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2 * Copyright (c) 1998 Free Software Foundation, Inc. *
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27 ****************************************************************************/
29 /****************************************************************************
30 * Author: Thomas E. Dickey <dickey@clark.net> 1997 *
31 ****************************************************************************/
36 ** Functions to manage the tree of partial-completions for keycodes.
40 #include <curses.priv.h>
42 MODULE_ID("$Id: tries.c,v 1.7 1998/02/11 12:13:57 tom Exp $")
44 #define SET_TRY(dst,src) if ((dst->ch = *src++) == 128) dst->ch = '\0'
45 #define CMP_TRY(a,b) ((a)? (a == b) : (b == 128))
47 void _nc_add_to_try(struct tries **tree, char *str, unsigned short code)
49 static bool out_of_memory = FALSE;
50 struct tries *ptr, *savedptr;
51 unsigned char *txt = (unsigned char *)str;
53 if (txt == 0 || *txt == '\0' || out_of_memory || code == 0)
57 ptr = savedptr = (*tree);
60 unsigned char cmp = *txt;
62 while (!CMP_TRY(ptr->ch, cmp)
66 if (CMP_TRY(ptr->ch, cmp)) {
67 if (*(++txt) == '\0') {
76 if ((ptr->sibling = typeCalloc(struct tries,1)) == 0) {
81 savedptr = ptr = ptr->sibling;
88 } else { /* (*tree) == 0 :: First sequence to be added */
89 savedptr = ptr = (*tree) = typeCalloc(struct tries,1);
100 /* at this point, we are adding to the try. ptr->child == 0 */
103 ptr->child = typeCalloc(struct tries,1);
108 out_of_memory = TRUE;
110 while ((ptr = savedptr) != 0) {
111 savedptr = ptr->child;
127 * Expand a keycode into the string that it corresponds to, returning null if
128 * no match was found, otherwise allocating a string of the result.
130 char *_nc_expand_try(struct tries *tree, unsigned short code, size_t len)
132 struct tries *ptr = tree;
137 if ((result = _nc_expand_try(ptr->child, code, len + 1)) != 0) {
140 if (ptr->value == code) {
141 result = typeCalloc(char, len+2);
148 if ((result[len] = ptr->ch) == 0)
149 *((unsigned char *)(result+len)) = 128;
152 _tracef("expand_key %s %s", _trace_key(code), _nc_visbuf(result));
159 * Remove a code from the specified tree, freeing the unused nodes. Returns
160 * true if the code was found/removed.
162 int _nc_remove_key(struct tries **tree, unsigned short code)
168 if (_nc_remove_key(&(*tree)->child, code)) {
171 if ((*tree)->value == code) {
173 /* don't cut the whole sub-tree */
176 struct tries *to_free = *tree;
177 *tree = (*tree)->sibling;
182 tree = &(*tree)->sibling;