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Mono optimizations (start with string concat and space eating)
author Adam Chlipala <adamc@hcoop.net>
date Thu, 03 Jul 2008 18:06:52 -0400
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children da760c34f5ed
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95:274116d1a4cd 96:82aaa1c406d3
1 (* Copyright (c) 2008, Adam Chlipala
2 * All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * - Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 * - Redistributions in binary form must reproduce the above copyright notice,
10 * this list of conditions and the following disclaimer in the documentation
11 * and/or other materials provided with the distribution.
12 * - The names of contributors may not be used to endorse or promote products
13 * derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 *)
27
28 structure MonoOpt :> MONO_OPT = struct
29
30 open Mono
31 structure U = MonoUtil
32
33 fun typ t = t
34 fun decl d = d
35
36 fun exp e =
37 case e of
38 EPrim (Prim.String s) =>
39 let
40 val (_, chs) =
41 CharVector.foldl (fn (ch, (lastSpace, chs)) =>
42 let
43 val isSpace = Char.isSpace ch
44 in
45 if isSpace andalso lastSpace then
46 (true, chs)
47 else
48 (isSpace, ch :: chs)
49 end)
50 (false, []) s
51 in
52 EPrim (Prim.String (String.implode (rev chs)))
53 end
54
55
56 | EStrcat ((EPrim (Prim.String s1), loc), (EPrim (Prim.String s2), _)) =>
57 let
58 val s =
59 if size s1 > 0 andalso size s2 > 0
60 andalso Char.isSpace (String.sub (s1, size s1 - 1))
61 andalso Char.isSpace (String.sub (s2, 0)) then
62 s1 ^ String.extract (s2, 1, NONE)
63 else
64 s1 ^ s2
65 in
66 EPrim (Prim.String s)
67 end
68 | _ => e
69
70 val optimize = U.File.map {typ = typ, exp = exp, decl = decl}
71
72 end