Program.cs

// Example program to demonstrate use of SymSharp.

using SymSharp;

// Top-level: simple interactive console for demonstration and manual testing.
Console.WriteLine("Welcome to Sym# CAS!");
bool exitted = false;
while (!exitted)
{
    // Present simple menu to choose modes (calculator vs differentiation).
    Console.WriteLine("\nChoose what you want from the following options:");
    Console.WriteLine("0: Quit");
    Console.WriteLine("1: Calculator");
    Console.WriteLine("2: Differentiation world (BETA, simplification is NOT perfect)");
    Console.Write("\nWhich option do you choose? ");
    string? optionChosen = Console.ReadLine();
    switch (optionChosen)
    {
        case "0":
            // Exit the interactive loop
            exitted = true;
            continue;
        case "1":
            // Calculator mode: evaluates purely numeric expressions
            Console.WriteLine("\nSym# CAS Mode 1: Calculator");
            Console.WriteLine("This works ONLY for numbers, NOT FOR LETTERS!");
            Console.WriteLine("    Quote: Numbers and letters are like gasoline and milk.");
            Console.WriteLine("    They should not be mixed together.");
            Console.WriteLine("TIP: Type nothing or 'q' to quit.");
            while (true)
            {
                Console.Write("\n> ");
                string expression = Console.ReadLine() ?? "q";
                if (expression == "q")
                {
                    Console.WriteLine("Exitting Sym# CAS Mode 1... ");
                    break;
                }
                // Evaluate numeric expression using the Evaluator helper.
                var result = Evaluator.Evaluate(expression);
                Console.WriteLine($"  = {result}");
            }
            break;
        case "2":
            // Differentiation mode: parse expression symbolically and compute derivative
            Console.WriteLine("\nSym# CAS Mode 2: Differentiation world");
            Console.WriteLine("This feature is still BETA.");
            Console.WriteLine("    Reason: Expression formatting problem");
            Console.WriteLine("TIP: Type nothing or 'q' to quit.");
            while (true)
            {
                // Create a sample variable for convenience when building expressions programmatically.
                var x = new Variable("x");
                Console.Write("\ny = ");
                string yDef = Console.ReadLine() ?? "q";
                if (yDef == "q")
                {
                    Console.WriteLine("Exitting Sym# CAS Mode 2... ");
                    break;
                }
                
                // Parse the user input into an expression and show its derivative.
                var y = SymFactory.FromString(yDef);
                Console.WriteLine($"dy/dx = {y.Derivative("x")}");
            }
            break;
        default:
            // Unrecognized menu option
            Console.WriteLine("Invalid Option.");
            break;
    }
}

Console.WriteLine("See you later! :D");