init.lua

function saveWindowsLayout(args)
   local layout = {}
   for _, w in pairs(hs.window.allWindows()) do
      layout[tostring(w:id())] = {
	 frame = w:frame().table,
	 title = w:title(),
      }
   end
   hs.settings.set("zWindowsLayout", hs.json.encode(layout))
end
function restoreWindowsLayout()
   local layout = hs.settings.get("zWindowsLayout")
   if nil == layout then return end
   hs.timer.doAfter(0, function()
		       local delay = 0.1
		       local frameRestoreDuration = 0.3
		       layout = hs.json.decode(layout)
		       for _, w in pairs(hs.window.allWindows()) do
			  local wLayout = layout[tostring(w:id())]
			  if wLayout then
			     local f = hs.geometry.new(wLayout["frame"])
			     if not f:equals(w:frame()) then
				hs.timer.doAfter(delay, function()
						    w:setFrameInScreenBounds(f, frameRestoreDuration)
				end)
				delay = delay + 0.1
			     end
			  end
		       end
   end)
end
hs.hotkey.bind({"cmd", "shift"}, "l", nil, function()
      saveWindowsLayout()
      hs.task.new("/usr/bin/pmset", nil, {"displaysleepnow"}):start()
end)
hs.hotkey.bind({"cmd", "shift", "option"}, "s", nil, function() 
      saveWindowsLayout()
      hs.alert.show("Windows layout is saved.")
end)
hs.hotkey.bind({"cmd", "shift", "option"}, "r", nil, restoreWindowsLayout)