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Comment by kstrauser | Hacker News Reader

I meant the collective bulk of legacy C code running the world that we can’t just rewrite in Rust in a finite and reasonable amount of time (however much I’d be all on board with that if we could).

There are a million internal C apps that have to be tended and maintained, and I’m glad to see people giving those devs options. Yeah, I wish we (collectively) could just switch to something else. Until then, yay for easier upgrade alternatives!

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I was also, in fact, referring to the bulk of legacy code bases that can't just be fully rewritten. Almost all good engineering is done incrementally, including the adoption of something like safe_c.h (I can hardly fathom the insanity of trying to migrate a million LOC+ of C to that library in a single go). I'm arguing that engineering effort would be better spent refactoring and rewriting the application in a fully safe language one small piece at a time.

I’m not sure I agree with that, especially if there were easy wins that could make the world less fragile with a much smaller intermediate effort, eg with something like FilC.

I wholeheartedly agree that a future of not-C is a much better long term goal than one of improved-C.

I don't really agree, at least if the future looks like Rust. I much prefer C and I think an improved C can be memory safe even without GC.

> I think an improved C can be memory safe even without GC

That's a very interesting belief. Do you see a way to achieve temporal memory safety without a GC, and I assume also without lifetimes?

A simple pointer ownership model can achieve temporal memory safety, but I think to be convenient to use we may need lifetimes. I see no reason this could not be added to C.

A C with lifetimes would be nice, I agree.

Would be awesome if someone did a study to see if it's actually achievable... Cyclone's approach was certainly not enough, and I think some sort of generics or a Hindley-Milner type system might be required to get it to work, otherwise lifetimes would become completely unusable.

Yes, one needs polymorphism. Let's see. I have some ideas.

C does have the concept of lifetimes. There is just no syntax to specify it, so it is generally described along all the other semantic details of the API. And no it is not the same as for Rust, which causes clashes with the Rust people.

What clashes?

I think there was a discussion in the Linux kernel between a kernel maintainer and the Rust people, which started by the Rust people demanding formal semantics, so that they could encode it in Rust, and the subsystem maintainer unwilling to do that.

Ah, I thought you were talking about core language semantics in C.

I don't know enough Rust, to do such a comparison.

“The rust people” were also kernel maintainers.

Sorry, I'm not familiar with the titles of kernel developers. I thought only one of them was the subsystem maintainer.

One of them was a maintainer of that particular subsystem, but that doesn't mean that the other folks aren't also maintainers of other parts of the kernel.

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