Haskell Weekly

<p>Thanks to everyone who filled out the 2021 State of Haskell Survey! This week Cameron and Taylor review the results.</p> <ul> <li><a href="https://taylor.fausak.me/2021/11/16/haskell-survey-results/">https://taylor.fausak.me/2021/11/16/haskell-survey-results/</a></li> </ul>

<p>This week Cameron and Taylor answer our first listener question: How should you structure large applications? We compare ReaderT with MTL along with other approaches.</p> <ul> <li><a href="https://join.slack.com/t/haskell-foundation/shared_invite/zt-mjh76fw0-CEjg2NbyVE8rVQDvR~0F4A">https://join.slack.com/t/haskell-foundation/shared_invite/zt-mjh76fw0-CEjg2NbyVE8rVQDvR~0F4A</a></li> </ul>

<p>We’re back! After a month off, Cameron and Taylor get together to talk about what’s new in the Haskell world.</p> <ul> <li><a href="https://www.haskell.org/ghc/blog/20211029-ghc-9.2.1-released.html">https://www.haskell.org/ghc/blog/20211029-ghc-9.2.1-released.html</a></li> <li><a href="https://haskellweekly.news/survey/2021.html">https://haskellweekly.news/survey/2021.html</a></li> </ul>

<p>Cameron Gera and Taylor Fausak discuss Drew Olson’s adventures in looping. What should you do if you want to loop forever, but break out of the loop early sometimes?</p> <ul> <li><a href="https://blog.drewolson.org/adventures-in-looping">https://blog.drewolson.org/adventures-in-looping</a></li> </ul>

<p>Special guest Tom Sydney Kerckhove talks with Taylor Fausak about a denial of service vulnerability in Aeson, a Haskell library for JSON.</p> <ul> <li><a href="https://cs-syd.eu/posts/2021-09-11-json-vulnerability">https://cs-syd.eu/posts/2021-09-11-json-vulnerability</a></li> <li><a href="https://hackage.haskell.org/package/sydtest-0.4.0.0">https://hackage.haskell.org/package/sydtest-0.4.0.0</a></li> <li><a href="https://hackage.haskell.org/package/genvalidity-0.11.0.2">https://hackage.haskell.org/package/genvalidity-0.11.0.2</a></li> <li><a href="https://hackage.haskell.org/package/yamlparse-applicative-0.2.0.0">https://hackage.haskell.org/package/yamlparse-applicative-0.2.0.0</a></li> </ul>

<p>Taylor Fausak talks with Cameron Gera about Evoke, Taylor’s latest GHC plugin for deriving instances without generics or Template Haskell.</p> <ul> <li><a href="https://taylor.fausak.me/2021/09/10/evoke/">https://taylor.fausak.me/2021/09/10/evoke/</a></li> </ul>

<p>Curious about dependent types? Special guest Vladislav Zavialov from Serokell breaks it down for us. We discuss comparisons to refinement types, sigma and pi types, interactions with linear types, and much more!</p> <ul> <li><a href="https://serokell.io/blog/developing-ghc-for-a-living">https://serokell.io/blog/developing-ghc-for-a-living</a></li> <li><a href="https://twitter.com/int_index">https://twitter.com/int_index</a></li> </ul>

<p>Stack, HLint, and Brittany, oh my! Cameron Gera and Taylor Fausak go on a deep dive into the ACI Learning tech stack.</p> <ul> <li><a href="https://www.acilearning.com">https://www.acilearning.com</a></li> </ul>

<p>Back from summer break, Cameron Gera discusses the Witch library with it’s author, Taylor Fausak. Learn about the many motivations behind this simple library for converting values between various types.</p> <ul> <li><a href="https://taylor.fausak.me/2021/07/13/witch/">https://taylor.fausak.me/2021/07/13/witch/</a></li> <li><a href="https://hackage.haskell.org/package/say-my-name-0.1.0.0">https://hackage.haskell.org/package/say-my-name-0.1.0.0</a></li> </ul>

<p>There’s a lot to like about Haskell, but what is it missing? We explore Alexander Granin’s post where he suggests some topics for books that could benefit the Haskell community.</p> <ul> <li><a href="https://github.com/graninas/The-Voids-Of-Haskell/blob/9b401e33af37f991dcb3ab2eedc023661237d845/README.md">https://github.com/graninas/The-Voids-Of-Haskell/blob/9b401e33af37f991dcb3ab2eedc023661237d845/README.md</a></li> </ul>

<p>Special guest Marco Sampellegrini talks with us about his recent book, The Simple Haskell Handbook. The book describes a project driven approach to Haskell development, using a continuous integration server as a motivating example.</p> <ul> <li><a href="https://leanpub.com/simple-haskell-book">https://leanpub.com/simple-haskell-book</a></li> </ul>

<p>Should you organize modules vertically or horizontally? This week we take a look at another article by Gabriella Gonzalez, this time about organizing projects and packages.</p> <ul> <li><a href="https://www.haskellforall.com/2021/05/module-organization-guidelines-for.html">https://www.haskellforall.com/2021/05/module-organization-guidelines-for.html</a></li> </ul>

<p>How can you avoid deeply nested error handling code? This week we review Gabriella Gonzalez’s trick for keeping error handling flat.</p> <ul> <li><a href="https://www.haskellforall.com/2021/05/the-trick-to-avoid-deeply-nested-error.html">https://www.haskellforall.com/2021/05/the-trick-to-avoid-deeply-nested-error.html</a></li> </ul>

<p>Curious about the Haskell Foundation? This week we interview Andrew Boardman, its Executive Director. He explains the Foundation’s purpose and how you can help.</p> <ul> <li><a href="https://haskell.foundation">https://haskell.foundation</a></li> <li><a href="https://fpchat-invite.herokuapp.com">https://fpchat-invite.herokuapp.com</a></li> <li><a href="https://funprog.zulipchat.com/login/">https://funprog.zulipchat.com/login/</a></li> <li><a href="https://wiki.haskell.org/IRC_channel">https://wiki.haskell.org/IRC_channel</a></li> <li><a href="https://discourse.haskell.org">https://discourse.haskell.org</a></li> <li><a href="https://twitter.com/myShoggoth">https://twitter.com/myShoggoth</a></li> <li><a href="https://myshoggoth.com">https://myshoggoth.com</a></li> <li><a href="https://joyofhaskell.com/posts/2021-02-24-why-stm.html">https://joyofhaskell.com/posts/2021-02-24-why-stm.html</a></li> </ul>

<p>What happens to exceptions when you don’t explicitly handle them? This week we review Taylor’s blog post about default exception handlers.</p> <ul> <li><a href="https://taylor.fausak.me/2021/04/03/default-exception-handler-in-haskell/">https://taylor.fausak.me/2021/04/03/default-exception-handler-in-haskell/</a></li> </ul>

<p>Special guest Cody Goodman walks us through an interesting PostgreSQL bug. Handling async exceptions properly is trickier than you might expect!</p> <ul> <li><a href="https://www.parsonsmatt.org/2021/03/17/async_control_flow.html">https://www.parsonsmatt.org/2021/03/17/async_control_flow.html</a></li> <li><a href="https://github.com/codygman/tech-roam/blob/master/20210326113249-haskell_persistent_issues_postgres_connections_are_returned_to_pool_too_quickly.org">https://github.com/codygman/tech-roam/blob/master/20210326113249-haskell_persistent_issues_postgres_connections_are_returned_to_pool_too_quickly.org</a></li> </ul>

<p>Byte string, text, and vector, oh my! This week we review Michael Snoyman’s proposal to unify vector-like types. Learn about boxed versus unboxed values, pinned versus unpinned memory, and more.</p> <ul> <li><a href="https://www.snoyman.com/blog/2021/04/haskell-base-proposal/">https://www.snoyman.com/blog/2021/04/haskell-base-proposal/</a></li> </ul>

<p>Special guests Michael Litchard and Brian Hurt talk with us about their new social networking site Chat Wisely. We hear about their experience using Haskell not only on the backend but also on the frontend through GHCJS.</p> <ul> <li><a href="https://www.chatwisely.com">https://www.chatwisely.com</a></li> <li><a href="https://www.patreon.com/chatwisely">https://www.patreon.com/chatwisely</a></li> </ul>

<p>Special guest Sandy Maguire talks with us about using Haskell Wingman for program synthesis, designing bulletproof abstractions with algebra, wrangling type level programming in Haskell, and managing effects with his Polysemy library.</p> <ul> <li><a href="https://www.patreon.com/wingman_for_haskell">https://www.patreon.com/wingman_for_haskell</a></li> <li><a href="https://leanpub.com/algebra-driven-design">https://leanpub.com/algebra-driven-design</a></li> <li><a href="https://leanpub.com/thinking-with-types">https://leanpub.com/thinking-with-types</a></li> <li><a href="https://github.com/polysemy-research/polysemy">https://github.com/polysemy-research/polysemy</a></li> <li><a href="https://reasonablypolymorphic.com">https://reasonablypolymorphic.com</a></li> <li><a href="https://sandymaguire.me">https://sandymaguire.me</a></li> </ul>

<p>Linear types finally landed in GHC 9.0.1! We talk through what that means along with other news from the Haskell Foundation and Tweag.</p> <ul> <li><a href="https://discourse.haskell.org/t/haskell-foundation-executive-director-and-chief-technology-officer/1861">https://discourse.haskell.org/t/haskell-foundation-executive-director-and-chief-technology-officer/1861</a></li> <li><a href="https://discourse.haskell.org/t/ghc-8-10-4-released/1847">https://discourse.haskell.org/t/ghc-8-10-4-released/1847</a></li> <li><a href="https://discourse.haskell.org/t/ghc-9-0-1-released/1840">https://discourse.haskell.org/t/ghc-9-0-1-released/1840</a></li> <li><a href="https://www.tweag.io/blog/2021-02-10-linear-base/">https://www.tweag.io/blog/2021-02-10-linear-base/</a></li> </ul>