1 files changed, 102 insertions, 0 deletions
diff --git a/list.c b/list.c
new file mode 100644
index 0000000..66b9d8a
--- /dev/null
+++ b/list.c
@@ -0,0 +1,102 @@
+#include "list.h"
+#include "util.h"
+
+int
+list_len(struct link *head)
+{
+	struct link *iter;
+	int len;
+
+	ASSERT(head != NULL);
+
+	len = 0;
+	for (iter = head->next; iter; iter = iter->next)
+		len += 1;
+
+	return len;
+}
+
+int
+list_ffind(struct link *head, struct link *link)
+{
+	struct link *iter;
+
+	ASSERT(head != NULL);
+
+	for (iter = head->next; iter && iter != link; iter = iter->next);
+
+	return (iter == link);
+}
+
+struct link *
+link_back(struct link *link)
+{
+	ASSERT(link != NULL);
+
+	for (; link->next; link = link->next);
+
+	return link;
+}
+
+void
+link_prepend(struct link *cur, struct link *link)
+{
+	ASSERT(cur != NULL && link != NULL);
+
+	link->prev = cur->prev;
+	link->next = cur;
+
+	if (link->prev)
+		link->prev->next = link;
+	if (link->next)
+		link->next->prev = link;
+}
+
+void
+link_append(struct link *cur, struct link *link)
+{
+	ASSERT(cur != NULL && link != NULL);
+
+	link->prev = cur;
+	link->next = cur->next;
+
+	if (link->prev)
+		link->prev->next = link;
+	if (link->next)
+		link->next->prev = link;
+}
+
+struct link *
+link_pop(struct link *link)
+{
+	ASSERT(link != NULL);
+
+	if (link->prev)
+		link->prev->next = link->next;
+	if (link->next)
+		link->next->prev = link->prev;
+
+	return link;
+}
+
+struct link *
+link_iter(struct link *link, int n)
+{
+	int i;
+
+	for (i = 0; i < n; i++) {
+		if (!link) return NULL;
+		link = link->next;
+	}
+
+	return link;
+}
+
+void
+list_push_back(struct link *cur, struct link *link)
+{
+	struct link *back;
+
+	back = link_back(cur);
+	link_append(back, link);
+}