/// <summary>
/// Checks and corrects mistakes in equation.
/// </summary>
/// <exception cref="EquationIsEmptyException">
/// The exception that is thrown when equation class has empty list of elements,
/// because given text is empty or correction of incorrectly written equation text left no elements in the equation.
/// </exception>
private void Integrity_Check()
{
Elements_Enumerator Equation_Rator = new Elements_Enumerator(Element_Colection);
Check_Integrity_Of_Equation_Begining(Equation_Rator);
if (Equation_Rator.MoveNext() == false)
{
IElement Even_Preious_Element = null;
do
{
Check_Integrity_Of_Current_Element(Equation_Rator, Even_Preious_Element);
Even_Preious_Element = Equation_Rator.Previous_Element;
} while (Equation_Rator.MoveNext() == false);
}
if (Element_Colection.Count < 1)
{
throw new EquationIsEmptyException();
}
while (Element_Colection[Element_Colection.Count - 1] is INot_At_The_End)
{
Element_Colection.RemoveAt(Element_Colection.Count - 1);
if (Element_Colection.Count < 1)
{
throw new EquationIsEmptyException();
}
}
}
/// <summary>
/// Removes wrong elements at the begining of the equation and returns number of removed elements.
/// </summary>
/// <param name="Equation_Rator"></param>
/// <exception cref="EquationIsEmptyException">
private int Check_Integrity_Of_Equation_Begining(Elements_Enumerator Equation_Rator)
{
int removed_Elements = 0;
if (Equation_Rator.MoveNext() == true)
{
throw new EquationIsEmptyException();
}
// If equation begings by operand[s] - removes it[them]
while (Equation_Rator.Current_Element is INot_At_the_Begining)
{
if (Element_Colection.RemoveAt(Equation_Rator.Current_Index) == false)
{
throw new EquationIsEmptyException();
}
removed_Elements++;
}
return(removed_Elements);
}
