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
|
(*---------------------------------------------------------------------------*
INTERFACE cf_cmonad.mli
Copyright (c) 2002-2006, James H. Woodyatt
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
OF THE POSSIBILITY OF SUCH DAMAGE.
*---------------------------------------------------------------------------*)
(** The continuation monad and its operators. *)
(** {6 Overview} *)
(** The continuation monad is provided here mostly for reference purposes,
since it is helpful to refer to it when lifting into a more complex
monad.
A continuation monad represents a computation composed of stages that can
be interrupted, resumed and rescheduled. Because Objective Caml is an
eager language programming in the continuation-passing style (CPS) can be
simplified by the use of the continuation monad and its operators.
Note: see the {!Cf_gadget} module for an example of its use.
*)
(** {6 Types} *)
(** The continuation monad: a function for passing intermediate results from
continuation context to continuation context.
*)
type ('x, 'a) t = ('a -> 'x) -> 'x
(** {6 Modules} *)
(** A module containing the [( >>= )] binding operator for composition of
continuation monads.
*)
module Op: sig
(** Use [m >>= f] to produce a monad that applies [f] to the result of
evaluating [m].
*)
val ( >>= ): ('x, 'a) t -> ('a -> ('x, 'b) t) -> ('x, 'b) t
end
(** {6 Operators} *)
(** A monad that returns [unit] and performs no operation. *)
val nil: ('x, unit) t
(** Use [return a] to produce a monad that returns [a] as an intermediate
result from the current continuation.
*)
val return: 'a -> ('x, 'a) t
(** Use [init x] to produce a monad that discards the current intermediate
result and returns [x] as the continuation context.
*)
val init: 'x -> ('x, 'a) t
(** Use [cont f] to produce a monad that passes the calling continuation to
the function [f] and returns the unit value as an intermediate result.
*)
val cont: ('x -> 'x) -> ('x, unit) t
(** Use [eval m] to evaluate the continuation monad to produce a function from
initial continuation context to final continuation context.
*)
val eval: ('x, unit) t -> 'x -> 'x
(*--- End of File [ cf_cmonad.mli ] ---*)
|
