Evil Haskell Tips

go forth, my statically typed minions. Eval! Apply!

[Tom Sydney Kerckhove @kerckhove_ts]

@lucasMnts yeah if you get stuck, you can just fix error

[Evil Haskell Tips @EvilHaskellTips]

Some things are too evil even for me

[One Happy Fellow @onehappyfellow]

finally, a language which combines the easiness of haskell and power of go type system

presenting: Goskell

[Evil Haskell Tips @EvilHaskellTips]

Ugh, wish I’d have thunk of this one

[Matti Palli 🧙‍♂️ @tritlo]

Haskell be like

RTS: do you have a value?
Thunk: I have a concept of a value.

[Evil Haskell Tips @EvilHaskellTips]

@defnotbeka @CarlHedgren 🔥

Now I want a dialect of Haskell written this way. Gruntskell?

[Evil Haskell Tips @EvilHaskellTips]

“Semigroup” and “Monoid” are exclusionary terminology. Prefer “smashy-smashy” and “smashy-smashy-with-extra-nothing”.

[Evil Haskell Tips @EvilHaskellTips]

Create a Brobdingnagian monstrosity of 1.2m lines of Haskell. That way, the tooling you create to make working on it tolerable will be practically instant on codebases that don’t need 18 lanes for a 3 point turn.

(With love and appreciation, @mercury)

[Evil Haskell Tips @EvilHaskellTips]

@yandereidiot The account isn’t called @preciseandcarefulhaskelltips Emily

[Evil Haskell Tips @EvilHaskellTips]

@CarlHedgren Frankly in my day to day as a Haskell dev I don’t call it anything at all

[WIRED @WIRED]

It's spooky. It's esoteric. It's also the key to understanding the rise and relevance of functional programming. https://t.co/dyNcH8nayO

[Evil Haskell Tips @EvilHaskellTips]

@kerckhove_ts This does have the flavour of “an ethical engineer would never write a procedure ‘destroyBaghdad’ - it should take a city as a parameter”

[Evil Haskell Tips @EvilHaskellTips]

Tired of probabilistic correctness guarantees?

instance Arbitrary UUID where
…
shrink uuid = case UUID.toWords uuid of
(a,b,c,d) -> [UUID.fromWords a' b' c' d' | a' <- sw a, b' <- sw b, c' <- sw c, d' <- sw d]
where sw w = take 10 $ iterate (`div` 2) w

[Evil Haskell Tips @EvilHaskellTips]

@kerckhove_ts True. And if we must be evil, we ought to at least be efficient.

[Evil Haskell Tips @EvilHaskellTips]

Do as thou wilt shall be the whole of the Law, and the type system is really just a suggestion.

[metameeee / 🦀 rust btw (aka ocaml 🐫 for sadists) @metameeee]

it's well known that satan and those who vibe with him are haskellers

[Evil Haskell Tips @EvilHaskellTips]

Performance tip:

s/sequence/mapConcurrently/g

Good code can be run in any order.

[Evil Haskell Tips @EvilHaskellTips]

The great thing about using Haskell with LLMs is that you can be absolutely precise about the nonsense you are ingesting and emitting.

[Evil Haskell Tips @EvilHaskellTips]

@DRMacIver has pointed out that Hypothesis will report all the assertions that fail rather than just the first. A decadent affordance to be avoided by the faithful.

[Evil Haskell Tips @EvilHaskellTips]

Testing is for programmers lacking the moral fibre to prove every useful property about their code in the type system.

[Evil Haskell Tips @EvilHaskellTips]

Yes, it will be extremely difficult to follow what's going on as the counterexample-finding algorithm dances between the different assertions. This is by design, and will help you back into the divine light of Writing Correct Code The First Time.