/// <summary>
/// Evalaute this node and return result.
/// </summary>
/// <param name="thisObject">Reference to object that is exposed as 'this'.</param>
/// <returns>Result value and type of that result.</returns>
public override EvalResult Evaluate(object thisObject)
{
// Always evaluate the first child
EvalResult left = this[0].Evaluate(thisObject);
// We can only handle a boolean result
if (left.Type != TypeCode.Boolean)
{
// Try and perform implicit conversion to a boolean
if (ImplicitConverter.CanConvertToBoolean(left.Value, _language))
{
left.Type = TypeCode.Boolean;
left.Value = ImplicitConverter.ConvertToBoolean(left.Value, _language);
}
else
{
throw new ApplicationException("Operator '" + OperationString + "' can only operate on 'bool' types.");
}
}
switch (Operation)
{
case CompareOp.Or:
// If 'true' then there is no need to evaluate the right side
if ((bool)left.Value)
{
return(left);
}
break;
case CompareOp.And:
// If 'false' then there is no need to evaluate the right side
if (!(bool)left.Value)
{
return(left);
}
break;
default:
throw new ApplicationException("Unimplemented conditional logical operator '" + Operation.ToString() + "'.");
}
// Need to evaluate the second child
left = this[1].Evaluate(thisObject);
// We can only handle a boolean result
if (left.Type != TypeCode.Boolean)
{
// Try and perform implicit conversion to a boolean
if (ImplicitConverter.CanConvertToBoolean(left.Value, _language))
{
left.Type = TypeCode.Boolean;
left.Value = ImplicitConverter.ConvertToBoolean(left.Value, _language);
}
else
{
throw new ApplicationException("Operator '" + OperationString + "' can only operate on 'bool' types.");
}
}
// Just return whatever the result is as the result of the conditional operation
return(left);
}