fantomas 5.0.0-beta-004

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There is a newer version of this package available.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-004
                    
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-004
                    
This package contains a .NET tool you can call from the shell/command line.
#tool dotnet:?package=fantomas&version=5.0.0-beta-004&prerelease
                    
nuke :add-package fantomas --version 5.0.0-beta-004
                    

Fantomas

Fantomas logo

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

Build Status Github Actions Discord

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

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.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-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
7.0.2 4,529 5/28/2025
7.0.1 26,381 2/21/2025
7.0.0 33,547 1/10/2025
7.0.0-beta-001 236 12/30/2024
7.0.0-alpha-004 951 12/12/2024
7.0.0-alpha-003 615 11/29/2024
7.0.0-alpha-002 285 11/2/2024
7.0.0-alpha-001 137 9/16/2024
6.3.16 43,177 10/29/2024
6.3.15 27,143 9/14/2024
6.3.14 331 9/14/2024
6.3.13 1,370 9/10/2024
6.3.12 10,839 9/5/2024
6.3.11 23,868 8/16/2024
6.3.10 118,572 7/12/2024
6.3.9 47,758 6/9/2024
6.3.8 1,434 6/6/2024
6.3.7 2,468 6/1/2024
6.3.6 391 6/1/2024
6.3.5 1,082 5/30/2024
6.3.4 37,584 4/16/2024
6.3.3 9,450 4/12/2024
6.3.2 580 4/12/2024
6.3.1 13,291 3/30/2024
6.3.0 15,111 3/15/2024
6.3.0-beta-001 1,169 3/7/2024
6.3.0-alpha-008 854 3/1/2024
6.3.0-alpha-007 2,056 1/27/2024
6.3.0-alpha-006 853 1/9/2024
6.3.0-alpha-005 1,229 12/22/2023
6.3.0-alpha-004 1,937 12/6/2023
6.3.0-alpha-003 1,490 11/15/2023
6.3.0-alpha-002 940 11/7/2023
6.3.0-alpha-001 788 11/3/2023
6.2.3 150,625 11/2/2023
6.2.2 33,072 10/18/2023
6.2.1 10,833 9/18/2023
6.2.0 24,749 8/29/2023
6.1.3 1,516 8/25/2023
6.1.2 15,478 7/23/2023
6.1.1 78,802 6/29/2023
6.1.0 7,565 6/28/2023
6.1.0-alpha-006 1,125 6/20/2023
6.1.0-alpha-005 1,050 6/20/2023
6.1.0-alpha-004 865 6/19/2023
6.1.0-alpha-003 1,139 6/2/2023
6.1.0-alpha-002 1,007 5/2/2023
6.1.0-alpha-001 1,010 5/2/2023
6.0.8 2,104 6/20/2023
6.0.7 1,313 6/20/2023
6.0.6 1,502 6/19/2023
6.0.5 5,353 6/6/2023
6.0.4 1,353 6/2/2023
6.0.3 13,060 5/14/2023
6.0.2 4,275 5/5/2023
6.0.1 84,793 4/19/2023
6.0.0 61,470 4/13/2023
6.0.0-beta-001 1,528 4/5/2023
6.0.0-alpha-010 7,829 4/3/2023
6.0.0-alpha-009 852 3/31/2023
6.0.0-alpha-008 2,102 3/27/2023
6.0.0-alpha-007 1,376 3/27/2023
6.0.0-alpha-006 1,520 3/17/2023
6.0.0-alpha-005 2,400 2/24/2023
6.0.0-alpha-004 9,514 2/22/2023
6.0.0-alpha-003 3,013 2/4/2023
6.0.0-alpha-002 933 2/1/2023
6.0.0-alpha-001 1,062 1/24/2023
5.2.4 6,247 3/17/2023
5.2.3 5,663 3/6/2023
5.2.2 13,859 2/21/2023
5.2.1 78,314 2/4/2023
5.2.0 6,911 1/19/2023
5.2.0-alpha-012 1,195 1/14/2023
5.2.0-alpha-011 1,415 1/12/2023
5.2.0-alpha-010 1,130 12/30/2022
5.2.0-alpha-009 1,056 12/29/2022
5.2.0-alpha-008 1,308 12/28/2022
5.2.0-alpha-007 1,044 12/26/2022
5.2.0-alpha-006 1,053 12/22/2022
5.2.0-alpha-005 1,177 12/16/2022
5.2.0-alpha-004 1,292 12/8/2022
5.2.0-alpha-003 1,068 12/6/2022
5.2.0-alpha-002 1,015 12/4/2022
5.2.0-alpha-001 960 11/30/2022
5.1.5 25,874 12/22/2022
5.1.4 27,889 11/30/2022
5.1.3 8,075 11/14/2022
5.1.2 1,593 11/10/2022
5.1.1 4,105 11/7/2022
5.1.0 2,796 11/4/2022
5.1.0-beta-002 1,029 10/29/2022
5.1.0-beta-001 1,397 10/19/2022
5.1.0-alpha-007 1,073 10/14/2022
5.1.0-alpha-006 1,037 10/14/2022
5.1.0-alpha-005 1,177 10/7/2022
5.1.0-alpha-004 1,191 10/7/2022
5.1.0-alpha-003 1,202 10/2/2022
5.1.0-alpha-002 1,086 9/29/2022
5.1.0-alpha-001 1,124 9/18/2022
5.0.6 25,700 10/13/2022
5.0.5 10,457 10/7/2022
5.0.4 2,226 10/4/2022
5.0.3 10,997 9/29/2022
5.0.2 8,489 9/22/2022
5.0.1 6,534 9/18/2022
5.0.0 21,302 9/16/2022
5.0.0-beta-010 30,137 9/10/2022
5.0.0-beta-009 10,442 9/2/2022
5.0.0-beta-008 3,068 8/30/2022
5.0.0-beta-007 1,663 8/19/2022
5.0.0-beta-006 2,979 8/12/2022
5.0.0-beta-005 5,115 8/3/2022
5.0.0-beta-004 2,356 7/27/2022
5.0.0-beta-003 3,752 7/26/2022
5.0.0-beta-002 1,941 7/19/2022
5.0.0-beta-001 2,930 7/15/2022
5.0.0-alpha-011 1,662 7/8/2022
5.0.0-alpha-010 2,244 6/27/2022
5.0.0-alpha-009 93,929 6/21/2022
5.0.0-alpha-008 3,113 5/28/2022
5.0.0-alpha-007 1,881 5/16/2022
5.0.0-alpha-006 1,901 5/13/2022
5.0.0-alpha-005 1,385 5/7/2022
5.0.0-alpha-004 1,480 5/7/2022
5.0.0-alpha-003 1,944 5/6/2022
5.0.0-alpha-002 786 4/4/2022
5.0.0-alpha-001 742 3/19/2022
4.7.9 11,455 5/2/2022
4.7.8 10,599 4/25/2022
4.7.7 1,213 4/20/2022
4.7.6 1,481 4/4/2022
4.7.5 1,339 3/27/2022
4.7.4 1,306 3/25/2022
4.7.3 4,869 3/12/2022
4.7.2 1,225 3/11/2022
4.7.1 1,226 3/8/2022
4.7.0 1,347 3/4/2022
4.6.6 1,260 3/4/2022
4.6.5 2,006 2/18/2022
4.6.4 1,777 2/11/2022
4.6.3 1,821 2/8/2022
4.6.2 1,802 2/6/2022
4.6.1 1,802 2/1/2022
4.6.0 2,304 1/14/2022
4.6.0-beta-001 862 1/8/2022
4.6.0-alpha-011 845 12/29/2021
4.6.0-alpha-010 864 12/4/2021
4.6.0-alpha-009 3,494 11/24/2021
4.6.0-alpha-008 1,275 11/19/2021
4.6.0-alpha-007 897 11/7/2021
4.6.0-alpha-006 260 11/3/2021
4.6.0-alpha-005 279 10/27/2021
4.6.0-alpha-004 261 10/20/2021
4.6.0-alpha-003 244 10/5/2021
4.6.0-alpha-002 248 9/7/2021
4.6.0-alpha-001 222 8/11/2021
4.5.12 1,672 1/8/2022
4.5.11 2,459 12/29/2021
4.5.10 2,700 12/4/2021
4.5.9 7,596 11/24/2021
4.5.8 1,809 11/19/2021
4.5.7 1,641 11/7/2021
4.5.6 1,432 11/3/2021
4.5.5 1,589 10/27/2021
4.5.4 1,503 10/5/2021
4.5.3 2,998 9/7/2021
4.5.2 1,642 8/11/2021
4.5.1 3,516 7/24/2021
4.5.0 3,421 7/7/2021
4.5.0-beta-005 962 7/6/2021
4.5.0-beta-004 936 7/5/2021
4.5.0-beta-003 980 7/5/2021
4.5.0-beta-002 970 6/27/2021
4.5.0-beta-001 1,470 6/5/2021
4.5.0-alpha-020 922 5/26/2021
4.5.0-alpha-019 930 5/22/2021
4.5.0-alpha-018 963 5/21/2021
4.5.0-alpha-017 923 5/15/2021
4.5.0-alpha-016 895 5/9/2021
4.5.0-alpha-015 997 5/8/2021
4.5.0-alpha-014 1,039 4/30/2021
4.5.0-alpha-013 958 4/27/2021
4.5.0-alpha-012 949 4/23/2021
4.5.0-alpha-011 1,038 4/20/2021
4.5.0-alpha-010 962 4/14/2021
4.5.0-alpha-009 971 4/11/2021
4.5.0-alpha-008 966 4/8/2021
4.5.0-alpha-007 991 4/8/2021
4.5.0-alpha-006 940 4/5/2021
4.5.0-alpha-005 969 4/3/2021
4.5.0-alpha-004 991 4/2/2021
4.5.0-alpha-003 1,027 3/28/2021
4.5.0-alpha-002 997 3/22/2021
4.5.0-alpha-001 2,625 2/26/2021
4.4.0 13,444 2/25/2021
4.4.0-beta-008 1,047 2/19/2021
4.4.0-beta-007 1,036 2/12/2021
4.4.0-beta-006 1,019 2/12/2021
4.4.0-beta-005 1,080 2/9/2021
4.4.0-beta-004 1,064 2/5/2021
4.4.0-beta-003 1,515 1/30/2021
4.4.0-beta-002 1,052 1/23/2021
4.4.0-beta-001 1,455 1/22/2021
4.4.0-alpha-008 1,226 1/15/2021
4.4.0-alpha-007 1,725 12/26/2020
4.4.0-alpha-006 1,144 12/25/2020
4.4.0-alpha-005 1,217 12/23/2020
4.4.0-alpha-004 1,248 12/22/2020
4.4.0-alpha-003 1,249 12/18/2020
4.4.0-alpha-002 1,224 12/17/2020
4.4.0-alpha-001 1,127 12/17/2020
4.3.0 5,932 12/17/2020
4.3.0-beta-002 1,184 12/11/2020
4.3.0-beta-001 1,139 12/7/2020
4.3.0-alpha-007 1,152 11/21/2020
4.3.0-alpha-006 1,146 11/20/2020
4.3.0-alpha-005 1,098 11/16/2020
4.3.0-alpha-004 1,589 11/12/2020
4.3.0-alpha-003 1,181 11/10/2020
4.3.0-alpha-002 1,160 10/26/2020
4.3.0-alpha-001 1,188 10/23/2020
4.2.0 5,048 9/25/2020
4.2.0-alpha-004 1,337 9/23/2020
4.2.0-alpha-003 1,135 9/21/2020
4.2.0-alpha-002 1,203 9/19/2020
4.2.0-alpha-001 1,248 9/18/2020
4.1.1 1,836 9/17/2020
4.1.0 2,050 9/10/2020
4.1.0-beta-004 1,286 9/5/2020
4.1.0-beta-003 1,220 9/4/2020
4.1.0-beta-002 1,571 9/4/2020
4.1.0-beta-001 1,197 9/3/2020
4.1.0-alpha-001 1,172 9/1/2020
4.0.0 4,236 8/27/2020
4.0.0-beta-003 1,244 8/21/2020
4.0.0-beta-002 1,275 8/7/2020
4.0.0-beta-001 1,589 7/20/2020
4.0.0-alpha-014 1,400 7/14/2020
4.0.0-alpha-013 1,209 7/11/2020
4.0.0-alpha-012 2,055 7/6/2020
4.0.0-alpha-011 1,060 6/25/2020
4.0.0-alpha-010 1,440 6/18/2020
4.0.0-alpha-009 1,111 6/12/2020
4.0.0-alpha-008 1,235 6/2/2020
4.0.0-alpha-007 1,108 6/1/2020
4.0.0-alpha-006 2,382 5/23/2020
4.0.0-alpha-005 2,216 5/16/2020
4.0.0-alpha-004 1,529 5/4/2020
4.0.0-alpha-003 1,177 5/3/2020
4.0.0-alpha-002 1,228 4/26/2020
4.0.0-alpha-001 1,120 4/20/2020
3.3.0 12,997 2/28/2020
3.3.0-beta-002 2,060 2/21/2020
3.3.0-beta-001 1,227 2/18/2020
3.2.0 21,260 2/3/2020
3.2.0-beta-002 1,797 1/7/2020
3.2.0-beta-001 1,356 12/26/2019
3.1.0 10,744 11/27/2019
3.0.0 5,092 10/11/2019
3.0.0-beta-006 1,942 10/2/2019
3.0.0-beta-005 1,129 9/27/2019
3.0.0-beta-004 1,704 9/18/2019
3.0.0-beta-003 1,260 9/13/2019
3.0.0-beta-002 16,782 7/20/2019
3.0.0-beta-001 6,001 7/12/2019
2.9.2 25,855 2/2/2019
2.9.1 5,052 11/20/2018
2.9.0 11,482 10/17/2018
2.8.1 2,890 9/12/2018
2.8.0 6,227 7/7/2018
2.7.1 5,117 5/2/2018
2.7.0 2,773 5/2/2018
2.6.1 45,909 4/22/2017
2.5.0 3,129 2/19/2017
2.4.0 3,250 10/24/2016
2.3.0 2,900 7/9/2016
2.2.0 2,642 4/24/2016
2.1.0 2,541 4/1/2016
2.0.2 9,285 11/15/2015
1.11.0 3,077 9/12/2015
1.10.0 2,430 8/29/2015
1.9.0 2,893 8/10/2015
1.8.0-beta 2,063 7/19/2015
1.7.0 2,545 6/10/2015
1.6.0 3,436 10/25/2014
1.5.0 2,900 9/18/2014
1.4.0 3,252 7/1/2014
1.3.0 2,752 5/17/2014
1.2.0 2,774 4/21/2014
1.1.0 2,674 3/29/2014
1.0.7 2,637 3/12/2014
1.0.5.1 2,740 1/15/2014
1.0.5 2,462 1/7/2014
1.0.4 2,532 11/16/2013
1.0.3 2,551 10/6/2013
1.0.2 2,494 8/16/2013
1.0.1 2,682 7/22/2013
1.0.0 5,782 7/16/2013
0.9.9.2 2,891 7/2/2013
0.9.9.1 2,657 6/22/2013
0.9.8 2,650 6/14/2013
0.9.7 2,597 6/7/2013
0.9.6 2,598 5/31/2013
0.9.5 2,677 5/23/2013
0.9.4 2,524 5/19/2013
0.9.3 2,547 5/9/2013
0.9.2 2,579 5/3/2013
0.9.1 2,787 4/26/2013
0.9.0 2,575 4/19/2013
0.8.9 2,630 4/12/2013
0.8.8 2,594 4/11/2013
0.8.7 2,514 4/9/2013
0.8.6 2,534 4/4/2013
0.8.5 2,634 4/2/2013
0.8.4 2,548 4/1/2013
0.8.3 2,615 4/1/2013
0.8.2 2,496 4/1/2013
0.8.1 2,682 3/31/2013
0.8.0 2,623 3/31/2013

### Fixed
* Shebang directives get removed from scripts [#2367](https://github.com/fsprojects/fantomas/issues/2367)