Programming Leftovers

posted by Roy Schestowitz on Jan 13, 2023

• Using Ninja Build to Build Projects Faster

  Ninja is a compact build system with a focus on fast incremental builds. It was originally developed by Evan Martin, a Google dev, partly in response to the needs of building large projects such as Google Chrome.

  If you’re developing a software system and you require a rebuild every few minutes to test your latest feature or code block, then Ninja will only rebuild what you have just modified or added and nothing else—as opposed to Make, which would rebuild the whole project every single time.

  This article will start by explaining build systems in a little more detail. It’ll then introduce Ninja and teach you how to use Ninja to build a simple C++ project.

• Johnnie 'QObject' Walker, replace a service locator pattern while you're at it

  I've seen many C++ code bases where there was the concept of a service locator. An global static object that anyone can query to get a class. This is handy with old legacy spiderweb intertwined code that gets everything from everywhere, but not so useful when you're trying to unit test code, it is not visible from the header what dependencies you need. My preference goes to dependency injection, give all the dependencies to the class' constructor and use them that way. Makes it easy to mock and if you have many dependencies, it serves as a starting point to refactor in to a more clearly separated architecture. This article shows a piece of code that uses QObject, the Qt object base class, to replace a servicelocator. All QObjects can have a parent QObject, thus a tree is formed, which you can walk back up and search. This effectively replaces the servicelocator, since you can just request a certain type of QObject.

• The Power of Prolog

  The goal of this material is to bridge the gap between the great traditional Prolog textbooks of the past and the language as it currently is, several decades after these books were written. You will see that many limitations of the past are no longer relevant, while several new constructs are now of great importance even though they are not yet covered in any available Prolog book. If you are new to Prolog, read the chapters in order for a self-contained exposition of many important language features. If you already have some experience with Prolog and would like to learn more about more recent aspects, I recommend you start with the chapter on integer arithmetic and proceed with the chapters it links to.

• Writing a TLA⁺ tree-sitter grammar

  Both TLA⁺ and tree-sitter itself ensured the project was fascinating on a technical level; even more interesting were the social and psychological aspects of my first real involvement with the free software community! I’ll go over why I wanted to create this project and the main technical challenges I faced doing so, then discuss the conditions that enabled me to create it and how free software development changed the way I think. If you’d rather get the technical part in video form (with demos!), you can watch the presentation I gave at TLA⁺ Conf 2021 (slides: pdf, odp): [...]

• Day 18 (Advent of Code 2022)

  This time around, we're porting a solution from C++ to Rust and seeing how it feels, how it performs, and what we can learn about both languages by doing that.

• Rust Should Own Its Debugger Experience

  40% of Rust Developers believe Rust's debugging experience could use improvement. And that's not surprising: when we write code we make assumptions, and sometimes we assume wrong. This leads to bugs, which we then track down and fix. This is what we call "debugging", and is a core part of programming. The purpose-built tools which help us with debugging are called "debuggers".

  Unlike the Rust compiler, the Rust project doesn't actually provide a "Rust debugger". Users of Rust are instead expected to use a third-party debugger such as gdb, lldb, or windbg to debug their programs. And support for Rust in these debuggers is not always great. Basic concepts such as "traits", "closures", and "enums" may have limited support. And debugging async code, or arbitrary user-defined data structures may be really hard if not impossible. This limits the utility of debuggers, and in turn limits the Rust user's debugging experience.

• Dirk Eddelbuettel: RcppGSL 0.3.13 on CRAN: Mandated Update

  A new release 0.3.13 of RcppGSL is now on CRAN. The RcppGSL package provides an interface from R to the GNU GSL by relying on the Rcpp package.

• Dirk Eddelbuettel: RDieHarder 0.2.5 on CRAN: Mandated Update

  An new version 0.2.5 of the random-number generator tester RDieHarder (based on the DieHarder suite developed / maintained by Robert Brown with contributions by David Bauer and myself along with other contributors) is now on CRAN.

• Java Is Now On The Nintendo 64!

  Whether it’s your favorite programming language, or your favorite beverage, there’s no denying Java is everywhere. Now, it’s even on the Nintendo 64, thanks to the valiant efforts of [Mike Kohn]. Even better, he’s coded a demo to show off its capabilities!

• Why Polars uses less memory than Pandas

  Processing large amounts of data with Pandas can be difficult; it’s quite easy to run out of memory and either slow down or crash. The Polars dataframe library is a potential solution.

  While Polars is mostly known for running faster than Pandas, if you use it right it can sometimes also significantly reduce memory usage compared to Pandas. In particular, certain techniques that you need to do manually in Pandas can be done automatically in Polars, allowing you to process large datasets without using as much memory—and with less work on your side!