GluonScript really doesn't need a garbage collector, because at the end of the day when a script is executing, it is just safe Rust code evaluating expressions. So it's just a Rust program running really, with its automatic static memory management guarantees.

As far as I researched, only closures could generate dangling references and therefore need memory cleanup, but only if I allowed closures to access their environment (variables and functions) by reference / mutable reference.

To avoid this and simplify both my code as well as the mental model for the users of GluonScript, as of now, closures capture their environment by cloning it immutably. There's an increased memory usage with all the copying of the environment but there are never references to something that isn't being used anymore and therefore no need for a GC. At the end of the day all values captured by closures are owned Rust values that are dropped by Rust when no longer in scope.

So this can lead to high memory usage in hot loops but it can't lead to memory leaks.