/// <summary>
/// Closes the current input object, indicating that its transformation has been completed.
/// </summary>
protected virtual void Close(object inputItem)
{
if (InputStack.Count == 0)
{
throw new InvalidOperationException("Cannot close: stack is already empty.");
}
TransformInfo ti = InputStack[InputStack.Count - 1];
if (!object.ReferenceEquals(inputItem, ti.inputElement))
{
throw new InvalidOperationException("Cannot close: supplied object is not on top of the stack: " + inputItem + "," + ti.inputElement);
}
InputStack.RemoveAt(InputStack.Count - 1);
}
/// <summary>
/// Opens the input object for transforming.
/// </summary>
/// <param name="inputItem">Input code element</param>
protected virtual void Open(object inputItem)
{
TransformInfo ti = new TransformInfo(inputItem);
InputStack.Add(ti);
}