Programming Languages
Crystal: A language for humans and computers
#concurrency
#crystal
#web-development
#ruby
#web-frameworks
#programming-languages
#compiler-design
Crystal: A language for humans and computers
by Serdar DoğruyolIn the video titled "Crystal: A language for humans and computers," Serdar Doğruyol presents an introduction to the Crystal programming language at the Balkan Ruby 2018 event. The talk begins with Serdar sharing his experiences in Sofia, Bulgaria, and his background before diving into an overview of Crystal.
Key Points Discussed:
- Introduction to Crystal:
- Crystal is a programming language inspired by Ruby but distinct in its design and functionality, aimed at providing human-friendly syntax while also being efficient for computers.
- Misconceptions about Crystal:
- Clarifies that Crystal is not simply a Ruby implementation but a separate language with its own features.
- Developer Community:
- Emphasizes the importance of community and explains how Crystal emerged from collaboration and contributions from developers worldwide.
- Technical Highlights of Crystal:
- Strongly typed with type inference, enhancing developer productivity while allowing flexibility.
- Features such as union types allow for multiple possible types for variables, promoting cleaner and less cumbersome code.
- Built-in support for method overloading simplifies function management across different input types.
- Concurrency through fibers, making kernel-level threading easier and more efficient than traditional thread management.
- Produces single native executables optimized for each platform, creating a streamlined deployment process.
- Real-world Adoption and Performance:
- Crystal is used by over 30 companies across various sectors including web development, cybersecurity, and AI, demonstrating its practical application in high-stakes environments.
- Serdar shares a case study from his work at Rainforest, detailing significant performance improvements after migrating a service from Ruby to Crystal, showcasing faster response times and lower memory usage.
- Learning Resources:
- Encourages the audience to utilize available resources such as books and an active online community for novice and experienced developers alike.
Conclusions/Takeaways:
- Crystal strives to blend the user-friendliness of Ruby with the performance and efficiency needed for modern application development.
- With its growing community, advanced features, and successful adoption in production environments, Crystal represents a promising tool for developers seeking both simplicity and power in their coding practices. Serdar invites the audience to engage with the community, try out the language, and explore ongoing developments in Crystal programming.
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Thanks, everyone.
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Hi again! It's my first time being in Sofia, and so far, it's been amazing.
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The people, the places, the culture, especially the food, is wonderful.
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I really like it here; it feels like I'm at home.
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It's been a great journey for me.
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I would like to thank everyone for organizing the first ever Balkan Ruby and inviting me.
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Also, I'd like to thank you for coming to listen to us.
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Today, I'm going to be talking about Crystal. As you can see from my t-shirt, I'm really excited about it, and I want to share my journey and experience with you.
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So, do you know where I come from? This is Istanbul, and it's such a unique place.
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I believe it's like the center of the world. You can debate about it, but it's the only place where you can cross continents on a daily basis with a bus.
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This is the Bosporus bridge, which connects Europe with the Anatolian side.
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For four years, I crossed continents, commuting about four hours a day.
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I'm pretty sure most of you are familiar with Turkish cuisine. I learned that you have sarma, baklava, and kebabs.
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One of my favorites is mantı. I'm not sure if you have it, but it's great.
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So, I really enjoy food, and I want to welcome you all.
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Also, my name is hard to pronounce. It’s Sardar Doğruyol, but you can call me Seto, which is a combination of the first two letters of my first and last name.
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Most of my friends, my mother, and my brothers call me Seto, so please feel free to use it.
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You can find me on GitHub, Twitter, and LinkedIn. Don't hesitate to reach out.
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This picture captures one of the happiest moments of my life. I was presenting at RubyConf back in 2016.
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I was even more fit in that picture!
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I have recently joined the Crystal programming language team as a core member.
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You can see me active on the issue tracker almost every day, so feel free to say hi.
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I'm also the author of a framework called Kemal, a web framework written in Crystal.
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It's inspired by Sinatra from the Ruby world, and I've maintained it for over three years.
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Currently, I work at a startup called Rainforest, which is based in the U.S., but I work remotely from Istanbul.
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We provide QA as a service, and you should check our website; it's pretty interesting.
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I also enjoy learning languages and consider myself a polyglot.
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I believe some of you can read Japanese, as this word, 'polyglot', is written in Japanese.
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Learning languages is fun, but enough about me; let's talk about Crystal.
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How many of you have heard of Crystal before? Wow, that's good! It seems we are doing a good job.
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First things first: Crystal is not Ruby, and that is certain.
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It’s not a type of Ruby; it’s a different language, but it takes many idioms and ideas from Ruby.
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This is because Ruby is an awesome language.
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In the past, we branded Crystal as fast as Ruby, but that turned out to lead people in the wrong direction.
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People thought it was just another implementation, like MRI or JRuby.
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However, Crystal is not just another implementation; it is a different language built from the ground up.
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We now call it 'a language for humans and computers,' which is unique.
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There aren’t many languages that share this attribute.
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You might be asking why. I have some strong proof.
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How many of you have seen this graph? This graph explains everything scientifically.
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The developer satisfaction in Ruby is declining.
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Sorry for the poor quality of the image; it’s generated by a Ruby program. Just kidding! Check the website 'Ruby is Dead' to see more of this.
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I can assure you, Ruby is alive and kicking.
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But the real question is why.
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Building a language is more than just writing code, building compilers, and other technical aspects.
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It's really about community and the people involved.
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When we look at Crystal, there are main reasons why it stands out.
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First and foremost, we are here because of Ruby's efficiency.
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Ruby gives us a lot of productivity, and we want something similar.
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We love efficiency, and we want the best of both worlds.
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We want the compiler to understand what we mean without having to specify everything in detail.
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Type systems are valuable; we wish to avoid the pitfalls of too much boilerplate.
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We value DRY principles, especially in mathematics.
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The last thing is that we don't want to write C code to make things faster.
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So, how is this possible? The good thing is that Crystal is real.
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It's not just a toy project; it’s being used in production by companies.
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So how is it functioning? The simple answer is that it's built on ideas from Ruby while using LLVM.
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For those unfamiliar, LLVM is a compiler infrastructure toolchain that many languages, such as Swift and Objective-C, utilize.
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It is a solid project, backed by corporations like Apple and Google.
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The original creators of Crystal thought about taking Ruby and making it work.
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It sounds crazy, but I love this idea.
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They believed that all our dreams could come true if we had the courage to pursue them.
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It's mainly attributed to two guys from Argentina who had the visionary idea of creating Crystal.
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Crystal doesn’t have any big corporation backing; it’s just a community effort.
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In fact, six years ago, a brilliant and friendly individual named Ary committed the first initial commit on September 5, 2012.
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You can consider Crystal a young language, but it has matured significantly in its short life.
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One year later, the first version of Crystal was released, and it was initially written in Ruby.
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Ary had a fondness for Ruby, and you could see that the project was heavily based on it.
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Eventually, Crystal became self-hosted.
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Self-hosted languages are written in their own language, which means Crystal is capable of writing and compiling its own code.
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As seen from the master branch, about ninety-eight percent of Crystal's codebase is written in Crystal.
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This allows Crystal to give you the ability to read its source code, which is fantastic.
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I loved Ruby and wanted to contribute, but learning C extensions was quite challenging.
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Therefore, I preferred a self-hosted language instead.
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In April 2015, I was looking for something new that had the best of both worlds.
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I discovered Crystal, and it truly changed my life.
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It felt like I had found my calling.
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Fast forward to today, it's been more than three years since I joined the community.
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We are significantly more established as a programming language now.
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Let's take a look at some statistics.
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We have over 250 contributors from all around the world.
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We have more than 10,000 stars on GitHub and over 2,500 packages.
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As of now, it is actually more than 3,000 packages.
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We rely on community donations and have raised over $2,000 per month.
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We're grateful to everyone who contributed.
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This year, we've seen tremendous growth.
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Lastly, we have a core developer working on Crystal full-time.
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It's fantastic that we now have sponsorship to support our developer.
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We have an exciting new release coming next week, version 0.25.
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We have optimized many features, and I hope we can successfully release it soon.
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Now, you might be wondering what makes Crystal stand out.
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I'll give you an overview, but I'm not going to delve too deeply.
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First and foremost, it's human-friendly.
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Drawing inspiration from Ruby, which is considered one of the most human-friendly languages, Crystal seeks to emulate that.
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For instance, this simple statement prints 'Hello,' which is very approachable.
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Similarly, this line represents a complete HTTP server written in just five lines of code.
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This simplicity makes it easy to use.
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Moreover, Crystal features a powerful type system. It is strongly typed, unlike Ruby.
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Narratively, the type system looks familiar because you don't need to specify types explicitly at most times.
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The compiler is intelligent enough to infer types and optimize them.
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You can also check the types at compile time through methods.
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Crystal offers a range of numeric types, including integers and floats, and we are currently implementing 128-bit integers.
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The array types also offer flexibility, allowing for a combination of various data types.
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This feature gives it a dynamic language feel, permitting a great deal of simplicity.
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One of Crystal's greatest features is Union types.
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They have been described as the missing piece in many compiled languages.
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For example, consider this expression: if one plus two equals three, then one else a equals 'hello.'
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The compiler must output all possible types, so utilizing Union types solves such problems.
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Like this, the type can be expressed as an integer or string.
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This is quite flexible since you can use as many variants as you want.
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The compiler optimizes the data types for better performance.
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If you look at runtime values, it's still just an integer.
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Another feature I really like is method overloading.
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How many of you have used method overloading in any language?
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It's quite useful, especially for making code cleaner.
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In Ruby, we often face cumbersome management of multiple types.
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In Crystal, you can define overloaded methods clearly with differentiating type signatures.
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You can specify the return type after a colon, allowing flexibility in its use.
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The compiler ensures that you call the appropriate method matching your types.
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If a type doesn’t fit the overloads, you won’t compile, meaning you handle errors more easily.
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Next, let's address reference checks.
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Many of us experience difficulties with nil handling in Ruby.
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In Crystal, the compiler ensures that you correctly handle potential nil cases.
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For example, if an expression can yield a nil value, the compiler will flag that potential issue.
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This prevents undefined method exceptions by verifying types at compile time.
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Adopting macro-based metaprogramming further values performance.
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Macros are processed at compile time, eliminating performance penalties.
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Unlike Ruby, you get to define methods dynamically without runtime performance hits.
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The cool thing about this approach is that if there's a problem with your syntax at compile time, the compiler will let you know.
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Now, let's talk about open classes.
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Some developers love monkey-patching… and others loathe it.
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The point is, Crystal allows you to reopen a class and define methods similar to Ruby's behavior.
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No performance is lost on that front either.
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Built-in concurrency is another noteworthy feature of Crystal.
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Crystal utilizes fibers, which are lightweight threads inspired by ideas from Go and Closure.
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Being cooperative and utilizing message passing, it avoids shared memory issues.
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This model follows the Communicating Sequential Processes (CSP) paradigm.
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Let me show you how it operates with a simple concurrency example using fibers.
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It is implemented with channels to send messages between them.
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You can pass values and receive them back using channel receive.
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The operations are blocking, ensuring data consistency.
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Currently, Crystal is not multi-threaded but leverages an event loop, making it exceptionally fast.
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Now let's discuss native code.
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When you use Crystal, it produces a single native executable tailored for your platform.
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It can create an ELF for Linux, a Mach-O for macOS, or a compatible executable for Windows.
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You can simply use Crystal build to create a standalone binary.
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But the Windows port is still under development.
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The community is welcome to contribute in aid of this port.
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Additionally, we have C bindings that make it easy to use C libraries.
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This means you don’t have to write extensive C code to interface with C libraries.
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Here’s a simple binding from Crystal to the LibGMP library.
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You can leverage the 'lib' keyword and access its methods easily.
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Creating bindings is straightforward and quick, as demonstrated by my friend's PostgreSQL binding.
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Now, when it comes to testing, we do have high hopes.
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Crystal has a built-in testing framework called Spec.
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It's akin to RSpec, though more straightforward.
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You would work with describe blocks but without the added context.
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You can write tests directly in Crystal's source, enabling clear visibility.
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To add dependencies, we use 'shards.'
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When you create a new project, the command generates a shards.yml for package management.
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It fetches dependencies directly from sources like GitHub.
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The crystal shards XY is an excellent place to find and explore available packages.
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And today, we already have over 3,000 up-to-date shards.
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It's steadily increasing, showcasing our active community.
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Some features bring a visual pleasure similar to what Ruby offers.
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Crystal Play, an interactive playground for experimentation, comes built-in.
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Once installed, just utilize 'crystal play' and have fun!
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I wish to demonstrate it here, but unfortunately, my PC is having issues.
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The overall development experience is enhanced with built-in formatting tools.
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Whenever you save a file in the editor, it formats automatically.
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It's a feature I truly admire and wish Ruby had.
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And in Crystal, we maintain coding standards by using double quotes exclusively.
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Furthermore, it reads like English; there are no odd inclusions as seen in Ruby.
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By avoiding global variables, we ensure better data integrity.
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Last year we made a conscious decision to remove global variables from our codebase.
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Instead, we now rely on classes and static variables.
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Now, you may wonder if anyone actually uses Crystal in production.
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No surprise! Many companies actively use Crystal.
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This is rapidly increasing; we have over 30 companies using it as we speak.
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Crystal is applied in various sectors, not just the web domain.
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Cybersecurity and AI companies are also adopting Crystal.
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For example, a startup called Deploys uses it for DNA analysis.
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They transitioned from Ruby and reported a tenfold speed improvement in Crystal.
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Imagine real-world cancer patients benefiting from Crystal code! That's incredible!
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Regarding performance, I opted to showcase real use cases instead of benchmarks.
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In my current role at Rainforest, we looked at several projects to improve them.
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We had one service that was critical and operated with a 700 ms 99 percentile response time, and I rewrote it in Kemal.
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Now, our response time is down to 50 ms on average.
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The graphs reflect performance gains and drastically reduced memory consumption.
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While it previously averaged around 100 MB with Ruby, it now operates at a mere 2 to 3 MB.
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The garbage collector also performs quite well.
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Featuring a lightweight framework like Kemal positions Crystal competitively.
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Looking at benchmarks from TechEmpower, Crystal is comparable to languages such as Go and Lua.
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Despite being single-threaded, its fibers are impressively efficient.
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The results are promising, indicating a bright future.
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Now, for those seeking resources, we offer several.
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We have a comprehensive Crystal book available on GitHub.
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Additionally, I wrote a guide titled 'Crystal for Rubies,' which offers a quick, free read.
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It distills major concepts and is available in PDF and Kindle formats.
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We also have an active community channel where you can engage.
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There are over 500 participants currently, and it's a growing resource.
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I have stickers here for anyone interested!
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On a related note, I'm writing a book called 'Learning Crystal Programming.'
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Though still in progress, I hope to finish it soon.
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Writing a book is undoubtedly a challenge.
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Thank you for listening, and feel free to ask any questions!
