteObservation>();
var lastExpressionString = string.Empty;
try
{
foreach (var expression in list)
{
// variable
if (!string.IsNullOrEmpty(expression.Value))
{
ConcreteObservation concreteObservation = MainWindow.GetCachedObservationByName(expression.Value);
concreteObservations.Add(concreteObservation);
stack.Push(concreteObservation);
continue;
}
// unary operator
object result;
if (expression.Operator == "-")
{
Observation tmpEval = stack.Pop() as Observation;
if (tmpEval.GetType() != typeof(ConcreteObservation))
{
tmpEval = new Parenthesis(tmpEval);
}
result = expression.Evaluate(tmpEval);
}
// binary operator
else
{
var p2 = stack.Pop();
var p1 = stack.Pop();
Observation tmpEval = expression.Evaluate(p1, p2);
if (expression.Operator == "ILI" && (lastExpressionString == "I" || lastExpressionString == "-"))
{
tmpEval = new Parenthesis(tmpEval);
}
result = tmpEval;
}
stack.Push(result);
lastExpressionString = expression.Operator;
}
var observation = stack.Pop() as Observation;
return(new Tuple <Observation, List <ConcreteObservation> >(observation, concreteObservations));
}
catch (InvalidOperationException e)
{
throw new ParsingException("parsing failed, reenter your expression!");
}
}