public void RemoveDigit()
{
if (!_state.Input.HasValue)
{
return;
}
if (_state.JustEvaluated)
{
_state = new CalculatorState();
}
else
{
if (_state.Input < 10)
{
_state.Input = null;
}
else
{
_state.Input /= 10;
}
_state.JustEvaluated = false;
}
SetOutput(_state.Input);
}
public void AppendDigit(int digit)
{
if (_state.JustEvaluated)
{
_state = new CalculatorState();
}
if (!_state.Input.HasValue)
{
_state.Input = digit;
}
else if (_state.Input <= AppendLimit)
{
_state.Input = _state.Input * 10 + digit;
}
_state.JustEvaluated = false;
SetOutput(_state.Input);
}
public void Reset()
{
_state = new CalculatorState();
SetOutput(PaddingChar.ToString());
}