2 * lists.c -- Functions to implement a double linked list XBoard
4 * Copyright 1995, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Free
5 * Software Foundation, Inc.
7 * Enhancements Copyright 2005 Alessandro Scotti
9 * ------------------------------------------------------------------------
11 * GNU XBoard is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or (at
14 * your option) any later version.
16 * GNU XBoard is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see http://www.gnu.org/licenses/. *
24 *------------------------------------------------------------------------
25 ** See the file ChangeLog for a revision history. */
28 * This file could well be a part of backend.c, but I prefer it this
37 #endif /* not STDC_HEADERS */
44 /* Check, if List l is empty; returns TRUE, if it is, FALSE
50 return(l->head == (ListNode *) &l->tail);
54 /* Initialize a list. Must be executed before list is used.
59 l->head = (ListNode *) &l->tail;
61 l->tailPred = (ListNode *) l;
65 /* Remove node n from the list it is inside.
68 ListRemove (ListNode *n)
70 if (n->succ != NULL) { /* Be safe */
71 n->pred->succ = n->succ;
72 n->succ->pred = n->pred;
73 n->succ = NULL; /* Mark node as no longer being member */
74 n->pred = NULL; /* of a list. */
82 ListNodeFree (ListNode *n)
91 /* Create a list node with size s. Returns NULL, if out of memory.
94 ListNodeCreate (size_t s)
98 if ((n = (ListNode*) malloc(s))) {
99 n->succ = NULL; /* Mark node as not being member of a list. */
106 /* Insert node n into the list of node m after m.
109 ListInsert (ListNode *m, ListNode *n)
118 /* Add node n to the head of list l.
121 ListAddHead (List *l, ListNode *n)
123 ListInsert((ListNode *) &l->head, n);
127 /* Add node n to the tail of list l.
130 ListAddTail (List *l, ListNode *n)
132 ListInsert((ListNode *) l->tailPred, n);
136 /* Return element with number n of list l. (NULL, if n doesn't exist.)
137 * Counting starts with 0.
140 ListElem (List *l, int n)
144 for (ln = l->head; ln->succ; ln = ln->succ) {