11 ms·

These sorts of articles are starting to pop up a bit more frequently, presumably because Rust is starting to get a bit of traction. The theme is "I know $LOW_LE

by adwhit 10y ago

These sorts of articles are starting to pop up a bit more frequently, presumably because Rust is starting to get a bit of traction. The theme is "I know $LOW_LEVEL_LANGUAGE therefore I should be able to program Rust. I spent a few days and couldn't. I don't like Rust." Unfortunately, things aren't that simple and Rust really is different from other languages. It takes months of steady investment (and yes, frustration), but the payoffs are spectacular. I would urge the author to persevere. In the meantime, the community is very helpful and I'm sure you'll get lots of useful advice on the back of this post.

sametmax 10y ago
Exactly. The fact that rust is easier than most low level languages made the high level language crowd forget than bare metal programming IS HARD. Try to do a big project in C++ or C and you'll see that making something that is production worthy takes months. Besides, as a Python trainer I can make you productive in it in a few days. But it will still take a lot of time for you to be good at it. The only difference with rust is that the first "reward stimuli" comes later down the road because you need to be better at it than at Python to make use of it.
trishume 10y ago
Agreed. Rust is different from other languages in that it is HARD to learn. It took me 3 projects and thousands of lines of code before I finally felt like I'm okay at Rust. Each project involved tons of compiler fighting that I now know how to avoid or solve. The problem is that instead of a general technique for solving borrow checker issues, every issue has a different specific technique. Hash map matches (like the article) require the entry API. Multiple mutable pointers into a buffer require either using a typed Vec or Vec#split_off. Cyclic data structures require an Arena or Rc<Refcell<>>. String casting issues sometimes require .map(|x| &x). Global state requires lazy_static. Nice error handling requires error_chain. When you run into problems with "Send" you need a Mutex. The list goes on... It's like pure lazy functional programming in Haskell in that unlike other languages you can't just pick it up based on previous knowledge and patterns. You need an entirely new toolbox of pure algorithms and data structures, or in this case borrow-safe algorithms and data structures.
- alkonaut 10y ago
  > Agreed. Rust is different from other languages in that it is HARD to learn But do you learn to code in a different paradigm where you don't struggle by iterating on a compilable and runnable piece of code, but rather struggle on iterating on a non-compilable piece of code and "once it compiles, it works"?
  - AsyncAwait 10y ago
    Definitely and I'd say the struggle is only there for the first couple of weeks. This will get shorter as tooling gets better this year.
- ajmurmann 10y ago
  The issues and solutions you list sound super valuable. Do you know if there is a write up about those issues somewhere or did you just learn through blood and sweat?
  - nebopolis 10y ago
    Learning Rust With Entirely Too Many Linked Lists (http://cglab.ca/~abeinges/blah/too-many-lists/book/ http://cglab.ca/~abeinges/blah/too-many-lists/book/) is the best resource I've found for learning how to create data structures in Rust. It goes over a lot of the pain points of interacting with cyclic data structures.
    - petersp 10y ago
      Thank you for this pointer!
- jononor 10y ago
  Are these strategies for solving borrow checker issues documented anywhere? Sounds like a case for which a best-practice reference would be golden.
  - 10y ago
rubber_duck 10y ago
>It takes months of steady investment (and yes, frustration), but the payoffs are spectacular. This was the exact same thing I kept reading back when functional programming was becoming in vogue - people were pushing for Haskell, saying that purity and laziness were amazing, type system could almost prove correctness at compile time, etc. etc. You just need to meditate deeply on category theory and draw direction graphs to become one with types and all would be revealed to you. Hybrid functional languages got adopted in the meantime (F#/Scala/Clojure come to mind) and a lot of FP was adopted by OO languages - it wasn't pure or fancy but it solved problems in an accessible way. Most people still don't use Haskell. I'm hoping Rust doesn't go down this path as I want a replacement for C++ badly. But saying "you need to spend a few months to get intimately acquainted with the language" is just not going to work in practice if you're hoping about breaking in to the mainstream.
- gcp 10y ago
  I'm hoping Rust doesn't go down this path as I want a replacement for C++ badly. So that's opposed to C++'s "It takes a few years to get acquainted to the language enough that people would want your stuff in production code"? Nobody hires junior C++ programmers.
  - rubber_duck 10y ago
    The problem with writing C++ is not so much the language as it is the problem domain - writing C++ as "C with some syntax sugar" is possible and a popular method by people who don't care about C++ complexity. And it gets you to results fast. Having something work right away and deal with the edge cases when you encounter them is preferable in a lot of scenarios - especially while learning, but also as a principle of iterative development, a lot of the time as you're iterating on code stuff fundamentally changes (requirements change, your interpretation changes, etc.) all that formalization up front ends up being an impediment - as much as it makes some people uncomfortable.
    - gcp 10y ago
      Is it common for code that fits those requirements to require C++ or Rust, though? Particularly in terms of performance?
wiremine 10y ago
> It takes months of steady investment (and yes, frustration), but the payoffs are spectacular. In my experience, most developers can't or won't put in this sort of investment. Which leads me to wonder what fields/niches will Rust land in? This might change if, as other commenters have stated, it is taught as a first or second language, but that doesn't seem likely anytime soon...
- gcp 10y ago
  Rust's niche seems very clear: C++ programmers that need better tools. This is an audience that should be willing to make a time investment, and understands the trade-off, for the most part.
  - sidlls 10y ago
    I disagree to some extent, for a couple of reasons. First, C++ programmers in aggregate have to consider more than the choice of language for their projects. Odds are they work for somebody else, on a team, an established project, whatever. In these cases "C++ programmers need better tools" doesn't mean "toss the bath out with the water." Rust isn't necessarily a good move in established products, in other words. Second, Rust would do better, in my opinion, to target folks who are new to systems programming and, for whatever (mostly invalid, in my opinion) reasons, are intimidated by C or C++. Rust is very powerful and in many ways I like it much better than C++. I think Rust offers a great way for these people to have a gentle introduction to the world of systems programming. I say "gentle" because a good portion of the "pain" of learning is front-loaded into getting a build, rather than back-loaded into futzing about with gdb (although that would be something these folks will miss out on--who doesn't like a good session with gdb with a satisfying bug squash at the end?). Get them while they're young, as they say.
    - gcp 10y ago
      I don't disagree - my statement was also directed to people new to this field. The overhead for existing C++ teams is learning the language, and (potentially AFAIK) interfacing with C++ code that has no good C style API. But Rust seems to tackle even the latter quite well. I don't think you'll get around the learning curve for a new language.
JepZ 10y ago
I never wrote a single line of rust, but when a language is hard to learn, the compiler error messages are probably just bad in terms of comprehensibility and offer the user no direct solution.
- valarauca1 10y ago
  when a language is hard to learn, the compiler error messages are probably just bad in terms of comprehensibility and offer the user no direct solution. I don't want to sound snarky but Rust really does have amazing error messages, and they literally do offer direct solutions/suggestions using literal examples and raw samples of your source code. It even offers the `rustc --explain EXXXX` (where XXXX is an error code) that give an in terminal deep dive + examples on why this is an error/how it is failing. I never wrote a single line of rust :|
  - JepZ 10y ago
    So what do you think, why is it so hard to learn rust, if it is not about the compiler messages?
sdenton4 10y ago
Yeah, I've seen a number of posts like this for go as well. I wonder if it may be useful to start programming in these languages with a more experienced buddy to ask questions if and do some coffee reviews, to reduce time spent banging one's head on the keyboard, and get better acquainted with the language's idioms.

by adwhit 10y ago

sametmax 10y ago

Exactly. The fact that rust is easier than most low level languages made the high level language crowd forget than bare metal programming IS HARD. Try to do a big project in C++ or C and you'll see that making something that is production worthy takes months. Besides, as a Python trainer I can make you productive in it in a few days. But it will still take a lot of time for you to be good at it. The only difference with rust is that the first "reward stimuli" comes later down the road because you need to be better at it than at Python to make use of it.

trishume 10y ago

Agreed. Rust is different from other languages in that it is HARD to learn. It took me 3 projects and thousands of lines of code before I finally felt like I'm okay at Rust. Each project involved tons of compiler fighting that I now know how to avoid or solve. The problem is that instead of a general technique for solving borrow checker issues, every issue has a different specific technique. Hash map matches (like the article) require the entry API. Multiple mutable pointers into a buffer require either using a typed Vec or Vec#split_off. Cyclic data structures require an Arena or Rc<Refcell<>>. String casting issues sometimes require .map(|x| &x). Global state requires lazy_static. Nice error handling requires error_chain. When you run into problems with "Send" you need a Mutex. The list goes on... It's like pure lazy functional programming in Haskell in that unlike other languages you can't just pick it up based on previous knowledge and patterns. You need an entirely new toolbox of pure algorithms and data structures, or in this case borrow-safe algorithms and data structures.

alkonaut 10y ago
> Agreed. Rust is different from other languages in that it is HARD to learn But do you learn to code in a different paradigm where you don't struggle by iterating on a compilable and runnable piece of code, but rather struggle on iterating on a non-compilable piece of code and "once it compiles, it works"?
- AsyncAwait 10y ago
  Definitely and I'd say the struggle is only there for the first couple of weeks. This will get shorter as tooling gets better this year.
ajmurmann 10y ago
The issues and solutions you list sound super valuable. Do you know if there is a write up about those issues somewhere or did you just learn through blood and sweat?
- nebopolis 10y ago
  Learning Rust With Entirely Too Many Linked Lists (http://cglab.ca/~abeinges/blah/too-many-lists/book/ http://cglab.ca/~abeinges/blah/too-many-lists/book/) is the best resource I've found for learning how to create data structures in Rust. It goes over a lot of the pain points of interacting with cyclic data structures.
  - petersp 10y ago
    Thank you for this pointer!
jononor 10y ago
Are these strategies for solving borrow checker issues documented anywhere? Sounds like a case for which a best-practice reference would be golden.
- 10y ago

rubber_duck 10y ago

>It takes months of steady investment (and yes, frustration), but the payoffs are spectacular. This was the exact same thing I kept reading back when functional programming was becoming in vogue - people were pushing for Haskell, saying that purity and laziness were amazing, type system could almost prove correctness at compile time, etc. etc. You just need to meditate deeply on category theory and draw direction graphs to become one with types and all would be revealed to you. Hybrid functional languages got adopted in the meantime (F#/Scala/Clojure come to mind) and a lot of FP was adopted by OO languages - it wasn't pure or fancy but it solved problems in an accessible way. Most people still don't use Haskell. I'm hoping Rust doesn't go down this path as I want a replacement for C++ badly. But saying "you need to spend a few months to get intimately acquainted with the language" is just not going to work in practice if you're hoping about breaking in to the mainstream.

gcp 10y ago
I'm hoping Rust doesn't go down this path as I want a replacement for C++ badly. So that's opposed to C++'s "It takes a few years to get acquainted to the language enough that people would want your stuff in production code"? Nobody hires junior C++ programmers.
- rubber_duck 10y ago
  The problem with writing C++ is not so much the language as it is the problem domain - writing C++ as "C with some syntax sugar" is possible and a popular method by people who don't care about C++ complexity. And it gets you to results fast. Having something work right away and deal with the edge cases when you encounter them is preferable in a lot of scenarios - especially while learning, but also as a principle of iterative development, a lot of the time as you're iterating on code stuff fundamentally changes (requirements change, your interpretation changes, etc.) all that formalization up front ends up being an impediment - as much as it makes some people uncomfortable.
  - gcp 10y ago
    Is it common for code that fits those requirements to require C++ or Rust, though? Particularly in terms of performance?

wiremine 10y ago

> It takes months of steady investment (and yes, frustration), but the payoffs are spectacular. In my experience, most developers can't or won't put in this sort of investment. Which leads me to wonder what fields/niches will Rust land in? This might change if, as other commenters have stated, it is taught as a first or second language, but that doesn't seem likely anytime soon...

gcp 10y ago
Rust's niche seems very clear: C++ programmers that need better tools. This is an audience that should be willing to make a time investment, and understands the trade-off, for the most part.
- sidlls 10y ago
  I disagree to some extent, for a couple of reasons. First, C++ programmers in aggregate have to consider more than the choice of language for their projects. Odds are they work for somebody else, on a team, an established project, whatever. In these cases "C++ programmers need better tools" doesn't mean "toss the bath out with the water." Rust isn't necessarily a good move in established products, in other words. Second, Rust would do better, in my opinion, to target folks who are new to systems programming and, for whatever (mostly invalid, in my opinion) reasons, are intimidated by C or C++. Rust is very powerful and in many ways I like it much better than C++. I think Rust offers a great way for these people to have a gentle introduction to the world of systems programming. I say "gentle" because a good portion of the "pain" of learning is front-loaded into getting a build, rather than back-loaded into futzing about with gdb (although that would be something these folks will miss out on--who doesn't like a good session with gdb with a satisfying bug squash at the end?). Get them while they're young, as they say.
  - gcp 10y ago
    I don't disagree - my statement was also directed to people new to this field. The overhead for existing C++ teams is learning the language, and (potentially AFAIK) interfacing with C++ code that has no good C style API. But Rust seems to tackle even the latter quite well. I don't think you'll get around the learning curve for a new language.

JepZ 10y ago

I never wrote a single line of rust, but when a language is hard to learn, the compiler error messages are probably just bad in terms of comprehensibility and offer the user no direct solution.

valarauca1 10y ago
when a language is hard to learn, the compiler error messages are probably just bad in terms of comprehensibility and offer the user no direct solution. I don't want to sound snarky but Rust really does have amazing error messages, and they literally do offer direct solutions/suggestions using literal examples and raw samples of your source code. It even offers the `rustc --explain EXXXX` (where XXXX is an error code) that give an in terminal deep dive + examples on why this is an error/how it is failing. I never wrote a single line of rust :|
- JepZ 10y ago
  So what do you think, why is it so hard to learn rust, if it is not about the compiler messages?

sdenton4 10y ago

Yeah, I've seen a number of posts like this for go as well. I wonder if it may be useful to start programming in these languages with a more experienced buddy to ask questions if and do some coffee reviews, to reduce time spent banging one's head on the keyboard, and get better acquainted with the language's idioms.