Ocaml 重写变量时如何访问全局构造函数？

我有这个密码

module Ignore = struct
  type double_asterisk = 
    | None
    | Leading of string
    | Trailing of string
    | Middle of string * string

  let double_asterisk (line:string) : double_asterisk =
    let open Re in
    let matches pat line =
      exec_opt pat line in
    let middle = matches @@ Perl.compile_pat {|^(.*?)/*\*\*/*(.*?)$|} in 
    let leading = matches @@ Perl.compile_pat {|^\*\*/*(.*)$|} in
    let trailing = matches @@ Perl.compile_pat {|^(.*?)/*\*\*$|} in 
    let open Re.Group in
    match trailing line with
      | Some group -> Trailing (get group 1)
      | None -> match leading line with
      | Some group -> Leading (get group 1)
      | None -> match middle line with
      | Some group -> Middle ((get group 1), (get group 2))
      | None -> None

  let%test _ = double_asterisk "**/foo"     = Leading "foo"
  let%test _ = double_asterisk "foo/**"     = Trailing "foo"
  let%test _ = double_asterisk "foo/**/bar" = Middle ("foo", "bar")

  let getpath filename =
    let open Base in
    let open Re.Perl in
    let open Re in
      match exec_opt (compile_pat {|^(.*)/|}) filename with
        | None -> None
        | Some g -> Some (Re.Group.get g 1) (* <- ERROR HEERE *)

  let%test _ = getpath "foo/bar/tar" = Some "foo/bar" 

end

---

自4.08起，您可以将其限定为

选项。无

在早期版本中，您可以自己创建名称空间别名，例如：

module MyOption = struct
  type 'a t = 'a option = None | Some of 'a
end

let _ = MyOption.None

但我强烈建议不要重写内置类型的构造函数。考虑使用<代码> No.< /代码>或其他一些等价的术语。
module MyOption = struct
  type 'a t = 'a option = None | Some of 'a
end

let _ = MyOption.None