Programming *

It is a new selection of tips and tricks about Python and programming from my Telegram-channel @pythonetc.

← Previous publications

At the last Tech Train IT festival, we met the legendary John Romero, who designed and developed the iconic Wolfenstein 3D, Doom, and Quake. We talked about whether game developers need soft skills, which working tools to pay attention to, and which co-founder of Id Software's favorite toys are. Questions were asked by Nikita Tsaplin, the founder of RUVDS.


→ Text and video in Russian

Some time ago, the creator of Lua programming language, Roberto Ierusalimschy, visited our Moscow office. We asked him some questions that we prepared with the participation of Habr.com users also. And finally, we’d like to share full-text version of this interview.

Hi! Though the 2019 conference season is not over yet, we'd like to talk about the bug-finding challenges we offered to visitors at our booth during the past conferences. Starting with the fall of 2019, we've been bringing a new set of challenges, so we can now reveal the solutions to the previous tasks of 2018 and the first half of 2019 – after all, many of them came from previously posted articles, and we had a link or QR code with information about the respective articles printed on our challenge leaflets.

Apache Dubbo is one of the most popular Java projects on GitHub. It's not surprising. It was created 8 years ago and is widely applied as a high-performance RPC environment. Of course, most of the bugs in its code have long been fixed and the quality of the code is maintained at a high level. However, there is no reason to opt out of checking such an interesting project using the PVS-Studio static code analyzer. Let's see how it turned out.

It has been three months since 2018 had ended. For many, it has just flew by, but for us, PVS-Studio developers, it was quite an eventful year. We were working up a sweat, fearlessly competing for spreading the word about static analysis and were searching for errors in open source projects, written in C, C++, C#, and Java languages. In this article, we gathered the top 10 most interesting of them right for you!

Hi all!

Every person is using barcodes nowadays, mostly without noticing this. When we are buying the groceries in the store, their identifiers are getting from barcodes. Its also the same with goods in the warehouses, postal parcels and so on. But not so many people actually know, how it works.

What is 'inside' the barcode, and what is encoded on this image?



Lets figure it out, and also lets write our own bar decoder.

There are only two hard things in Computer Science: cache invalidation
and naming things.

— Phil Karlton

We, developers, spend more time reading code than writing it. It is important for the code to be readable and clear about its intent.

Below are some advice based on my experience naming things.

It is a new selection of tips and tricks about Python and programming from my Telegram-channel @pythonetc.

Previous publications.

Java developers have access to a number of useful tools that help to write high-quality code such as the powerful IDE IntelliJ IDEA, free analyzers SpotBugs, PMD, and the like. The developers working on CUBA Platform have already been using all of these, and this review will show how the project can benefit even more from the use of the static code analyzer PVS-Studio.

SafeHandle / CriticalHandle / SafeBuffer / derived types

I feel I’m going to open the Pandora’s box for you. Let’s talk about special types: SafeHandle, CriticalHandle and their derived types.

This is the last thing about the pattern of a type that gives access to an unmanaged resource. But first, let’s list everything we usually get from unmanaged world:

The first and obvious thing is handles. This may be an meaningless word for a .NET developer, but it is a very important component of the operating system world. A handle is a 32- or 64-bit number by nature. It designates an opened session of interaction with an operating system. For example, when you open a file you get a handle from the WinApi function. Then you can work with it and do Seek, Read or Write operations. Or, you may open a socket for network access. Again an operating system will pass you a handle. In .NET handles are stored as IntPtr type;

This chapter was translated from Russian jointly by author and by professional translators. You can help us with translation from Russian or English into any other language, primarily into Chinese or German.

Also, if you want thank us, the best way you can do that is to give us a star on github or to fork repository github/sidristij/dotnetbook.

Let me share an interesting experience in promotion of a mobile game.

1. Introduction

I am going to describe all the benefits and of course show the final results. The example will be the mobile game Quick Brain which is available for Android и iOS. Quick Brain Android was released the first that's why its possibilities differ considerably from iOS version.

I have been always kept by the thoughts that everyone's talking about high returns in contrast with Android. I just couldn't resist such attractive prospects and started more active refinement of iOS version in order to feel less embarrassed about it.

After Google play iOS has become an absolutely new field for the games for me. During my comparative experiment I've found out that iOS version can bring comparable earnings to Android with daily audience 3 to 10 times less depending on the country.

2019 is coming to an end, and it's Christmas soon. It is also the time to grab all data and collect statistics and a rating of the most interesting Habr's articles for this period.



In this post the best articles and best Habr authors 2019 will be presented, I also will show some statistical graphs that I find interesting or unusual.

Let's get started.

Christmas has always been one of my favourite times of the year. For me, Christmas is a season that brings so much love, laughter, happiness, and other magical things into our lives.

I was born and raised in Spain, more specifically in Tenerife, a sunny subtropical island in the middle of the Atlantic Ocean just off the African coast. I have to say that Christmas in Tenerife is very different to my the last two Christmases I’ve spent in London since joining Badoo.

One amazing plus of living in London is that I have got to see snow for the first time in my life, real snowflakes falling from the sky. Just incredible!

Talking of snowflakes, I have an interesting story to tell you about something that happened to me one day in the office the last Christmas.  It was right before I was heading home to Tenerife to spend a few days with my family.

It just so happened that last December I’d been assigned a very interesting ticket with the following description

In autumn, we announced we were going to expand our IT team from 49 to 250 developers. And immediately we were buried under an avalanche of questions — mostly, people were interested why a pizza chain needs so many software engineers. How did we come up with such a number? So now I want to answer that.

Visual Studio 2019 pushes the boundaries of individual and team productivity. We hope that you will find these new capabilities compelling and start your upgrade to Visual Studio 2019 soon.

As you are considering this upgrade, rest assured that Visual Studio 2019 makes it distinctively easy to move your codebase from previous versions of Visual Studio. This post captures the reasons why your upgrade to Visual Studio 2019 will be pain-free.

• You can install the latest IDE side-by-side with any older VS versions
• You can continue building your C++ code with the MSVC v140 (VS 2015.3) or v141 (VS 2017) toolsets
• You can upgrade to the latest MSVC v142 (VS 2019) and maintain binary compatibility with any of your 3rd party libraries that haven’t migrated yet
• Regardless of the toolset you’re on, you get access to the full collection of OSS libraries available in Vcpkg

I strain to make the far-off echo yield
A cue to the events that may come in my day.
(‘Doctor Zhivago’, Boris Pasternak)

I’ll be honest: I don’t write in pure C that often anymore and I haven’t been following the language’s development for a long time. However, two unexpected things happened recently: С won back the title of the most popular programming language according to TIOBE, and the first truly interesting book in years on this language was published. So, I decided to spend a few evenings studying material on C2x, the future version of C.

Here I will share with you what I consider to be its most interesting new features.

It is a new selection of tips and tricks about Python and programming from my Telegram-channel @pythonetc.

← Previous publications


You can’t mutate closure variables by simply assigning them. Python treats assignment as a definition inside a function body and doesn’t make closure at all.

In order to verify the quality of software, you have to use a lot of different tools, including static and dynamic analyzers. In this article, we'll try to figure out why only one type of analysis, whether static or dynamic, may not be enough for comprehensive software analysis and why it's preferable to use both.

MessageBox — useful window for different GUI frameworks, but you can't find it in AvaloniaUI.
Let's try to do it.