Xtykutl

I know that this general topic has been discussed here before. What I am interested in is if there is a good solution for my specific case:

I have a command line tool like this (simplified):

static void Main(string args)

{

    if (args.Length < 2)

    {

        Console.WriteLine("Usage: MyTool <InputFolder> <OutputFolder>");

        return;

    }



    string inputFolder = args[0];

    string outputFolder = args[1];



    // ...

}

I assign names to the argument values to make the code more readable. I would also like to express that these values will not be modified later.

Neither const nor readonly can be used here because the values is not known at compile time and because they are local 'variables' and not class members.

So how could I make this code more expressive and readable?

My proposition is creating a class holding your variables

public class Immutable

{

    public Immutable(string args)

    {

         InputFolder = args[0];

         OutputFolder = args[1];

    }

    public readonly string InputFolder;

    public readonly string OutputFolder;

}

then

var m = new Immutable(args)

How about the C# 7.2 ref readonly?

static void Main(string args)

{

    if (args.Length < 2)

    {

        Console.WriteLine("Usage: MyTool <InputFolder> <OutputFolder>");

        return;

    }



    ref readonly var inputFolder = ref args[0];

    ref readonly var outputFolder = ref args[1];

}

You could create some sort of Inputs class where you could parse the array into its parts and make the properties that expose the parsed values readonly. Simple Example:

public class Inputs {

    private string _args;



    public string InputFolder { get { return _args[0]; } }

    public string OutputFolder { get { return _args[1]; } }



    public Inputs(string args) { _args = args.Clone(); }



}

I'd do something like this:

public class ImmutableObject

{

    public ImmutableObject(string inputFolder, string outputFolder)

    {

        InputFolder = inputFolder;

        OutputFolder = outputFolder;

    }



    public string InputFolder {get;}

    public string OutputFolder {get;}

 }



static void Main(string args)

{

    if (args.Length < 2)

    {

        Console.WriteLine("Usage: MyTool <InputFolder> <OutputFolder>");

        return;

    }



    var folders = new ImmutableObject(args[0], args[1]);



    // ...

}