fantomas 5.0.0-beta-007

This is a prerelease version of fantomas.
There is a newer version of this package available.
See the version list below for details.
dotnet tool install --global fantomas --version 5.0.0-beta-007                
This package contains a .NET tool you can call from the shell/command line.
dotnet new tool-manifest # if you are setting up this repo
dotnet tool install --local fantomas --version 5.0.0-beta-007                
This package contains a .NET tool you can call from the shell/command line.
#tool dotnet:?package=fantomas&version=5.0.0-beta-007&prerelease                
nuke :add-package fantomas --version 5.0.0-beta-007                

Fantomas

Fantomas logo

F# source code formatter, inspired by scalariform for Scala, ocp-indent for OCaml and PythonTidy for Python.

GitHub Workflow Status (event) Discord Nuget (with prereleases)

Quick install

How to use

Command line tool / API

Use this command to install Fantomas as a .NET 5 SDK global tool:

dotnet tool install -g fantomas --prerelease

For detailed guidelines, please read Fantomas: How to use.

FAKE build system

Fantomas can be easily integrated with FAKE build system.<br /> Check out the sample.

JetBrains Rider

The resharper-fsharp uses fantomas under the hood to format the source code. No need for any additional plugins.

Using the latest version inside Rider

For technical reasons Rider cannot always use the latest version of Fantomas found on NuGet. As a workaround you could install fantomas locally with dotnet tool install fantomas-tool and configure it as an External tool.

Rider external tool window

Rider action window

This will have an impact on your editing experiencing in Rider, the external change to the file by the command line application might trigger more internal logic inside Rider than necessary. It could be noticeable in regards to the default formatting experience.

Visual Studio Code

The recommended way to use Fantomas is by using the Ionide plugin. Fantomas is integrated in FSAutoComplete which is the language server used by Ionide.

Alternatively, you can install the fantomas-fmt extension.

Visual Studio

The F# Formatting extension sets up Fantomas as the default formatter for F# files, configurable from Visual Studio's options.

Visual Studio for Mac

Install fantomas locally with dotnet tool install fantomas-tool and configure it as an [External tool]

VS Mac external tool window

Online

Try the Fantomas online.

Early builds

Every once in a while an alpha or beta version is published to https://www.nuget.org/. Our previous MyGet feed is now deprecated.

Benchmarks

Some figures can be found at https://fsprojects.github.io/fantomas/ <br/> We use BenchmarkDotNet to collect data for each build on the master branch.

Purpose

This project aims at formatting F# source files based on a given configuration. Fantomas will ensure correct indentation and consistent spacing between elements in the source files. We assume that the source files are parsable by F# compiler before feeding into the tool. Fantomas follows two F# style guides: the F# code formatting guidelines from Microsoft by default and the G-Research F# code formatting guidelines via various settings.

Use cases

The project is developed with the following use cases in mind:

  • Reformatting an unfamiliar code base. It gives readability when you are not the one originally writing the code. To illustrate, the following example

     type Type
         = TyLam of Type * Type
         | TyVar of string
         | TyCon of string * Type list
         with override this.ToString () =
                 match this with
                 | TyLam (t1, t2) -> sprintf "(%O -> %O)" t1 t2
                 | TyVar a -> a
                 | TyCon (s, ts) -> s
    

    will be rewritten to

     type Type =
         | TyLam of Type * Type
         | TyVar of string
         | TyCon of string * Type list
         override this.ToString() =
             match this with
             | TyLam(t1, t2) -> sprintf "(%O -> %O)" t1 t2
             | TyVar a -> a
             | TyCon(s, ts) -> s
    
  • Converting from verbose syntax to light syntax. Feeding a source file in verbose mode, Fantomas will format it appropriately in light mode. This might be helpful for code generation since generating verbose source files is much easier. For example, this code fragment

     let Multiple9x9 () =
         for i in 1 .. 9 do
             printf "\n";
             for j in 1 .. 9 do
                 let k = i * j in
                 printf "%d x %d = %2d " i j k;
             done;
         done;;
     Multiple9x9 ();;
    

    is reformulated to

     let Multiple9x9() =
         for i in 1..9 do
             printf "\n"
             for j in 1..9 do
                 let k = i * j
                 printf "%d x %d = %2d " i j k
    
     Multiple9x9()
    
  • Formatting F# signatures, especially those generated by F# compiler and F# Interactive.

For more complex examples, please take a look at F# outputs of 20 language shootout programs and 10 CodeReview.SE source files.

Why the name "Fantomas"?

There are a few reasons to choose the name as such. First, it starts with an "F" just like many other F# projects. Second, Fantomas is my favourite character in the literature. Finally, Fantomas has the same Greek root as "phantom"; coincidentally F# ASTs and formatting rules are so mysterious to be handled correctly.

Contributing Guidelines

See the Contribution Guidelines.

Credits

We would like to gratefully thank the following persons for their contributions.

License

The library and tool are available under Apache 2.0 license. For more information see the License file.

Product Compatible and additional computed target framework versions.
.NET net6.0 is compatible.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed.  net9.0 was computed.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

This package has no dependencies.

Version Downloads Last updated
7.0.1 6,216 2/21/2025
7.0.0 20,477 1/10/2025
7.0.0-beta-001 228 12/30/2024
7.0.0-alpha-004 940 12/12/2024
7.0.0-alpha-003 488 11/29/2024
7.0.0-alpha-002 268 11/2/2024
7.0.0-alpha-001 132 9/16/2024
6.3.16 30,988 10/29/2024
6.3.15 22,130 9/14/2024
6.3.14 196 9/14/2024
6.3.13 1,148 9/10/2024
6.3.12 8,560 9/5/2024
6.3.11 21,271 8/16/2024
6.3.10 61,829 7/12/2024
6.3.9 34,243 6/9/2024
6.3.8 1,213 6/6/2024
6.3.7 2,096 6/1/2024
6.3.6 259 6/1/2024
6.3.5 949 5/30/2024
6.3.4 31,699 4/16/2024
6.3.3 7,063 4/12/2024
6.3.2 424 4/12/2024
6.3.1 12,659 3/30/2024
6.3.0 14,612 3/15/2024
6.3.0-beta-001 1,141 3/7/2024
6.3.0-alpha-008 825 3/1/2024
6.3.0-alpha-007 2,042 1/27/2024
6.3.0-alpha-006 841 1/9/2024
6.3.0-alpha-005 1,220 12/22/2023
6.3.0-alpha-004 1,922 12/6/2023
6.3.0-alpha-003 1,480 11/15/2023
6.3.0-alpha-002 934 11/7/2023
6.3.0-alpha-001 780 11/3/2023
6.2.3 135,513 11/2/2023
6.2.2 30,679 10/18/2023
6.2.1 10,553 9/18/2023
6.2.0 24,629 8/29/2023
6.1.3 1,470 8/25/2023
6.1.2 15,206 7/23/2023
6.1.1 78,518 6/29/2023
6.1.0 7,554 6/28/2023
6.1.0-alpha-006 1,112 6/20/2023
6.1.0-alpha-005 1,037 6/20/2023
6.1.0-alpha-004 850 6/19/2023
6.1.0-alpha-003 1,123 6/2/2023
6.1.0-alpha-002 988 5/2/2023
6.1.0-alpha-001 996 5/2/2023
6.0.8 2,091 6/20/2023
6.0.7 1,295 6/20/2023
6.0.6 1,482 6/19/2023
6.0.5 5,201 6/6/2023
6.0.4 1,339 6/2/2023
6.0.3 12,846 5/14/2023
6.0.2 4,240 5/5/2023
6.0.1 75,566 4/19/2023
6.0.0 53,663 4/13/2023
6.0.0-beta-001 1,510 4/5/2023
6.0.0-alpha-010 7,814 4/3/2023
6.0.0-alpha-009 831 3/31/2023
6.0.0-alpha-008 2,086 3/27/2023
6.0.0-alpha-007 1,364 3/27/2023
6.0.0-alpha-006 1,501 3/17/2023
6.0.0-alpha-005 2,382 2/24/2023
6.0.0-alpha-004 9,289 2/22/2023
6.0.0-alpha-003 2,969 2/4/2023
6.0.0-alpha-002 909 2/1/2023
6.0.0-alpha-001 1,049 1/24/2023
5.2.4 6,213 3/17/2023
5.2.3 5,628 3/6/2023
5.2.2 13,628 2/21/2023
5.2.1 70,575 2/4/2023
5.2.0 6,882 1/19/2023
5.2.0-alpha-012 1,183 1/14/2023
5.2.0-alpha-011 1,401 1/12/2023
5.2.0-alpha-010 1,105 12/30/2022
5.2.0-alpha-009 1,038 12/29/2022
5.2.0-alpha-008 1,292 12/28/2022
5.2.0-alpha-007 1,031 12/26/2022
5.2.0-alpha-006 1,035 12/22/2022
5.2.0-alpha-005 1,162 12/16/2022
5.2.0-alpha-004 1,274 12/8/2022
5.2.0-alpha-003 1,046 12/6/2022
5.2.0-alpha-002 1,000 12/4/2022
5.2.0-alpha-001 942 11/30/2022
5.1.5 25,641 12/22/2022
5.1.4 27,305 11/30/2022
5.1.3 7,826 11/14/2022
5.1.2 1,562 11/10/2022
5.1.1 4,088 11/7/2022
5.1.0 2,782 11/4/2022
5.1.0-beta-002 1,009 10/29/2022
5.1.0-beta-001 1,379 10/19/2022
5.1.0-alpha-007 1,057 10/14/2022
5.1.0-alpha-006 1,014 10/14/2022
5.1.0-alpha-005 1,159 10/7/2022
5.1.0-alpha-004 1,171 10/7/2022
5.1.0-alpha-003 1,179 10/2/2022
5.1.0-alpha-002 1,065 9/29/2022
5.1.0-alpha-001 1,105 9/18/2022
5.0.6 25,372 10/13/2022
5.0.5 10,428 10/7/2022
5.0.4 2,206 10/4/2022
5.0.3 10,868 9/29/2022
5.0.2 8,472 9/22/2022
5.0.1 6,460 9/18/2022
5.0.0 21,278 9/16/2022
5.0.0-beta-010 26,410 9/10/2022
5.0.0-beta-009 10,150 9/2/2022
5.0.0-beta-008 3,044 8/30/2022
5.0.0-beta-007 1,635 8/19/2022
5.0.0-beta-006 2,955 8/12/2022
5.0.0-beta-005 5,093 8/3/2022
5.0.0-beta-004 2,335 7/27/2022
5.0.0-beta-003 3,729 7/26/2022
5.0.0-beta-002 1,914 7/19/2022
5.0.0-beta-001 2,906 7/15/2022
5.0.0-alpha-011 1,630 7/8/2022
5.0.0-alpha-010 2,212 6/27/2022
5.0.0-alpha-009 90,736 6/21/2022
5.0.0-alpha-008 3,082 5/28/2022
5.0.0-alpha-007 1,859 5/16/2022
5.0.0-alpha-006 1,880 5/13/2022
5.0.0-alpha-005 1,360 5/7/2022
5.0.0-alpha-004 1,452 5/7/2022
5.0.0-alpha-003 1,912 5/6/2022
5.0.0-alpha-002 760 4/4/2022
5.0.0-alpha-001 712 3/19/2022
4.7.9 11,323 5/2/2022
4.7.8 10,564 4/25/2022
4.7.7 1,185 4/20/2022
4.7.6 1,455 4/4/2022
4.7.5 1,310 3/27/2022
4.7.4 1,272 3/25/2022
4.7.3 4,842 3/12/2022
4.7.2 1,197 3/11/2022
4.7.1 1,197 3/8/2022
4.7.0 1,317 3/4/2022
4.6.6 1,227 3/4/2022
4.6.5 1,979 2/18/2022
4.6.4 1,747 2/11/2022
4.6.3 1,793 2/8/2022
4.6.2 1,777 2/6/2022
4.6.1 1,772 2/1/2022
4.6.0 2,276 1/14/2022
4.6.0-beta-001 832 1/8/2022
4.6.0-alpha-011 816 12/29/2021
4.6.0-alpha-010 829 12/4/2021
4.6.0-alpha-009 3,469 11/24/2021
4.6.0-alpha-008 1,246 11/19/2021
4.6.0-alpha-007 871 11/7/2021
4.6.0-alpha-006 228 11/3/2021
4.6.0-alpha-005 249 10/27/2021
4.6.0-alpha-004 228 10/20/2021
4.6.0-alpha-003 209 10/5/2021
4.6.0-alpha-002 223 9/7/2021
4.6.0-alpha-001 195 8/11/2021
4.5.12 1,642 1/8/2022
4.5.11 2,429 12/29/2021
4.5.10 2,672 12/4/2021
4.5.9 7,568 11/24/2021
4.5.8 1,780 11/19/2021
4.5.7 1,611 11/7/2021
4.5.6 1,403 11/3/2021
4.5.5 1,558 10/27/2021
4.5.4 1,467 10/5/2021
4.5.3 2,970 9/7/2021
4.5.2 1,615 8/11/2021
4.5.1 3,476 7/24/2021
4.5.0 3,382 7/7/2021
4.5.0-beta-005 934 7/6/2021
4.5.0-beta-004 910 7/5/2021
4.5.0-beta-003 947 7/5/2021
4.5.0-beta-002 944 6/27/2021
4.5.0-beta-001 1,434 6/5/2021
4.5.0-alpha-020 887 5/26/2021
4.5.0-alpha-019 896 5/22/2021
4.5.0-alpha-018 934 5/21/2021
4.5.0-alpha-017 892 5/15/2021
4.5.0-alpha-016 863 5/9/2021
4.5.0-alpha-015 953 5/8/2021
4.5.0-alpha-014 1,002 4/30/2021
4.5.0-alpha-013 919 4/27/2021
4.5.0-alpha-012 912 4/23/2021
4.5.0-alpha-011 1,004 4/20/2021
4.5.0-alpha-010 919 4/14/2021
4.5.0-alpha-009 929 4/11/2021
4.5.0-alpha-008 928 4/8/2021
4.5.0-alpha-007 950 4/8/2021
4.5.0-alpha-006 904 4/5/2021
4.5.0-alpha-005 934 4/3/2021
4.5.0-alpha-004 948 4/2/2021
4.5.0-alpha-003 993 3/28/2021
4.5.0-alpha-002 960 3/22/2021
4.5.0-alpha-001 2,588 2/26/2021
4.4.0 13,374 2/25/2021
4.4.0-beta-008 1,004 2/19/2021
4.4.0-beta-007 991 2/12/2021
4.4.0-beta-006 984 2/12/2021
4.4.0-beta-005 1,041 2/9/2021
4.4.0-beta-004 1,028 2/5/2021
4.4.0-beta-003 1,480 1/30/2021
4.4.0-beta-002 1,012 1/23/2021
4.4.0-beta-001 1,418 1/22/2021
4.4.0-alpha-008 1,184 1/15/2021
4.4.0-alpha-007 1,679 12/26/2020
4.4.0-alpha-006 1,097 12/25/2020
4.4.0-alpha-005 1,175 12/23/2020
4.4.0-alpha-004 1,209 12/22/2020
4.4.0-alpha-003 1,213 12/18/2020
4.4.0-alpha-002 1,183 12/17/2020
4.4.0-alpha-001 1,087 12/17/2020
4.3.0 5,712 12/17/2020
4.3.0-beta-002 1,141 12/11/2020
4.3.0-beta-001 1,099 12/7/2020
4.3.0-alpha-007 1,113 11/21/2020
4.3.0-alpha-006 1,105 11/20/2020
4.3.0-alpha-005 1,055 11/16/2020
4.3.0-alpha-004 1,550 11/12/2020
4.3.0-alpha-003 1,136 11/10/2020
4.3.0-alpha-002 1,115 10/26/2020
4.3.0-alpha-001 1,147 10/23/2020
4.2.0 5,009 9/25/2020
4.2.0-alpha-004 1,295 9/23/2020
4.2.0-alpha-003 1,094 9/21/2020
4.2.0-alpha-002 1,165 9/19/2020
4.2.0-alpha-001 1,211 9/18/2020
4.1.1 1,794 9/17/2020
4.1.0 2,009 9/10/2020
4.1.0-beta-004 1,243 9/5/2020
4.1.0-beta-003 1,184 9/4/2020
4.1.0-beta-002 1,532 9/4/2020
4.1.0-beta-001 1,155 9/3/2020
4.1.0-alpha-001 1,135 9/1/2020
4.0.0 4,192 8/27/2020
4.0.0-beta-003 1,205 8/21/2020
4.0.0-beta-002 1,236 8/7/2020
4.0.0-beta-001 1,552 7/20/2020
4.0.0-alpha-014 1,361 7/14/2020
4.0.0-alpha-013 1,171 7/11/2020
4.0.0-alpha-012 2,015 7/6/2020
4.0.0-alpha-011 1,019 6/25/2020
4.0.0-alpha-010 1,393 6/18/2020
4.0.0-alpha-009 1,073 6/12/2020
4.0.0-alpha-008 1,195 6/2/2020
4.0.0-alpha-007 1,068 6/1/2020
4.0.0-alpha-006 2,338 5/23/2020
4.0.0-alpha-005 2,170 5/16/2020
4.0.0-alpha-004 1,484 5/4/2020
4.0.0-alpha-003 1,135 5/3/2020
4.0.0-alpha-002 1,176 4/26/2020
4.0.0-alpha-001 1,073 4/20/2020
3.3.0 12,940 2/28/2020
3.3.0-beta-002 2,011 2/21/2020
3.3.0-beta-001 1,186 2/18/2020
3.2.0 21,217 2/3/2020
3.2.0-beta-002 1,753 1/7/2020
3.2.0-beta-001 1,314 12/26/2019
3.1.0 10,699 11/27/2019
3.0.0 5,049 10/11/2019
3.0.0-beta-006 1,896 10/2/2019
3.0.0-beta-005 1,080 9/27/2019
3.0.0-beta-004 1,660 9/18/2019
3.0.0-beta-003 1,219 9/13/2019
3.0.0-beta-002 16,705 7/20/2019
3.0.0-beta-001 5,935 7/12/2019
2.9.2 25,794 2/2/2019
2.9.1 5,005 11/20/2018
2.9.0 11,425 10/17/2018
2.8.1 2,837 9/12/2018
2.8.0 6,095 7/7/2018
2.7.1 4,988 5/2/2018
2.7.0 2,640 5/2/2018
2.6.1 45,797 4/22/2017
2.5.0 3,036 2/19/2017
2.4.0 3,157 10/24/2016
2.3.0 2,810 7/9/2016
2.2.0 2,548 4/24/2016
2.1.0 2,441 4/1/2016
2.0.2 9,184 11/15/2015
1.11.0 2,978 9/12/2015
1.10.0 2,338 8/29/2015
1.9.0 2,790 8/10/2015
1.8.0-beta 1,961 7/19/2015
1.7.0 2,449 6/10/2015
1.6.0 3,329 10/25/2014
1.5.0 2,800 9/18/2014
1.4.0 3,152 7/1/2014
1.3.0 2,647 5/17/2014
1.2.0 2,675 4/21/2014
1.1.0 2,577 3/29/2014
1.0.7 2,537 3/12/2014
1.0.5.1 2,630 1/15/2014
1.0.5 2,357 1/7/2014
1.0.4 2,437 11/16/2013
1.0.3 2,450 10/6/2013
1.0.2 2,395 8/16/2013
1.0.1 2,582 7/22/2013
1.0.0 5,682 7/16/2013
0.9.9.2 2,789 7/2/2013
0.9.9.1 2,559 6/22/2013
0.9.8 2,553 6/14/2013
0.9.7 2,500 6/7/2013
0.9.6 2,491 5/31/2013
0.9.5 2,571 5/23/2013
0.9.4 2,424 5/19/2013
0.9.3 2,450 5/9/2013
0.9.2 2,476 5/3/2013
0.9.1 2,686 4/26/2013
0.9.0 2,472 4/19/2013
0.8.9 2,533 4/12/2013
0.8.8 2,497 4/11/2013
0.8.7 2,417 4/9/2013
0.8.6 2,434 4/4/2013
0.8.5 2,532 4/2/2013
0.8.4 2,448 4/1/2013
0.8.3 2,515 4/1/2013
0.8.2 2,398 4/1/2013
0.8.1 2,582 3/31/2013
0.8.0 2,522 3/31/2013

### Fixed
* `abstract` with docstring and comment gets split up. [#2433](https://github.com/fsprojects/fantomas/issues/2433)
* Invalid removal of space in operator which starts with `*`. [#2434](https://github.com/fsprojects/fantomas/issues/2434)
* Incorrect concatenation of lines with functions. [#2435](https://github.com/fsprojects/fantomas/issues/2435)