2018 — what a year!

Sat, 29 Dec 2018 00:21:52 +0000

2018, my favorite year so far, has come to its end. So, I decided to recap what happened in my life this year, as well as to tell about events I haven’t covered yet.

2018 was the first year for me that started with exams. Not that I haven’t spent holidays studying for exams before, though, so with some persistence and tangerine fuel 🍊 I passed them all good enough and had a week of TV series and open source contribution before the upcoming semester. With some help from Halium project maintainers and a steep learning curve, I was finally able to conquer graphics libraries on an x86 Android phone and start a Wayland compositor. At the same time, my efforts on the Russian-speaking KDE community became visible, as our friendly local group crossed a symbolic border of 1000 members!

The new courses at university were difficult at first, so I had to really focus on my studies. I had a nice weekend break at the C++ Russia conference, but otherwise had been immersed, and that helped me catch up and finish the freshman year proudly. 🏆

In July, August, and September I could finally participate in the world of free software again. I was mostly focused on Plasma Mobile, KDE’s mobile platform, and KDE Russia. I prepared and gave an introductory talk about GNU/Linux on mobile devices, then developed and launched the kde.ru website. I’m thankful to Chaos Constructions conference managers and local FOSS news platforms for the chance to promote KDE’s amazing work to wider audiences. 📱

VK Hackathon

As part of an amateur yet motivated team, I was working on a corporate assistant application for the State Hermitage Museum. Our aim was to provide a 3-in-1 cross-platform solution: a task management system, an internal messenger and a navigation system (Hermitage is huge). The deadline was tough, but we managed to deliver a working prototype.

Our application was not selected by case managers, but the atmosphere of passionate hacking is unforgettable. Besides, some of my work went upstream and will benefit many applications to come 🙂

ICPC NEERC 2018

My second time in this competitive programming contest as a Technical Committee assistant. It is an amazing experience, as well as a steep learning curve. Thanks to everyone who participated in this year’s programming competitions at ITMO University, both teams and fellow volunteers! 👨‍💻💪

Rust

An ordinary algorithm class assignment can become a challenging experiment if you give up on your habits and try solving it using a different programming language, like Rust. I’ve had a deep dive into the Rust ecosystem, implementing some algorithms, trying a game framework and building a research web browser (with small fixes along the way).

I’ll definitely continue learning the ways of oxidized metal in 2019! 📔

To the awesome new year!

Let 2019 be even better for us all! Thank you for reading, and all the best in 2019! 😃

Rust for algorithms

Sun, 23 Dec 2018 20:54:31 +0000

This week I was assigned to implement a number of string related algorithms that perform substring search and count, calculate helper functions and build performant structures on them, etc. Algorithms themselves were not too complicated, so I decided to challenge myself and solve the problems using Rust (instead of my main language C++).

Now that I’ve solved the task, I can tell a bit about my experience, things that I found convenient or complicated. I’m a beginner in Rust, but if my idea of the language is interesting to you, read on! 🙂

The assignment I had to solve is part of my Algorithms and Data Structures course at ITMO University. It has been published on the Codeforces competitive programming platform that has recently moved to ITMO. The version of Rust available on Codeforces is 1.26, so I haven’t yet had a chance to check out the new features of Rust 2018 edition.

Searching for an IDE for Rust, I’ve chosen CLion with JetBrains’ official Rust plugin. This IDE is proprietary, but of all IDEs and editors I checked only CLion provided debugging out of the box. I also enjoyed VSCode quite much, but couldn’t get any plugins that provide debug support to work with Rust. I am aware of some efforts to support Rust in KDevelop, as well as of an official Vim plugin, but decided to stick to something I use regularly anyway.

In the end, I solved 12 of 13 tasks using Rust and wrote some extra code for personal tests. I published all of it in a GitHub repository, in case it might be useful for someone.

Generally, the C++ → Rust switch felt pretty natural. With Rust, it takes a lot more time to persuade the compiler that the code is worth building, but it actually helps to fix bugs, and in the end you’re thankful to the borrow checker for its hard work. Then a number of issues gets fixed during a couple of first launches, when the program panics on integer overflows and out-of-bounds array indexes. And finally, a nice static analyzer called clippy suggests some final touches to optimize and prettify the code. Compiler errors feel unexpectedly pleasant and friendly after GCC’s text walls.

Built-in collections were sufficient for the programs I needed to write. Not much to say here really, except for that data structures want to be cloned rather than copied to avoid memory errors.

Sadly, there’s a couple of negative aspects I discovered, both related to performance. First is that rustc does not support tail call optimization (TCO), and likely won’t anytime soon. That was a big disappointment for me because there are so many algorithms out there that are described in a recursive manner, have proper asymptotics limits, but expect a compiler to do the optimization. Of course, they can be rewritten using loops, but usually you want to stick to idiomatic implementations and not reinvent.

Second, the file IO speed. Buffered file input-output in Rust is as fast as fstream in C++ unless the latter is “optimized” with sync_with_stdio(false), tie(nullptr) and no flushes (like std::endl). It’s the sole reason for that 13th program to not be submitted in Rust: it was really hitting the time limit. And even though it may seem to be a rare case, it can play its role in competitive programming.

To sum up, I loved Rust for its strict yet friendly compiler, a nice standard library, and a nice community ready to help (check out #rust on irc.mozilla.org!). There are many cool libraries out there, and I am very eager to try Qt with Rust as soon as I get some free time.