Haskell Weekly: Recent Episodes
Taylor Fausak
Haskell Weekly covers the Haskell progamming language. Listen to professional software developers discuss using functional programming to solve real-world business problems. Each episode uses a conversational two-host format and runs for about 15 minutes.
Thanks to everyone who filled out the 2021 State of Haskell Survey! This week Cameron and Taylor review the results.
- https://taylor.fausak.me/2021/11/16/haskell-survey-results/
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.
- https://join.slack.com/t/haskell-foundation/shared_invite/zt-mjh76fw0-CEjg2NbyVE8rVQDvR~0F4A
We’re back! After a month off, Cameron and Taylor get together to talk about what’s new in the Haskell world.
- https://www.haskell.org/ghc/blog/20211029-ghc-9.2.1-released.html
- https://haskellweekly.news/survey/2021.html
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?
- https://blog.drewolson.org/adventures-in-looping
Special guest Tom Sydney Kerckhove talks with Taylor Fausak about a denial of service vulnerability in Aeson, a Haskell library for JSON.
- https://cs-syd.eu/posts/2021-09-11-json-vulnerability
- https://hackage.haskell.org/package/sydtest-0.4.0.0
- https://hackage.haskell.org/package/genvalidity-0.11.0.2
- https://hackage.haskell.org/package/yamlparse-applicative-0.2.0.0
Taylor Fausak talks with Cameron Gera about Evoke, Taylor’s latest GHC plugin for deriving instances without generics or Template Haskell.
- https://taylor.fausak.me/2021/09/10/evoke/
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!
- https://serokell.io/blog/developing-ghc-for-a-living
- https://twitter.com/int_index
Stack, HLint, and Brittany, oh my! Cameron Gera and Taylor Fausak go on a deep dive into the ACI Learning tech stack.
- https://www.acilearning.com
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.
- https://taylor.fausak.me/2021/07/13/witch/
- https://hackage.haskell.org/package/say-my-name-0.1.0.0
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.
- https://github.com/graninas/The-Voids-Of-Haskell/blob/9b401e33af37f991dcb3ab2eedc023661237d845/README.md
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.
- https://leanpub.com/simple-haskell-book
Should you organize modules vertically or horizontally? This week we take a look at another article by Gabriel Gonzalez, this time about organizing projects and packages.
- https://www.haskellforall.com/2021/05/module-organization-guidelines-for.html
How can you avoid deeply nested error handling code? This week we review Gabriel Gonzalez’s trick for keeping error handling flat.
- https://www.haskellforall.com/2021/05/the-trick-to-avoid-deeply-nested-error.html
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.
- https://haskell.foundation
- https://fpchat-invite.herokuapp.com
- https://funprog.zulipchat.com/login/
- https://wiki.haskell.org/IRC_channel
- https://discourse.haskell.org
- https://twitter.com/myShoggoth
- https://myshoggoth.com
- https://joyofhaskell.com/posts/2021-02-24-why-stm.html
What happens to exceptions when you don’t explicitly handle them? This week we review Taylor’s blog post about default exception handlers.
- https://taylor.fausak.me/2021/04/03/default-exception-handler-in-haskell/
Special guest Cody Goodman walks us through an interesting PostgreSQL bug. Handling async exceptions properly is trickier than you might expect!
- https://www.parsonsmatt.org/2021/03/17/async_control_flow.html
- https://github.com/codygman/tech-roam/blob/master/20210326113249-haskell_persistent_issues_postgres_connections_are_returned_to_pool_too_quickly.org
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.
- https://www.snoyman.com/blog/2021/04/haskell-base-proposal/
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.
- https://www.chatwisely.com
- https://www.patreon.com/chatwisely
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.
- https://www.patreon.com/wingman_for_haskell
- https://leanpub.com/algebra-driven-design
- https://leanpub.com/thinking-with-types
- https://github.com/polysemy-research/polysemy
- https://reasonablypolymorphic.com
- https://sandymaguire.me
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.
- https://discourse.haskell.org/t/haskell-foundation-executive-director-and-chief-technology-officer/1861
- https://discourse.haskell.org/t/ghc-8-10-4-released/1847
- https://discourse.haskell.org/t/ghc-9-0-1-released/1840
- https://www.tweag.io/blog/2021-02-10-linear-base/
Come @ me bro! In this episode we review Zac Wood’s post about the type applications language extension.
- https://zacwood.me/posts/haskell-type-application/
Special guest Matt Parsons talks to us about his upcoming book, Production Haskell.
- https://leanpub.com/production-haskell
- https://twitter.com/prodhaskell
Is Maybe problematic? Well, maybe. Robert Peszek thinks that Maybe is overused. Cameron Gera and Taylor Fausak break it down and consider alternatives.
- https://rpeszek.github.io/posts/2021-01-17-maybe-overuse.html
Christian Charukiewicz at Foxhound Systems wrote a list of reasons to prefer Haskell for building production systems. Cameron Gera and Taylor Fausak review the list and share their experience at ITProTV.
- https://www.foxhound.systems/blog/why-haskell-for-production/
Using Adam Wespiser’s blog post as a jumping off point, Cameron Gera and Taylor Fausak look back on a year of Haskell.
- https://wespiser.com/posts/2021-01-03-Lessons-Learned-From-A-Year-Of-Haskell.html
Are you curious about how Parsec is implemented behind the scenes? Cameron Gera and Taylor Fausak follow Antoine Leblanc’s walkthrough.
- https://hasura.io/blog/parser-combinators-walkthrough/
- http://dev.stephendiehl.com/fun/002_parsers.html
Can Haskell’s deriving mechanism be simplified? Cody Goodman, Cameron Gera, and Taylor Fausak walk through the changes that Matt Parsons suggested.
- https://www.parsonsmatt.org/2020/11/10/simplifying_deriving.html
Newtypes let you give things names, but is that type safety? Andres Schmois, Cameron Gera, and Taylor Fausak explore a blog post by Alexis King.
- https://lexi-lambda.github.io/blog/2020/11/01/names-are-not-type-safety/
- https://www.youtube.com/watch?v=MEmRarBL9kw
- https://www.reddit.com/r/haskell/comments/jnwg7i/haskell_foundation_ama/
Even well-designed languages have rough edges. Cameron Gera and Taylor Fausak review some of the bad parts of Haskell.
- https://www.snoyman.com/blog/2020/10/haskell-bad-parts-1
- https://haskellweekly.news/survey/2020.html
Does the idea of -XGHC2021 excite you? Cameron Gera and Taylor Fausak work through this proposed set of language extensions.
- https://np.reddit.com/r/haskell/comments/je1t82/does_the_idea_of_xghc2021_excite_you/
- https://github.com/ghc-proposals/ghc-proposals/pull/372
- https://hacktoberfest.digitalocean.com
- https://github.com/kowainik/learn4haskell
Learn how to answer common technical interview questions with Haskell. Cameron Gera and Taylor Fausak discuss Chris Penner’s blog post.
- https://chrispenner.ca/posts/interview
- https://hacktoberfest.digitalocean.com
- https://github.com/kowainik/learn4haskell
Sara Lichtenstein, Cameron Gera, and Taylor Fausak get recursively drunk on semigroups and monoids.
- https://dev.to/sshine/getting-recursively-drunk-with-monoids-2jek
Cameron Gera and Taylor Fausak discuss the pros and cons of various deriving strategies.
- https://kowainik.github.io/posts/deriving
- https://hacktoberfest.digitalocean.com
- https://dev.to/tfausak/how-to-define-json-instances-quickly-5ei7
- https://www.parsonsmatt.org/2019/11/27/keeping_compilation_fast.html
- https://www.youtube.com/watch?v=pwnrfREbhWY
Jose Silvestri and Cameron Gera go over the 2019 State of Haskell Survey and encourage you to fill it out.
- https://haskellweekly.news/survey/2019.html
- https://taylor.fausak.me/2018/11/18/2018-state-of-haskell-survey-results/
- https://taylor.fausak.me/2017/11/15/2017-state-of-haskell-survey-results/
Jose Silvestri and Dustin Segers give a whirlwind tour of FRP, exploring what it is and why you might want to use it.
- https://begriffs.com/posts/2015-07-22-essence-of-frp.html
- https://www.seas.upenn.edu/~cis194/fall16/lectures/11-frp.html
- https://apfelmus.nfshost.com/blog/2011/05/06-frp-why-functors.html
- https://stackoverflow.com/questions/1028250/what-is-functional-reactive-programming
- https://wiki.haskell.org/FRP_explanation_using_reactive-banana
- https://wiki.haskell.org/Reactive-banana/Examples
- https://github.com/gelisam/frp-zoo
Cameron Gera and Taylor Fausak discuss using types to guide refactoring toward better design.
- http://h2.jaguarpaw.co.uk/posts/good-design-and-type-safety-in-yahtzee/
Cody Goodman and Taylor Fausak explore the event log that GHC can produce when compiling or running.
- https://www.well-typed.com/blog/2019/09/eventful-ghc/
Sara Lichtenstein and Taylor Fausak discuss converting between numeric types with polymorphic functions.
- https://typeclasses.com/featured/rounding
Cameron Gera and Andres Schmois talk about practical uses for profunctor lenses and optics.
- https://thomashoneyman.com/articles/practical-profunctor-lenses-optics/
Cody Goodman and Taylor Fausak walk through inventing monads from scratch in JavaScript.
- https://blog.kabir.sh/posts/inventing-monads.html
Sara Lichtenstein and Andres Schmois discuss quickly learning Haskell by studying annotated examples.
- https://typeclasses.com/news/2019-07-phrasebook
Dustin Segers and Cody Goodman talk about developing video games using Haskell.
- https://linearity.itch.io/peoplemon
- http://jxv.io/blog/2018-02-28-A-Game-in-Haskell.html
- https://www.indiedb.com/games/nikki-and-the-robots/downloads
- https://github.com/FailWhaleBrigade/water-wars
- https://www.allureofthestars.com/
- https://np.reddit.com/r/haskellgamedev
- https://mmhaskell.com/blog/2019/3/25/making-a-glossy-game-part-1
- https://ocharles.org.uk/posts/2013-12-10-24-days-of-hackage-gloss.html
- http://andrew.gibiansky.com/blog/haskell/haskell-gloss/
- https://fumieval.github.io/rhythm-game-tutorial/
- https://cdry.wordpress.com/2016/10/11/tetris-in-haskell-in-a-weekend/
- https://blog.aas.sh/posts/2018-09-10-Making-A-Game-With-Haskell-And-Apecs/
- http://keera.co.uk/blog/2013/03/19/creating-board-games-in-haskell/
- https://www.youtube.com/watch?v=1MNTerD8IuI
- https://jshaskell.blogspot.com
- https://ocharles.org.uk/blog/posts/2013-08-18-asteroids-in-netwire.html
- https://prog21.dadgum.com/23.html
- https://github.com/meteficha/Hipmunk
Cameron Gera and Taylor Fausak talk about how function calls are evaluated in Haskell with regards to non-strictness.
- https://treszkai.github.io/2019/07/13/haskell-eval
Andres Schmois and Cody Goodman talk about using the Refined library to turn runtime checks into types.
- https://danieljharvey.github.io/posts/2019-07-05-refined-types.html
Cameron Gera and Taylor Fausak talk about why the Semantic team at GitHub decided to use Haskell.
- https://github.com/github/semantic/blob/eaf13783838861fe5eb6cd46d59354774a8eb88d/docs/why-haskell.md
Dustin Segers and Cody Goodman talk about formatting Haskell source code with automated tools like Ormolu.
- https://www.tweag.io/posts/2019-05-27-ormolu.html
Sara Lichtenstein and Taylor Fausak talk about improving the performance of Haskell programs by profiling them.
- https://blog.jez.io/profiling-in-haskell/
Cameron Gera and Taylor Fausak talk about how Haskell encourages you to use the ports and adapters architecture.
- https://blog.ploeh.dk/2016/03/18/functional-architecture-is-ports-and-adapters/
Jason Fry and Cameron Gera talk about four small ways to improve Haskell as a language.
- https://medium.com/daml-driven/four-tweaks-to-improve-haskell-b1de9c87f816
Cameron Gera and Cody Goodman talk about enforcing best practices with HLint and refactoring.
- https://medium.com/co-star-engineering/continuous-improvement-with-hlint-code-smells-e490886558a1
Cameron Gera and Taylor Fausak talk about how regular expressions compare to parser combinators in Haskell.
- https://williamyaoh.com/posts/2019-04-11-cheatsheet-to-regexes-in-haskell.html
Jason Fry and Taylor Fausak talk about getting fast feedback when developing Haskell by using ghcid.
- https://functor.tokyo/blog/2019-04-07-ghcid-for-web-app-dev
Cameron Gera and Taylor Fausak talk about build tools in Haskell, including Stack and Cabal.
- https://sakshamsharma.com/2018/03/haskell-proj-struct/
Dustin Segers and Taylor Fausak talk about avoiding boolean blindness by using custom types.
- https://runtimeverification.com/blog/code-smell-boolean-blindness/
Jason Fry and Taylor Fausak compare frontend and backend languages, including PureScript and Elm.
- https://www.parsonsmatt.org/2015/10/03/elm_vs_purescript.html
Sara Lichtenstein and Taylor Fausak talk about the good and bad of upgrading from Elm 0.18 to 0.19.
- https://engineering.itpro.tv/2019/03/01/upgrading-elm-to-v19/
Cody Goodman and Taylor Fausak talk about handling errors in Haskell by using exceptions.
- https://markkarpov.com/tutorial/exceptions.html