ncurses 5.0

[ncurses.git] / ncurses / base / tries.c

diff --git a/ncurses/base/tries.c b/ncurses/base/tries.c
new file mode 100644 (file)
index 0000000..3c39652
--- /dev/null
+++ b/ncurses/base/tries.c
@@ -0,0 +1,138 @@
+/****************************************************************************
+ * Copyright (c) 1998 Free Software Foundation, Inc.                        *
+ *                                                                          *
+ * Permission is hereby granted, free of charge, to any person obtaining a  *
+ * copy of this software and associated documentation files (the            *
+ * "Software"), to deal in the Software without restriction, including      *
+ * without limitation the rights to use, copy, modify, merge, publish,      *
+ * distribute, distribute with modifications, sublicense, and/or sell       *
+ * copies of the Software, and to permit persons to whom the Software is    *
+ * furnished to do so, subject to the following conditions:                 *
+ *                                                                          *
+ * The above copyright notice and this permission notice shall be included  *
+ * in all copies or substantial portions of the Software.                   *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
+ *                                                                          *
+ * Except as contained in this notice, the name(s) of the above copyright   *
+ * holders shall not be used in advertising or otherwise to promote the     *
+ * sale, use or other dealings in this Software without prior written       *
+ * authorization.                                                           *
+ ****************************************************************************/
+
+/****************************************************************************
+ *  Author: Thomas E. Dickey <dickey@clark.net> 1997                        *
+ ****************************************************************************/
+
+/*
+**     tries.c
+**
+**     Functions to manage the tree of partial-completions for keycodes.
+**
+*/
+
+#include <curses.priv.h>
+
+MODULE_ID("$Id: tries.c,v 1.12 1999/03/01 23:23:59 tom Exp $")
+
+/*
+ * Expand a keycode into the string that it corresponds to, returning null if
+ * no match was found, otherwise allocating a string of the result.
+ */
+char *_nc_expand_try(struct tries *tree, unsigned short code, int *count, size_t len)
+{
+       struct tries *ptr = tree;
+       char *result = 0;
+
+       if (code != 0) {
+               while (ptr != 0) {
+                       if ((result = _nc_expand_try(ptr->child, code, count, len + 1)) != 0) {
+                               break;
+                       }
+                       if (ptr->value == code) {
+                               *count -= 1;
+                               if (*count == -1) {
+                                       result = typeCalloc(char, len+2);
+                                       break;
+                               }
+                       }
+                       ptr = ptr->sibling;
+               }
+       }
+       if (result != 0) {
+               if ((result[len] = ptr->ch) == 0)
+                       *((unsigned char *)(result+len)) = 128;
+#ifdef TRACE
+               if (len == 0)
+                       _tracef("expand_key %s %s", _trace_key(code), _nc_visbuf(result));
+#endif
+       }
+       return result;
+}
+
+/*
+ * Remove a code from the specified tree, freeing the unused nodes.  Returns
+ * true if the code was found/removed.
+ */
+int _nc_remove_key(struct tries **tree, unsigned short code)
+{
+       T((T_CALLED("_nc_remove_key(%p,%d)"), tree, code));
+
+       if (code == 0)
+               returnCode(FALSE);
+               
+       while (*tree != 0) {
+               if (_nc_remove_key(&(*tree)->child, code)) {
+                       returnCode(TRUE);
+               }
+               if ((*tree)->value == code) {
+                       if((*tree)->child) {
+                               /* don't cut the whole sub-tree */
+                               (*tree)->value = 0;
+                       } else {
+                               struct tries *to_free = *tree;
+                               *tree = (*tree)->sibling;
+                               free(to_free);
+                       }
+                       returnCode(TRUE);
+               }
+               tree = &(*tree)->sibling;
+       }
+       returnCode(FALSE);
+}
+
+/*
+ * Remove a string from the specified tree, freeing the unused nodes.  Returns
+ * true if the string was found/removed.
+ */
+int _nc_remove_string(struct tries **tree, char *string)
+{
+       T((T_CALLED("_nc_remove_string(%p,%s)"), tree, _nc_visbuf(string)));
+
+       if (string == 0 || *string == 0)
+               returnCode(FALSE);
+               
+       while (*tree != 0) {
+               if ((unsigned char)(*tree)->ch == (unsigned char)*string) {
+                       if (string[1] != 0)
+                               returnCode(_nc_remove_string(&(*tree)->child, string+1));
+                       if((*tree)->child) {
+                               /* don't cut the whole sub-tree */
+                               (*tree)->value = 0;
+                       } else {
+                               struct tries *to_free = *tree;
+                               *tree = (*tree)->sibling;
+                               free(to_free);
+                       }
+                       returnCode(TRUE);
+               }
+               tree = &(*tree)->sibling;
+       }
+       returnCode(FALSE);
+}