xref: /dragonfly/contrib/ncurses/ncurses/base/tries.c (revision e6d22e9b)
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 
43 MODULE_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  */
49 NCURSES_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  */
90 NCURSES_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  */
122 NCURSES_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