在makefile中使用模块时遇到问题（Ocaml）

Question

我在测试文件中使用模块时遇到问题。 我在这里创建了一个更简单的版本，该版本仍然可以解决问题。

(* person.ml *)
module Person = struct
    type person = {name: string; age: int}

    let create_person name age = {name=name; age=age}

end

---

(*makefile *)
test:
    ocamlbuild -pkgs oUnit,yojson,str,ANSITerminal test.byte && ./test.byte

check:
    bash checkenv.sh

clean:
    ocamlbuild -clean

---

(* test.ml *)
open OUnit2
open Person

let person = create_person "john" 40

---

(* utop *)
#use "person.ml"
open Person
let person = create_person "john" 40

Output: val person : person = {name = "john"; age = 40}  

---

(* when I type in "make" in the terminal *)

ocamlbuild -pkg oUnit test.byte && ./test.byte
+ /Users/user/.opam/4.03.0/bin/ocamlc.opt -c -I /Users/user/.opam/4.03.0/lib/oUnit -I /Users/user/.opam/4.03.0/lib/ocaml -o test.cmo test.ml
File "test.ml", line 4, characters 13-26:
Error: Unbound value create_person
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 4 targets (2 cached) in 00:00:00.
make: *** [test] Error 10

Answer 1

问题出在一个事实，即person_create可通过Person.create_person而不是仅person_create访问。 在ocaml中，文件已经是一个模块。 因此，当您打开Person时，您将打开文件名是person.ml的模块。 在该模块中，创建一个名为Person的模块，在其中定义person_create。 因此，您可以删除文件中的“人”模块，或者键入“ Person.create_person”而不是create_person。
在utop中进行测试时：#use指令就像一个include。 因此，您将丢失文件名，并且在打开Person后可以直接访问person_create。