/// <summary>
/// A method changes the infix expression to the postfix expression. </summary>
/// <param name="separated"> A infix notation expression InputElement list </param>
/// <param name="ret"> A postfix notation InputElement queue </param>
/// <returns> A result status of expression's reorder </returns>
private bool ChangeToPostfix(IEnumerable <InputElement> separated, out Queue <InputElement> ret)
{
Queue <InputElement> postfix = new Queue <InputElement>();
Stack <InputElement> operators = new Stack <InputElement>();
try
{
foreach (InputElement token in separated)
{
if (token is Literal)
{
postfix.Enqueue(token);
}
else if (token.CompareTo("(") == 0)
{
operators.Push(token);
}
else if (token.CompareTo(")") == 0)
{
InputElement topToken = operators.Pop();
while (topToken.CompareTo("(") != 0)
{
postfix.Enqueue(topToken);
topToken = operators.Pop();
}
}
else
{
while ((operators.Count > 0) &&
(OperatorsPriority[operators.Peek()].Priority >= OperatorsPriority[token].Priority))
{
postfix.Enqueue(operators.Pop());
}
operators.Push(token);
}
}
while (operators.Count > 0)
{
postfix.Enqueue(operators.Pop());
}
}
#pragma warning disable CS0168
catch (Exception e)
#pragma warning restore CS0168
{
postfix.Clear();
ret = postfix;
return(false);
}
ret = postfix;
return(true);
}