bio.std.hts.utils.array source code

1 /*
2     This file is part of BioD.
3     Copyright (C) 2012    Artem Tarasov <lomereiter@gmail.com>
4 
5     Permission is hereby granted, free of charge, to any person obtaining a
6     copy of this software and associated documentation files (the "Software"),
7     to deal in the Software without restriction, including without limitation
8     the rights to use, copy, modify, merge, publish, distribute, sublicense,
9     and/or sell copies of the Software, and to permit persons to whom the
10     Software is furnished to do so, subject to the following conditions:
11     
12     The above copyright notice and this permission notice shall be included in
13     all copies or substantial portions of the Software.
14     
15     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21     DEALINGS IN THE SOFTWARE.
22 
23 */
24 module bio.std.hts.utils.array;
25 
26 import core.stdc..string;
27 import std.traits;
28 
29 /// Modifies array in-place so that $(D slice) is replaced by
30 /// $(D replacement[]).
31 ///
32 /// WARNING: it's you who is responsible that $(D slice) is indeed
33 /// a slice of $(D s).
34 void replaceSlice(T, U)(ref T[] s, in U[] slice, in T[] replacement)
35     if (is(Unqual!U == T)) 
36 {
37 
38     auto offset = slice.ptr - s.ptr;
39     auto slicelen = slice.length;
40     auto replen = replacement.length;
41 
42     auto newlen = s.length - slicelen + replen;
43 
44     if (slicelen == replen) {
45         s[offset .. offset + slicelen] = replacement;
46         return;
47     }
48 
49     if (replen < slicelen) {
50         // overwrite piece of slice
51         s[offset .. offset + replen] = replacement;
52         // and then move the remainder
53         memmove(s.ptr + (offset + replen),
54                 s.ptr + (offset + slicelen),
55                 (newlen - offset - replen) * T.sizeof);
56 
57         s.length = newlen;
58         return;
59     }
60 
61     // replen > slicelen
62     s.length = newlen;
63     // here, first move the remainder
64     memmove(s.ptr + (offset + replen),
65             s.ptr + (offset + slicelen),
66             (newlen - offset - replen) * T.sizeof);
67     // and then overwrite
68     s[offset .. offset + replen] = replacement;
69 }
70 
71 /// Does almost the same, but does not require $(D replacement),
72 /// instead only its length, $(D n) bytes. This is useful for
73 /// avoiding memory allocations.
74 void prepareSlice(T, U)(ref T[] s, in U[] slice, size_t n)
75     if (is(Unqual!U == T))
76 {
77 
78     auto offset = slice.ptr - s.ptr;
79     auto slicelen = slice.length;
80     auto replen = n;
81 
82     auto newlen = s.length - slicelen + replen;
83 
84     if (slicelen == replen) {
85         return;
86     }
87 
88     if (replen < slicelen) {
89         memmove(s.ptr + (offset + replen),
90                 s.ptr + (offset + slicelen),
91                 (newlen - offset - replen) * T.sizeof);
92 
93         s.length = newlen;
94         return;
95     }
96 
97     // replen > slicelen
98     s.length = newlen;
99     memmove(s.ptr + (offset + replen),
100             s.ptr + (offset + slicelen),
101             (newlen - offset - replen) * T.sizeof);
102 }
103 
104 
105 unittest {
106     auto array = [1, 2, 3, 4, 5];
107     replaceSlice(array, array[2 .. 4], [-1, -2, -5]);
108     assert(array == [1, 2, -1, -2, -5, 5]);
109     replaceSlice(array, array[1 .. 4], cast(int[])[]);
110     assert(array == [1, -5, 5]);
111     replaceSlice(array, array[0 .. 1], [3]);
112     assert(array == [3, -5, 5]);
113 }