与使用makefile模块(Ocaml)的问题
问题描述:
我在测试文件中使用我的模块时出现问题。我在这里创建了一个更简单的版本,它仍然复制了这个问题。与使用makefile模块(Ocaml)的问题
(* 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
答
问题来自事实person_create是可访问的VI Person.create_person不是person_create。在ocaml中,文件已经是一个模块。因此,当您打开Person时,将打开其名称为person.ml的模块。在该模块中,您将创建一个名为Person的模块,您可以在其中定义person_create。因此,要么删除文件中的Person模块,要么输入“Person.create_person”而不是create_person。
当你在utop中测试时:#use指令就像是一个include。所以你失去了文件名,一旦你打开Person就可以直接访问person_create。