From 3340f8831f389c3f4f61112f4bcc842b2b707721 Mon Sep 17 00:00:00 2001
From: Isaac Freund <ifreund@ifreund.xyz>
Date: Mon, 5 Oct 2020 13:29:23 +0200
Subject: [PATCH] Add wl_list implementation

---
 src/common_core.zig | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/src/common_core.zig b/src/common_core.zig
index f8281f5..2c38ff6 100644
--- a/src/common_core.zig
+++ b/src/common_core.zig
@@ -23,6 +23,49 @@ pub const Array = extern struct {
     data: *c_void,
 };
 
+pub const List = extern struct {
+    prev: *List,
+    next: *List,
+
+    pub fn init(list: *List) void {
+        list.* = .{ .prev = list, .next = list };
+    }
+
+    pub fn insert(list: *List, elm: *List) void {
+        elm.prev = list;
+        elm.next = list.next;
+        list.next = elm;
+        elm.next.prev = elm;
+    }
+
+    pub fn remove(elm: *elm) void {
+        elm.prev.next = elm.next;
+        elm.next.prev = elm.prev;
+        elm = undefined;
+    }
+
+    pub fn length(list: *const List) usize {
+        var count: usize = 0;
+        var current = list.next;
+        while (current != list) : (current = current.next) {
+            count += 1;
+        }
+        return count;
+    }
+
+    pub fn empty(list: *const List) bool {
+        return list.next == list;
+    }
+
+    pub fn insertList(list: *List, other: *List) void {
+        if (other.empty()) return;
+        other.next.prev = list;
+        other.prev.next = list.next;
+        list.next.prev = other.prev;
+        list.next = other.next;
+    }
+};
+
 pub const Fixed = extern enum(i32) {
     _,