Eiffel, Rust and memory management

It already passed one year almost two years since in “Oh my lazyness!” when I wrote

I shall restart my efforts on Liberty EIffel and Monodes… 🙁 I hope to integrate them in my current effort.

While I haven’t been able to integrate Eiffel in the endeavour that is keeping me busy until autumn 2022, I haven’t forgotten it. Actually I’ve been keeping documenting and studying. One of the many reasons why Eiffel hasn’t become widespread as I wish is that all Eiffel implementations rely on garbage collection. While most “modern” languages relies on GC, for example Python uses reference counting with cycle-detecting to manage memory, people tends to think about Java‘s “infamous” reputation for being a memory-hungry language.

Liberty Eiffel uses the Boehm garbage collector. It works really good, but the idea of letting it handle the memory has always left the Amiga die-hard fan inside me quite disappointed. So when I learned that Rust does not require or even use garbage collecting excites me. See

• 🚀 Visualizing memory management in Rust
• Memory Management & Rust

for further informations.

So it seems that first we need to let DISPOSABLE work on expanded classes, or make the collector or the compiler aware of their life-cycle.

As far as I can say, but I can be wrong as it is just a first impression, is that owning an object in Rust is equivalent of having a “full” reference in Eiffel, while any borrowed object could be semantically like a

class BORROWED[A]
inherit 
  A
  WEAK_REFERENCE[A]
end

and having feature infix “&”: BORROWED[like Current] in ANY, if such a syntax were admissable.