Extensions: result.GetValueOrDefault() and result.GetValue()

[thebestgin]

I am looking for an easy way to get the value of a result.
Have I possibly overlooked a possibility or is it missing?

I would like to use it like this:

SomeEntity someEntity = result.GetValue();
SomeEntity? someNullableEntity = result.GetValueOrDefault();

Can be implemented very easily via an extension:

public static class ResultExtensions
{
    public static T? GetValueOrDefault<T>(this Result<T> result)
    {
        return result.Match(
            Succ: entity => entity,
            Fail: _ => default(T)
        );
    }
    
    public static T GetValue<T>(this Result<T> result)
    {
        return result.Match(
            Succ: entity => entity,
            Fail: _ => throw new Exception("Result value null not allowed")
        )!;
    }
}

[louthy]

Result is an intermediate type for Try and was never designed for general use. Instead use Fin<A>, it is fully featured and is isomorphic to Result<A>.

In v5 of language-ext, which is in beta right now, Result<A> has been removed because of this confusion.

If you want to get the value from a Fin<A> then you can use:

Fin<string> ma = FinSucc("thebestgin");

var r1 = ma.Match(Succ: x => $"Hello, {x}", Fail: e => e.ToString());
var r2 = ma.IfFail(e => e.ToString());
var r3 = ma.IfFail("default value");

If you definitely know the case, then you can cast:

if(ma)  // if in a `Succ` state
{
    r4 = (string)ma;
}

if(!ma)  // if in a `Fail` state
{
    r5 = (Error)ma;
}

In language-ext v5 you can also use C#'s pattern-matching:

var r6 = ma switch
{
    Fin.Succ<string>(var x) => x,
    Fin.Fail<string>(var e) => e.ToString()
}

[thebestgin]

Hi Louthy,

Thank you very much for pointing this out to me.
I'll use the Fin type from now on.

Very cool code snippet. I was really pleased.
Exactly what I was looking for.