+/*
+ * Copyright (C) 2011 Andy Spencer <andy753421@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include "util.h"
+
+/* Doubly linked lists */
+list_t *list_insert(list_t *next, void *data)
+{
+ list_t *node = new0(list_t);
+ node->data = data;
+ node->next = next;
+ node->prev = next ? next->prev : NULL;
+ if (node->next) node->next->prev = node;
+ if (node->prev) node->prev->next = node;
+ return node;
+}
+
+void list_insert_after(list_t *prev, void *data)
+{
+ // prev must be valid,
+ // as we cannot return the original list head
+ list_t *node = new0(list_t);
+ node->data = data;
+ node->prev = prev;
+ node->next = prev->next;
+ prev->next = node;
+ if (node->next) node->next->prev = node;
+}
+
+list_t *list_append(list_t *head, void *data)
+{
+ list_t *last = head;
+ while (last && last->next)
+ last = last->next;
+ list_t *node = new0(list_t);
+ node->data = data;
+ node->prev = last;
+ if (last) last->next = node;
+ return last ? head : node;
+}
+
+list_t *list_remove(list_t *head, list_t *node)
+{
+ list_t *next = node->next;
+ list_t *prev = node->prev;
+ if (next) next->prev = prev;
+ if (prev) prev->next = next;
+ free(node);
+ return head == node ? next : head;
+}
+
+int list_length(list_t *node)
+{
+ int len = 0;
+ for (; node; node = node->next)
+ len++;
+ return len;
+}
+
+list_t *list_last(list_t *list)
+{
+ while (list && list->next)
+ list = list->next;
+ return list;
+}
+
+list_t *list_find(list_t *list, void *data)
+{
+ for (list_t *cur = list; cur; cur = cur->next)
+ if (cur->data == data)
+ return cur;
+ return NULL;
+}
+
+/* Misc */
+int error(char *fmt, ...)
+{
+ va_list ap;
+ va_start(ap, fmt);
+ fprintf(stderr, "Error: ");
+ vfprintf(stderr, fmt, ap);
+ fprintf(stderr, "\n");
+ va_end(ap);
+ exit(1);
+ return 0;
+}