1/****************************************************************************
2 * Copyright (c) 1998-2003,2005 Free Software Foundation, Inc.              *
3 *                                                                          *
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11 *                                                                          *
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14 *                                                                          *
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22 *                                                                          *
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28
29/****************************************************************************
30 *  Author: Thomas E. Dickey <dickey@clark.net> 1997                        *
31 ****************************************************************************/
32
33/*
34**	tries.c
35**
36**	Functions to manage the tree of partial-completions for keycodes.
37**
38*/
39
40#include <curses.priv.h>
41
42MODULE_ID("$Id: tries.c,v 1.20 2005/04/30 19:14:18 tom Exp $")
43
44/*
45 * Expand a keycode into the string that it corresponds to, returning null if
46 * no match was found, otherwise allocating a string of the result.
47 */
48NCURSES_EXPORT(char *)
49_nc_expand_try(struct tries *tree, unsigned short code, int *count, size_t len)
50{
51    struct tries *ptr = tree;
52    char *result = 0;
53
54    if (code != 0) {
55	while (ptr != 0) {
56	    if ((result = _nc_expand_try(ptr->child, code, count, len + 1))
57		!= 0) {
58		break;
59	    }
60	    if (ptr->value == code) {
61		*count -= 1;
62		if (*count == -1) {
63		    result = typeCalloc(char, len + 2);
64		    break;
65		}
66	    }
67	    ptr = ptr->sibling;
68	}
69    }
70    if (result != 0) {
71	if ((result[len] = ptr->ch) == 0)
72	    *((unsigned char *) (result + len)) = 128;
73#ifdef TRACE
74	if (len == 0 && _nc_tracing != 0)
75	    _tracef("expand_key %s %s", _tracechar(code), _nc_visbuf(result));
76#endif
77    }
78    return result;
79}
80
81/*
82 * Remove a code from the specified tree, freeing the unused nodes.  Returns
83 * true if the code was found/removed.
84 */
85NCURSES_EXPORT(int)
86_nc_remove_key(struct tries **tree, unsigned short code)
87{
88    T((T_CALLED("_nc_remove_key(%p,%d)"), tree, code));
89
90    if (code == 0)
91	returnCode(FALSE);
92
93    while (*tree != 0) {
94	if (_nc_remove_key(&(*tree)->child, code)) {
95	    returnCode(TRUE);
96	}
97	if ((*tree)->value == code) {
98	    if ((*tree)->child) {
99		/* don't cut the whole sub-tree */
100		(*tree)->value = 0;
101	    } else {
102		struct tries *to_free = *tree;
103		*tree = (*tree)->sibling;
104		free(to_free);
105	    }
106	    returnCode(TRUE);
107	}
108	tree = &(*tree)->sibling;
109    }
110    returnCode(FALSE);
111}
112
113/*
114 * Remove a string from the specified tree, freeing the unused nodes.  Returns
115 * true if the string was found/removed.
116 */
117NCURSES_EXPORT(int)
118_nc_remove_string(struct tries **tree, const char *string)
119{
120    T((T_CALLED("_nc_remove_string(%p,%s)"), tree, _nc_visbuf(string)));
121
122    if (string == 0 || *string == 0)
123	returnCode(FALSE);
124
125    while (*tree != 0) {
126	if (UChar((*tree)->ch) == UChar(*string)) {
127	    if (string[1] != 0)
128		returnCode(_nc_remove_string(&(*tree)->child, string + 1));
129	    if ((*tree)->child == 0) {
130		struct tries *to_free = *tree;
131		*tree = (*tree)->sibling;
132		free(to_free);
133		returnCode(TRUE);
134	    } else {
135		returnCode(FALSE);
136	    }
137	}
138	tree = &(*tree)->sibling;
139    }
140    returnCode(FALSE);
141}
142