1/****************************************************************************
2 * Copyright 2020 Thomas E. Dickey                                          *
3 * Copyright 1998-2009,2010 Free Software Foundation, Inc.                  *
4 *                                                                          *
5 * Permission is hereby granted, free of charge, to any person obtaining a  *
6 * copy of this software and associated documentation files (the            *
7 * "Software"), to deal in the Software without restriction, including      *
8 * without limitation the rights to use, copy, modify, merge, publish,      *
9 * distribute, distribute with modifications, sublicense, and/or sell       *
10 * copies of the Software, and to permit persons to whom the Software is    *
11 * furnished to do so, subject to the following conditions:                 *
12 *                                                                          *
13 * The above copyright notice and this permission notice shall be included  *
14 * in all copies or substantial portions of the Software.                   *
15 *                                                                          *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23 *                                                                          *
24 * Except as contained in this notice, the name(s) of the above copyright   *
25 * holders shall not be used in advertising or otherwise to promote the     *
26 * sale, use or other dealings in this Software without prior written       *
27 * authorization.                                                           *
28 ****************************************************************************/
29
30/****************************************************************************
31 *  Author: Thomas E. Dickey <dickey@clark.net> 1997                        *
32 ****************************************************************************/
33
34/*
35**	tries.c
36**
37**	Functions to manage the tree of partial-completions for keycodes.
38**
39*/
40
41#include <curses.priv.h>
42
43MODULE_ID("$Id: tries.c,v 1.31 2020/02/02 23:34:34 tom Exp $")
44
45/*
46 * Expand a keycode into the string that it corresponds to, returning null if
47 * no match was found, otherwise allocating a string of the result.
48 */
49NCURSES_EXPORT(char *)
50_nc_expand_try(TRIES * tree, unsigned code, int *count, size_t len)
51{
52    TRIES *ptr = tree;
53    char *result = 0;
54
55    if (code != 0) {
56	while (ptr != 0) {
57	    if ((result = _nc_expand_try(ptr->child, code, count, len + 1))
58		!= 0) {
59		break;
60	    }
61	    if (ptr->value == code) {
62		*count -= 1;
63		if (*count == -1) {
64		    result = typeCalloc(char, len + 2);
65		    break;
66		}
67	    }
68	    ptr = ptr->sibling;
69	}
70    }
71    if (result != 0) {
72	if (ptr != 0 && (result[len] = (char) ptr->ch) == 0)
73	    *((unsigned char *) (result + len)) = 128;
74#ifdef TRACE
75	if (len == 0 && USE_TRACEF(TRACE_MAXIMUM)) {
76	    _tracef("expand_key %s %s",
77		    _nc_tracechar(CURRENT_SCREEN, (int) code),
78		    _nc_visbuf(result));
79	    _nc_unlock_global(tracef);
80	}
81#endif
82    }
83    return result;
84}
85
86/*
87 * Remove a code from the specified tree, freeing the unused nodes.  Returns
88 * true if the code was found/removed.
89 */
90NCURSES_EXPORT(int)
91_nc_remove_key(TRIES ** tree, unsigned code)
92{
93    T((T_CALLED("_nc_remove_key(%p,%d)"), (void *) tree, code));
94
95    if (code == 0)
96	returnCode(FALSE);
97
98    while (*tree != 0) {
99	if (_nc_remove_key(&(*tree)->child, code)) {
100	    returnCode(TRUE);
101	}
102	if ((*tree)->value == code) {
103	    if ((*tree)->child) {
104		/* don't cut the whole sub-tree */
105		(*tree)->value = 0;
106	    } else {
107		TRIES *to_free = *tree;
108		*tree = (*tree)->sibling;
109		free(to_free);
110	    }
111	    returnCode(TRUE);
112	}
113	tree = &(*tree)->sibling;
114    }
115    returnCode(FALSE);
116}
117
118/*
119 * Remove a string from the specified tree, freeing the unused nodes.  Returns
120 * true if the string was found/removed.
121 */
122NCURSES_EXPORT(int)
123_nc_remove_string(TRIES ** tree, const char *string)
124{
125    T((T_CALLED("_nc_remove_string(%p,%s)"), (void *) tree, _nc_visbuf(string)));
126
127    if (string == 0 || *string == 0)
128	returnCode(FALSE);
129
130    while (*tree != 0) {
131	if (UChar((*tree)->ch) == UChar(*string)) {
132	    if (string[1] != 0)
133		returnCode(_nc_remove_string(&(*tree)->child, string + 1));
134	    if ((*tree)->child == 0) {
135		TRIES *to_free = *tree;
136		*tree = (*tree)->sibling;
137		free(to_free);
138		returnCode(TRUE);
139	    } else {
140		returnCode(FALSE);
141	    }
142	}
143	tree = &(*tree)->sibling;
144    }
145    returnCode(FALSE);
146}
147