miri VS too-many-lists

Miri [0] is an interpreter for the mid-level intermediate representation (MIR) generated by the Rust compiler. MIR is input for more processing steps of the compiler. However miri also runs MIR directly. This means miri is a VM. Of course it's not a bytecode VM, because MIR is not a bytecode AFAIK. I still think that miri is a interesting example.

And why does miri exist?

It is a lot slower. However it can check for some undefined behavior.

[0]: https://github.com/rust-lang/miri

Provenance is a dynamic property of pointer values. The actual underlying rules that a program must follow, even when using raw pointers and `unsafe`, are written in terms of provenance. Miri (https://github.com/rust-lang/miri) represents provenance as an actual value stored alongside each pointer's address, so it can check for violations of these rules.

Lifetimes are a static approximation of provenance. They are erased after being validated by the borrow checker, and do not exist in Miri or have any impact on what transformations the optimizer may perform. In other words, the provenance rules allow a superset of what the borrow checker allows.

There has been discussion of doing this with MIRI, which would be easier than all of rustc.

This issue has been fixed: https://github.com/rust-lang/miri/issues/2964

Actually, I've done more advanced tests with MIRI (see https://github.com/rust-lang/miri/issues/2920 for example) which allowed me to fix some issues. I've also made the code compatible with loom, but I didn't found the time yet to write and execute loom tests. That's on the TODO-list, and I need to track it with an issue too.

He is one of the big brains behind Miri, which is a interpreter that runs on the MIR (compiler representation between human code and asm/machine code) and detects undefined behavior. Super useful tool for language safety, pretty interesting on its own.

I would also run your tests in Miri (https://github.com/rust-lang/miri) to try to cover more bases.

You can run miri and it will tell you if the given run triggered any undefined behavior. It will not analyze it for every possible use of the code, but checking for the presence of this specific issue using it should be fairly simple.

You seem to have a preset opinion, and I'm not sure you are interested in re-evaluating it. So this is not written to change your mind.

I've developed production code in C, C++, Rust, and several other languages. And while like pretty much everything, there are situations where it's not a good fit, I find that the solutions tend to be the most robust and require the least post release debugging in Rust. That's my personal experience. It's not hard data. And yes occasionally it's annoying to please the compiler, and if there were no trait constraints or borrow rules, those instances would be easier. But way more often in my experience the compiler complained because my initial solution had problems I didn't realize before. So for me, these situations have been about going from building it the way I wanted to -> compiler tells me I didn't consider an edge case -> changing the implementation and or design to account for that edge case. Also using one example, where is Rust is notoriously hard and or un-ergonomic to use, and dismissing the entire language seems premature to me. For those that insist on learning Rust by implementing a linked list there is https://rust-unofficial.github.io/too-many-lists/.

Advent of Code was okay until I encounterd a problem that required a graph, tree or linked list to solve, where I hit a wall. Most coding exercises are similar--those requiring arrays and hashmaps and sets are okay, but complex data structures are a PITA. (There is an online course dedicated to linked lists in Rust but I couldn't grok it either). IMO you should simply skip problems that you can't solve with your current knowledge level and move on.

I feel obligated to point to the original cannon literature: https://rust-unofficial.github.io/too-many-lists/

I started learning Rust and like how the compiler is fussy about things. My plan was to implement the data structures I knew, but I got stuck at the singly linked list's remove() method. I've read the book as well, but I have no clue how to simplify this further:

My impression from the article is that Zig provides several different hashtables and not all of them are broken in this way.

This reminds me of Aria's comment in her Rust tutorial https://rust-unofficial.github.io/too-many-lists/ about failing to kill LinkedList. One philosophy (and the one Rust chose) for a stdlib is that this is only where things should live when they're so commonly needed that essentially everybody needs them either directly or to talk about. So, HashTable is needed by so much otherwise unrelated software that qualifies, BloomFilter, while it's real useful for some people, not so much. Aria cleaned out Rust's set of standard library containers before Rust 1.0, trying to keep only those most people would need. LinkedList isn't a good general purpose data structure, but, it was too popular and Aria was not able to remove it.

Having multiple hash tables feels like a win (they're optimized for different purposes) but may cost too much in terms of the necessary testing to ensure they all hit the quality you want.

> Cyclic references can be dealt with runtime safety checks too - like Rc and Weak.

Indeed. Starting out with code sprinkled with Rc, Weak, RefCell, etc is perfectly fine and performance will probably not be worse than in any other safe languages. And if you do this, Rust is pretty close to those languages in ease of use for what are otherwise complex topics in Rust.

A good reference for different approaches is Learn Rust With Entirely Too Many Linked Lists https://rust-unofficial.github.io/too-many-lists/

Second, once you've finished something introductory like The Book, read Learning Rust With Entirely Too Many Linked Lists. It really helped me to understand what ownership and borrowing actually mean in practical terms. If you don't mind paying for learning materials, a lot of people recommend Programming Rust, Second Edition by Blandy, Orendorff, and Tindall as either a complement, follow-up, or alternative to The Book.

Learning Rust With Entirely Too Many Linked Lists which highlights a lot of the differences with how you need to structure your code in Rust compared to other languages.