Hammerspoon script for saving windows layout on macOS

init.lua

frames = {}

hs.hotkey.bind({ "cmd", "alt" }, "S", function()
    frames = {}
    local windows = hs.window.allWindows()
    for i, _ in ipairs(windows) do
        local window = windows[i]
        frames[window:id()] = window:frame()
    end
    hs.alert.show("Saved")
end)

hs.hotkey.bind({ "cmd", "alt", }, "R", function()
    local windows = hs.window.allWindows()
    for i, _ in ipairs(windows) do
        local window = windows[i]
        local saved_frame = frames[window:id()]
        if saved_frame ~= nil then
            window:setFrame(saved_frame)
        end
    end
    hs.alert.show("Restored")
end)