OCaml Programming: Correct and Efficient and Beautiful

Post by pizlonator » Sun, Jul 27, 2025, 6:43 PM UTC

differentmod wrote: post #40

pizlonator wrote: post #29

I would take the FP zealots more seriously if they stopped asserting that FP makes things more correct. Zero evidence that this is the case. I can tell you that debugging a compiler written in ML is a dumpster fire compared to debugging a compiler written in C++. If take C++ over any FP language for compilers any day of the week.

> I would take the FP zealots more seriously if they stopped asserting that FP makes things more correct. Depends on the correctness requirements in question. But overall you are 100% correct about this. FP, among other aspects, enables and promotes some ways of reasoning, for instance when mutation is avoided, that can be relatively easy to use to verify correctness of certain types of properties. For instance, indu…

Post by teiferer » Mon, Jul 28, 2025, 8:37 AM UTC

AnimalMuppet wrote: post #16

OneDeuxTriSeiGo wrote: post #10

Earlier quoted context omitted.

At least theoretically they could be however OCaml is in large part driven by Jane Street and has been for some time now and Jane Street's entire business model is built around optimizing for ultra high throughput, ultra low latency software where mistakes could cost on the order of hundreds of billions of dollars. So my guess would be less that Haskell is not these things (nor couldn't it be) but rather that OCaml h…

Is OCaml lazy? I'm not an expert, but if you want ultra high throughput, you might not want lazy. If I understand correctly, in Haskell some nonobvious things can slow you down because of the laziness.

Post by debugnik » Mon, Jul 28, 2025, 10:59 AM UTC

anon-3988 wrote: post #48

debugnik wrote: post #31

Earlier quoted context omitted.

You can use the ReasonML syntax with the standard OCaml toolchain, it's the same language with curly braces. (Not to be confused with ReScript which spun off of it, but is now a different language that only targets the JavaScript stack.) Do you simply dislike the OCaml syntax or is it some particular quirk? > the variable scope thing The what thing? Variables are just lexically scoped, are you referring to shadowing?

IIRC every variable have an anonymous name based on their scope. So a = 10; { a = 20; } print(a) This would print 10. Something like that. I just remembered that the first time I encountered this, I thought "this is going to be one of those things where I will unnecessarily trip over" and closed the page.

  let a = 10;
  {
    let a = 20;
  }
  print(a);

  let a = 10 in
  begin
    let a = 20 in
    ()
  end;
  print a

Post by mbac32768 » Mon, Jul 28, 2025, 1:59 PM UTC

Mk2000 wrote: post #45

mbac32768 wrote: post #23

Earlier quoted context omitted.

FP is great but not necessarily at all costs. OCaml is immediate by default instead of lazy, and allows imperative code with side-effects. Both escape hatches from the pure FP world. So, performance is easier to reason about and you can interact with your side-effecty real world stuff without having to reorganize your whole program around the correct monad. Most of the time you want your loops to be higher order func…

I really like Ocaml, but the error handling is very bad, some libraries use Option/Result, some use exceptions, the inconsistency makes it a little hard to work with. I much prefer Rust in this regard.

Post by dev_hugepages » Tue, Jul 29, 2025, 9:02 AM UTC

teiferer wrote: post #53

AnimalMuppet wrote: post #16

Earlier quoted context omitted.

Is OCaml lazy? I'm not an expert, but if you want ultra high throughput, you might not want lazy. If I understand correctly, in Haskell some nonobvious things can slow you down because of the laziness.

How does laziness cause a slowdown? It merely reorders work done, it doesn't necessarily create more work.