static void Main(string[] args)
{
int counter = 0;
string lastAnswer = "";
string lastCommand = "";
while (true)
{
Console.Write("[{0}]>", counter);
string inputString = Console.ReadLine();
//all the patterns
//exit pattern
string exitPattern = @"^(exit|quit|EXIT|QUIT)$";
Match exit = Regex.Match(inputString.ToLower(), exitPattern);
//lastAnswer Pattern
string lastAnswerPattern = @"^last$";
Match lastAnswerP = Regex.Match(inputString.ToLower(), lastAnswerPattern);
//lastCommand Pattern
string lastCommandPattern = @"^lastq$";
Match lastCommandP = Regex.Match(inputString.ToLower(), lastCommandPattern);
//regular calculation pattern
string RegurlarCalculationPattern = @"^(?<digit1>[0-9]+)(?<operation>(\+|\-|\*|\/))(?<digit2>[0-9]+)$";
Match m1 = Regex.Match(inputString, RegurlarCalculationPattern);
//modulus pattern
string modulusPattern = @"^\|(?<sign>\-?)(?<number>\d+)\|$";
Match modulusOperation = Regex.Match(inputString, modulusPattern);
//x=5 pattern
string constSetPattern = @"^(?<constantLetter>[a-zA-Z])(\s?)\=(\s?)(?<constantNumber>\d+)$";
Match constantOperation = Regex.Match(inputString, constSetPattern);
//x pattern
string constGetPattern = @"^(?<constLetter>[a-zA-Z])$";
Match constantGet = Regex.Match(inputString, constGetPattern);
//x+1 pattern
string letterPlusNumPattern = @"^(?<const>[a-zA-Z])(?<operation>(\+|\-|\*|\/))(?<digit>[0-9]+)$";
Match constOperation = Regex.Match(inputString, letterPlusNumPattern);
//1+x pattern
string numPlusLetterPattern = @"^(?<digit>[0-9]+)(?<operation>(\+|\-|\*|\/))(?<const>[a-zA-Z])$";
Match numPlusLetterP = Regex.Match(inputString, numPlusLetterPattern);
//x+y pattern
string letterPlusLetterPattern = @"^(?<const1>[a-zA-Z])(?<operation>(\+|\-|\*|\/))(?<const2>[a-zA-Z])$";
Match letterPlusLetterP = Regex.Match(inputString, letterPlusLetterPattern);
//exit pattern
if (exit.Success == true)
{
break;
}
//lastAnswer Pattern
else if (lastAnswerP.Success == true)
{
Console.WriteLine(lastAnswer);
}
//lastCommand Pattern
else if (lastCommandP.Success == true)
{
Console.WriteLine(lastCommand);
}
//regular calculation pattern
else if (m1.Success == true)
{
lastCommand = inputString;
int number1 = int.Parse(m1.Groups["digit1"].Value);
int number2 = int.Parse(m1.Groups["digit2"].Value);
string operation = m1.Groups["operation"].Value;
if (operation == "+")
{
Addition addition = new Addition();
int additionResult = addition.AdditionOperation(number1, number2);
Console.WriteLine("=" + additionResult);
lastAnswer = "=" + additionResult;
counter++;
continue;
}
else if (operation == "-")
{
Subtraction subtraction = new Subtraction();
int subtractionResult = subtraction.SubtractionOperation(number1, number2);
Console.WriteLine("=" + subtractionResult);
lastAnswer = "=" + subtractionResult;
counter++;
continue;
}
else if (operation == "*")
{
Multiplication multi = new Multiplication();
int multiResult = multi.MultiplicationOperation(number1, number2);
Console.WriteLine("=" + multiResult);
lastAnswer = "=" + multiResult;
counter++;
continue;
}
else if (operation == "/")
{
Division divi = new Division();
string diviResult = divi.DivisionOperation(number1, number2);
Console.WriteLine("=" + diviResult);
lastAnswer = "=" + diviResult;
counter++;
continue;
}
}
//modulus pattern
else if (modulusOperation.Success == true)
{
lastCommand = inputString;
int modulusNum = int.Parse(modulusOperation.Groups["number"].Value);
string ifSign = modulusOperation.Groups["sign"].Value;
Modulus modulus = new Modulus();
int modulusResult = modulus.ModulusFunction(ifSign, modulusNum);
Console.WriteLine(modulusResult);
lastAnswer = Convert.ToString(modulusResult);
counter++;
continue;
}
//x=5 pattern
else if (constantOperation.Success == true)
{
lastCommand = inputString;
char consLetter = char.Parse(constantOperation.Groups["constantLetter"].Value.ToLower());
double consNumber = int.Parse(constantOperation.Groups["constantNumber"].Value);
Constant consta = new Constant();
lastAnswer = consta.ConstantSetFunction(consLetter, consNumber);
counter++;
continue;
}
//x pattern
else if (constantGet.Success == true)
{
lastCommand = inputString;
char consLetter = char.Parse(constantGet.Groups["constLetter"].Value.ToLower());
Constant consGet = new Constant();
lastAnswer = consGet.ConstantGetFunction(consLetter);
counter++;
continue;
}
//x+1 pattern
else if (constOperation.Success == true)
{
lastCommand = inputString;
char consLetter = char.Parse(constOperation.Groups["const"].Value.ToLower());
string operation = constOperation.Groups["operation"].Value;
int number = int.Parse(constOperation.Groups["digit"].Value);
Constant constOper = new Constant();
lastAnswer = constOper.constOperationFunction(consLetter, operation, number);
counter++;
continue;
}
//1+x pattern
else if (numPlusLetterP.Success == true)
{
lastCommand = inputString;
char consLetter = char.Parse(numPlusLetterP.Groups["const"].Value.ToLower());
string operation = numPlusLetterP.Groups["operation"].Value;
int number = int.Parse(numPlusLetterP.Groups["digit"].Value);
Constant constOper = new Constant();
lastAnswer = constOper.constOperationFunction(consLetter, operation, number);
counter++;
continue;
}
//x+y pattern
else if (letterPlusLetterP.Success == true)
{
lastCommand = inputString;
char consLetter1 = char.Parse(letterPlusLetterP.Groups["const1"].Value.ToLower());
string operation = letterPlusLetterP.Groups["operation"].Value;
char consLetter2 = char.Parse(letterPlusLetterP.Groups["const2"].Value.ToLower());
Constant constOper = new Constant();
lastAnswer = constOper.constOperationFunction(consLetter1, operation, consLetter2);
counter++;
continue;
}
else
{
Console.WriteLine("Input Format should be '1+2','|-2|', 'x=1', 'x', 'x+1', '1+x', or 'x+y'");
counter++;
continue;
}
//3. catch error
}
Console.WriteLine("End");
//Console.ReadLine();
}