Comment by ttoinou
Comment by ttoinou 13 hours ago
Does it look like functional programming anymore ?
Comment by ttoinou 13 hours ago
Does it look like functional programming anymore ?
Technically you are right but too much mutation for my tastes and probably many other ocaml developers.
(author here) The mutation is only for performance critical code. I'm first trying to match C/Rust performance in my code, and then transform it to more idiomatic functional code (which flambda2 in OxCaml can optimise).
It's too difficult right now to directly jump to the functional version since I don't understand the flambda2 compiler well enough to predict whta optimisations will work! OxCaml is stabilising more this year so that should get easier in time.
Looks pretty ML:ish to me, even in a segment like this:
let parse_int64 (local_ buf) (sp : span) : int64# =
let mutable acc : int64# = #0L in
let mutable i = 0 in
let mutable valid = true in
while valid && i < I16.to_int sp.#len do
let c = Bytes.get buf (I16.to_int sp.#off + i) in
match c with
| '0' .. '9' ->
acc <- I64.add (I64.mul acc #10L) (I64.of_int (Char.code c - 48));
i <- i + 1
| _ -> valid <- false
done;
acc
Yes - high-performance Haskell code looks similar. There isn't much to be said there - it's a little less clean-looking because FP optimizes for the most useful scenario and trying to do highly advanced stuff like that will be more verbose. This is in contrast to OOP where everything is verbose, and sometimes high-perf stuff that falls into the shape of globals + mutation + goto looks very succinct.