I am trying to run OCaml here and when I type 2;; I get nothing, I used utop interpreter before, but I am confused now ..read more

To use an infix operator as a prefix function in OCaml, you can put parenthesis around it. for example, 1 + 2 is equivalent to (+) 1 2. How do you do the opposite? For example, in Haskell, a prefix function taking two parameters can be used as an infix operator by wrapping it in backticks. prefixFunction x y is equivalent to x `prefixFunction` y. Is there an equivalent in OCaml ..read more

I'm looking at the List documentation. It seems the library does not provide a sublist function. I'm trying to get list of elements from i to j. Now I have to write it as: let rec sublist list i j = if i > j then [] else (List.nth list i) :: (sublist list (i+1) j) which is quite concise but I'm questioning the efficiency of List.nth, because if it's O(n), I would rather have to write it in a less concise way. I'm wondering why didn't they provide List.sublist func, if List.nth is not O(1), because it's such a quite common operation ..read more

I need to install unison on a mac M1 Ventura that follows the same specs of the one installed on a Debian Buster server (where I am just an user). I tried to install unison using homebrew but the version is not compatible. I also tried to follow the instructions on a similar question but I couldn't pass the first command (something to do with ocam that is not installed on my mac). Could somebody out there help me out? Many thanks ..read more

In OCaml, there is a construct called univ_map.t. The idea is you can create unique ids, that are genericed over a type 'a. Then, the univ_map allows you to map from those keys to values also of type 'as. Here is an example. The thing that makes these univ_maps special is that they allow you to store values with many different types in the same dictionary, where you retain type safety because the key of the dictionary tells you what type you're getting out. Is there a construct that would allow me to do something similar in Rust? I know in OCaml they are implemented with open variants, which I ..read more

I'm trying to write a program using the OCaml language, but am experiencing problems utilizing nested functions. Here's the code I wrote: let prime : int -> bool = fun x -> if x > 2 then let a = x - 1 in let rec checkZero a x = if a > 1 then match x mod a with 0 -> false |_ -> checkZero (a - 1) x else if a = 1 then true else if x = 2 then true else false ;; To briefly explain my code, I'm using a nested function called checkZero to determine whether or not x is divisible by a value a which star ..read more

Hi I am kind of confused about substitution in Ocaml. I know something like v[15/v] would evaluate to 15 because it is replacing all free variable in the expression v, but for a function like fun v -> v [15/v], what would the answer be? would it be fun v -> 15? or simply fun v -> v, because I thought fun v -> v is a closed expression, so there is no free variable in it ..read more

The Ocaml 5 manual section 11.4 says a typeexpr can have the form typexpr as ' ident. What are these as aliases for? Here are some examples that compile: type 'a x = 'a as int type y = 'a as int` At first I thought as aliases were like type-level lets, but I couldn't figure out how to use the new type variable, or how this would differ from constraint: type x = 'a as int in ('a, 'a) (* doesn't compile ..read more

I just want to code OCaml on VSC, with my Mac and I can't despite installing the extensions necessary on VSC, and installing OCaml language, opam and dune on the terminal, I still can't run on VSC. I was expecting to code OCaml on VSC and then run, but I can´t run it and when I try to run with compiler on the console, but the feedback is not the best so I was really wanting to be able to work fluently but i can´t ..read more

New to ocaml world, I have installed Chamo all seams ok but I can't start it, whats wrong?? ~/opam list # Packages matching: installed # Name # Installed # Synopsis astring 0.8.5 Alternative String module for OCaml base-bigarray base base-bytes base Bytes library distributed with the OCaml compiler base-domains base base-nnp base Naked pointers prohibited in the OCaml heap base-threads base base-unix base cairo2 0.6.4 Binding to Cairo, a 2D Vector Graphics Librar ..read more