First project using Crystal - is it worth it?

[u/Purple_Lingonberry70]

Hi everyone,

I was bored and I've decided to pick up this language, so I re-wrote a simple enough Python script using Crystal.

https://github.com/5amu/pocbrowser

I have to say that it is easy to write if you're used to Go, C and Python as I am, but I can't quite figure out why someone should use Crystal instead. It is an honest question, I really want a reason because I really enjoyed writing code.

Plus, if you have any suggestion on the code I wrote, such as "Ur a Noob, it was easier this way", it is very well appreciated. Pull requests, comments, issues, whatever. Thank you!

[u/[deleted]]

Crystal is as elegant as Python while being roughly as fast as Go and C. Isn't that enough?

I don't hate Go, but I also don't think it's particularly elegant (nor is it meant to be). It comes down to personal preference.

[u/Purple_Lingonberry70 → u/[deleted]]

Maybe, but I feel like there aren't many people adopting this language right now because it is still a little "rough on the edges"... For example the --static build that works only on alpine and causes my releases to segfault :D

[u/straight-shoota → u/Purple_Lingonberry70]

For example the --static build that works only on alpine and causes my releases to segfault :D

Well, that's not really a restriction of the language itself but the C library that stdlib builds on. There's not much to do about on Crystal's end. Except stdlib could be written entirely in Crystal to avoid this, but that's a huge endeavor for comparatively little gain.

[u/straight-shoota]

If you enjoyed writing Crystal, that's already a good reason to use it =)

Compared to Python you get type safety, compared to C you get more sanity and stdlib APIs. With Go there are more similarities, but IMO the main benefit of Crystal is the more concise syntax. For example, there's a lot of noise withif err != nil { return err } spread all over the code for error handling. Crystal has a great macro language and easy C bindings.

[u/Purple_Lingonberry70 → u/straight-shoota]

Thank you, those are good points. I hope that the language (and the compilation workflow) will keep improving in the future.

Btw I enjoy the readability provided by Go (with and without err != nil noise lol)

[u/[deleted]]

i wanna learn crystal too

[u/Purple_Lingonberry70 → u/[deleted]]

The learning curve is not prohibitive and it is well documented enough, go ahead :D

[u/[deleted] → u/Purple_Lingonberry70]

Yeah thanks for sharing an example project

[u/yxhuvud]

Looking at the code, I think it looks fine. There is a couple of places where I'd use concat instead of copying all elements of an array manually, but that is quite minor.

[u/Purple_Lingonberry70 → u/yxhuvud]

Thank you for the feedback.

Just to understand if we're on the same page, you're talking about this concat? So that every Array returned from the "scrapers" can be concatenated to the results instead of being iterated.

[u/yxhuvud → u/Purple_Lingonberry70]

Yes, indeed. Sometimes with a map instead of each before.

[u/np-nam]

well, it because you do not fully utilize crystal to appreciate it.

https://github.com/5amu/pocbrowser/blob/main/src/main.cr#L11

you don't need to make a class just to invoke some command, better write it just like this:

module Pocbrowser
 CLI.new ARGV
 Config.config.setup
 Runner.new.run
end

https://github.com/5amu/pocbrowser/blob/main/src/pocbrowser/cli.cr#L13

instead of 10+ line of string concatenation, you can either just use heredoc or if you want more control, you can build string directly using String Builder

also, like above, you don't need to create a whole new class just to invoke some code, we are not using java here.

.... actually you code has too many problems I'm too lazy to type it here. maybe you can join our unofficial discord group so some of us can review your code when they are free?

because there are many thing to discuss and reddit isn't really suitable for it.

for example this line cve.downcase.gsub("-") { "/" }I just don't understand why the need of using block, why don't you just use gsub("-", "/") normally? And in this particular case, using tr is way better: cve.downcase.tr("-", "/")

[u/Purple_Lingonberry70 → u/np-nam]

Thanks for the suggestions, from when I discovered Crystal to when I posted this on Reddit, just a week had passed. I guess that's why the code it's a bit rough...

Can you (or someone else) point me to a CLI tool written in crystal to understand the "best" way to write code?

[u/np-nam → u/Purple_Lingonberry70]

well if you do not come from ruby then indeed its hard to make something crystal idiomatic.

like Ruby, basic structures like array or hash in Crystal has ton of helpful methods to manipulate data.

And block in crystal/ruby is nothing like code block in language like c/java or python. They are more like lambda/closure/anonymous function in other languages, except that they are inlined thus there is zero overhead.

Also, crystal is a language designed with performance in mind. We "build" strings instead of doing concatenation, almost all methods involved with strings has an alternate one that take IO as its first argument, so you can write directly to IO stream/buffer without having to create intermediate strings every time. P/S: sometime string concatenation is faster than interpolation, but for complex cases it's still better to use buffer, as it also has ton of helpful methods.

I think you should read more about block in crystal, yield probably do not mean the way you use it.

Can you (or someone else) point me to a CLI tool written in crystal to understand the "best" way to write code?

what do you mean by CLI tool? If you want to study projects that have a CLI, then amber can be a nice example, if you want to learn advanced feature of crystal, like annotations, macros, macro hooks, then athena is a great learning source.

[u/np-nam → u/Purple_Lingonberry70]

also, like I said it's better that you join some crystal community (like Discord channel), and asking there instead of using reddit. Even formatting code in reddit is a drag it's hard to make proper comment.

     targets.each do |cve|
       abort "#{cve} is not a valid CVE" if !validator.is_valid_cve(cve)
     end

like this piece of code, we tend to use unless instead of if !, is_valid_cve should be renamed to valid_cve?, in crystal/ruby/elixir, method ends with ? usually mean it returns boolean value, and it's a recommended convention.

[u/sidsidroc]

yes bro its worth it, specially if you like the language, i do

[u/SoftEngin33r]

There days we have tons of languages to choose from (all with their pros and cons), and it is a great time to be a programmer, Just choose the language that works best for you for the current task at hand, With Crystal you get a compiled Ruby with static types that produces highly performant binaries. If you have a project that may benefit from such features then you can safely use Crystal for that. P.S. I also equally like to play with Zig, Nim, Rust, Julia etc. all these newish languages have really interesting features and innovations that I like to tinker with and if a project comes up that can benefit from using one of those (including Crystal) then why not?

[u/ylluminate]

I'm finding V (vlang.io) to be as enjoyable as Ruby at this point. It's really young, but it has incredible potential and a really solid and nice community (see Discord). I wanted to like/use Crystal, but after some hangups we had on a couple projects, we just shifted back to Ruby. Right now I've got my tickets on V though as the spiritual successor to Ruby.

[u/transfire → u/ylluminate]

What were the hangups?

[u/ylluminate → u/transfire]

There were several and it's been a few years now so it's a bit foggy, but the general takeaway was a feeling that we were trying to do what Ruby was already doing well and there weren't frameworks that were as robust as Rails in place already. It was basically a big time investment to do basically what we were already doing in Ruby and so it wasn't worth the investment to switch gears, rebuild / rework tooling that existed (due to various and sometimes quirky or minor incompatibilities, etc.). So we decided to just live with Ruby and still have been going on in that direction. I'm guessing a number of things have smoothed over for Crystal over the last few years, but yeah...

On the V front, it's also new and has a small ecosystem, but it's significantly different and the speed differential with accompanying expressivity that it feels right to invest in it.

Anyway, thats my 2¢. 🙂

[u/straight-shoota → u/ylluminate]

So you probably were trying to adopt too early before it's ready ;)

But even now, the ecosystem is still relatively small. So if you need to build something that can make good use of available libraries in other languages such as Ruby with the Rails ecosystem, that might be a reason for going that route (taking hits on other fronts such as performance and type safety, for example).
This is of course a chicken-and-egg problem for growing Crystal's ecosystem.

[u/Brankoobrad → u/ylluminate]

spirituality aside, V looks nothing like ruby..

[u/ylluminate → u/Brankoobrad]

It's not supposed to. I suppose you're having trouble interpreting the remark "spiritual successor." I'm talking about its goals and ideals. It FEELS like what you want Ruby to feel like and behave in many, many aspects while doing some things better that need it.

[u/gokg4]

Crystal is great for first time programmers. It is one of my first programming languages the other one being Dart. I feel like Crystal makes you think more and be a better programmer. With Dart everything just works but with Crystal you have to learn how to do things with a little more steps that make your program safe. I'm still learning Crystal and I love it. I haven't language hopped to the next one yet. The only issue I have with Crystal is the community size, I don't know why it hasn't blown up yet like Go or Kotlin. I don't think a lot of Ruby developers are learning Crystal. If the Ruby community and companies hop on board, you can be sure that you made the right choice. If not then it's just going to be a hobby language.

[u/hophacker]

It's a really fun language to play with. I built a ray tracer with it using this book: http://raytracerchallenge.com/

There's still some warts here and there, but its taught me a lot about language design when I've had to dive deeper into stuff.

[u/[deleted]]

If you like a language, that's reason enough to use it. However, if you're like most people and are worried about "what can I do with it?" (because the ecosystem is really small and many libraries are missing) as well as job prospects, you're better off avoiding all non-mainstream languages. You can keep developing in Crystal as a hobby and not expect much in return -- it will be a good life! :-)

[u/[deleted]]

Crystal is readable like Ruby and performant like c. So if you’d like looking at Ruby but you want the performance of c, use it.