Fast F#: Intro to Classes 

Glad to hear it!

🤣

You're welcome 😊

@@FastFSharp looking forward to the next series. 💯

I was aware of that feature. That's nice to know. I rarely use self-identifiers but this is good to know!

Well, Records are Classes under the hood. `type` just means you are expressing a type definition, it could be a Record, a DU, or a Class.

Could you elaborate on what you are looking for? I did some validation on the input in this video.

​@@FastFSharp When I work with domain logic, I like to try and ensure that there's no way my instances of entities or value objects can be instantiated without proper validation. Using exceptions for validating this is one option (and sometimes the correct one, especially for things that are just obviously horribly wrong), but using a factory pattern and creating a Result or Option is my preferred approach. That way you can do partitioning and applicative validation, and also have nice, readable code, that doesn't need exception handlers for things that really aren't very exceptional. I think in F# this is perhaps not as straight forward to do (at least to me) as in less functionally inclined languages. I think it's possible by using modules, and only exposing create/tryCreate methods, but it can be a daunting thing to try when you're getting started.

Two reasons 1. To make it easier to follow for people watching the videos to know exactly what I am doing 2. I have found that I prefer the compiler messages that I get when I specify the types. When you rely on type inference, you can get wild compiler errors when refactoring. This is the style that I prefer, others are welcome to just rely on type inference 😊. This is one of the areas where my style diverges from the broader F# community.