[vicda]

Haskell is held back by pushing category theory into their tutorials. Want to do IO? Great, first learn about monads.

[kqr]

That's not true and never has been. Want to do I/O?

    main = do
        putStrLn "Who are you?"
        name <- readLn
        putStrLn ("Hello, " ++ name)

There. Do you really need to know something about monads to understand that example? No.

Do you need to know how do syntax and the assignment operator <- works? Sure. But that has nothing to do with category theory. That's just syntax.

[quickthrower2]

To be fair, once you get a compiler error you’ll at least need to know:

a. do notation is converted to haskell b. what the bind and return functions do, for IO

So you can figure out;

c. Why your types are not lining up

To understand Haskell in general you need to realise do, bind and return are generic and can be used for not just IO but say for Maybe, List etc.

Basically you need to know most practical things about monads!

I had a bad time writing Haskell do notation until I understood monads. I used to write imperative code, try =, try <-, always undo typing back to known working states etc. to try and magic the code into compiling.

[kqr]

That's a good point. It was long enough since I learned this stuff that I mentally translate "Monad m => m a" into "IO String" for example in type errors, to the point of not even noticing how cryptic the generic types can be!

[d3nj4l]

Cunningham's law in action, everyone!

[quickthrower2]

I’ve not seen much category theory in tutorials. I have seen it in some conference talks but they are aimed at people who want that, and you don’t need to watch those.

I’m doing a take 2 now of getting into Haskell again but ignoring advanced language features (unless forced on me by a library) and ignoring category theory. The goal this time is using Haskell to just build stuff.