Haskell Weekly

Welcome to another issue of Haskell Weekly! Haskell is a safe, purely functional programming language with a fast, concurrent runtime. This is a weekly summary of what’s going on in its community.

Featured

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• Calling C++ from Haskell by Luc Tielen

  In this article, I show some techniques for calling C++ code from Haskell without using TemplateHaskell.

• Hacking with Haskell by Max Harley

  There’s probably a tool for managing nmap scans already, but with the power of the semigroup, an nmap management tool should be easy to implement.

• Hakyll how-to: Fancy title formatting by Fraser Tweedale

  Sometimes you need special formatting in an article title. The standard Hakyll metadata block doesn’t offer a good way of doing this. But Hakyll is very flexible.

• Haskell dark arts, part I: Importing hidden values by Cheng Shao & Richard Eisenberg

  What if we tell you this encapsulation can be broken, and you can import hidden functions with ease? Of course, this comes with some caveats, but no spoilers — read the rest of the post to find out how (and when).

• Making an IO by Lúcás Meier

  Now, this is not really an attempt on explaining monads, or IO. This post is just a progression of ideas around implementing something like IO.

• Permutate parsers, don’t validate by Ju Liu

  In this post, I would like to go through a practical example that shows the power of bringing this concept to its limits.

• Philosophies of Rust and Haskell by Michael Snoyman

  In this post, I want to look at some of the philosophical underpinnings that explain some of the similarities and differences in the languages.

• Trouble in paradise: Fibonacci

  In this post I’ll demonstrate just how easy it is to shoot yourself in the foot with laziness using the classic example of computing Fibonacci numbers.

• Why Haskell is our first choice for building production software systems by Christian Charukiewicz

  In this post I will cover some of the defining features of Haskell that make it an excellent, industrial-strength language that is well-suited for building commercial software, and why it is usually the first tool we consider using for new projects.

Jobs

Trying to hire a Haskell developer? You should advertise with us!

In brief

• 2020 Retrospective by Haskell Weekly Podcast

  Using Adam Wespiser’s blog post as a jumping off point, Cameron Gera and Taylor Fausak look back on a year of Haskell.

• Benchmarks of discrimination package by Oleg Grenrus

  I originally posted these as a Twitter thread. Its point is to illustrate that constant factors matter, not only the whether it is O(n), O(n log n) or O(n^2) (though quadratic is quite bad quite soon).

• Generate PureScript data types from Haskell data types by Ong Yi Ren

  This seemes to be an automatable process so I decided to find a way to let the computer do the work for me!

• The Haskell Language Server with Zubin Duggal by Compositional

  In this episode, Roman Cheplyaka talks to Zubin Duggal who contributed to HLS for years, personally, through various Summer of Code projects and recently as a Tweag Open Source Fellow.

• An introduction to ghc-debug: precise memory analysis for Haskell programs

  I will be introducing ghc-debug to Zubin Duggal in the context of using it to analyse memory usage of ghcide.

• Learn how to build Haskell applications by Marco Sampellegrini

  In this book we will create a Continuous Integration Server from scratch. We’ll start from zero lines of code and will finish with a working CI Server.

• Overlappable instances by Łukasz Gołębiewski

  There are many patterns, styles and libraries which can be chosen for dealing with effects in Haskell. Today I’ll try to bring closer one of them.

• Scrive Nix Workshop

  This book contains the workshop materials used for training Haskell developers at Scrive.

• Why exactly I want Boring Haskell to happen by Artyom Kazak

  My working hypothesis right now is that Haskell should be split into “Haskell” and “Boring Haskell”.

Call for participation

• owenbot-hs: Add support for Nitro emojis in ReactHandler.hs
• spacecookie: Let users configure custom file type mappings