> The C# of my day job often feels like banging rocks together with its c-style enums and lack of sum types.

Hah, I agree. I switched over to F# and never looked back. It plays nicely enough with C# that my colleagues couldn't stop me (but didn't join me either).

> But there is always an article about go that makes you appreciate what you do have.

Yes. Go seems like a time machine back to about 1985.

Starting a new project and trying to decide between Go and F# of all things. Go seems fast and very widely used which means resources and help is widely available and it’ll be easier to find contributors. Meanwhile coming from the C# world at my job I really like the syntax of F# from what I’ve seen so far. The type system seems incredibly expressive in a way Go’s isn’t, access to C# libraries means I can do pretty much anything I’ll need to, and I enjoy FP paradigms even though I’m not looking for full FP (I generally like loops and escape hatches from FP if I need to do something specific). What’s your experience with F#? I’m worried about support and finding other people familiar with the language, not a huge fan of nuget, and I prefer to use VSCode but C# has been impossible to program in VSCode imo.

I’ve had a great experience with F#. It’s now my preferred language in almost all cases, and it’s plenty fast enough for the vast majority of applications. I use Visual Studio and the UX is excellent. (A lot of F# developers use Paket instead of Nuget.)

MS seems committed to F# as at least a source of future C# language enhancement ideas (although C# will never fully catch up). There’s also a vibrant F# community on Stack Overflow, Reddit, etc. I never have trouble getting help if I need it.

Unfortunely switching to F# also means throwing away what actually makes .NET relevant in terms of end to end developer experience, and the Redmond overloads don't seem to care that much to change that, as the C in CLR seems to refer to C# and no longer to Common, in the ways VS and VS4Mac are designed.

I do like the way they added type-switch and switch expressions to get some of the sum-type ergonomics out of the existing object oriented type system.

C# has sum types

C# does not have sum types.

It has "enumeration types" but their behaviour is exactly that of C's, with various additional conveniences but critically (and unlike Java for instance) no more type-safety.

Not without squinting really hard and making some OO monstrosity with internal impls of an outer abstract type it doesn’t. And that’s not really language support it’s banging your rocks together really hard trying to bend it into being ML.