F# Online
@fsharponline.bsky.social
Supporting the worldwide #fsharp community via online channels
https://hachyderm.io/@fsharponline
https://x.com/fsharponline
https://hachyderm.io/@fsharponline
https://x.com/fsharponline
Pinned
F# Online
@fsharponline.bsky.social
· Nov 12
F# Online is now moved to Bluesky (as well as Mastodon, YouTube), and will no longer amplify content posted on X.
Here's an F# starter pack on Bluesky go.bsky.app/SZQgDn8
Here's an F# starter pack on Bluesky go.bsky.app/SZQgDn8
Reposted by F# Online
C# and F# Interop (2026 edition)
How to easily start with F# in your existing C# codebase.
www.planetgeek.ch/2026/01/06/c...
#dotnet #csharp #fsharp #Interop
How to easily start with F# in your existing C# codebase.
www.planetgeek.ch/2026/01/06/c...
#dotnet #csharp #fsharp #Interop
C# – F# Interop (2026 edition)
One of the great features of .NET is that you can mix its programming languages (C#, F#, VB.NET) in a single solution and that assemblies written in one language can call assemblies written in other…
www.planetgeek.ch
January 6, 2026 at 1:01 PM
C# and F# Interop (2026 edition)
How to easily start with F# in your existing C# codebase.
www.planetgeek.ch/2026/01/06/c...
#dotnet #csharp #fsharp #Interop
How to easily start with F# in your existing C# codebase.
www.planetgeek.ch/2026/01/06/c...
#dotnet #csharp #fsharp #Interop
Reposted by F# Online
Currently watching "Why Rust isn't everywhere (yet)". youtu.be/nOSxuaDgl3s?...
A great interview.
And as an F# developer, I see many parallels.
And I will stick with F# - fits our needs better regarding application development.
#fsharp #rust
A great interview.
And as an F# developer, I see many parallels.
And I will stick with F# - fits our needs better regarding application development.
#fsharp #rust
Rust 2025: $400K Salaries, Go, AI & Why It's Not Everywhere (Yet) — Jon Gjengset Explains
What’s next for Rust in 2025?
In this in-depth interview, Jon Gjengset (Rust educator, MIT PhD, and author of Rust for Rustaceans) discusses how Rust salaries are reaching $400,000, how AI is…
youtu.be
January 9, 2026 at 2:08 PM
Currently watching "Why Rust isn't everywhere (yet)". youtu.be/nOSxuaDgl3s?...
A great interview.
And as an F# developer, I see many parallels.
And I will stick with F# - fits our needs better regarding application development.
#fsharp #rust
A great interview.
And as an F# developer, I see many parallels.
And I will stick with F# - fits our needs better regarding application development.
#fsharp #rust
Reposted by F# Online
And systems programming is coming to #fsharp speakez.tech/blog/fsharp-...
F# on Metal Revisited
From Stack-Only to Graduated Memory: A Year Of Fidelity Framework Evolution
speakez.tech
January 9, 2026 at 2:13 PM
And systems programming is coming to #fsharp speakez.tech/blog/fsharp-...
Reposted by F# Online
I know when you think about GameDev you think about C++ C# or even rust!
Welp, I'd like you to consider giving F# a chance
Mibo aims to become micro framework on top MonoGame.
It'll give you some ergonomics, and pathways for you to write your games in seamless F# 👇
#dotnet #gamedev #fsharp #monogame
Welp, I'd like you to consider giving F# a chance
Mibo aims to become micro framework on top MonoGame.
It'll give you some ergonomics, and pathways for you to write your games in seamless F# 👇
#dotnet #gamedev #fsharp #monogame
January 9, 2026 at 9:40 PM
Reposted by F# Online
F# Weekly #2, 2026 - Mibo and WREN Stack #fsharp sergeytihon.com/2026/01/10/f...
F# Weekly #2, 2026 – Mibo and WREN Stack
Welcome to F# Weekly, A roundup of F# content from this past week: News Mibo: A Functional Game Framework for F# Generative AI: The Future of Consumer Technology – .NET Blog XAML Studio is no…
sergeytihon.com
January 10, 2026 at 9:18 PM
F# Weekly #2, 2026 - Mibo and WREN Stack #fsharp sergeytihon.com/2026/01/10/f...
Reposted by F# Online
We've written about #fsharp CEs, Active Patterns and Quotations getting first-class treatment in 'fsnative' - our fork of the fsharp compiler. But units of measure gets its own entry as it's critical to so many of our broader ambitions for the platform. speakez.tech/blog/dimensi...
Dimensional Type Safety Across Execution Models
From Ada to Dataflow: How Intrinsic Units of Measure Puts F# in a New Orbit
speakez.tech
January 10, 2026 at 10:35 PM
We've written about #fsharp CEs, Active Patterns and Quotations getting first-class treatment in 'fsnative' - our fork of the fsharp compiler. But units of measure gets its own entry as it's critical to so many of our broader ambitions for the platform. speakez.tech/blog/dimensi...
Reposted by F# Online
F#+ 1.9.1 released ✨🥳
#fsharp
www.nuget.org/packages/FSh...
www.nuget.org/packages/FSh...
See the release notes here:
github.com/fsprojects/F...
Many thanks to everyone that made this release possible! 😘
#fsharp
www.nuget.org/packages/FSh...
www.nuget.org/packages/FSh...
See the release notes here:
github.com/fsprojects/F...
Many thanks to everyone that made this release possible! 😘
www.nuget.org
January 11, 2026 at 6:19 PM
F#+ 1.9.1 released ✨🥳
#fsharp
www.nuget.org/packages/FSh...
www.nuget.org/packages/FSh...
See the release notes here:
github.com/fsprojects/F...
Many thanks to everyone that made this release possible! 😘
#fsharp
www.nuget.org/packages/FSh...
www.nuget.org/packages/FSh...
See the release notes here:
github.com/fsprojects/F...
Many thanks to everyone that made this release possible! 😘
Reposted by F# Online
Reposted by F# Online
What happens when you compile F# without a garbage collector? Every partial application needs somewhere to live. We adapted #OCaml's approach: track arity explicitly, optimize saturated calls, and stack-allocate closures when needed. #FSharp speakez.tech/blog/arity-o...
Arity On The Side of Caution
Why Fidelity Tracking Function Arity Puts the Machine Back In ML
speakez.tech
January 14, 2026 at 10:21 PM
What happens when you compile F# without a garbage collector? Every partial application needs somewhere to live. We adapted #OCaml's approach: track arity explicitly, optimize saturated calls, and stack-allocate closures when needed. #FSharp speakez.tech/blog/arity-o...
Reposted by F# Online
Why didn't I find this great feature of Rider earlier?
It makes initialising records so much easier.
And with a quick invocation of Fantomas, the record is reformatted to match our settings regarding { } alignment. We prefer the Aligned option.
#fsharp #JetBrainsRider
It makes initialising records so much easier.
And with a quick invocation of Fantomas, the record is reformatted to match our settings regarding { } alignment. We prefer the Aligned option.
#fsharp #JetBrainsRider
January 16, 2026 at 9:20 AM
Why didn't I find this great feature of Rider earlier?
It makes initialising records so much easier.
And with a quick invocation of Fantomas, the record is reformatted to match our settings regarding { } alignment. We prefer the Aligned option.
#fsharp #JetBrainsRider
It makes initialising records so much easier.
And with a quick invocation of Fantomas, the record is reformatted to match our settings regarding { } alignment. We prefer the Aligned option.
#fsharp #JetBrainsRider
Reposted by F# Online
While F# has great features, many can be replicated in other langs:
* Result/Option
* Pipes
* Expressive types
* Unions and exhaustive pattern matching
* Collection iterations
They may not be as elegant but they often can be done.
F# Sucks - hamy.xyz/blog/2025-06...
#fsharp
* Result/Option
* Pipes
* Expressive types
* Unions and exhaustive pattern matching
* Collection iterations
They may not be as elegant but they often can be done.
F# Sucks - hamy.xyz/blog/2025-06...
#fsharp
7 Reasons F# Sucks
Date: 2025-06-18 | build | create | csharp | fsharp | tech |
hamy.xyz
January 18, 2026 at 4:59 PM
While F# has great features, many can be replicated in other langs:
* Result/Option
* Pipes
* Expressive types
* Unions and exhaustive pattern matching
* Collection iterations
They may not be as elegant but they often can be done.
F# Sucks - hamy.xyz/blog/2025-06...
#fsharp
* Result/Option
* Pipes
* Expressive types
* Unions and exhaustive pattern matching
* Collection iterations
They may not be as elegant but they often can be done.
F# Sucks - hamy.xyz/blog/2025-06...
#fsharp
Reposted by F# Online
It's kind of funny that due to AI/LLMs these days another metric to rate #programming languages on has become "token efficiency".
On the bright side - some of the beloved languages like #Clojure, #Ruby, #FSharp and #OCaml fared pretty well due to their expressive and compact syntax.
On the bright side - some of the beloved languages like #Clojure, #Ruby, #FSharp and #OCaml fared pretty well due to their expressive and compact syntax.
January 16, 2026 at 9:29 AM
It's kind of funny that due to AI/LLMs these days another metric to rate #programming languages on has become "token efficiency".
On the bright side - some of the beloved languages like #Clojure, #Ruby, #FSharp and #OCaml fared pretty well due to their expressive and compact syntax.
On the bright side - some of the beloved languages like #Clojure, #Ruby, #FSharp and #OCaml fared pretty well due to their expressive and compact syntax.
Reposted by F# Online
F# Weekly #3, 2026 – Most token-efficient static language? #fsharp sergeytihon.com/2026/01/17/f...
F# Weekly #3, 2026 – Most token-efficient static language?
Welcome to F# Weekly, A roundup of F# content from this past week: News Which programming languages are most token-efficient? – Martin Alderson How to Build Android Widgets with .NET MAUI …
sergeytihon.com
January 17, 2026 at 8:15 PM
F# Weekly #3, 2026 – Most token-efficient static language? #fsharp sergeytihon.com/2026/01/17/f...
Reposted by F# Online
Reposted by F# Online
Reposted by F# Online
One thing that always gets me a while to get used to after not working in #fsharp for a while is the ordering
For those not aware, F# reads things in order, both in a module, and the file system. So the entry point for a program must be the last file, and in any module, the entry point is last.
For those not aware, F# reads things in order, both in a module, and the file system. So the entry point for a program must be the last file, and in any module, the entry point is last.
January 21, 2026 at 10:10 AM
One thing that always gets me a while to get used to after not working in #fsharp for a while is the ordering
For those not aware, F# reads things in order, both in a module, and the file system. So the entry point for a program must be the last file, and in any module, the entry point is last.
For those not aware, F# reads things in order, both in a module, and the file system. So the entry point for a program must be the last file, and in any module, the entry point is last.
Reposted by F# Online
This is how I've implemented string interpolation in Terrabuild last year - it's easy once you understand lexer needs to be context sensitive (kind of aha moment) - at least with FsLexYacc. Link to implementation in #fsharp, as there are few simple materials on the topic.
github.com/MagnusOpera/...
github.com/MagnusOpera/...
terrabuild/src/Terrabuild.Lang at main · MagnusOpera/terrabuild
Seamless CI/CD tool for building and deploying monorepos. Support HCL-like configuration, builds in containers, outputs caching, extensions. - MagnusOpera/terrabuild
github.com
January 25, 2026 at 7:27 PM
This is how I've implemented string interpolation in Terrabuild last year - it's easy once you understand lexer needs to be context sensitive (kind of aha moment) - at least with FsLexYacc. Link to implementation in #fsharp, as there are few simple materials on the topic.
github.com/MagnusOpera/...
github.com/MagnusOpera/...
Reposted by F# Online
Xah Ep735 Learning Fsharp by Asking AI. Write a Find/Replace Script #fsharp www.youtube.com/watch?v=dfZq...
Xah Ep735 Learning Fsharp by Asking AI. Write a Find/Replace Script
YouTube video by Xah Lee
www.youtube.com
January 24, 2026 at 10:52 AM
Xah Ep735 Learning Fsharp by Asking AI. Write a Find/Replace Script #fsharp www.youtube.com/watch?v=dfZq...
Reposted by F# Online
🚀 Agent.NET has evolved significantly since the alpha.1 announcement — alpha.2 and now alpha.3 bring proper MAF execution, symmetrical InProcess/Durable workflows, and a more cohesive workflow CE with ROP built in.
Full release history:
github.com/JordanMarr/A...
#fsharp #dotnet #aiagents
Full release history:
github.com/JordanMarr/A...
#fsharp #dotnet #aiagents
Releases · JordanMarr/Agent.NET
A composable AI agent framework for .NET. Contribute to JordanMarr/Agent.NET development by creating an account on GitHub.
github.com
January 21, 2026 at 4:46 PM
🚀 Agent.NET has evolved significantly since the alpha.1 announcement — alpha.2 and now alpha.3 bring proper MAF execution, symmetrical InProcess/Durable workflows, and a more cohesive workflow CE with ROP built in.
Full release history:
github.com/JordanMarr/A...
#fsharp #dotnet #aiagents
Full release history:
github.com/JordanMarr/A...
#fsharp #dotnet #aiagents
Reposted by F# Online
F# Weekly #3, 2026 - F# event / (un)conference in 2026? #fsharp sergeytihon.com/2026/01/24/f...
F# Weekly #3, 2026 – F# event / (un)conference in 2026?
Welcome to F# Weekly, A roundup of F# content from this past week: News Bringing work context to your code in GitHub Copilot – Microsoft for Developers Context-Driven Development: Agent Skill…
sergeytihon.com
January 24, 2026 at 10:56 AM
F# Weekly #3, 2026 - F# event / (un)conference in 2026? #fsharp sergeytihon.com/2026/01/24/f...
Reposted by F# Online
Big update for the Fable + Lit ecosystem!
✨ Fable.Lit.Dsl
✨ Fable.Lit.Dsl.Shoelace
✨ Fullstack template update (.NET 10 + Fable 5)
#fsharp #webcomponents #lit
github.com/JordanMarr/f...
✨ Fable.Lit.Dsl
✨ Fable.Lit.Dsl.Shoelace
✨ Fullstack template update (.NET 10 + Fable 5)
#fsharp #webcomponents #lit
github.com/JordanMarr/f...
GitHub - JordanMarr/fable-lit-fullstack-template: A SAFE-style template with Fable.Lit, Fable.Remoting and Giraffe
A SAFE-style template with Fable.Lit, Fable.Remoting and Giraffe - JordanMarr/fable-lit-fullstack-template
github.com
January 27, 2026 at 12:43 AM
Big update for the Fable + Lit ecosystem!
✨ Fable.Lit.Dsl
✨ Fable.Lit.Dsl.Shoelace
✨ Fullstack template update (.NET 10 + Fable 5)
#fsharp #webcomponents #lit
github.com/JordanMarr/f...
✨ Fable.Lit.Dsl
✨ Fable.Lit.Dsl.Shoelace
✨ Fullstack template update (.NET 10 + Fable 5)
#fsharp #webcomponents #lit
github.com/JordanMarr/f...
Reposted by F# Online
#AdventOfCode #FSharp Day 5, part 2
Arrange the ranges. Did allmost everthing right but got wrong answer. Didn't check in and deleted the code. Left it for a day. Started over only to find I had done this one thing wrong:
Ids = MaxValue - MinValue.
Only needs a +1. 🫢
Now I can watch Jo van Eyck!
Arrange the ranges. Did allmost everthing right but got wrong answer. Didn't check in and deleted the code. Left it for a day. Started over only to find I had done this one thing wrong:
Ids = MaxValue - MinValue.
Only needs a +1. 🫢
Now I can watch Jo van Eyck!
December 7, 2025 at 12:16 PM
#AdventOfCode #FSharp Day 5, part 2
Arrange the ranges. Did allmost everthing right but got wrong answer. Didn't check in and deleted the code. Left it for a day. Started over only to find I had done this one thing wrong:
Ids = MaxValue - MinValue.
Only needs a +1. 🫢
Now I can watch Jo van Eyck!
Arrange the ranges. Did allmost everthing right but got wrong answer. Didn't check in and deleted the code. Left it for a day. Started over only to find I had done this one thing wrong:
Ids = MaxValue - MinValue.
Only needs a +1. 🫢
Now I can watch Jo van Eyck!