Optional VS vigil

Since then C# introduced nullable which takes away some of the needs for a Option type. So what is your opionion? Do libraries like Optional still have a place when nullable is enabled?

Optional is my go-to for c# (you could also use the F# Option of course but pulling fsharp.core into a C# project tends to raise eyebrows in my experience)

This library provides similar functionality to F#'s Option type. I can't vouch for it, but it's there.

Not really. C# doesn't have monads but you can easily add something like https://github.com/nlkl/Optional which is great for a team familiar with option types and IMO will lead to a more productive team with a more concise code base.

You can use Optional

The option type is a different way to represent an optional value. This type asks if a value exists and, if so, accesses the value. When trying to access the value which doesn’t exist, it raises an exception. This solves the problem of NullPointerException raised in code areas away from the bug. In Java there is the Optional class. In C# (until C# 7 ) there is the Nullable type which is only for value types but you can create your own or use a library.

Reminds me of Vigil. https://github.com/munificent/vigil

Should it be a variation on another programming language, so something that just looks through another language's code and modifies it a little bit like this: https://github.com/munificent/vigil/ or should it have a fully fleshed out parser, lexer, interpreter/compiler etc.?

I code in Vigil. If some part of the code throws an unhandled exception it gets automatically deleted. Bug free app in few invocations!

This reminds me of Vigil, a very odd language derived from python that deletes your code if you break your promises.

Easy, just program in Vigil

Sounds kind of like vigil, where things that are wrong are duly punished

Vigil, but for moral rather than practical reasons.