1 files changed, 39 insertions, 0 deletions
diff --git a/lua/scheduler.lua b/lua/scheduler.lua
new file mode 100644
index 0000000..e526efa
--- /dev/null
+++ b/lua/scheduler.lua
@@ -0,0 +1,39 @@
+pending = {}
+
+function schedule(time, action)
+   pending[#pending+1] = {
+      time = time,
+      action = action
+   }
+
+   sort_by_time(pending)
+end
+
+function sort_by_time(array)
+   table.sort(array, function(e1, e2) return e1.time < e2.time end)
+end
+
+function wait(seconds)
+   coroutine.yield(seconds)
+end
+
+function run()
+   while #pending > 0 do
+      while os.clock() < pending[1].time do end -- busy-wait
+
+      local item = remove_first(pending)
+      local _, seconds = coroutine.resume(item.action)
+
+      if seconds then
+         later = os.clock() + seconds
+         schedule(later, item.action)
+      end
+   end
+end
+
+function remove_first(array)
+   result = array[1]
+   array[1] = array[#array]
+   array[#array] = nil
+   return result
+end