Save data in LÖVE

save_data.lua

-- initialize a save file holding a `savedata` sequence
function init_savedata()
  local info=love.filesystem.getInfo("savedata.lua", "file")
  if info then
    local data=love.filesystem.read("savedata.lua")
    savedata={love.data.unpack("f",data,1)}
  else
    local file=love.filesystem.newFile("savedata.lua")
    local ok,err=file:open("w")
    if not ok then
      error(err)
    end
    local data=love.data.pack("string","f",unpack(savedata))
    ok,err=love.filesystem.write("savedata.lua", data)
    if not ok then
      error(err)
    end
  end
end

-- load a value from the save file (entails loading all values, as they are serialized)
function load_value(index)
  local data=love.filesystem.read("savedata.lua")
  savedata={love.data.unpack("f",data,1)}
  return savedata[index]
end

-- save a value to the save file (entails saving all values, as they are serialized)
function save_value(index, value)
  local old_value=savedata[index]
  savedata[index]=value
  local data=love.data.pack("string","f",unpack(savedata))
  local ok,err=love.filesystem.write("savedata.lua", data)
  if not ok then
    savedata[index]=old_value
  end
  return ok
end