Haskell Weekly


Issue 128 2018-10-11

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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.


  • An introduction to linear regression using Haskell

    I decided to stray a little off the beaten track and implement the programming exercises from Andrew’s course in Haskell instead. Haskell feels well-suited for this problem.

  • elm-beam

    I’ve been exploring the idea of an Elm compiler that produces assembly for the Erlang Virtual Machine. This essay documents some interesting parts of the project.

  • Fullstack Haskell: Reflex and Servant

    If it were 2005 you may have been able to get away with just blaze. But we are in 2018+, and JavaScript is a problem. In this blog post we will explore how to deal with JavaScript trough reflex and GHCJS.

  • RAII is better than the bracket pattern

    The RAII (Resource Acquisition Is Initialization) approach in both C++ and Rust leads to a nicer solution than even our bracket pattern in Haskell, by (mostly) avoiding the possibility of a premature close.

  • Announce: Haskell code explorer: Tool that helps understand Haskell codebases

    Haskell code explorer is a web application for exploring and understanding Haskell codebases. It provides the following features: Types and documentation on hover, go to definition, find references, type of each expression & semantic highlighting.

  • Comprehending monoids with class

    For expressing queries over collections of data, monoid comprehension can be more flexible, simpler, more efficient, and safer than its monadic counterpart.

  • Counting inversions with monoidal sparks

    Time for me to reveal the example I had in mind that led to the generalization in my previous post. Thanks for all the interesting comments: it seems like there are some interesting connections to be explored.

  • Detailed walkthrough for a beginner Haskell program

    This post walks through the development of a small Haskell program for aligning equals symbols in a block of text. This walkthrough targets a beginning programmer by describing several steps and concepts in extra detail.

  • Making a Haskell interface for the Rosie pattern language

    The Rosie Pattern Language (RPL) is a DSL for parsing strings which is more convenient and easier to work with than regular expressions. RPL is a Lua library with a C Foreign Function Interface (FFI). I noticed that there wasn’t a way to call it from Haskell.

  • Writing a simple web application

    I’ve talked about adding metrics to the Haskell application. I decided to prepare a full example that can be looked at and reused in later posts and projects.


In brief

Package of the week

This week’s package of the week is Autoexporter, a tool for automatically writing modules that simply re-export other modules.

Call for participation

Looking to participate in the fifth annual Hacktoberfest? Check out some of these issues with the “Hacktoberfest” label from Haskell repositories on GitHub!