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
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
/*
* Copyright © 2025 Behdad Esfahbod
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Author(s): Behdad Esfahbod
*/
#include "hb.hh"
#include "hb-decycler.hh"
static void
tree_recurse_binary (unsigned value,
unsigned max_value,
hb_decycler_t &decycler)
{
if (value >= max_value)
return;
hb_decycler_node_t node (decycler);
bool ret = node.visit (value);
assert (ret);
tree_recurse_binary (value * 2 + 1, max_value, decycler);
tree_recurse_binary (value * 2 + 2, max_value, decycler);
}
static void
tree_recurse_tertiary (unsigned value,
unsigned max_value,
hb_decycler_t &decycler)
{
/* This function implements an alternative way to use the
* decycler. It checks for each node before visiting it.
* It demonstrates reusing a node for multiple visits. */
if (value >= max_value)
return;
hb_decycler_node_t node (decycler);
value *= 3;
for (unsigned i = 1; i <= 3; i++)
{
bool ret = node.visit (value + i);
assert (ret);
tree_recurse_tertiary (value + i, max_value, decycler);
}
}
static void
test_tree ()
{
hb_decycler_t decycler;
tree_recurse_binary (0, 64, decycler);
tree_recurse_tertiary (0, 1000, decycler);
}
static void
cycle_recurse (signed value,
signed cycle_length,
hb_decycler_t &decycler)
{
assert (cycle_length > 0);
hb_decycler_node_t node (decycler);
if (!node.visit (value))
return;
if (value >= cycle_length)
value = value % cycle_length;
cycle_recurse (value + 1, cycle_length, decycler);
}
static void
test_cycle ()
{
hb_decycler_t decycler;
cycle_recurse (0, 1, decycler);
cycle_recurse (0, 2, decycler);
cycle_recurse (2, 3, decycler);
cycle_recurse (-20, 8, decycler);
}
int
main (int argc, char **argv)
{
test_tree ();
test_cycle ();
return 0;
}