static void Main(string[] args)
{
while (true)
{
string input = PromptGetResponse(Messages.Prompt_EnterExpression);
if (input.ToLower() == QuitKeyword.ToLower())
{
break;
}
string postfix;
int result;
try
{
postfix = ShuntingYardAlgorithm.Convert(input);
}
catch (Exception)
{
DisplayMessage(Messages.ErrorMessage_PostfixParseFailed, isError: true);
continue;
}
try
{
result = ReversePolishNotation.Evaluate(postfix);
}
catch (Exception ex)
{
// special case in that it's very clear what the problem is
if (ex is DivideByZeroException)
{
DisplayMessage(Messages.ErrorMessage_EvaluationGeneratesDivideByZero, isError: true);
}
else
{
DisplayMessage(Messages.ErrorMessage_EvaluationFailed, isError: true);
}
continue;
}
DisplayMessage($"{Messages.Message_Result} {result}");
}
}
public void WhenConvert_InvalidExpression_ThrowsException(string input)
{
Assert.ThrowsException <FormatException>(() => ShuntingYardAlgorithm.Convert(input));
}
public void WhenConvert_ValidExpression_Returns_CorrectResult(string input, string expectedOutput)
{
var output = ShuntingYardAlgorithm.Convert(input);
Assert.AreEqual(expectedOutput, output);
}
