Ruby is Awesome and Rust is Awesome and Building a Game in Both is AWESOME

Editor's Notes

• #2: Hi everyone! My name is Liz, and I’m from the United States.
• #3: I’m sorry. I apologize for that, but unfortunately there’s nothing I can do about it.
• #4: I’m really into your prime minister though. He seems pretty cool, so way to go on that one. I mean seriously, look at him with those pandas! It’s so great.
• #5: Anyway, I live and work in Portland, OR at a company called Tilde. I work on our product, Skylight, which is a Rails profiler. So that basically means we have an app that helps Rails apps be better Rails apps.
• #6: So I’m here today to talk to you about two programming languages, Ruby and Rust, and how I built basically the same text-based adventure game twice - once with Ruby, once with Rust. So, why Ruby? Why Rust? Why did I do any of this at all?
• #7: So, Ruby and Rust are both pretty different but they’re both really cool.
• #8: I had a few false starts over the years, trying to learn how to program, but Ruby was the first language I was able to really get into.
• #9: If you don’t already know anything about it, Ruby was designed around the idea of programmer happiness.
• #10: It’s very expressive and easy to learn, very similar to written English. As you can see here, writing something like “ten times do puts “Ruby is great!” “ will print “Ruby is great!” to the console, ten times. You can read it almost like a sentence, so it’s a very popular first language for people getting into programming. You don’t have to think too hard about what’s happening under the hood to get started and make things work, even if you don’t know very much about programming yet.
• #11: One of the first things I made when I started learning to code was a text-based adventure game. I’ve written a few really little ones over the years, usually when I’m trying to learn a new language or if I’m playing with a new idea. Some of you may never have played one, but it’s basically a game where everything is text. In my case, the whole game is played in your terminal, like it’s the 80s.
• #12: So the way it works is, you get a prompt, usually a sentence or two followed by a question, like “You are in a dark forest.
• #13: You see a light in the north.
• #14: you have a map
• #15: what do you do? And then you type something like
• #16: “look at map”
• #17: then the computer responds with something else,
• #18: and you type something else,
• #19: The computer responds to that, and so on and so forth, until your character dies or the game is over. I think nowadays games like this are also called “interactive fiction.” Let’s take a quick look at the actual game I wrote to give you a better idea of what I’m talking about. (go to terminal)
• #20: So anyway, it made sense that when I decided I wanted to learn Rust, that I build yet another text-based adventure game.
• #21: So what is Rust and why did I want to learn it in the first place? I realize that Ashley already talked a lot about Rust but here I am to talk about it some more! I might repeat some things and if I do, sorry.
• #22: Well, about a year ago, I decided I wanted to start learning a lower-level language,
• #23: something more “close to the metal,” so to speak, that didn’t abstract as much away as Ruby does. I wanted to understand more about what goes on under the hood when I’m trying to talk to my computer. Fortunately, at that time, I had just started working at Tilde
• #24: where I get to work with Yehuda Katz,
• #25: who is on the Rust core team. Which means, if anybody’s gonna know about Rust, it’s gonna be this guy.
• #26: and at least part of our product (Skylight) is written in Rust. So it made perfect sense for me learn.
• #27: I also knew that it was a newer language being actively developed.
• #28: I really wanted to get involved in open source
• #29: and I’m really interested in how programming languages work, so it seemed like the perfect thing to get into.
• #30: I mean, I love Ruby, but the whole ecosystem was pretty much all set by the time I got to it,
• #31: but Rust, on the other hand! Everything with Rust was still new, so it was very exciting and changing all the time and I wanted to learn all about it.
• #32: So, I decided to build basically the same game, one version with Ruby and one version with Rust
• #33: so I could more easily compare and contrast the pros and cons of each language
• #34: but also so I could build my confidence a bit, building one piece of the game using a language I was pretty comfortable with, and then implementing the same or similar feature in a new language that I was still learning, and on and on until I had some kind of working game.
• #35: Before writing a single line of code, I had to think about the architecture of the game, and there were a million different ways I could find to structure it. In the end, I wanted something extremely simple, so I went with a really basic loop
• #36: that continues to ask what the player wants to do next until a particular condition is met, at which point the game ends. So in this example, which I stress is not real code, just an example of the structure I was using, we start by defining “playing” as true, and while playing is true, the game asks “What do you want to do next?” It then parses whatever the subsequent user input is and it performs an action based on that input (like, if the user says “move north” then the player’s position is changed and maybe we output something like “You have moved north”). We don’t exit the loop unless the user dies or the game ends, at which point playing is redefined as “false”. So what does this look like in Ruby or Rust?
• #37: In Ruby, there’s a lot going on before we get to the “play” method, but that’s where the loop is so that’s what I’m showing you. This is a method on the “Game” class, which is initialized with a player, a map, an array of rooms, and with the value of playing as “true” so as long as playing remains true, the game will keep asking “What now?”, then parse whatever the user types, and respond to that.
• #38: So, this example is ignoring a lot of other code that I wrote to support this, much like the Ruby example, but for the sake of simplicity here you can see we are creating a Player, a Map, and a Game, and you can see that while game dot playing, game play! Pretty close to what I illustrated earlier. What you can’t see, though is that unlike Ruby, I had to write my own “new” method, because Rust does not automatically give you anything like Ruby’s “initialize”. Otherwise, it seems pretty similar to the Ruby version, just a little more code, which is fine.
• #39: At first glance, both implementations of a similar idea look pretty similar! However, there is a lot of code I am NOT showing you, just because there is SO much of it, and we don’t have a lot of time. So what I’d like to focus on instead is the experience of writing it. You can look at all the real code on GitHub after the talk if you want to see the whole thing (and don’t worry, I’ll give you a link)
• #40: With Ruby, I felt like I could just write whatever I wanted, make something work quickly, and then reorganize the code as I went. It’s easy to have a real “flow” like you’re just writing your ideas down in your journal and making things up as you go along. The downside of this is that it’s easy to get caught up in that flow and forget to check things out as you go, forget to test, forget to run every single part of the program that you just wrote.
• #41: So I’d periodically run the program and things would just break. Without adding a whole bunch of tests after the fact, which isn’t great, I didn’t have a lot of confidence that something wouldn’t unexpectedly fall apart at runtime. All because I got caught up writing the game and forgot to check things out as I went along.
• #42: Rust, on the other hand, is kind of the reverse experience. Since Rust needs to be compiled before you run it, the compiler literally won’t let you run the program until you fix all the stuff it doesn’t like. Not coincidentally, I have NOT run into any of those pesky random bugs in the Rust version of the game,
• #43: probably because the compiler caught them before they would have become a problem. This can be super frustrating when you’re first learning Rust, because it can be oh so satisfying to just see SOMETHING working, and you could be working for hours just seeing errors like this over and over. It can easily become disheartening if you’re new to it. This example, by the way, I had to force an error because it had been so long since the Rust version of the game had any compiler errors. It’s just that good.
• #44: So the best way I can think to compare Ruby and Rust, in terms of my personal experience with the two, is they’re like two different parenting styles. This might seem like an odd comparison, but bear with me!
• #45: Ruby is like those hippie parents who let their kids do basically whatever they want and don’t put a whole lot of restrictions on them because they know the kids will figure things out on their own eventually and they’ll be ok. The downside, of course, is that the kids will hit all kinds of bumps in the road along the way because no one ever told them they should or shouldn’t do any particular thing.
• #46: Rust is like those parents who are constantly telling their kids what’s best for them. They’re a little bit strict, not that bad, but just always giving unsolicited advice based on their own experiences. And yeah, maybe it turns out their advice was right, but it’s definitely a little annoying to be hearing it all the time.
• #47: And just like parents, you can’t really say one way of doing things is better or worse than another, but they both have their pros and cons depending on what you’re trying to do and how you prefer to work. I’m sure someone with more experience could give you a more in-depth analysis, but this is my opinion based on my limited experience just writing a simple text game. So if you’re thinking of learning Rust, or Ruby, or both, I say go for it.
• #48: Feel free to take a look at the repo for the game, there’s instructions in the README about how to set it up. Both the Ruby and Rust games should work as of right now, though both of them don’t really have a proper “story” there’s just some weird placeholder stuff, which you might enjoy anyway. There’s a bug that allows you to pick up a jar of unicorn farts over and over and over, for example. I also have a few issues on that repo if anyone’s interested in contributing. I would love to learn more about testing in Rust, and more Rust tests just happens to be one of the things I’m looking for, so if you know anything about that, feel free to check it out.
• #49: And if you want to talk about any of this, I’ll be around today and tomorrow, otherwise you can talk to me on Twitter! Thank you so much!