Haskell Planetarium

Link aggregator of discussions about the Haskell programming language

Discourse

Can I coax GHC to unbox `Maybe (Int, Int)` to `(# (# #) | (# Int#, Int# #) #)` in not so many words?
Tue 2025/10/28
Implementing a basic continuation based Monadic Effect
7 answers
Tue 2025/10/28
Open role with Core Strats at Standard Chartered, Singapore or Hong Kong
Tue 2025/10/28
Force evaluation in order to time computation
2 answers
Tue 2025/10/28
[ANN] Hindsight: Typesafe, Evolvable Event Sourcing
1 answer
Tue 2025/10/28
Atomicity of `readChan`?
29 answers
Mon 2025/10/27
Abs from Num for Int8 uses (>) from Ord but Num specified without Ord. Why and How?
2 answers
Mon 2025/10/27
Ghc now runs in your browser
13 answers
Mon 2025/10/27
How to modify request headers in a Servant client?
2 answers
Sat 2025/10/25
New package for dimensional units
5 answers
Fri 2025/10/24

Reddit

Open role with Core Strats at Standard Chartered, Singapore or Hong Kong
Tue 2025/10/28
Disable "Type applications in constructor patterns will require the TypeAbstractions extension starting from GHC 9.12" error
5 comments
Tue 2025/10/28
[ANN] Hindsight: Typesafe, Evolvable Event Sourcing for Haskell
1 comment
Tue 2025/10/28
[Tool] Thanks Stars — A CLI that automatically stars all GitHub repos from your project (now supports Cabal and Stack)
3 comments
Mon 2025/10/27
How to implement Functor for a kind and its second type parameter instead of its first?
9 comments
Mon 2025/10/27
Is your application, built with Haskell, objectively safer than one built in Rust?
43 comments
Mon 2025/10/27
Lists are Geometric Series
6 comments
Sun 2025/10/26
Vienna Haskell Meetup on the 6th of November 2025
Sun 2025/10/26
Trying to study for my exam
4 comments
Sun 2025/10/26
Strictness analysis with GHC
4 comments
Sun 2025/10/26

Planet Haskell

Monday Morning Haskell: Stock Market Shark: More Multidimensional DP
Mon 2025/10/27
Ken T Takusagawa: [blyqokgn] simultaneously define record type and data
Sun 2025/10/26
Edward Z. Yang: Draw high dimensional tensors as a matrix of matrices
Sat 2025/10/25
Tweag I/O: Introduction to Agentic Coding
Thu 2025/10/23
Abhinav Sarkar: A Fast Bytecode VM for Arithmetic: The Virtual Machine
Tue 2025/10/21
Monday Morning Haskell: Spatial DP: Finding the Largest Square
Mon 2025/10/20
Haskell Interlude: 71: Stefan Wehr
Thu 2025/10/16
Chris Penner: Exploring Arrows for sequencing effects
Thu 2025/10/16
Sandy Maguire: Arrows to Arrows, Categories to Queries
Tue 2025/10/14
Monday Morning Haskell: Making Change: Array-Based DP
Mon 2025/10/13

The Haskell Café mailing list

Takeover of AvlTree and COrdering
Fri 2025/08/22
GHC 9.10.3-rc4 is now available
Mon 2025/08/18
GHC 9.10.3-rc3 is now available
1 reply
Fri 2025/08/08
TargirDotCom
Thu 2025/08/07
شهادة الأبوة في المغرب
Thu 2025/08/07
Correct parsers for bounded integral values
24 replies
Thu 2025/08/07
GHC 9.10.3-rc2 is now available
Wed 2025/08/06
POPL 2026 Call For Tutorials
Wed 2025/08/06
ICFP 2025 (Co-Located with SPLASH!): Call for Participation
Sun 2025/08/03
-i in OPTIONS_GHC
4 replies
Wed 2025/07/30

Stack Overflow

What is the formal name for GHC automatically adapting less-constrained functions to more-constrained rank-2 arguments?
1 answer
Thu 2025/10/23
Understanding usage of withFileBlocking with named pipes
1 answer
Mon 2025/10/20
How do I make the "return" function from the Monad class return a phantom parameter?
1 answer
Fri 2025/10/17
Merge every element of 2 lists of lists
2 answers
Thu 2025/10/16
Is there a way to check for an instance of a class (with Haskell extensions)?
1 answer
Wed 2025/10/15
On implementing map in terms of fold for a binary tree in Haskell
1 answer
Mon 2025/10/13
Haskell ghci ocupying too much memory
2 answers
Wed 2025/10/08
How does the point-free expression ((*) .) . (*) work in Haskell?
1 answer
Wed 2025/10/08
Why doesn't readFile block on unix pipe in which no write has happened yet?
2 answers
Wed 2025/10/08
Polymorphic function in class and polymorphic instance: how to bind parameter types?
1 answer
Wed 2025/10/08

Code Review Stack Exchange

Augment vi editing mode in haskeline by implementing the ; and , commands
Wed 2025/09/03
How to implement an AVL tree efficient enough in Haskell?
1 answer
Tue 2025/04/01
Pattern Finding In Lists of Strings (2d Char Array), Advent of Code Day 04 Solution
2 answers
Fri 2024/12/20
Value-level proofs of type-level membership and subset relations in Haskell
Fri 2024/12/06
HackerRank, Haskell simple "compression" algorithm
3 answers
Sun 2024/08/18
Scraping the calendar of some public libraries from their websites
1 answer
Sat 2024/08/03
Haskell 2-player TicTacToe terminal game
1 answer
Fri 2024/06/07
Parse 2D Cartesian coordinates and output their Polar form
1 answer
Mon 2024/05/13
Last Stone Weight Problem in Haskell Using `fold`
Fri 2024/03/29
Last Stone Weight Problem in Haskell using list `insert`
1 answer
Tue 2024/03/19

Haskell Weekly

Issue 495 - 2025-10-23
Thu 2025/10/23
Issue 494 - 2025-10-16
Thu 2025/10/16
Issue 493 - 2025-10-09
Thu 2025/10/09
Issue 492 - 2025-10-02
Thu 2025/10/02
Issue 491 - 2025-09-25
Thu 2025/09/25
Issue 490 - 2025-09-18
Thu 2025/09/18
Issue 489 - 2025-09-11
Thu 2025/09/11
Issue 488 - 2025-09-04
Thu 2025/09/04
Issue 487 - 2025-08-28
Thu 2025/08/28
Issue 486 - 2025-08-21
Thu 2025/08/21