Initial working commit

bin/octal.ml

@@ -0,0 +1,40 @@
+
+let until_nul s =
+  match String.index_opt s '\x00' with
+  | None -> s
+  | Some i -> String.sub s 0 i
+
+module type IntType = sig
+  type t
+  val add : t -> t -> t
+  val sub : t -> t -> t
+  val mul : t -> t -> t
+  val of_int : int -> t
+  val to_int : t -> int
+end
+
+
+module IntForInt = struct
+  type t = int
+  let add = Int.add
+  let sub = Int.sub
+  let mul = Int.mul
+  let of_int x = x
+  let to_int x = x
+end
+
+let octal_reader (type a) (module I : IntType with type t = a) sin : a =
+    let ( + ) = I.add in
+    let ( * ) = I.mul in
+    let ( - ) = I.sub in
+    let s = (until_nul sin) in
+    let l = List.init (String.length s) (String.get s) in
+    let rec aux a = function
+      | c :: rest ->
+         aux ((a * (I.of_int 8)) + (I.of_int (int_of_char c)) - (I.of_int (int_of_char '0'))) rest
+      | [] -> a
+    in aux (I.of_int 0) l
+
+(* lmao *)
+let to_int = octal_reader (module IntForInt)
+let to_int64 = octal_reader (module Int64)