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|
(* TEST
* expect
*)
module type S = sig type t [@@immediate] end;;
module F (M : S) : S = M;;
[%%expect{|
module type S = sig type t [@@immediate] end
module F : functor (M : S) -> S
|}];;
(* VALID DECLARATIONS *)
module A = struct
(* Abstract types can be immediate *)
type t [@@immediate]
(* [@@immediate] tag here is unnecessary but valid since t has it *)
type s = t [@@immediate]
(* Again, valid alias even without tag *)
type r = s
(* Mutually recursive declarations work as well *)
type p = q [@@immediate]
and q = int
end;;
[%%expect{|
module A :
sig
type t [@@immediate]
type s = t [@@immediate]
type r = s
type p = q [@@immediate]
and q = int
end
|}];;
(* Valid using with constraints *)
module type X = sig type t end;;
module Y = struct type t = int end;;
module Z = ((Y : X with type t = int) : sig type t [@@immediate] end);;
[%%expect{|
module type X = sig type t end
module Y : sig type t = int end
module Z : sig type t [@@immediate] end
|}];;
(* Valid using an explicit signature *)
module M_valid : S = struct type t = int end;;
module FM_valid = F (struct type t = int end);;
[%%expect{|
module M_valid : S
module FM_valid : S
|}];;
(* Valid for empty types *)
module Empty_valid : S = struct type t = | end;;
[%%expect{|
module Empty_valid : S
|}];;
(* Practical usage over modules *)
module Foo : sig type t val x : t ref end = struct
type t = int
let x = ref 0
end;;
[%%expect{|
module Foo : sig type t val x : t ref end
|}];;
module Bar : sig type t [@@immediate] val x : t ref end = struct
type t = int
let x = ref 0
end;;
[%%expect{|
module Bar : sig type t [@@immediate] val x : t ref end
|}];;
let test f =
let start = Sys.time() in f ();
(Sys.time() -. start);;
[%%expect{|
val test : (unit -> 'a) -> float = <fun>
|}];;
let test_foo () =
for i = 0 to 100_000_000 do
Foo.x := !Foo.x
done;;
[%%expect{|
val test_foo : unit -> unit = <fun>
|}];;
let test_bar () =
for i = 0 to 100_000_000 do
Bar.x := !Bar.x
done;;
[%%expect{|
val test_bar : unit -> unit = <fun>
|}];;
(* Uncomment these to test. Should see substantial speedup!
let () = Printf.printf "No @@immediate: %fs\n" (test test_foo)
let () = Printf.printf "With @@immediate: %fs\n" (test test_bar) *)
(* INVALID DECLARATIONS *)
(* Cannot directly declare a non-immediate type as immediate *)
module B = struct
type t = string [@@immediate]
end;;
[%%expect{|
Line 2, characters 2-31:
2 | type t = string [@@immediate]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Types marked with the immediate attribute must be non-pointer types
like int or bool.
|}];;
(* Not guaranteed that t is immediate, so this is an invalid declaration *)
module C = struct
type t
type s = t [@@immediate]
end;;
[%%expect{|
Line 3, characters 2-26:
3 | type s = t [@@immediate]
^^^^^^^^^^^^^^^^^^^^^^^^
Error: Types marked with the immediate attribute must be non-pointer types
like int or bool.
|}];;
(* Can't ascribe to an immediate type signature with a non-immediate type *)
module D : sig type t [@@immediate] end = struct
type t = string
end;;
[%%expect{|
Lines 1-3, characters 42-3:
1 | ..........................................struct
2 | type t = string
3 | end..
Error: Signature mismatch:
Modules do not match:
sig type t = string end
is not included in
sig type t [@@immediate] end
Type declarations do not match:
type t = string
is not included in
type t [@@immediate]
The first is not an immediate type.
|}];;
(* Same as above but with explicit signature *)
module M_invalid : S = struct type t = string end;;
module FM_invalid = F (struct type t = string end);;
[%%expect{|
Line 1, characters 23-49:
1 | module M_invalid : S = struct type t = string end;;
^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Signature mismatch:
Modules do not match: sig type t = string end is not included in S
Type declarations do not match:
type t = string
is not included in
type t [@@immediate]
The first is not an immediate type.
|}];;
(* Can't use a non-immediate type even if mutually recursive *)
module E = struct
type t = s [@@immediate]
and s = string
end;;
[%%expect{|
Line 2, characters 2-26:
2 | type t = s [@@immediate]
^^^^^^^^^^^^^^^^^^^^^^^^
Error: Types marked with the immediate attribute must be non-pointer types
like int or bool.
|}];;
|
