For someone new to systems programming, should I just start with Rust?
Or should I learn C/C++ first and then learn Rust?
I've just done projects in Python,JS & Java so far.
Or should I learn C/C++ first and then learn Rust?
I've just done projects in Python,JS & Java so far.
If you want just to "play" and do some tiny projects as low level as reasonable - go for learning C first. You'll learn a lot - and then when you learn rust, the reasons why things are done that way will make a lot of sense. Also, so many low level utils are written in C - having a basic knowledge of it is really useful. But don't try to build a big complex thing in it unless you have a really good reason to (or you fall in love with C. Some people do!)
If you want to actually build something big and complex and for real world use - probably go for Rust.
If you want to build a big production system using an already established tech that's based on C++, learn that. (Eg. one of the C++ based game engines, or a C++ GUI framework, or whatever).
C++ has everything C has plus many layers of complexity deposited over it that can make you more productive but also obscure your relationship with the machine. If you're going to go on to Rust I wouldn't bother with C++ at all right now.
If you're coming from Java, the most difficult thing you'll need to learn is memory management, as all of those languages do that for you. The other difficult thing is threading, but that's 1) unnecessary and 2) not actually that different from Java.
Rust forces you (unsafe aside) to do memory management in one specific way, and verifies it in the compiler. C and C++ let you do whatever you want, though C++ encourages (without requiring) a Rust-like approach.
I think Rust will probably be better if you want to have a constrained environment that tries to prevent mistakes. C will be better if you want to explore on your own, learn from the mistakes, and thus understand why Rust wants you to do particular things. C++ frankly doesn't have a whole lot to recommend it unless you are working with a C++ codebase, already know C, or really need one of its features.
I'm coming from a largely Java background (though I program a lot of C and assembly as a hobby), and this statement is very true. Getting used to the borrow checker and reference lifetimes has been the largest obstacle so far. But once that is understood, the rest of Rust is basically learning the idioms and ecosystem.
I will likely change how I write C based on my experience with Rust's memory ownership model..
Moving from high-level languages to Rust is going to be a nice punch in the face :)
Some people suggest to learn C/C++ but that ultimately depends on the resources available. If one has infinite time, certainly it's ideal, but with limited time, I think learning Rust will already be very demanding.
My suggestion: find some small projects you find interesting. Follow the usual Rust learning path (reference book first, then find other books), and apply it to the projects you've chosen; after an year or so, ask the question again.
Other small suggestion: don't start from book that pretend to teach Rust by learning another topic, because the amount of Rust that can be taught in 100 pages is useless (a lot of books pretend to do so). On the other hand, there are way more books to find fun projects/topics than there were an year ago.
IMHO, if your end-goal is Rust, learn Rust directly.
The angle I am coming from: I've been doing C++ for 20 years and Rust for over a year.
Learning C/C++ can provide great value on its own, through gaining knowledge of how lower-level programming primitives work, but many of your C/C++ skills won't be subsequently applicable to Rust, except perhaps for core concepts such as a stack, a heap, owning memory, a `struct`, etc. This is caused by the fact that Rust takes many programming abstractions much _farther_ than C and in a substantially _different_ direction than C++. For example: where C uses manually managed pointers, Rust uses compile-time checked ownership and borrowing; where C++ uses inheritance, Rust uses generics and composition; where C uses void pointers ;) and C++ uses pure virtual functions, Rust uses traits and `where` clauses; where C and C++ use... a programmer's eyeballs to guarantee multi-threaded correctness ;), Rust uses compile-time "marker" traits; and so on.
Don't get me wrong: C and C++ are extremely able, powerhouse languages worth your time in their own respect, it is just that most of the C/C++ -specific knowledge you invest your time to learn beforehand won't be directly applicable to Rust later on, because Rust just does things in a significantly different way than C/C++.
Oh, don't forget to RTFM - Rust is easy to learn by reading (in order to understand its unique concepts), but Rust is hard to learn by experimentation alone (trying 100 different syntax variations to see what compiles).
You don't need to 100% the language, a few months experience will be be handy for the rest of your computing career. It'll be a perfectly reasonable stepping stone for reading C++ without really needing to learn all the details to write it.
As much as any language can be: C is still the lingua franca, a relative common denominator. As you explore different parts of the computing environment around you, you'll run into it constantly.
Learning about python? C. Digging into how your program talks to the OS? glibc and the man pages and most examples will be C oriented. Any documentation ever explains how something is laid out in memory? It'll be explained in C structs. How function calls work? The assembly will be explained in terms of C code and C's calling convention. Any language's FFI? C. Digging into the JVM, browsers, Javascript? It's C++ but you'll know enough to eyeball the code.
This is mostly about all the things you'll want to be able to read about well. Anything you'll want to know has been done in C or C++ — Nothing big exists that you'll want to explore is mostly written in Rust or Zig yet. And there are still things that can't reasonably be yet either (oversimplification).
There's no real problem starting with Rust, especially if you have some experience with other languages. The biggest difference is going to be getting used to dealing explicitly with memory, since all the languages you listed have a garbage collector; but this is true of all of C, C++ and, Rust. Be kind to yourself -- don't expect it all to click instantly.
Rust is it's own thing; I personally really like it but going from C to Rust is harder than just going to Rust as you have to "unlearn" C paradigms.
You'll probably be "better" if you go C first, but it will take a lot of time and energy.
In the end its completely up to you.
It will teach you how a PDP-11 thinks, at best. The cache hierarchy and speculative execution are completely hidden at the level of C, to start with.
You want to learn how computers think, pick up an assembly language. (Any one will do.) You want to build portable low-level software, learn Rust, Zig, C, or C++ (in my personal order of preference).
[0] https://www.intel.com/content/www/us/en/developer/articles/t...
The performance gains of fine-tuned code is typically two orders of magnitude higher
A quick glance at Intel's Software Developer's Manuals [0] falsifies this:
>> TLB and Cacheability control: CLFLUSH, CLFLUSHOPT, CLWB, INVD, WBINVD, INVLPG, INVPCID, and memory instructions with a non-temporal hint (V/MOVNTDQA, V/MOVNTDQ, V/MOVNTI, V/MOVNTPD, V/MOVNTPS, V/MOVNTQ, V/MASKMOVQ, and V/MASKMOVDQU).
> [..] speculative execution are completely hidden at the level of assembly too
Section 18.1.13 specifically mentions side-channels for speculative execution, and there are more than 100 other matches for "speculative" across the document (some of which also refer to load barriers).
So no, these things are not completely hidden at the assembly level, and at least in the case of the (or one of the?) most popular consumer CPU architecture in the world, they are actively documented in the primary reference for an assembly programmer.
[0] https://www.intel.com/content/www/us/en/developer/articles/t...
And error recovery (that is fucking crazy on x86), and wide instructions, and I/O, and stack management, and... I am not sure C is even a good approximation for the PDP-11.
For which you'd need to be familiar with a low-level language like C.
It's a good way of helping people with no programming knowledge get past the stage of "what are those magic colourful words you type that somehow make the computer do things?".
https://tobiasvl.github.io/blog/write-a-chip-8-emulator/
I haven't made a Gameboy emulator, just learned the assembly so I could modify some roms.
You can check out my blog post[1] if you're interested how I went about it (there are a couple resources at the bottom I used to build it, including the one that HideousKojima recommended).
As for language, in hindsight, C was fine. CHIP-8 is so basic that you don't really need to worry about performance or to implement a JIT compiler unless you want to learn how to do those things specifically. Just pick any one out of the three (assembly is a bit of a weird choice though, why not write a CHIP-8 emulator and then a brand new program to run on that emulator in CHIP-8 assembly if you want to learn assembly?)
As for Gameboy, it would have more instructions, a different graphics system, sound etc. and overall be more complicated than CHIP-8. Try it out if you either feel a bit more adventurous or have implemented CHIP-8.
[0](https://sr.ht/~gotlou/chip8-emulator) [1](https://gotlou.srht.site/chip8-emulator.html)
Check this post out - Should you learn C to "learn how the computer works"? (https://steveklabnik.com/writing/should-you-learn-c-to-learn...). Spoiler alert - no.
I think summarizing that article as "no" really undercuts how diplomatic and reasonable Steve Klabnik is in it.
But is it necessary to understand now a computer works? No.
You can also check out "C is how the computer works" is a dangerous mindset for C programmers (https://steveklabnik.com/writing/c-is-how-the-computer-works...)
If, however, we're talking about the kernel then perhaps we should listen to what Torvalds says about this topic.
"People who designed C, designed it at a time where the language had to be geared towards the output, so when I read C I can think about the Assembly that it will create":
http://www.youtube.com/watch?v=MShbP3OpASA&t=20m45s
Consider that he said this in a time with C++, even if Rust was in its infancy: it is not as tied to the assembly it produces. Not by a long shot.
The issue with Assembly directly is that it's absurdly non-portable, too low level and too unstructured to do anything reasonable with it.
There's a reason that Linux is written in C and not ASM Directly.
Even interpreting this as charitably as possible--that you don't mean literally learning assembly but rather learning everything besides specific assembly syntax that you would have picked up from learning assembly--this claim doesn't hold water.
For starters, C isn't that much closer to hardware than, say, Java. The main differences you have with C are that a) C has a pointers-are-almost-integers model [1] and b) C has a more limited runtime than other languages. C is still a fundamentally based on an abstract machine semantics model, and that abstract machine doesn't have a close bearing on modern hardware.
In particular, C does not distinguish between registers and memory, and if I had to pick the single most salient feature of modern hardware you need to understand well to be able to say you understand how computers work, it's the register/memory distinction. If you think processors are mostly like they were in the 1970s--when you could say "add 1 to this memory location"--then C's shrugging off the register/memory distinction makes sense, but this is a situation that hasn't been true for several decades.
Another failure of C is that it's far less expressive than assembly. There are features in other languages that are impossible to express in C. How do you write a function with multiple entry points, as you can in Fortran? Or a coroutine, as you can in Algol? Or nested functions, as in Pascal? Or try-catch, as in C++? Or functions with multiple return values, as in Matlab? Indeed, how do you write something like JMP *reg in C, a useful primitive for state machines?
No, C does not come close to being a good description of modern processors, where "modern" means "anything that came out since I was born."
[1] Not going to open up the can of worms that is pointer provenance.
Just nitpicking, but doesn't C have the register keyword? (I know it does nothing at all nowadays, but AFAIK it did make a slight difference back in the dark ages.)
Your C compiler might conclude - even if it doesn't decide to put the variable in a register - that since the variable notionally doesn't have an address some optimisations are available which it can't otherwise be sure are safe.
[1] Okay, the official semantics of "volatile" strictly speaking are completely orthogonal to memory, but the practical effect that everyone agrees on (don't optimize this memory access) is inherently oriented towards memory, and the fact that the semantics are so vague about what it actually does is partially a reflection of the fact the semantics themselves don't distinguish between register and memory.
I don't believe this at all. You won't learn how to deal with limited numbers of registers. You won't learn about method prologues and epilogues. You won't learn about oodles of stuff.
Those things takes like an hour to learn, translating C to assembly is trivial, it takes time and will be verbose but it isn't hard at all. So even though you don't learn all the details you still learn all the higher level stuff related to assembly programming when you program in C.
This isn't true for other languages, translating arbitrary C++ or Java or Javascript to assembly is really hard, so they don't teach you to think like an assembly programmer.
I mean; you will likely end up stepping through debuggers where you will see registers being used. At least if you learned C like I learned C.
Similarly for Prologue and Epilogue.
"why does a function call have a cost" is a common question and it's solved forever after an hour googling.
If you're willing to accept, at face value, that certain easy tasks are convoluted for Good Reasons, you can go straight to Rust. If you want figure out why for yourself, start with C.
I always want to learn bottom up, and personally recommend starting with C.
A)
Rust gives you many great abstractions that you will want to use, even if you skip the standard library. This gets in the way of really learning to work with and understanding pointers and low level mechanisms. You can certainly do that in Rust, but you have to force yourself to ignore most oft the language.
B)
You will have to read and interact with C code eventually, and be it just calling out to libraries or wrapping libraries in Rust interfaces.
A solid understanding of C is critical to do that correctly.
There's also a lot of safety tooling that you rarely need with Rust, but should be comfortable with. (Like valgrind)
After learning Rust you will hate working with C (well, I do...), so it's better to do it early.
You don't want to get fooled into thinking C's abstract machine is what your actual machine is like, because it really, really isn't. A bunch of the stuff C is deliberately vague about because it wasn't portable in the 1970s is very concrete and important to understand about on a real computer. Rust's Wrapping<u8> and Saturating<i16> have behaviour that you could buy with a real CPU (indeed your actual CPU almost certainly can do Wrapping<u8> with no extra work) but C doesn't promise anything like this and names types things like "short int" which could be anything.
On the other hand, some things C makes seem obviously concretely real, are just being simulated convincingly and that's not necessarily how your CPU works at all. Nobody really promised "pointers" are just integers you can go around doing arithmetic with for example.
If your endpoint is Rust anyway, just start there. You can always learn C (and/or C++) later.
I don't think it matters (much) which language you start with. Any one of the suggested languages (or commonly suggested languages in general) will be fine. I think this applies in general too, at any levels of skill/experience, but probably matters more for someone with less experience.
Between C and Rust, Rust has better tooling and an easy to use library ecosystem. C is a smaller and easier to grasp language.
I would start with Rust if you want to write a real world project. And probably start with Rust if you just want to write some leetcode algorithms as well (but C is fine here too)
People that learn C or C++ first often end up fighting the Rust compiler a bit until they adjust their mindset.
Rust's borrowing and ownership semantics are not bizarre and novel solutions to things that aren't problems in other languages. Rust's borrowing and ownership semantics are a compiler-level reification of problems that exist in all languages, and especially multithreaded languages. This 100% includes C. You may not adopt Rust's exact solutions in all cases, but if your are programming at a system's level at all and you're not thinking about the problems that Rust exposes directly, you're in trouble and you don't even know it. Using Rust is a great way to work in an environment where the compiler is forcing you to learn how that all works, and will train you good and hard about how to think about issues of ownership and what code is allowed to touch what.
I primarily work in Go, a garbage collected language, and I heavily use the concurrency features. That doesn't mean I don't have to think about ownership because the language lacks any support for it, or that I don't have to worry about who is responsible for deallocating things because I work in a GC'd language. It means I have to think about those things, but I lack support from the language. My personal career experience means this is not a terrible tradeoff; as a result of all my time in Erlang and Haskell it is no big deal for me to operate concurrently in a manner that I know will work, because while they are different than Rust, they were also harsh taskmasters in terms of only allowing me to do certain things that work. Other tradeoffs make Go worth it for me despite this lack of language support. But the lack of support doesn't make the problems go away. It just makes it so you can't see them immediately at compile time.
I would expect that someone who learned Rust for a year, then learned C for a year, would probably produce better C code than someone who learned C for two years. Eventually, the C programmer will, by hook and by crook, learn all the things that Rust would have taught you, but you'll be learning it in an enviromnent that lets you make mistakes, then build on them for months before they finally blow up in your face. It is far easier to learn about what mistakes you are making in an environment where it instantly tells you that you made a mistake.
(Also, I should clarify something: By "C" here, I mean programming in raw C, without any particular additional support. For the sort of purposes I'm talking about here, I actually consider "C with a strong static analysis tool like Coverity" a separate language. If you use such a tool pervasively and work in a code base that has either been cleaned to its satisfaction or started from scratch under the analyzer's support, you can also learn in a fast-feedback environment what not to do. It won't be the exact same lessons as Rust, but it'll be good enough; there are many paths to enlightenment in this case, just as I trod a completely different one as mentioned above. The important point is to use one of these, or perhaps another, and not simply stand in front of the monster that is Raw C with nothing but your own wits to guide you. I don't care how smart you are. It'll eat you alive. You do not want to be responsible for trying to tame the thing yourself under your own power and nothing else.)
The story I’m seeing at most companies is that they have a few old guys taking care of maintaining their legacy C/C++ codebase, and there’s a diverse bunch of young folks shipping new components in Rust.
When the time comes you can start with Rust