The F# compiler, F# core library, and F# editor tools
You're invited to contribute to future releases of the F# compiler, core library, and tools. Development of this repository can be done on any OS supported by .NET Core.
Quickstart on Windows
Build from the command line:
The build depends on an installation of Visual Studio. To build the compiler without this dependency use:
After it's finished, open either
VisualFSharp.sln in your editor of choice. The latter solution is larger but includes the F# tools for Visual Studio and its associated infrastructure.
Quickstart on Linux or macOS
Build from the command line:
After it's finished, open
FSharp.sln in your editor of choice.
Visual Studio Online quickstart
If you'd like to use Visual Studio online (or VSCode with VSO as backend), just click this button to create a new online environment:
This will provision an environment with all necessary dependencies. Initial build of the environment may take up to 10 minutes, as it's also performing initial build of the F# compiler.
Documentation for contributors
See DEVGUIDE.md for more details on configurations for building the codebase. In practice, you only really need to run
See TESTGUIDE.md for information about the various test suites in this codebase and how to run them individually.
See the Compiler Guide for an in-depth guide to the F# compiler. It is essential reading for any larger contributions to the F# compiler codebase.
See the F# Language Specification for an in-depth description of the F# language. This is essential for understanding some behaviors of the F# compiler and some of the rules within the compiler codebase. For example, the order and way name resolution happens is specified here, which greatly impacts how the code in Name Resolutions works and why certain decisions are made.
No contribution is too small
Even if you find a single-character typo, we're happy to take the change! Although the codebase can feel daunting for beginners, we and other contributors are happy to help you along.
Using nightly releases in Visual Studio
You can use the latest
main build of the F# compiler and tools for Visual Studio via our nightly releases if you are a Visual Studio user. See details on setup here:
Even more nightly than the nightly
Alternatively, if you really want to live on the bleeding edge, you can set up a nightly feed for the Visual Studio preview releases, which use the latest commit in the preview branch. To do so, follow the same instructions as the above blog post, but instead with these links:
- Set your feed to the preview feed: https://dotnet.myget.org/F/fsharp-preview/vsix
- Install a VSIX manually from the preview feed: https://dotnet.myget.org/feed/fsharp-preview/package/vsix/VisualFSharp
Per-build NuGet packages
Per-build verions of our NuGet packages are available via this URL:
These are the branches in use:
- Almost all contributions go here.
- Able to be built, installed and used in the latest public Visual Studio release.
- May contain updated F# features and logic.
- Used to build nightly VSIX (see above).
- Long-term servicing branch for VS 2017 update 15.9.x. We do not expect to service that release, but if we do, that's where the changes will go.
- Latest release branch for the particular point release of Visual Studio.
- Incorporates features and fixes from main up to a particular branch point, then selective cherry-picks.
- May contain new features that depend on new things or fixes in the corresponding forthcoming Visual Studio release.
- Gets integrated back into main once the corresponding Visual Studio release is made.
F# language and core library evolution
Evolution of the F# language and core library follows a process spanning two additional repositories. The process is as follows:
- Use the F# language suggestions repo to search for ideas, vote on ones you like, submit new ideas, and discuss details with the F# community.
- Ideas that are "approved in principle" are eligible for a new RFC in the F# language design repo. This is where the technical specification and discussion of approved suggestions go.
- Implementations and testing of an RFC are submitted to this repository.
This project is subject to the MIT License. A copy of this license is in License.txt.
Code of Conduct
Get In Touch
Additionally, you can use the
#fsharp tag on Twitter if you have general F# questions, including about this repository. Chances are you'll get multiple responses.
If you're curious about F# itself, check out these links: