OCaml 引用 mli 内的 ml 文件中的模块

Question

这里我有一个文件set.ml带有一个名为 IntSet 的模块.如何引用模块IntSet里面对应的接口(interface)文件set.mli ?

module IntSet = struct
  type t = int list;;
  let empty = [];;
  let rec is_member key = function
    | [] -> false
    | (x::xs) -> (
      if x = key then true
      else is_member key xs
    );;
end;;

let join xs ys = xs @ ys;;

这里是 set.mli val join : IntSet.t -> IntSet.t -> IntSet.t
如果我尝试编译它，我会收到一个错误，声称模块 IntSet是未绑定(bind)的。

% corebuild set.native
+ ocamlfind ocamlc -c -w A-4-33-40-41-42-43-34-44 -strict-sequence -g -bin-annot -short-paths -thread -package core -ppx 'ppx-jane -as-ppx' -o set.cmi set.mli
File "set.mli", line 1, characters 11-19:
Error: Unbound module IntSet
Command exited with code 2.
Hint: Recursive traversal of subdirectories was not enabled for this build,
  as the working directory does not look like an ocamlbuild project (no
  '_tags' or 'myocamlbuild.ml' file). If you have modules in subdirectories,
  you should add the option "-r" or create an empty '_tags' file.

  To enable recursive traversal for some subdirectories only, you can use the
  following '_tags' file:

      true: -traverse
      <dir1> or <dir2>: traverse

Compilation unsuccessful after building 3 targets (1 cached) in 00:00:00.

如何公开 set.ml 中定义的模块所以我可以在定义中使用它？

Answer 1

我将 set.mli 更改为此，编译器似乎很高兴:

module IntSet : sig type t end
val join : IntSet.t -> IntSet.t -> IntSet.t

可能还有更多工作可以使东西可用。无法生成 IntSet.t 类型的值， 例如。