Optional VS FsToolkit.ErrorHandling

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.

Isn't this similar to what https://github.com/demystifyfp/FsToolkit.ErrorHandling does?

I do think at least some of FSToolkit.ErrorHandling should be part of the core library though, it has nearly everything you could want for using these types.

I'm having trouble following exactly what you're trying to do, but it would probably be easier if you used the builtin Result type in conjunction with FsToolkit.ErrorHandling. The library provides many useful combinators as well as a result, option, and resultOption computation expression.

Also shout out to the wonderful FsToolkit.ErrorHandling library, it simplifies working with these so much.

Monad stacks, most commonly Async>, require a lot of boilerplate to deal with or using something like https://github.com/demystifyfp/FsToolkit.ErrorHandling . Which is fine, but it causes dependency mismatches between libs or type mismatches as everyone is implementing their own. A language solution would be nice...

This library is nice: https://github.com/demystifyfp/FsToolkit.ErrorHandling