Director Class in 24 lines

local director, coronaMetaTable = {scene = 'main'}, getmetatable(display.getCurrentStage())
local function cleanGroups (object)
    if type(object) ~= 'table' or getmetatable(object) ~= coronaMetaTable then return end
    if object.numChildren then
        while object.numChildren > 0 do
            cleanGroups(object[object.numChildren])
        end
    end
    object:removeSelf()
end
function director:changeScene (moduleName)
    if type(moduleName) == 'nil' or self.scene == moduleName then return end
    local loadedModule = package.loaded[self.scene]
    if type(loadedModule) == 'table' and loadedModule.clean and type(loadedModule.clean) == 'function' then
        loadedModule.clean()
    end
    cleanGroups(self.view)
    if self.scene ~= 'main' and type(loadedModule) == 'table' then
        package.loaded[self.scene], loadedModule = nil
        collectgarbage('collect')
    end
    self.view, self.scene = require(moduleName).new(), moduleName
end
return director