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|
(* TEST
expect;
*)
(* cannot_alias.ml *)
module Termsig = struct
module Term0 = struct
module type S = sig
module Id : sig end
end
end
module Term = struct
module type S = sig
module Term0 : Term0.S
module T = Term0
end
end
end;;
[%%expect{|
module Termsig :
sig
module Term0 : sig module type S = sig module Id : sig end end end
module Term :
sig module type S = sig module Term0 : Term0.S module T = Term0 end end
end
|}]
module Make1 (T' : Termsig.Term.S) = struct
module T = struct
include T'.T
let u = 1
end
end;;
[%%expect{|
module Make1 :
functor
(T' : sig
module Term0 : Termsig.Term0.S
module T : sig module Id : sig end end
end)
-> sig module T : sig module Id : sig end val u : int end end
|}]
module Make2 (T' : Termsig.Term.S) = struct
module T = struct
include T'.T
module Id2 = Id
let u = 1
end
end;;
[%%expect{|
module Make2 :
functor
(T' : sig
module Term0 : Termsig.Term0.S
module T : sig module Id : sig end end
end)
->
sig
module T : sig module Id : sig end module Id2 = Id val u : int end
end
|}]
module Make3 (T' : Termsig.Term.S) = struct
module T = struct
include T'.T
module Id2 = Id
let u = 1
let u = 1
end
end;;
[%%expect{|
module Make3 :
functor
(T' : sig
module Term0 : Termsig.Term0.S
module T : sig module Id : sig end end
end)
->
sig
module T : sig module Id : sig end module Id2 = Id val u : int end
end
|}]
(* cannot_alias2.ml *)
module type S = sig
module Term0 : sig module Id : sig end end
module T = Term0
end;;
module Make1 (T' : S) = struct
module Id = T'.T.Id
module Id2 = Id
end;;
[%%expect{|
module type S =
sig module Term0 : sig module Id : sig end end module T = Term0 end
module Make1 :
functor
(T' : sig
module Term0 : sig module Id : sig end end
module T : sig module Id : sig end end
end)
-> sig module Id : sig end module Id2 = Id end
|}]
module Make2 (T' : S) : sig module Id : sig end module Id2 = Id end
with module Id := T'.Term0.Id = struct
module Id = T'.T.Id
module Id2 = Id
end;;
[%%expect{|
Lines 2-5, characters 57-3:
2 | .........................................................struct
3 | module Id = T'.T.Id
4 | module Id2 = Id
5 | end..
Error: Signature mismatch:
Modules do not match:
sig module Id : sig end module Id2 = Id end
is not included in
sig module Id2 = T'.Term0.Id end
In module Id2:
Module T'.Term0.Id cannot be aliased
|}]
module Make3 (T' : S) = struct
module T = struct
module Id = T'.T.Id
module Id2 = Id
let u = 1
let u = 1
end
end;;
[%%expect{|
module Make3 :
functor
(T' : sig
module Term0 : sig module Id : sig end end
module T : sig module Id : sig end end
end)
->
sig
module T : sig module Id : sig end module Id2 = Id val u : int end
end
|}]
(* unsoundness if Make1 returned an Id.x field *)
module M = Make1 (struct module Term0 =
struct module Id = struct let x = "a" end end module T = Term0 end);;
M.Id.x;;
[%%expect{|
module M : sig module Id : sig end module Id2 = Id end
Line 3, characters 0-6:
3 | M.Id.x;;
^^^^^^
Error: Unbound value M.Id.x
|}]
(* cannot_alias3.ml *)
module MkT(X : sig end) = struct type t end
module type S = sig
module Term0 : sig module Id : sig end end
module T = Term0
type t = MkT(T).t
end;;
module Make1 (T' : S) = struct
module Id = T'.T.Id
module Id2 = Id
type t = T'.t
end;;
module IS = struct
module Term0 = struct module Id = struct let x = "a" end end
module T = Term0
type t = MkT(T).t
end;;
module M = Make1(IS);;
[%%expect{|
module MkT : functor (X : sig end) -> sig type t end
module type S =
sig
module Term0 : sig module Id : sig end end
module T = Term0
type t = MkT(T).t
end
module Make1 :
functor
(T' : sig
module Term0 : sig module Id : sig end end
module T : sig module Id : sig end end
type t = MkT(T).t
end)
-> sig module Id : sig end module Id2 = Id type t = T'.t end
module IS :
sig
module Term0 : sig module Id : sig val x : string end end
module T = Term0
type t = MkT(T).t
end
module M : sig module Id : sig end module Id2 = Id type t = IS.t end
|}]
(* cannot_alias4.ml *)
(* Can be used to break module abstraction *)
(* Still sound ? *)
(* It seems to only work if Term0 and Term contain identical types *)
(* It may also be possible to do the same thing using
Mtype.nondep_supertype anyway *)
type (_,_) eq = Eq : ('a,'a) eq
module MkT(X : Set.OrderedType) = Set.Make(X)
module type S = sig
module Term0 : Set.OrderedType with type t = int
module T = Term0
type t = E of (MkT(T).t,MkT(T).t) eq
type u = t = E of (MkT(Term0).t,MkT(T).t) eq
end;;
module F(X:S) = X;;
module rec M : S = M;;
module M' = F(M);;
module type S' = module type of M';;
module Asc = struct type t = int let compare x y = x - y end;;
module Desc = struct type t = int let compare x y = y - x end;;
module rec M1 : S' with module Term0 := Asc and module T := Desc = M1;;
(* And now we have a witness of MkT(Asc).t = MkT(Desc).t ... *)
let (E eq : M1.u) = (E Eq : M1.t);;
[%%expect{|
type (_, _) eq = Eq : ('a, 'a) eq
module MkT :
functor (X : Set.OrderedType) ->
sig
type elt = X.t
type t = Set.Make(X).t
val empty : t
val add : elt -> t -> t
val singleton : elt -> t
val remove : elt -> t -> t
val union : t -> t -> t
val inter : t -> t -> t
val disjoint : t -> t -> bool
val diff : t -> t -> t
val cardinal : t -> int
val elements : t -> elt list
val min_elt : t -> elt
val min_elt_opt : t -> elt option
val max_elt : t -> elt
val max_elt_opt : t -> elt option
val choose : t -> elt
val choose_opt : t -> elt option
val find : elt -> t -> elt
val find_opt : elt -> t -> elt option
val find_first : (elt -> bool) -> t -> elt
val find_first_opt : (elt -> bool) -> t -> elt option
val find_last : (elt -> bool) -> t -> elt
val find_last_opt : (elt -> bool) -> t -> elt option
val iter : (elt -> unit) -> t -> unit
val fold : (elt -> 'acc -> 'acc) -> t -> 'acc -> 'acc
val map : (elt -> elt) -> t -> t
val filter : (elt -> bool) -> t -> t
val filter_map : (elt -> elt option) -> t -> t
val partition : (elt -> bool) -> t -> t * t
val split : elt -> t -> t * bool * t
val is_empty : t -> bool
val mem : elt -> t -> bool
val equal : t -> t -> bool
val compare : t -> t -> int
val subset : t -> t -> bool
val for_all : (elt -> bool) -> t -> bool
val exists : (elt -> bool) -> t -> bool
val to_list : t -> elt list
val of_list : elt list -> t
val to_seq_from : elt -> t -> elt Seq.t
val to_seq : t -> elt Seq.t
val to_rev_seq : t -> elt Seq.t
val add_seq : elt Seq.t -> t -> t
val of_seq : elt Seq.t -> t
end
module type S =
sig
module Term0 : sig type t = int val compare : t -> t -> int end
module T = Term0
type t = E of (MkT(T).t, MkT(T).t) eq
type u = t = E of (MkT(Term0).t, MkT(T).t) eq
end
module F :
functor
(X : sig
module Term0 : sig type t = int val compare : t -> t -> int end
module T : sig type t = int val compare : t -> t -> int end
type t = E of (MkT(T).t, MkT(T).t) eq
type u = t = E of (MkT(Term0).t, MkT(T).t) eq
end)
->
sig
module Term0 : sig type t = int val compare : t -> t -> int end
module T : sig type t = int val compare : t -> t -> int end
type t = X.t = E of (MkT(T).t, MkT(T).t) eq
type u = t = E of (MkT(Term0).t, MkT(T).t) eq
end
module rec M : S
module M' :
sig
module Term0 : sig type t = int val compare : t -> t -> int end
module T : sig type t = int val compare : t -> t -> int end
type t = M.t = E of (MkT(T).t, MkT(T).t) eq
type u = t = E of (MkT(Term0).t, MkT(T).t) eq
end
module type S' =
sig
module Term0 : sig type t = int val compare : t -> t -> int end
module T : sig type t = int val compare : t -> t -> int end
type t = M.t = E of (MkT(T).t, MkT(T).t) eq
type u = t = E of (MkT(Term0).t, MkT(T).t) eq
end
module Asc : sig type t = int val compare : int -> int -> int end
module Desc : sig type t = int val compare : int -> int -> int end
Line 15, characters 0-69:
15 | module rec M1 : S' with module Term0 := Asc and module T := Desc = M1;;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: This variant or record definition does not match that of type M.t
Constructors do not match:
E of (MkT(M.T).t, MkT(M.T).t) eq
is not the same as:
E of (MkT(Desc).t, MkT(Desc).t) eq
The type (MkT(M.T).t, MkT(M.T).t) eq is not equal to the type
(MkT(Desc).t, MkT(Desc).t) eq
Type MkT(M.T).t = Set.Make(M.Term0).t is not equal to type
MkT(Desc).t = Set.Make(Desc).t
|}]
|
