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Crystal looks interesting although I decided to learn Golang instead. It's more mature and the WIP features described below made me cautious (i.e. what other fe

Crystal looks interesting although I decided to learn Golang instead. It's more mature and the WIP features described below made me cautious (i.e. what other features are immature). Anyone know when Crystal will get concurrency-a-la-golang? i.e. running concurrent processes in parallel? At the moment I think it's still single-threaded. https://crystal-lang.org/docs/guides/concurrency.html https://crystal-lang.org/docs/guides/concurrency.html Still no windows support: https://github.com/crystal-lang/crystal/issues/5430 https://github.com/crystal-lang/crystal/issues/5430

RX14 8y ago
Crystal has had concurrency, almost identical to goroutines, for a long time. It's just as if you're always running with GOMAXPROCS=1. And you can still get some excellent performance on IO bound workloads with a single core. The challenge is expanding what crystal is already good at to CPU bound parallelizable workloads by implementing parallelism. This work should be done before 1.0, we have a lot more resources to work on crystal from now on, because brian is working on it full time. And as for windows support, I'm working on it right now. Cross-compiling "hello world" has been working for a while.
- Blackstone4 8y ago
  Thanks for the response. I'm no expert but when you have a server, would each request be handled concurrently by a separate thread (/fibre?)? So in that sense would the server's I/O be non-blocking? (I know each thread would be blocked as it waits for the response). Do you have a rough time frame for parallel concurrency? What's your view on the maturity of the language?
  - RX14 8y ago
    No, each request is handled concurrently in the same thread using evented IO. You spawn fibers, which are the analogue to go's goroutines, and many of those run in one thread. Just like nodejs (without callbacks/promises/async/await) and similar to go with GOMAXPROCS=1. Unfortunately, I don't have a timeframe for parallelism, it's not my area of crystal and it's a fairly tricky issue. My (biased, i'm a core developer) view on Crystal's maturity, after using it in a few of my own side-projects, is that once crystal code compiles, it runs pretty much rock solid in production. Compiler bugs are fairly rare too, although the compiler clearly isn't as mature as gcc. The main issue you face is lack of available libraries, and being forced to make a few changes every couple months when a new release comes out with breaking changes. Depending on the size of your codebase, that could be a big issue or it could be a 5 minute easy commit.
    - Blackstone4 8y ago
      Thank you for adding more color around Crystal. I'm somewhat new to this so bear with me. With regards to the I/O, is it like node.js? i.e. all requests are handled inside a single thread (until Crystal gets parallelism) and when the thread waits for an I/O response (i.e. a database call), it will process some of the other requests?
      - RX14 8y ago
        Yep, exactly like that.
bsdnoob 8y ago
What do you think of Nim?
- Blackstone4 8y ago
  No opinion as I didn't look at it. I was more focused on more mature languages and Crystal came up on my radar so I read around it.
  - dom96 8y ago
    Hrm. Your post implies that Crystal is more mature than Nim, is that intentional? If so, what makes you think that?
    - Blackstone4 8y ago
      Oh I didn't mean to imply that. I meant I was researching mature/mainstream languages and outside of the scope of that research, it just so happened a friend mentioned Crystal. So I looked into it. I know absolutely nothing about Nim so I can't comment either way.
everdev 8y ago
I've programmed in both and as far as I can tell here's the best use case for each: Go - I want to program explicitly and don't mind a little extra code or syntax to do it. I want close to the best performance possible and a single distributable binary. I don't mind being encouraged to "roll my own" api / web app rather than using a framework. Crystal - I want to feel like I'm writing in Ruby, but with type checking at compile time and much better performance. I don't mind being a little less performant than other compiled languages. I want access to Rails/Sinatra-like frameworks for web/API apps rather than having to "roll my own". Basically, if you want something quick and fun that can run in production, I love Crystal. If you want something that needs to be custom and highly performant, I love Go.
- Blackstone4 8y ago
  Great response. [EDIT - as highlighted by the replies below you can't use Rails with Crystal...my fault for misreading the parent] I didn't quite realize that I could use Rails with Crystal. That would be make it more interesting if I knew how to use Rails ^^
  - RX14 8y ago
    You can't use rails with crystal, the keyword is "rails-like".
  - nlh 8y ago
    Unfortunately, you can’t use actual-Rails in Crystal (it’s written in Ruby which is similar but not exactly the same). But there are Rails-like frameworks you can use in Crystal that are just as much fun (though understandably less mature). Check out Amber, Lucky, and Kemal to give you an idea of what’s out there.
  - theIV 8y ago
    While you can't use Rails, there are frameworks that I have heard are "similar", such as https://luckyframework.org/ https://luckyframework.org/. Disclaimer: I haven't used it, just read a bit about it.
  - 8y ago
kodablah 8y ago
I think what we'll see coming soon, assuming some people work on it, is the recognition that Go's stdlib and all the supporting libs is where the real awesomeness lives. And for langs that support Go-style concurrency (like Crystal basically does, Kotlin, etc), people will start transpiling with only a couple of things dropping into the target language. There're just too many good pieces of crypto, http2, etc to rewrite it over and over.
- RX14 8y ago
  I can attest to this, the amount of times I've had a look and used go's stdlib as a reference for what to do when implementing something in the std for crystal is too many to count! Unfortunately, transpiling has a huge bunch of problems, which you can see in for example how quickly nim vs crystal compiler matured - even though the crystal compiler is more complex. I'd be interested in seeing go's stdlib, ssa backend, and toolchain turned into a robust library. Like LLVM but including a GC, a stdlib with a CSP implementation, and a complete toolchain for static compilation.
  - kodablah 8y ago
    I'm curious about the transpiling problems from, say, Go to Crystal (not after SSA, but before w/ the high level constructs). I have toyed with Go to Kotlin and even though duck typing is unimplemented in the latter, I can basically get there. I even started a project to dump Go AST and type info[0] but I haven't completed it really. There are just too many amazing Go libs out there to not exercise this option. Go does have a buildmode for c-archive and c-shared, but it's built around the hobbled Cgo, so you have to explicitly export funcs, and things like structs cannot be exported. Still, a swig-like shim/bridge could be developed, but I am unsure at what cost (I think the go mobile stuff does a form of this). 0 - https://github.com/cretz/go-dump https://github.com/cretz/go-dump
vram22 8y ago
>I decided to learn Golang instead So what has been your experience with Golang so far?

RX14 8y ago

Crystal has had concurrency, almost identical to goroutines, for a long time. It's just as if you're always running with GOMAXPROCS=1. And you can still get some excellent performance on IO bound workloads with a single core. The challenge is expanding what crystal is already good at to CPU bound parallelizable workloads by implementing parallelism. This work should be done before 1.0, we have a lot more resources to work on crystal from now on, because brian is working on it full time. And as for windows support, I'm working on it right now. Cross-compiling "hello world" has been working for a while.

Blackstone4 8y ago
Thanks for the response. I'm no expert but when you have a server, would each request be handled concurrently by a separate thread (/fibre?)? So in that sense would the server's I/O be non-blocking? (I know each thread would be blocked as it waits for the response). Do you have a rough time frame for parallel concurrency? What's your view on the maturity of the language?
- RX14 8y ago
  No, each request is handled concurrently in the same thread using evented IO. You spawn fibers, which are the analogue to go's goroutines, and many of those run in one thread. Just like nodejs (without callbacks/promises/async/await) and similar to go with GOMAXPROCS=1. Unfortunately, I don't have a timeframe for parallelism, it's not my area of crystal and it's a fairly tricky issue. My (biased, i'm a core developer) view on Crystal's maturity, after using it in a few of my own side-projects, is that once crystal code compiles, it runs pretty much rock solid in production. Compiler bugs are fairly rare too, although the compiler clearly isn't as mature as gcc. The main issue you face is lack of available libraries, and being forced to make a few changes every couple months when a new release comes out with breaking changes. Depending on the size of your codebase, that could be a big issue or it could be a 5 minute easy commit.
  - Blackstone4 8y ago
    Thank you for adding more color around Crystal. I'm somewhat new to this so bear with me. With regards to the I/O, is it like node.js? i.e. all requests are handled inside a single thread (until Crystal gets parallelism) and when the thread waits for an I/O response (i.e. a database call), it will process some of the other requests?
    - RX14 8y ago
      Yep, exactly like that.

bsdnoob 8y ago

What do you think of Nim?

Blackstone4 8y ago
No opinion as I didn't look at it. I was more focused on more mature languages and Crystal came up on my radar so I read around it.
- dom96 8y ago
  Hrm. Your post implies that Crystal is more mature than Nim, is that intentional? If so, what makes you think that?
  - Blackstone4 8y ago
    Oh I didn't mean to imply that. I meant I was researching mature/mainstream languages and outside of the scope of that research, it just so happened a friend mentioned Crystal. So I looked into it. I know absolutely nothing about Nim so I can't comment either way.

everdev 8y ago

I've programmed in both and as far as I can tell here's the best use case for each: Go - I want to program explicitly and don't mind a little extra code or syntax to do it. I want close to the best performance possible and a single distributable binary. I don't mind being encouraged to "roll my own" api / web app rather than using a framework. Crystal - I want to feel like I'm writing in Ruby, but with type checking at compile time and much better performance. I don't mind being a little less performant than other compiled languages. I want access to Rails/Sinatra-like frameworks for web/API apps rather than having to "roll my own". Basically, if you want something quick and fun that can run in production, I love Crystal. If you want something that needs to be custom and highly performant, I love Go.

Blackstone4 8y ago
Great response. [EDIT - as highlighted by the replies below you can't use Rails with Crystal...my fault for misreading the parent] I didn't quite realize that I could use Rails with Crystal. That would be make it more interesting if I knew how to use Rails ^^
- RX14 8y ago
  You can't use rails with crystal, the keyword is "rails-like".
- nlh 8y ago
  Unfortunately, you can’t use actual-Rails in Crystal (it’s written in Ruby which is similar but not exactly the same). But there are Rails-like frameworks you can use in Crystal that are just as much fun (though understandably less mature). Check out Amber, Lucky, and Kemal to give you an idea of what’s out there.
- theIV 8y ago
  While you can't use Rails, there are frameworks that I have heard are "similar", such as https://luckyframework.org/ https://luckyframework.org/. Disclaimer: I haven't used it, just read a bit about it.
- 8y ago

kodablah 8y ago

I think what we'll see coming soon, assuming some people work on it, is the recognition that Go's stdlib and all the supporting libs is where the real awesomeness lives. And for langs that support Go-style concurrency (like Crystal basically does, Kotlin, etc), people will start transpiling with only a couple of things dropping into the target language. There're just too many good pieces of crypto, http2, etc to rewrite it over and over.

RX14 8y ago
I can attest to this, the amount of times I've had a look and used go's stdlib as a reference for what to do when implementing something in the std for crystal is too many to count! Unfortunately, transpiling has a huge bunch of problems, which you can see in for example how quickly nim vs crystal compiler matured - even though the crystal compiler is more complex. I'd be interested in seeing go's stdlib, ssa backend, and toolchain turned into a robust library. Like LLVM but including a GC, a stdlib with a CSP implementation, and a complete toolchain for static compilation.
- kodablah 8y ago
  I'm curious about the transpiling problems from, say, Go to Crystal (not after SSA, but before w/ the high level constructs). I have toyed with Go to Kotlin and even though duck typing is unimplemented in the latter, I can basically get there. I even started a project to dump Go AST and type info[0] but I haven't completed it really. There are just too many amazing Go libs out there to not exercise this option. Go does have a buildmode for c-archive and c-shared, but it's built around the hobbled Cgo, so you have to explicitly export funcs, and things like structs cannot be exported. Still, a swig-like shim/bridge could be developed, but I am unsure at what cost (I think the go mobile stuff does a form of this). 0 - https://github.com/cretz/go-dump https://github.com/cretz/go-dump

vram22 8y ago

>I decided to learn Golang instead So what has been your experience with Golang so far?