The bytecode sandbox approach has been attempted: GitHub - robinhilliard/safeish: NOT FOR PRODUCTION USE: Safe-ish is an experimental sandbox for BEAM modules that examines and rejects BEAM bytecode containing instructions that could cause side effects. You can provide an optional whitelist of opcodes and functions the module is allowed to use. · GitHub
It turns out to be quite difficult to implement at that level, because of the various ways high-level language features are compiled down to bytecode, after the various optimizations and handling of special cases. Once all the sandbox escape paths have been fully blocked (if that ever happens) I suspect it will also block many perfectly harmless and possibly essential language features just because they happen to compile down to bytecode that is considered too powerful.
Personally I would stick with Luerl until the BEAM offers a native, runtime sandboxing feature…
