Array holes can be quite nasty, as they lead to incorrect return values for the length operator. Protecting individual tables with a custom solution, on top of

Array holes can be quite nasty, as they lead to incorrect return values for the length operator. Protecting individual tables with a custom solution, on top of prohibiting undefined globals, naturally makes one wonder why the language doesn't behave this way natively. Lua is praised for being unafraid to break backwards compatibility in major releases because embedders can retain their existing versions of the codebase indefinitely. This seems like an opportunity for a future version.