blob: 2f0cce46ef32ca94bff1f6d98e570dedf296f1e6 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
(* 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
|}];;
(* 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{|
Line 1, characters 42-70:
1 | ..........................................struct
| 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
|}];;
|
