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1/*
2 * This file is part of the PulseView project.
3 *
4 * Copyright (C) 2000, 2004 by Martin Pool <mbp sourcefrog net>
5 *
6 * This software is provided 'as-is', without any express or implied
7 * warranty. In no event will the authors be held liable for any damages
8 * arising from the use of this software.
9 *
10 * Permission is granted to anyone to use this software for any purpose,
11 * including commercial applications, and to alter it and redistribute it
12 * freely, subject to the following restrictions:
13 *
14 * 1. The origin of this software must not be misrepresented; you must not
15 * claim that you wrote the original software. If you use this software
16 * in a product, an acknowledgment in the product documentation would be
17 * appreciated but is not required.
18 * 2. Altered source versions must be plainly marked as such, and must not be
19 * misrepresented as being the original software.
20 * 3. This notice may not be removed or altered from any source distribution.
21 */
22
23// strnatcmp.c -- Perform 'natural order' comparisons of strings in C.
24// This file has been modified for C++ compatibility.
25// Original at https://github.com/sourcefrog/natsort/blob/master/strnatcmp.c
26
27#ifndef PULSEVIEW_PV_STRNATCMP_HPP
28#define PULSEVIEW_PV_STRNATCMP_HPP
29
cafe470e 30#include <cctype>
aca9aa83 31#include <cstddef> /* size_t */
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32#include <string>
33
34using std::string;
35
36static int compare_right(char const *a, char const *b)
37{
38 int bias = 0;
39
40 // The longest run of digits wins. That aside, the greatest
41 // value wins, but we can't know that it will until we've scanned
42 // both numbers to know that they have the same magnitude, so we
43 // remember it in bias.
44 for (;; a++, b++) {
45 if (!isdigit(*a) && !isdigit(*b))
46 return bias;
47 if (!isdigit(*a))
48 return -1;
49 if (!isdigit(*b))
50 return +1;
51
52 if (*a < *b) {
53 if (!bias)
54 bias = -1;
55 } else if (*a > *b) {
56 if (!bias)
57 bias = +1;
58 } else if (!*a && !*b)
59 return bias;
60 }
61
62 return 0;
63}
64
65static int compare_left(char const *a, char const *b)
66{
67 // Compare two left-aligned numbers: the first to have a
68 // different value wins.
69 for (;; a++, b++) {
70 if (!isdigit(*a) && !isdigit(*b))
71 return 0;
72 if (!isdigit(*a))
73 return -1;
74 if (!isdigit(*b))
75 return +1;
76 if (*a < *b)
77 return -1;
78 if (*a > *b)
79 return +1;
80 }
81
82 return 0;
83}
84
85static int strnatcmp0(char const *a, char const *b, int fold_case)
86{
87 int ai, bi, fractional, result;
88 char ca, cb;
89
90 ai = bi = 0;
91
0402d7a3 92 while (true) {
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93 ca = a[ai];
94 cb = b[bi];
95
96 // Skip over leading spaces or zeroes
97 while (isspace(ca))
98 ca = a[++ai];
99
100 while (isspace(cb))
101 cb = b[++bi];
102
103 // Process run of digits
104 if (isdigit(ca) && isdigit(cb)) {
105 fractional = (ca == '0' || cb == '0');
106
107 if (fractional) {
108 if ((result = compare_left(a + ai, b + bi)) != 0)
109 return result;
110 } else {
111 if ((result = compare_right(a + ai, b + bi)) != 0)
112 return result;
113 }
114 }
115
116 if (!ca && !cb) {
117 // The strings compare the same. Perhaps the caller
118 // will want to call strcmp to break the tie
119 return 0;
120 }
121
122 if (fold_case) {
123 ca = toupper(ca);
124 cb = toupper(cb);
125 }
126
127 if (ca < cb)
128 return -1;
129
130 if (ca > cb)
131 return +1;
132
133 ++ai;
134 ++bi;
135 }
136}
137
138// Compare, recognizing numeric strings and being case sensitive
139int strnatcmp(char const *a, char const *b)
140{
141 return strnatcmp0(a, b, 0);
142}
143
144int strnatcmp(const string a, const string b)
145{
146 return strnatcmp0(a.c_str(), b.c_str(), 0);
147}
148
149// Compare, recognizing numeric strings and ignoring case
150int strnatcasecmp(char const *a, char const *b)
151{
152 return strnatcmp0(a, b, 1);
153}
154
155int strnatcasecmp(const string a, const string b)
156{
157 return strnatcmp0(a.c_str(), b.c_str(), 1);
158}
159
160#endif // PULSEVIEW_PV_STRNATCMP_HPP