xref: /dragonfly/contrib/ncurses/ncurses/base/tries.c (revision dcd37f7d)
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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 
42 MODULE_ID("$Id: tries.c,v 1.27 2008/08/16 19:22:55 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  */
48 NCURSES_EXPORT(char *)
49 _nc_expand_try(TRIES * tree, unsigned code, int *count, size_t len)
50 {
51     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 (ptr != 0 && (result[len] = (char) ptr->ch) == 0)
72 	    *((unsigned char *) (result + len)) = 128;
73 #ifdef TRACE
74 	if (len == 0 && USE_TRACEF(TRACE_MAXIMUM)) {
75 	    _tracef("expand_key %s %s", _nc_tracechar(SP, code), _nc_visbuf(result));
76 	    _nc_unlock_global(tracef);
77 	}
78 #endif
79     }
80     return result;
81 }
82 
83 /*
84  * Remove a code from the specified tree, freeing the unused nodes.  Returns
85  * true if the code was found/removed.
86  */
87 NCURSES_EXPORT(int)
88 _nc_remove_key(TRIES ** tree, unsigned code)
89 {
90     T((T_CALLED("_nc_remove_key(%p,%d)"), tree, code));
91 
92     if (code == 0)
93 	returnCode(FALSE);
94 
95     while (*tree != 0) {
96 	if (_nc_remove_key(&(*tree)->child, code)) {
97 	    returnCode(TRUE);
98 	}
99 	if ((*tree)->value == code) {
100 	    if ((*tree)->child) {
101 		/* don't cut the whole sub-tree */
102 		(*tree)->value = 0;
103 	    } else {
104 		TRIES *to_free = *tree;
105 		*tree = (*tree)->sibling;
106 		free(to_free);
107 	    }
108 	    returnCode(TRUE);
109 	}
110 	tree = &(*tree)->sibling;
111     }
112     returnCode(FALSE);
113 }
114 
115 /*
116  * Remove a string from the specified tree, freeing the unused nodes.  Returns
117  * true if the string was found/removed.
118  */
119 NCURSES_EXPORT(int)
120 _nc_remove_string(TRIES ** tree, const char *string)
121 {
122     T((T_CALLED("_nc_remove_string(%p,%s)"), tree, _nc_visbuf(string)));
123 
124     if (string == 0 || *string == 0)
125 	returnCode(FALSE);
126 
127     while (*tree != 0) {
128 	if (UChar((*tree)->ch) == UChar(*string)) {
129 	    if (string[1] != 0)
130 		returnCode(_nc_remove_string(&(*tree)->child, string + 1));
131 	    if ((*tree)->child == 0) {
132 		TRIES *to_free = *tree;
133 		*tree = (*tree)->sibling;
134 		free(to_free);
135 		returnCode(TRUE);
136 	    } else {
137 		returnCode(FALSE);
138 	    }
139 	}
140 	tree = &(*tree)->sibling;
141     }
142     returnCode(FALSE);
143 }
144