Haskell Weekly


Issue 210 2020-05-07

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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.


  • Haskell on AWS Lambda - A Detailed Tutorial by Saurabh Nanda

    This tutorial, along with the accompanying source-code walks you through the process of managing AWS Lambda Functions completely in Haskell.

  • Eat Haskell String Types for Breakfast by Ziyang Liu

    This blog post summarizes, with bite-size bullet points, some knowledge on Haskell string types that I think is important to recognize when writing Haskell.

  • Environment variables parsing for free (applicatives) by Clément Delafargue

    The base library provides a really bare-bones way to get them, with getEnv and lookupEnv. This gets cumbersome quickly, if you want proper error reporting.

  • Google Summer of Code: Haskell.org

    In Google Summer of Code, we attempt to improve not only the language, but the whole ecosystem.

  • HLint 3.0 by Neil Mitchell

    As of now, if your code can be parsed with GHC, it can probably be parsed with HLint. As new GHC releases come out, with new features and new forms of syntax, HLint will follow along closely.

  • Indexed Monads: Examples and Discussion by Adam Wespiser

    Is it possible to compose parsers and state monad transformers with different input and output types?

  • Intervals and their relations by Marco Perone

    I realised that interpreting Allen’s interval algebra relations without ambiguities was not trivial and in the end I decided to reimplement it in a more general and unambiguous way.

  • A Journey into Haskell and Open Source by Romain Gerard

    I want to write something to celebrate the latest and I hope the last release of wstunnel, a TCP/UDP tunneling websocket tool, and share with you at the same time my story with Haskell and OpenSource projects.

  • JSON Parsing from Scratch in Haskell by Abhinav Sarkar

    Writing a parser for JSON is a great exercise for learning the basics of parsing. Let’s write one from scratch in Haskell.

  • Template Haskell by Jonathan Dowland

    Part of what I am doing at the moment is investigating Template Haskell to see whether it would usefully improve our system implementation.


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In brief

  • Algorithm Design with Haskell by Richard Bird and Jeremy Gibbons

    This book is devoted to five main principles of algorithm design: divide and conquer, greedy algorithms, thinning, dynamic programming, and exhaustive search.

  • Documentation plans by Théophile Choutri

    You may have seen me on various community channels and on social media to recruit motivated volunteers to help improve the documentation of the base library.

  • Frozen Lake in Haskell by Monday Morning Haskell

    Last time on MMH, we began our investigation into Open AI Gym. We started by using the Frozen Lake toy example to learn about environments.

  • A guide to monads in Haskell by Jean-Sébastien Basque-Girouard

    Monads are the most important structures in Haskell but they are difficult to grasp for most programmers because they have few analogs in other languages.

  • Haskell Language Server version 0.1 by Alan Zimmerman

    Changes: This is the initial version, so too many to list individually.

  • Hierarchical Free Monads: The Most Developed Approach In Haskell by Alexander Granin

    It also provides a technical perspective on HFM in comparison to Final Tagless / mtl and demonstrates how to solve typical tasks with it.

  • Monthly Hask Anything (May 2020)

  • More Random Access Lists by Donnacha Oisín Kidney

    I’m going to look today at using the zeroless binary system to implement a similar structure, and see what the differences are.

  • overloaded-0.2.1: Overloaded:Categories by Oleg Grenrus

    The Overloaded:Categories is another of the new features of recent overloaded 0.2.1 release.

  • RecordDotSyntax language extension proposal by Shayne Fletcher

    (The proposal has been accepted.) We propose a new language extension RecordDotSyntax that provides syntactic sugar to make the features introduced in the HasField proposal more accessible, improving the user experience.

  • A taste of Bazel: Build a library, a service and Hspec tests by Clément Hurlin

    In this post, we’ll show how to get started with Bazel on a small but non-trivial project, featuring a library, a web service and an Hspec test suite.

Call for participation