[ori_b]

I'm not sure why the next thing you'd consider is bind. It seems like plenty of languages with ADTs and generics still either don't have it available in their libraries, or use it extremely lightly, in spite of being able to implement it.

[nine_k]

I'm referring specifically to the error-handling situation.

If you replace the two-value assignment with an `Either`, it feels very natural to also eschew the constant `if (err != nil) return err` lines, and adopt a continuation-passing style, the way you do with Futures in JavaScript. You could even consider some syntactic sugar around it, like the `?` operator of C# and Kotlin, or a full-on Haskell-like do-notation.

[ori_b]

Again, it doesn't seem like this is something that many communities do, in spite of having languages that support it. The '?' operators in the languages you cited, as far as I recall, are specific to null, and don't work on generic option types.