LLVM
-
I don't know what you read on my reply. But your reply makes no sense.
Let me rephrase it if you prefer:
Claiming that Rusty's borrow checker is reference counting is hugely misleading. Since the borrow checker was made specifically to prevent the runtime cost of garbage collection and reference counting while still being safe.
To anyone unaware, it may read as "rust uses reference counting to avoid reference counting, but they just call it borrow checking". Which is objectively false, since rust's solution doesn't require counting references at runtime.
I don't know what mutable string or any of the other rant has to do with reference counting. Looks like you're just looking to catch a "rust evangelist" in some kind of trap. Without even reading what I said.
A boolean is a non-negative integer with a maximum of one, often literally, but I see that calling the borrow checker a static reference counter with a maximum of one is frustrating you in the same way that you calling roc's reference counting a garbage collector is frustrating me.
The string example is because the thing you're calling runtime overhead is cheap compared to freeing up a string that's been extended even just a couple of times. It's not a trap. It's an example where freeing the string itself could be considerably more expensive than the
DEC candBRZthat you're calling overhead.It's a bit hypocritical to tell me off for not reading what you said when you haven't bothered to figure out the relevance of the memory management examples I gave and just dismissed them out of hand as "rant" and a "trap".
-
That's fair; Python, Swift, and most Lisps all use or have previously used reference-counting. But the quoted sentence isn't wrong, since it said no "garbage collection pauses" rather than "garbage collection."
wrote last edited by [email protected]Yes, I read or interpreted that wrong at first.
-
Roc has runtime overhead to do garbage collection, it says so right on their own page.
I was sceptical about your assertion because the language authors made a design decision not do do garbage collection. So I did a google search for garbage on roc-lang.org to try and find evidence of your claim. It doesn't say it does garbage collection. It does say overhead, but you're talking about it like it's a big slow thing that takes up time and makes thread pauses, but it's a small thing like array bounds checking. You do believe in array bounds checking, don't you?
So no, that's not what it says and you're using the phrase garbage collection to mean a much wider class of things than is merited. Garbage collection involves searching the heap for data which has fallen out of scope and freeing that memory up. It's slow and it necessitates pausing the main thread, causing unpredictably long delays. Roc does not do this.
Here's what the website actually says on the topic.
Roc is a memory-safe language with automatic memory management. Automatic memory management has some unavoidable runtime overhead, and memory safety based on static analysis rules out certain performance optimizations—which is why unsafe Rust can outperform safe Rust. This gives Roc a lower performance ceiling than languages which support memory unsafety and manual memory management, such as C, C++, Zig, and Rust.
Just in case you missed it, that was unsafe rust that lacks the overheads. If you're advocating for using unsafe to gain a tiny performance benefit, you may as well be writing C, or zig, which at least has some tools to cope with all that stuff.
When benchmarking compiled Roc programs, the goal is to have them normally outperform the fastest mainstream garbage-collected languages (for example, Go, C#, Java, and JavaScript)
Just in case you missed it, roc is not in the list of garbage collected languages.
https://www.roc-lang.org/platforms
The bigger benefit is tailoring memory management itself based on the domain. For example, nea is a work-in-progress Web server which performs arena allocation on each request handler. In Roc terms, this means the host's implementation of malloc can allocate into the current handler's arena, and free can be a no-op. Instead, the arena can be reset when the response has been sent.
In this design, heap allocations in a Web server running on nea are about as cheap as stack allocations, and deallocations are essentially free. This is much better for the server's throughput, latency, and predictability than (for example) having to pay for periodic garbage collection!
Summary: roc doesn't have the performance disadvantages of garbage collected languages because it's not a garbage collected language.
wrote last edited by [email protected]Just in case you missed it, that was unsafe rust that lacks the overheads.
It says some overheads. It's different overheads, because Rust does not have reference counting garbage collection, even when safe.
Either you should go back and read what I said about reference counting being a runtime garbage collecting algorithm, or I think we're just done. Why say more if it's ignored anyway?
I don't think I'm the zealot here.
-
Just in case you missed it, that was unsafe rust that lacks the overheads.
It says some overheads. It's different overheads, because Rust does not have reference counting garbage collection, even when safe.
Either you should go back and read what I said about reference counting being a runtime garbage collecting algorithm, or I think we're just done. Why say more if it's ignored anyway?
I don't think I'm the zealot here.
Well if you're calling any form of automatic memory management garbage collection, then it's only C that doesn't have garbage collection.
Rust does have explicit reference counting with Rc<T> and Arc<T>.
I'm trying to explain to you that static analysis that limits references to one can be done in a similar way without the limit of one (especially with the assumption of immutability) whilst retaining in-place mutation where the count really is one. It upsets you when I try to explain that it's a generalisation of the borrow checker (without the programmer pain) by calling the borrow checker a static (compile time) reference counter with a limit of one. I'm making a comparison. But don't be surprised if a lot of programming languages implement their boolean variables as an unsigned int with a maximum of one.
If roc does the equivalent of putting a call to drop where there were two or three references that fell out of scope rather than one, in what sense is that more overhead than rust calling drop when one reference went out of scope? Rust is still "garbage collecting" the references that turned up on the RHS of assignment statements as it goes along.
The overhead we're talking about with reference counting is like
DEC rBRZ. It's like array bounds checking. Yes, it's an overhead, but no, it's not worth making a big deal about it if you get to allocate arrays of sizes unknown at compile time or you get to make multiple references without messing with keywords and reference symbols, fighting the borrow checker all day long or manually adding clones.It says some overheads. It’s different overheads,
What? Overheads are overheads. Either they're small and useful like roc's reference counting when it turns out to need to be at runtime or array bounds checking, or rust calling drop when some variable falls out of scope, or they're big, stop the main thread at random points and take a long time, like garbage collection in garbage collected languages like java.
Why say more if it’s ignored anyway?
I know - I wrote a whole bunch of stuff and this other person just ignored every single nuance and explanation and kept saying the same thing again and again without trying to understand a new thing they didn't know about before, just repeating their favourite criticisms of other programming languages whether they applied or not. Oh wait, that was you.
I don’t think I’m the zealot here.
Interesting.
-
A boolean is a non-negative integer with a maximum of one, often literally, but I see that calling the borrow checker a static reference counter with a maximum of one is frustrating you in the same way that you calling roc's reference counting a garbage collector is frustrating me.
The string example is because the thing you're calling runtime overhead is cheap compared to freeing up a string that's been extended even just a couple of times. It's not a trap. It's an example where freeing the string itself could be considerably more expensive than the
DEC candBRZthat you're calling overhead.It's a bit hypocritical to tell me off for not reading what you said when you haven't bothered to figure out the relevance of the memory management examples I gave and just dismissed them out of hand as "rant" and a "trap".
I haven't read 90% of your comment since it is out of the topic of the discussion. The "trap" is trying to argue with mee about something I haven't even mentioned.
-
GCC is adding cool new languages too!
They just recently added COBOL and Modula-2. Algol 68 is coming in GCC 16.
BEGIN BEGIN Wow, Modula 2! END; I remember Modula 2. END. -
I guess I should have put a /s but I thought it was pretty obvious. The 68 in Algol 68 is 1968. COBOL is from 1959. Modula-2 is from 1977.
My point exactly was that all the hot new languages are built with LLVM while the “new” language options on GCC are languages from the 50’s, 60’s, and 70’s.
I am not even exaggerating. That is just what the projects look like right now.
I had my suspicions that that's what you were going for, I just thought I'd make it obvious.
-
I have built single pass compilers that do everything in one shot without an AST. You are not going to get great error messages or optimization though.
Oh! Okay, that's interesting to me! What was the input language? I imagine it might be a little more doable if it's closer to hardware?
I don't remember that well, but I think the object oriented stuff with dynamic dispatch was hard to deal with.
-
I guess I should have put a /s but I thought it was pretty obvious. The 68 in Algol 68 is 1968. COBOL is from 1959. Modula-2 is from 1977.
My point exactly was that all the hot new languages are built with LLVM while the “new” language options on GCC are languages from the 50’s, 60’s, and 70’s.
I am not even exaggerating. That is just what the projects look like right now.
I would guess those languages are added for preservation and compatibility reasons, and it's also an important thing