In OCaml, function application syntax has the function first and argument second: f 123 But for functions at the type-level, it's written in the opposite order: let x : int option = None If option is thought of a function at the type-level, then why is it not written like this? option int Is there a technical or perhaps historical reason ..read more

I have some record types with overlapping fields. This causes a type mismatch: type apple = { price : int } type banana = { price : int } Is it possible to force the type of a record literal to be one or the other? (Hypothetical syntax) { apple.price = 123 } { banana.price = 123 ..read more

I would like to print each integer in a list. I can do this with List.iter like so: digits |> List.iter (fun i -> print_int i; print_newline ()) However, I generally prefer to keep imperative code outside of pipelines of functions. Is it possible to write this in a for-each loop in OCaml? (Hypothetical syntax) for i in digits do print_int i ; print_newline () end ..read more

Having a disjoint union type like this: type yolo = | A | B | C Is it possible in OCaml to iterate/enumerate over each possible value of type yolo without prior knowledge of how many/what these values are? What I want to achieve is a function that takes a type and returns a list with all of its values. For example: let yolos = extractor yolo val yolos : yolo list = [A; B; C] (I am looking for a way to implement extractor function from the above snippet) In F# my goal is achievable with something similar to this: open Microsoft.FSharp.Reflection type yolo = | A | B | C let yol ..read more

I'm currently working on a project in Ocaml (I love this language), and I need to create a graphical interface. I've tried LabelGTK, it works but it's REALLY tiring... As a regular Glade user, I'd like to be able to use it, but I can't find anything on it... Just an old page from 2009 that gives an example code but without the library that goes with it... I know that using an xml file to create a GUI in Ocaml is a bit of a shame (since Ocaml is statically typed and reading an unsafe, modifiable file into it is a bit counter-productive), but I'd like to not have to bother with LabelGTK... Thank ..read more

I've recently been learning about compilers, more specifically Ocaml ones, and I was wondering how does the compiler actually determine which regex a string matches. Does it build a DFA for each regex defined by the lexer and then test each string on each DFA until it finds a match or is there some other algorithm/intuition. Couldn't find a clear answer online ..read more

I wrote simple OCaml code like: let rec fib(n: int) = match n with | 0 -> 0 | 1 -> 1 | _ -> fib(n-1) + fib(n-2) With -dcmm option to ocamlopt, I could generate .cmm files following: cmm: (data) (data int 3063 "camlTest__1": addr "camlTest__fib_267" int 72057594037927941) (data int 1792 global "camlTest" "camlTest": int 1) (data global "camlTest__gc_roots" "camlTest__gc_roots": addr "camlTest" int 0) (function{test.ml:1,11-88} camlTest__fib_267 (n/268: val) (if (!= n/268 1) (if (!= n/268 3) (+ (+ (app{test.ml:5,9-17} "camlTest__fib_267" (+ n/268 -2) val ..read more

I am trying to create a function which interleaves a pair of triples such as ((6, 3, 2), ( 4, 5 ,1)) and create a 6-tuple out of this interleaving. I made some research but could understand how interleaving is supposed to work so I tried something on my own end ended up with a code that is creating a 6-tuple but not in the right interleaved way. This is my code let interleave ((a, b, c), (a', b', c')) = let sort2 (a, b) = if a > b then (a, b) else (b, a) in let sort3 (a, b, c) = let (a, b) = sort2 (a, b) in let (b, c) = sort2 (b, c) in let (a, b) = sort2 (a, b) in (a ..read more

I have to execute z3 module in OCaml. But when I try to execute dune utop then I meet under error mingyu809@DESKTOP-NTK8E0T:~/ocaml/COSE419-2024-main/hw2$ dune utop File "_none_", line 1: Error: Error on dynamically loaded library: /home/mingyu809/.opam/default/lib/lwt/../stublibs/dllz3ml.so: /home/mingyu809/.opam/default/lib/lwt/../stublibs/dllz3ml.so: undefined symbol: Z3_mk_u32string But I execute dune build and dune exec -- ./main.exe, it works well. I use WSL2 on Windows 11 I tried to remove opam and other package and reinstall but same error occurs ..read more

I'm trying to write a module that convert something like x:int = if true then 3 else 5 to a string Here's the code I have so far module Ast = struct type typ = Bool | Int type var = A | B | C | D | E | F type exp = Const of int * typ | App of string * exp list | If of exp * exp * exp | And of exp * exp | Or of exp * exp | Id of var * typ * exp let rec toString (t) = let formatDec1(va,ty,e) = ??? match t with Const(n, _) -> print_int n | App(id, [e1; e2]) -> formatter(" " ^ id ^ " ", e1, e2) | App(id, [e1]) -&g ..read more