Live data from Hacker News

Thoughts on Go vs. Rust vs. Zig

sinclairtarget.com

241–250 of 599 posts

Re: Thoughts on Go vs. Rust vs. Zig

#242

The last paragraph captures the essence that all the PL theory arguments do not. "Zig has a fun, subversive feel to it". It gives you a better tool than C to apply your amazing human skills, freely, whereas both Rust and Go are fundamentally sceptical about you.

When it comes to our ability to write bug-free code, I feel like humans are not actually not that good at writing bug-free code. We just don't have any better way of producing software than that, and software is useful. This doesn't mean we're particularly good at it though, just that it's hard to motivate people to spend effort up front to avoid bugs when the cost of them is easy to ignore in the short term when they're not obvious. I feel like the mindset that languages that try to make them more apparent up front (which I honestly would not include Go as one of) are somehow getting in the way of us is pretty much exactly the opposite of what's needed, especially in the systems programming space (which also does not really include Go in my mind).

Re: Thoughts on Go vs. Rust vs. Zig

#243

Earlier quoted context omitted.

This is a miscommunication between the values of “shipping” which optimizes for fastest time to delivery and “correctness” which optimizes for the quality of the code. Rust makes it easy to write correct software quickly, but it’s slower for writing incorrect software that still works for an MVP. You can get away with writing incorrect concurrent programs in other languages… for a while. And sometimes that’s what bus…

> Rust makes it easy to write correct software quickly, but it’s slower for writing incorrect software that still works for an MVP. I don't find that to be the case. It may be slower for a month or two while you learn how to work with the borrow checker, but after the adjustment period, the ideas flow just as quickly as any other language. Additionally, being able to tell at a glance what sort of data functions requi…

I disagree. I've been writing heavy Rust for 5 years, and there are many tasks for which what you say is true. The problem is Rust is a low level language, so there is often ceremony you have to go through, even if it doesn't give you value. Simple lifetimes aren't too bad, but between that and trait bounds on some one else traits that have 6 or 7 associated types, it can get hairy FAST. Then consider a design that would normally have self referential structs, or uses heavy async with pinning, async cancellation, etc. etc.

I do agree that OFTEN you can get good velocity, but there IS a cost to any large scale program written in Rust. I think it is worth it (at least for me, on my personal time), but I can see where a business might find differently for many types of programs.

Re: Thoughts on Go vs. Rust vs. Zig

#244

> In both Go and Rust, allocating an object on the heap is as easy as returning a pointer to a struct from a function. I can't figure out what the author is envisioning here for Rust. Maybe, they actually think if they make a pointer to some local variable and then return the pointer, that's somehow allocating heap? It isn't, that local variable was on the stack and so when you return it's gone, invalidating your poi…

Yeah, this is very confusing to me. I don't see how someone can conflate Go implicitly deciding whether to promote a pointer to the heap based on escape analysis without any way for the programmer to tell other than having to replicate the logic that's happening at runtime with needing to explicitly use one on the APIs that literally exist for the sole purpose of allocating on the heap without either fundamentally misunderstanding something or intentionally being misleading.

Re: Thoughts on Go vs. Rust vs. Zig

#245

The last paragraph captures the essence that all the PL theory arguments do not. "Zig has a fun, subversive feel to it". It gives you a better tool than C to apply your amazing human skills, freely, whereas both Rust and Go are fundamentally sceptical about you.

Self-aware people are mindful about what "future them" might do in various scenarios, and they plan ahead to tamp down their worse tendencies. I don't keep a raspberry cheesecake in my fridge, even though that would maximize a certain kind of freedom (the ability to eat cheesecake whenever I want). I much prefer the freedom that comes with not being tempted, as it leads to better outcomes on things I really care about.

In a sense, it is a powerful kind of freedom to choose a language that protects us from the statistically likely blunders. I prefer a higher-level kind of freedom -- one that provides peace of mind from various safety properties.

This comment is philosophical -- interpret and apply it as you see fit -- it is not intended be interpreted as saying my personal failure modes are the same as yours. (e.g. Maybe you don't mind null pointer exceptions in the grand scheme of things.)

Random anecdote: I still have a fond memory of a glorious realization in Haskell after a colleague told me "if you design your data types right, the program just falls into place".

Re: Thoughts on Go vs. Rust vs. Zig

#246
post #87
post #29

> In Rust, creating a mutable global variable is so hard that there are long forum discussions on how to do it. In Zig, you can just create one, no problem. Well, no, creating a mutable global variable is trivial in Rust, it just requires either `unsafe` or using a smart pointer that provides synchronization. That's because Rust programs are re-entrant by default, because Rust provides compile-time thread-safety. If…

That seems unusual. I would assume trivial means the default approach works for most cases. Perhaps mutable global variables are not a common use case. Unsafe might make it easier, but it’s not obvious and probably undesired. I don’t know Rust, but I’ve heard pockets of unsafe code in a code base can make it hard to trust in Rust’s guarantees. The compromise feels like the language didn’t actually solve anything.

So I've got a crate I built that has a type that uses unsafe. Couple of things I've learned. First, yes, my library uses unsafe, but anyone who uses it doesn't have to deal with that at all. It behaves like a normal implementation of its type, it just uses half the memory. Outside of developing this one crate, I've never used unsafe.

Second, unsafe means the author is responsible for making it safe. Safe in rust means that the same rules must apply as unsafe code. It does not mean that you don't have to follow the rules. If one instead used it to violate the rules, then the code will certainly cause crashes.

I can see that some programmers would just use unsafe to "get around a problem" caused by safe rust enforcing those rules, and doing so is almost guaranteed to cause crashes. If the compiler won't let you do something, and you use unsafe to do it anyway, there's going to be a crash.

If instead we use unsafe to follow the rules, then it won't crash. There are tools like Miri that allow us to test that we haven't broken the rules. The fact that Miri did find two issues in my crate shows that unsafe is difficult to get right. My crate does clever bit-tricks and has object graphs, so it has to use unsafe to do things like having back pointers. These are all internal, and you can use the crate in safe rust. If we use unsafe to implement things like doubly-linked lists, then things are fine. If we use unsafe to allow multiple threads to mutate the same pointers (Against The Rules), then things are going to crash.

The thing is, when you are programming in C or C++, it's the same as writing unsafe rust all the time. In C/C++, the "pocket of unsafe code" is the entire codebase. So sure, you can write safe C, like I can write safe "unsafe rust". But 99% of the code I write is safe rust. And there's no equivalent in C or C++.

Re: Thoughts on Go vs. Rust vs. Zig

#247

> I’m not the first person to pick on this particular Github comment, but it perfectly illustrates the conceptual density of Rust: But you only need about 5% of the concepts in that comment to be productive in Rust. I don't think I've ever needed to know about #[fundamental] in about 12 years or so of Rust… > In both Go and Rust, allocating an object on the heap is as easy as returning a pointer to a struct from a fu…

> there is an allocator concept in Rust, too.

aren't allocators types in rust?

suppose you had an m:n system (like say an evented http request server split over several threads so that a thread might handle several inbound requests), would you be able to give each request its own arena?

Re: Thoughts on Go vs. Rust vs. Zig

#248

The reason I really like Zig is because there's finally a language that makes it easy to gracefully handle memory exhaustion at the application level. No more praying that your program isn't unceremoniously killed just for asking for more memory - all allocations are assumed fallible and failures must be handled explicitly. Stack space is not treated like magic - the compiler can reason about its maximum size by exam…

I don't know Zig. The article says "Many people seem confused about why Zig should exist if Rust does already." But I'd ask instead why does Zig exist when C does already? It's just a "better" C? But has the drawback that makes C problematic for development, manual memory management? I think you are better off using a language with a garbage collector, unless your usage really needs manual management, and then you ca…

yeah, its a better c, but like wouldnt it be nice if c had stadardized fat pointers so that if you move from project to project you don't have to triple check the semantics? for example and like say 50+ "learnings" from 40 years c that are canonized and first class in the language + stdlib

Re: Thoughts on Go vs. Rust vs. Zig

#249

> I’m not the first person to pick on this particular Github comment, but it perfectly illustrates the conceptual density of Rust: But you only need about 5% of the concepts in that comment to be productive in Rust. I don't think I've ever needed to know about #[fundamental] in about 12 years or so of Rust… > In both Go and Rust, allocating an object on the heap is as easy as returning a pointer to a struct from a fu…

> Rust can also do arena allocations,

Is there a language that can't?

The author isn't saying it's literally impossible to batch allocate, just that the default happy path of programming in Rust & Go tends to produce a lot of allocations. It's a take more nuanced than the binary possible vs impossible.

Re: Thoughts on Go vs. Rust vs. Zig

#250

Earlier quoted context omitted.

> Go programmer attitude is "do what I said, and trust that I read the library docs before I said it". I agree and think Go gets unjustly blamed for some things: most of the foot guns people say Go has are clearly laid out in the spec/documentation. Are these surprising behaviors or did you just not read? Getting a compiler and just typing away is not a great way of going about learning things if that compiler is not…

It's not unjust to blame the tool if it behaves contrary to well established expectation, even if that's documented - it's just poor ergonomics then.

ironically with zig most of the things that violate expectations are keywords. so you run head first into a whole ton of them when you first start (but at least it doesn't compile) and then it you have a very solid mental model of whats going on.
Post reply on HN