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by mort96 245 days ago
I feel like back when D might've been a language worth looking into, it was hampered by the proprietary compilers.

And still today, the first thought that comes to mind when I think D is "that language with proprietary compilers", even though there has apparently been some movement on that front? Not really worth looking into now that we have Go as an excellent GC'd compiled language and Rust as an excellent C++ replacement.

Having two different languages for those purposes seems like a better idea anyway than having one "optionally managed" language. I can't even imagine how that could possibly work in a way that doesn't just fragment the community.

4 comments

D has been fully unproprietary since 2017. https://forum.dlang.org/post/oc8acc$1ei9$1@digitalmars.com

But that's only the reference compiler, DMD. The other two compilers were fully open source (including gcc, which includes D) before that.

Fully disagree on your position that having all possibilities with one language is bad. When you have a nice language, it's nice to write with it for all things.

Sounds like you should look into it instead of idly speculating! Also, the funny thing about a divisive feature is that it doesn't matter if it fragments the community if you can use it successfully. There are a lot of loud people in the D community who freak out and whine about the GC, and there are plenty more quiet ones who are happily getting things done without making much noise. It's a great language.
Are you saying that if I'm using D-without-GC, I can use any D library, including ones written with the assumption that there is a GC? If not, how does it not fracture the community?

> There are a lot of loud people in the D community who freak out and whine about the GC, and there are plenty more quiet ones who are happily getting things done without making much noise

This sounds like an admission that the community is fractured, except with a weirdly judgemental tone towards those who use D without a GC?

> Are you saying that if I'm using D-without-GC, I can use any D library, including ones written with the assumption that there is a GC? If not, how does it not fracture the community?

"Are you saying that if I'm using Rust in the Linux kernel, I can use any Rust library, including ones written with the assumption they will be running in userspace? If not, how does that not fracture the community?"

"Are you saying that if I'm using C++ in an embedded environment without runtime type information and exceptions, I can use any C++ library, including ones written with the assumption they can use RTTI/exceptions? If not, how does that not fracture the community?"

You can make this argument about a lot of languages and particular subsets/restrictions on them that are needed in specific circumstances. If you need to write GC-free code in D you can do it. Yes, it restricts what parts of the library ecosystem you can use, but that's not different from any other langauge that has wide adoption in a wide variety of applications. It turns out that in reality most applications don't need to be GC-free (the massive preponderance of GC languages is indicative of this) and GC makes them much easier and safer to write.

I think most people in the D community are tired of people (especially outsiders) constantly rehashing discussions about GC. It was a much more salient topic before the core language supported no-GC mode, but now that it does it's up to individuals to decide what the cost/benefit analysis is for writing GC vs no-GC code (including the availability of third-party libraries in each mode).

The RTTI vs no-RTTI thing and the exceptions vs no-exceptions thing definitely does fracture the C++ community to some degree, and plenty of people have rightly criticized C++ for it.

> If you need to write GC-free code in D you can do it.

This seems correct, with the emphasis. Plenty of people make it sound like the GC in D is no problem because it's optional, so if you don't want GC you can just write D without a GC. It's a bit like saying that the stdlib in Rust is no problem because you can just use no_std, or that exceptions in C++ is no problem because you can just use -fno-exceptions. All these things are naïve for the same reason; it locks you out of most of the ecosystem.

> This sounds like an admission that the community is fractured, except with a weirdly judgemental tone towards those who use D without a GC?

That's not what I'm saying, and who cares if it's fractured or not? Why should that influence your decision making?

There are people who complain loudly about the GC, and then there are lots of other people who do not complain loudly and also use D in many different interesting ways. Some use the GC, some don't. People get hyper fixated on the GC, but it isn't the only thing going on in the language.

> who cares if it's fractured or not? Why should that influence your decision making?

Because, if I want to write code in D without the GC, it impacts me negatively if I can't use most of the libraries created by the community.

What domain are you working in? It's hard to be able to say anything specific that might help you if you can't explain a little more clearly what you're working on.

I will say there are a larger and larger number of no-GC libraries. Phobos is getting an overhaul which is going to seriously reduce the amount that the GC is used.

It is probably also worth reflecting for a moment why the GC is causing problems for you. If you're doing something where you need some hard-ish realtime guarantee, bear in mind that the GC only collects when you allocate.

It's also possible to roll your own D runtime. I believe people have done things like replace the GC with allocators. The interface to the GC is not unduly complicated. It may be possible to come up with a creative solution to your problem.

I work in many domains, some where a GC is totally no problem, and some where I'd rather not have a GC (such as microcontrollers, games, the occasional kernel code, software running on embedded Linux devices with very limited memory).

I'm happy with C++ and Rust for those tasks. For other tasks where I want a GC, I'm perfectly happy with some combination of Go, Python and Typescript. I'm realistically never going to look into D.

Go is a GC language that has eaten a chunk of the industry (Docker, TypeScript, Kubernetes... Minio... and many more I'm sure) and only some people cry about it, but you know who else owns sizable chunks of the industry? Java and C# which are both GC languages. While some people waste hours crying about GCs the rest of us have built the future around it. Hell, all of AI is eaten by Python another GC language.
And in D, there's nothing stopping from either using or not using the GC. One of the key features of D is that it's possible to mix and match different memory management strategies. Maybe I have a low level computational kernel written C-style with memory management, and then for scripting I have a quick and dirty implementation of Scheme also written in D but using the GC. Perfectly fine for those two things to co-exist in the same codebase, and in fact having them coexist like that is useful.
> And in D, there's nothing stopping from either using or not using the GC.

Wait so are you, or are you not, saying that a GC-less D program can use libraries written with the assumption that there's a GC? The statement "there's nothing stopping [you] from not using the GC" implies that all libraries work with D-without-GC, otherwise the lack of libraries written for D-without-GC would be stopping you from not using the GC

Sorry, but it's more complicated than this. I understand the point you're making, but if your desiderata for using a language is "If any feature prevents me from using 100% of the libraries that have been written for the language, then the language is of no use to me", well... I'm not sure what to tell you.

It's not all or nothing with the GC, as I explained in another reply. There are many libraries that use the GC, many that don't. If you're writing code with the assumption that you'll just be plugging together libraries to do all the heavy lifting, D may not be the right language for you. There is a definite DIY hacker mentality in the community. Flexibility in attitude and approach are rewarded.

Something else to consider is that the GC is often more useful for high level code while manual memory management is more useful for low level code. This is natural because you can always use non-GC (e.g. C) libraries from GC, but (as you point out) not necessarily the other way around. That's how the language is supposed to be used.

You can use the GC for a GUI or some other loose UI thing and drop down to tighter C style code for other things. The benefit is that you can do this in one language as opposed to using e.g. Python + C++. Debugging software written in a mixture of languages like this can be a nightmare. Maybe this feature is useful for you, maybe not. All depends on what you're trying to do.

You're the guy who said that "nothing is preventing you" from using D without a GC. A lack of libraries which work without a GC is something preventing you from using D without a GC. Just be honest.
I'm not strongly for or against (non-deterministic) GC. Deterministic GC in Rust or the (there's no real Scotsman) correctly written C++ has benefits, but often I don't care and go / java / c# / python are all fine.

I think you're really overstepping with AI is eaten by python. I can imagine an AI stack with out python llama.cpp (for inference not training... isn't completely that, but most of the core functionality is not python, and not-GCd at all), I can not imagine an AI stack with out CUDA + C++. Even the premier python tools (pytorch, vllm) would be non-functional with out these tools.

While some very common interfaces to AI require a GC'd language I think if you deleted the non-GC parts you'd be completely stuck and have years of digging your self out, but if you deleted the 'GC' parts you can end up with a usable thing in very short order.

NVidia has decided that the market demand to do everything in Python justifies the development cost of making Python fast in CUDA.

Thus now you can use PTX directly from Python, and with the new cu Tiles approach, you can write CUDA kernels in a Python subset.

Many of these tools get combined because that is what is already there, and the large majority of us don't want, or has the resources, to spend bootstrapting a whole new world.

Until there is some monetary advantage in doing so.

For 99% of the industry use cases, some kind of GC is good enough, and even when that isn't the case, there is no need to throw away the baby with the babywater, a two language approach also works.

Unfortunely those that cry about GCs are still quite vocal, at least we can now throw Rust into their way.

There's a place for GC languages, and there's a place for non-GC languages. I don't understand why you seem so angry towards people who write in non-GC languages.
And there's a place for languages that smoothly support both GC and non-GC. D is the best language at that.
"AI" is built on C, C++, and Fortran, not Python.
Once one realizes that the GC is just another way to allocate memory in D, it becomes quite wonderful to have a diverse collection of memory management facilities at hand. They coexist quite smoothly. Why should programs be all GC or no GC? Why should you have to change languages to switch between them?
Indeed the GC is just a library with some helpful language hooks to make the experience nice.

If you understand how it's hooked into, it's very easy to work with. There is only one area of the language related to closure context creation that can be unexpected.

I don't think the proprietary compilers is a true set back, look at for example C# before it became as open as .NET has become today (MIT licensed!) and yet the industry took it. I think what D needed was what made Ruby mainly relevant: Rails. D needs a community framework that makes it a strong candidate for a specific domain.

I honestly think if Walter Bright (or anyone within D) invested in having a serious web framework for D even if its not part of the standard library, it could be worth its weight in gold. Right now there's only Vibe.d that stands out but I have not seen it grow very much since its inception, its very slow moving. Give me a feature rich web framework in D comparable to Django or Rails and all my side projects will shift to D. The real issue is it needs to be batteries included since D does not have dozens of OOTB libraries to fill in gaps with.

Look at Go as an example, built-in HTTP server library, production ready, its not ultra fancy but it does the work.

C# has Microsoft behind it. D ... doesn't.

There are plenty of people who aren't interested in using languages with proprietary toolchains. Those people typically don't use C#. The people who don't mind proprietary toolchains typically write software for an environment where D isn't relevant, such as .NET or the Apple world.

I do agree with you that there needs to be a good framework though. Either in Web or Games. Web because it's more familiar than Go but also has Fibers, and Games because it's an easier C++. There is also Inochi2D which looks rather professional: https://inochi2d.com/

One of the issues I've seen in the community is just that there aren't enough people in the community with enough interest and enough spare time to spend on a large project. Everyone in the core team is focused on working on the actual language (and day-jobs), while everyone else is doing their own sort of thing.

From your profile you seem to have a lot of experience in the field and in software in general, so I'd like to ask you if you have any other advice for getting the language un-stuck, especially with regards to the personnel issues. I think I'd like to take up your proposal for a web framework as well, but I don't really have any knowledge of web programming beyond the basics. Do you have any advice on where to start or what features/use case would be best as well?

Getting a web framework into the standard library is something I want to get working, along with a windowing library.

Currently we need to get a stackless coroutine into the language, actors for windowing event handling, reference counting and a better escape analysis story to make the experience really nice.

This work is not scheduled for PhobosV3 but a subset such as a web client with an event loop may be.

Lately I've been working on some exception handling improvements and start on the escape analysis DFA (but not on the escape analysis itself). So the work is progressing. Stackless coroutine proposal needs editing, but it is intended to be done at the start of next year for approval process.

Go would be an excellent GC'd compiled language if it actually learnt from history of computing.

I rather give that to languages like C# with Native AOT, or Swift (see chapter 5 of GC Handbook).

D only lacks someone like Google to push it into mainstream no matter what, like Go got to benefit from Docker and Kubernetes.