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

• Announcing Dekking: Next generation code coverage reports for Haskell by Tom Sydney Kerckhove

  This post announces Dekking, a next-generation code coverage tool for Haskell.

• Haddock Performance by Matt Parsons

  I decided to look at the source code and see if there were any low hanging fruit. Fortunately, there was!

• Haskell and C++ FFI for Fun and Profit by Topi Kettunen

  Lately, I’ve been banging my head against the wall with the FFI of Haskell since I wanted to write a particular piece of code in mainly Haskell, but I needed something from the world of C++.

• How does Prettyprinter print pretty?

  This is a very brief and rough introduction into how Prettyprinter actually works. It is not a guide on how to use it, but after understanding the big ideas it should be easier to read the documentation and source code.

• Nixpkgs support for incremental Haskell builds by Gabriella Gonzalez

  By “incrementally” I mean that these Nix builds only need to build what changed since the last full build of the package so that the package doesn’t need to be built from scratch every time.

• Probability Monads from scratch in 100 lines of Haskell by Denny Britz

  The result is not comparable to a real probabilistic programming language in terms of performance or expressiveness, but I think it’s a great learning tool to get an intuitive understanding for manipulating probability distributions.

• sqlite-easy: A primitive yet easy to use sqlite library by Gil Mizrahi

  sqlite-easy is a new database library for interacting with SQLite3 databases.

• Writing a Static Site Generator Using Shake by Abhinav Sarkar

  In this post, we write a bespoke SSG using the Shake build system.

Jobs

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

In brief

• Building Dhall with stacklock2nix by Dennis Gosnell

  This post uses stacklock2nix to build Dhall and all its tools with Nix. The Dhall project is a good example for stacklock2nix, since it is comprised of quite a few different Haskell packages.

• Day 20 - Shifting Sequences by Monday Morning Haskell

  For this problem we are tracking a queue of numbers.

• Digit strings easy to count their length by Ken

• GHC+DH Weekly Update #2, 2022-12-21 by Vladislav Zavialov

  Hi all, here’s another update on the implementation of dependent types in GHC.

• Haskell Foundation DevOps Weekly Update, 2022-12-21 by Bryan Richter

  Like last week, I am working on Mac notarization for GHC. Since it’s my main focus, I will say a few more words about it.

Show & tell

• Stack version 2.9.3 by Mike Pilgrem

Call for participation

• Cabal: Document which programs can be overridden with flags like –with-gcc
• natskell: Consider adding validators alongside transformers