ncurses/base/tries.c

   1 /****************************************************************************
   2  * Copyright (c) 1998 Free Software Foundation, Inc.                        *
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   9  * copies of the Software, and to permit persons to whom the Software is    *
  10  * furnished to do so, subject to the following conditions:                 *
  11  *                                                                          *
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  13  * in all copies or substantial portions of the Software.                   *
  14  *                                                                          *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
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  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
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  21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
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  23  * Except as contained in this notice, the name(s) of the above copyright   *
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  25  * sale, use or other dealings in this Software without prior written       *
  26  * authorization.                                                           *
  27  ****************************************************************************/
  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 1.12 1999/03/01 23:23:59 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 char *_nc_expand_try(struct tries *tree, unsigned short code, int *count, size_t len)
  49 {
  50         struct tries *ptr = tree;
  51         char *result = 0;
  52
  53         if (code != 0) {
  54                 while (ptr != 0) {
  55                         if ((result = _nc_expand_try(ptr->child, code, count, len + 1)) != 0) {
  56                                 break;
  57                         }
  58                         if (ptr->value == code) {
  59                                 *count -= 1;
  60                                 if (*count == -1) {
  61                                         result = typeCalloc(char, len+2);
  62                                         break;
  63                                 }
  64                         }
  65                         ptr = ptr->sibling;
  66                 }
  67         }
  68         if (result != 0) {
  69                 if ((result[len] = ptr->ch) == 0)
  70                         *((unsigned char *)(result+len)) = 128;
  71 #ifdef TRACE
  72                 if (len == 0)
  73                         _tracef("expand_key %s %s", _trace_key(code), _nc_visbuf(result));
  74 #endif
  75         }
  76         return result;
  77 }
  78
  79 /*
  80  * Remove a code from the specified tree, freeing the unused nodes.  Returns
  81  * true if the code was found/removed.
  82  */
  83 int _nc_remove_key(struct tries **tree, unsigned short code)
  84 {
  85         T((T_CALLED("_nc_remove_key(%p,%d)"), tree, code));
  86
  87         if (code == 0)
  88                 returnCode(FALSE);
  89
  90         while (*tree != 0) {
  91                 if (_nc_remove_key(&(*tree)->child, code)) {
  92                         returnCode(TRUE);
  93                 }
  94                 if ((*tree)->value == code) {
  95                         if((*tree)->child) {
  96                                 /* don't cut the whole sub-tree */
  97                                 (*tree)->value = 0;
  98                         } else {
  99                                 struct tries *to_free = *tree;
 100                                 *tree = (*tree)->sibling;
 101                                 free(to_free);
 102                         }
 103                         returnCode(TRUE);
 104                 }
 105                 tree = &(*tree)->sibling;
 106         }
 107         returnCode(FALSE);
 108 }
 109
 110 /*
 111  * Remove a string from the specified tree, freeing the unused nodes.  Returns
 112  * true if the string was found/removed.
 113  */
 114 int _nc_remove_string(struct tries **tree, char *string)
 115 {
 116         T((T_CALLED("_nc_remove_string(%p,%s)"), tree, _nc_visbuf(string)));
 117
 118         if (string == 0 || *string == 0)
 119                 returnCode(FALSE);
 120
 121         while (*tree != 0) {
 122                 if ((unsigned char)(*tree)->ch == (unsigned char)*string) {
 123                         if (string[1] != 0)
 124                                 returnCode(_nc_remove_string(&(*tree)->child, string+1));
 125                         if((*tree)->child) {
 126                                 /* don't cut the whole sub-tree */
 127                                 (*tree)->value = 0;
 128                         } else {
 129                                 struct tries *to_free = *tree;
 130                                 *tree = (*tree)->sibling;
 131                                 free(to_free);
 132                         }
 133                         returnCode(TRUE);
 134                 }
 135                 tree = &(*tree)->sibling;
 136         }
 137         returnCode(FALSE);
 138 }