FScript got new features in latest release: - asynchronous tasks - LSP enhancements for built-in functions - a simple BASIC interpreter in FScript (yes an interpreter in an interpreter 😁) magnusopera.github.io/FScript/

Just released SwaggerProvider 4.0.0-beta01 that wrap nullable strings in Option<string>. Try it out and share your feedback! fsprojects.github.io/SwaggerProvi... #fsharp

The wait is over! Fable 5 Release Candidate is officially here. After a year of hard work from the community, we're bringing you: ✨ .NET 10 & F# 10 support 🐍 A massive Python update (now powered by a Rust core & PyPI!) 🌐 Cleaner JS/TS Pojo bindings fable.io/blog/2026/20... #fsharp #fablecompiler

"Pure-F# training/inference workflow around Qwen3-4B with NVFP4" by @ingted.bsky.social #fsharp github.com/ingted/Qwen3...

FScript has grown a lot ! It's now a fully fledge embeddable functional language with nice features: - tuples, records, unions, lists, options, map - great matching ergonomics - standard library for types - embeddable with clear sandbox model Enjoy ! Link to tutorial: github.com/MagnusOpera/...

I'm really happy with current state of FScript: - F#/ML-style scripting focused on safe embedding: strong type inference, explicit host extensibility, and sandboxed execution. - Hindley–Milner inference with optional parameter annotations. github.com/MagnusOpera/...

Trend is to generate a compiler using LLM... So here is my contribution: FScript, an embeddable #fsharp lang inspired interpreter. Entirely developed with Codex, no shame 😃 Execution is sandboxed and extensible, also support structural record annotation (think Typescript). github.com/MagnusOpera/...

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/...

It's been a while I shall have completed FSharp.MongoDB - but literally had no time to spend on fixing a stack overflow. Now it is feature complete and fully supports NRT 🎉 Enjoy F# + MongoDB ! #fsharp #mongodb github.com/fsprojects/F...

I love when ChatGPT writes "production-ready" code 😏

GitHub merge queues are a great tool but such a pita to configure and terribly buggy. Go in Hell @github.com 🤬

The best thing I did last week was to disable copilot. For PR it’s useful but as a tool to get things done in IDE, what a waste of time. I just want smart completion based on my types, not this shit that understands nothing to what I’m doing. Unfortunately it seems IntelliSense is no more.

The type inference difference in C# between a nullable struct and a nullable class is shitty at best.

Just a quick note to say that I'm currently looking for work. Either Node/Typescript or .NET/C#. Happy to consider contract or perm, but must be remote. Thanks all! RT appreciated 🙏

🚀 .NET 10 Preview 4 is here! ✨ Tons of Blazor & OpenAPI improvements 📱 Android app size reduction 🤖 AI data upgrades for EF Core ⚡ Inlining improvements 📦 New async ZIP APIs & so much more! Learn more: devblogs.microsoft.com/dotnet/dotne... #dotnet

I't s been a while I wanted to implement interpolated string for Terrabuild but was always feared how to do this due to the strong relationship between parser and lexer. I've finally come to something easy to understand using rules in FsLex. Parser is available here: github.com/MagnusOpera/...

I was reading the announcement of @rescript-lang.org about upcoming nested record definitions and asking myself if #fsharp was able to do this. And of course, #fsharp is able to do this using anonymous records !

Prague has the most beautiful churches ! Love this town, Easter week-end is ending tomorrow 🥲

I honestly hate node and zod - even with Typescript - it's so bad. This is probably why I prefer to stay in .net world and use only typescript/react on the front only. But I came across deepkit.io, this looks crazy good on the surface: strongly typed & looks similar to aspnet .

I've done shitty things in my professional life, but ruby on rails is for sure the worst. In 2025, this feels like a punishment 😭

Why the hell is AWS so complicated 😭

Announcing FSharp.Aspire.Hosting: A package to write Aspire app hosts in F#! https://github.com/Tarmil/FSharp.Aspire.Hosting * Includes the msbuild machinery and library extensions necessary to write Aspire AppHosts in F# * There's a project template to […] [Original post on mastodon.tarmil.fr]

Blogged (my little rant): "Is Rust a good fit for business apps?" www.bartoszsypytkowski.com/is-rust-a-go...

Always wanted @github.com to have a sticky header. It's a pain when you are deep in actions to go somewhere else. Yes I can navigate back, but well 🤷‍♂️

Is an embeddable #fsharp interpreter (and without dependency on .net sdk) a thing ?

So… How things are going on regarding better #fsharp support for MongoDB ? Well, I’ve stopped investing in previous fork because there were a lot of issues. Looking at the MongoDB C# driver implementation, conventions were not correctly defined so more work had to be done here...

as a command line junky, it's impressive how fast Ghostty is. ghostty.org

I have updated MongoDB.FSharp (it was old and abandoned) to .net 9/nullable and latest MongoDB.Driver. Support for #fsharp List, Map, Set, DU, Option, ValueOption. As it's be revamped, it is now named 𝗙𝗦𝗵𝗮𝗿𝗽.𝗠𝗼𝗻𝗴𝗼𝗗𝗕.𝗗𝗿𝗶𝘃𝗲𝗿 and is available on NuGet. github.com/pchalamet/FS...

Looking for a replacement library for ProcessStartInfo with support for jobs in .net (interested mostly in killing children if parent die). Found something for Windows (from @meziantou.net). Does a cross-platform implementation for .net core exist somewhere (macOS and Linux is mandatory) ? Thanks.

And something to read for next vacation 😱 Hope I will finally understand how LLM work 🤓

At least! @terrabuild.io is now available on brew!

#fsharp 𝗦𝗲𝘁.𝗶𝘀𝗦𝘂𝗯𝘀𝗲𝘁 always tricks me (I always reverse arguments when piping). Hopefully, it's easy to "extend" a type using a module in F#. This way, one can write 𝘀𝗺𝗮𝗹𝗹 |> 𝗦𝗲𝘁.𝗶𝘀𝗦𝘂𝗯𝘀𝗲𝘁𝗢𝗳 𝗯𝗶𝗴 and ensure better readability. 𝗺𝗼𝗱𝘂𝗹𝗲 𝗦𝗲𝘁 = 𝗹𝗲𝘁 𝗶𝘀𝗦𝘂𝗯𝘀𝗲𝘁𝗢𝗳 𝗯𝗶𝗴 𝘀𝗺𝗮𝗹𝗹 = 𝗯𝗶𝗴 |> 𝗦𝗲𝘁.𝗶𝘀𝗦𝘂𝗯𝘀𝗲𝘁 𝘀𝗺𝗮𝗹𝗹

It's time to look at HTTP redirection impact on your requests and... on my dotnet-http tool :^) chnasarre.medium.com/56e13d7c5899...

I love this one. It states the obvious we often overlook. #fsharp

Something strange with .net 9 and nuget... For eg, FSharp.STJ (@tarmil.mastodon.tarmil.fr.ap.brid.gy) has a dependency on STJ >= 6.0.0. The problem is when building with .net 9, this ends with STJ 6 and not 9 as expected. I can't recall this was happening with .net 8. Any ideas ? Or am I numb ?

Another lang to play with ! borgo-lang.github.io

Une fois de plus, pour les meilleurs gains de productivité, il faut attendre que Microsoft améliore ses outils. C'était déjà flagrant avec les gains de performance en changeant de version de .NET. Maintenant on va restorer en qq secondes au lieu de 15-25 min. ⚡ devblogs.microsoft.com/dotnet/dotne...

New versions of Ionide and FsAutoComplete are now available with support for #fsharp 9 and #dotnet 9 and the new features therein - including nullability! Go forth and download, friends :)

I kinda suck at my #fsharp formatting skill. Reviewing some of my code, it's either K&R, Lisp and depending on the context K&R + Lisp 😅 One constant thing I see now is that I do not like standalone right parenthesis (inline fun for eg). And I do not care about 80 columns.

Both Rider and Ionide sucks at understanding (and explaining) F# NRT support. Crossing of the desert has begun 😭

Friday at 1400 UTC (in 4 hours), join the call with @amplifyingfsharp.io to discuss 🎉What's New in F# 9🎉 amplifyingfsharp.io/sessions/202... #fsharp #fablecompiler

Did some cable management this afternoon 😃 At least the big box can close now 🎉

I've already written on testing NRT support in upcoming F# 9. This was done right after the merge of the feature (August). I will try to revise this blog with latest version. As far as I remember there were problems at IL level which have been fixed since then. pierre.chalamet.net/posts/fsharp...

Hey @sergeytihon.com Nice to see you here! If you need to find folks, I have a not exhaustive list in form of this starter pack (I have a few others on my profile) go.bsky.app/GwduSaU

If you've ever wanted (or had the idea) to contribute to the F# compiler but found the task too daunting, be sure to follow these folks! bsky.app/profile/ampl... Several community contributors have landed PRs in #fsharp thanks to their help! Be sure to follow them and add them to starter packs!