|
adamc@2
|
1 (* Copyright (c) 2008, Adam Chlipala
|
|
adamc@2
|
2 * All rights reserved.
|
|
adamc@2
|
3 *
|
|
adamc@2
|
4 * Redistribution and use in source and binary forms, with or without
|
|
adamc@2
|
5 * modification, are permitted provided that the following conditions are met:
|
|
adamc@2
|
6 *
|
|
adamc@2
|
7 * - Redistributions of source code must retain the above copyright notice,
|
|
adamc@2
|
8 * this list of conditions and the following disclaimer.
|
|
adamc@2
|
9 * - Redistributions in binary form must reproduce the above copyright notice,
|
|
adamc@2
|
10 * this list of conditions and the following disclaimer in the documentation
|
|
adamc@2
|
11 * and/or other materials provided with the distribution.
|
|
adamc@2
|
12 * - The names of contributors may not be used to endorse or promote products
|
|
adamc@2
|
13 * derived from this software without specific prior written permission.
|
|
adamc@2
|
14 *
|
|
adamc@2
|
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
adamc@2
|
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
adamc@2
|
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
adamc@2
|
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
adamc@2
|
19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
adamc@2
|
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
adamc@2
|
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
adamc@2
|
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
adamc@2
|
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
adamc@2
|
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
adamc@2
|
25 * POSSIBILITY OF SUCH DAMAGE.
|
|
adamc@2
|
26 *)
|
|
adamc@2
|
27
|
|
adamc@2
|
28 structure Search :> SEARCH = struct
|
|
adamc@2
|
29
|
|
adamc@2
|
30 datatype ('state, 'abort) result =
|
|
adamc@2
|
31 Return of 'abort
|
|
adamc@2
|
32 | Continue of 'state
|
|
adamc@2
|
33
|
|
adamc@2
|
34 type ('data, 'state, 'abort) mapfold_arg =
|
|
adamc@2
|
35 'data * 'state -> ('data * 'state, 'abort) result
|
|
adamc@2
|
36
|
|
adamc@2
|
37 type ('data, 'state, 'abort) mapfolder =
|
|
adamc@2
|
38 'data -> 'state -> ('data * 'state, 'abort) result
|
|
adamc@2
|
39
|
|
adamc@11
|
40 type ('context, 'data, 'state, 'abort) mapfolderB =
|
|
adamc@11
|
41 'context -> 'data -> 'state -> ('data * 'state, 'abort) result
|
|
adamc@11
|
42
|
|
adamc@2
|
43 fun return2 v acc = Continue (v, acc)
|
|
adamc@2
|
44
|
|
adamc@2
|
45 fun map (r, f) =
|
|
adamc@2
|
46 case r of
|
|
adamc@2
|
47 Continue acc => Continue (f acc)
|
|
adamc@2
|
48 | Return x => Return x
|
|
adamc@2
|
49
|
|
adamc@2
|
50 fun map2 (r, f) acc =
|
|
adamc@2
|
51 case r acc of
|
|
adamc@2
|
52 Continue (x, acc) => Continue (f x, acc)
|
|
adamc@2
|
53 | Return x => Return x
|
|
adamc@2
|
54
|
|
adamc@2
|
55 fun bind (r, f) =
|
|
adamc@2
|
56 case r of
|
|
adamc@2
|
57 Continue acc => f acc
|
|
adamc@2
|
58 | Return x => Return x
|
|
adamc@2
|
59
|
|
adamc@2
|
60 fun bind2 (r, f) acc =
|
|
adamc@2
|
61 case r acc of
|
|
adamc@2
|
62 Continue (x, acc) => f x acc
|
|
adamc@2
|
63 | Return x => Return x
|
|
adamc@2
|
64
|
|
adamc@2
|
65 fun bindP (r, f) =
|
|
adamc@2
|
66 case r of
|
|
adamc@2
|
67 Continue ((x, pos), acc) =>
|
|
adamc@6
|
68 map (f x acc,
|
|
adamc@2
|
69 fn (x', acc') =>
|
|
adamc@2
|
70 ((x', pos), acc'))
|
|
adamc@2
|
71 | Return x => Return x
|
|
adamc@2
|
72
|
|
adamc@2
|
73 end
|
