fantomas 5.0.0-beta-008

.NET 6.0
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There is a newer version of this package available.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-008
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-008
This package contains a .NET tool you can call from the shell/command line.
#tool dotnet:?package=fantomas&version=5.0.0-beta-008&prerelease
nuke :add-package fantomas --version 5.0.0-beta-008

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 Versions
.NET net6.0 net6.0-android net6.0-ios net6.0-maccatalyst net6.0-macos net6.0-tvos net6.0-windows net7.0 net7.0-android net7.0-ios net7.0-maccatalyst net7.0-macos net7.0-tvos net7.0-windows
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.

This package has no dependencies.

Version Downloads Last updated
5.2.0-alpha-001 19 11/30/2022
5.1.4 42 11/30/2022
5.1.3 1,380 11/14/2022
5.1.2 394 11/10/2022
5.1.1 1,266 11/7/2022
5.1.0 1,066 11/4/2022
5.1.0-beta-002 86 10/29/2022
5.1.0-beta-001 128 10/19/2022
5.1.0-alpha-007 62 10/14/2022
5.1.0-alpha-006 37 10/14/2022
5.1.0-alpha-005 75 10/7/2022
5.1.0-alpha-004 41 10/7/2022
5.1.0-alpha-003 74 10/2/2022
5.1.0-alpha-002 59 9/29/2022
5.1.0-alpha-001 127 9/18/2022
5.0.6 8,080 10/13/2022
5.0.5 3,964 10/7/2022
5.0.4 408 10/4/2022
5.0.3 2,333 9/29/2022
5.0.2 1,282 9/22/2022
5.0.1 2,080 9/18/2022
5.0.0 7,107 9/16/2022
5.0.0-beta-010 4,158 9/10/2022
5.0.0-beta-009 3,735 9/2/2022
5.0.0-beta-008 1,485 8/30/2022
5.0.0-beta-007 467 8/19/2022
5.0.0-beta-006 1,824 8/12/2022
5.0.0-beta-005 3,672 8/3/2022
5.0.0-beta-004 476 7/27/2022
5.0.0-beta-003 2,668 7/26/2022
5.0.0-beta-002 560 7/19/2022
5.0.0-beta-001 1,894 7/15/2022
5.0.0-alpha-011 452 7/8/2022
5.0.0-alpha-010 1,059 6/27/2022
5.0.0-alpha-009 13,234 6/21/2022
5.0.0-alpha-008 1,162 5/28/2022
5.0.0-alpha-007 618 5/16/2022
5.0.0-alpha-006 679 5/13/2022
5.0.0-alpha-005 181 5/7/2022
5.0.0-alpha-004 400 5/7/2022
5.0.0-alpha-003 606 5/6/2022
5.0.0-alpha-002 94 4/4/2022
5.0.0-alpha-001 84 3/19/2022
4.7.9 5,135 5/2/2022
4.7.8 9,590 4/25/2022
4.7.7 270 4/20/2022
4.7.6 471 4/4/2022
4.7.5 355 3/27/2022
4.7.4 262 3/25/2022
4.7.3 3,865 3/12/2022
4.7.2 245 3/11/2022
4.7.1 245 3/8/2022
4.7.0 344 3/4/2022
4.6.6 247 3/4/2022
4.6.5 979 2/18/2022
4.6.4 385 2/11/2022
4.6.3 380 2/8/2022
4.6.2 439 2/6/2022
4.6.1 419 2/1/2022
4.6.0 900 1/14/2022
4.6.0-beta-001 106 1/8/2022
4.6.0-alpha-011 113 12/29/2021
4.6.0-alpha-010 125 12/4/2021
4.6.0-alpha-009 2,782 11/24/2021
4.6.0-alpha-008 595 11/19/2021
4.6.0-alpha-007 205 11/7/2021
4.6.0-alpha-006 144 11/3/2021
4.6.0-alpha-005 169 10/27/2021
4.6.0-alpha-004 140 10/20/2021
4.6.0-alpha-003 126 10/5/2021
4.6.0-alpha-002 132 9/7/2021
4.6.0-alpha-001 121 8/11/2021
4.5.12 701 1/8/2022
4.5.11 1,498 12/29/2021
4.5.10 1,795 12/4/2021
4.5.9 6,473 11/24/2021
4.5.8 842 11/19/2021
4.5.7 693 11/7/2021
4.5.6 520 11/3/2021
4.5.5 699 10/27/2021
4.5.4 549 10/5/2021
4.5.3 2,093 9/7/2021
4.5.2 653 8/11/2021
4.5.1 2,200 7/24/2021
4.5.0 2,431 7/7/2021
4.5.0-beta-005 262 7/6/2021
4.5.0-beta-004 247 7/5/2021
4.5.0-beta-003 252 7/5/2021
4.5.0-beta-002 265 6/27/2021
4.5.0-beta-001 764 6/5/2021
4.5.0-alpha-020 256 5/26/2021
4.5.0-alpha-019 224 5/22/2021
4.5.0-alpha-018 234 5/21/2021
4.5.0-alpha-017 284 5/15/2021
4.5.0-alpha-016 218 5/9/2021
4.5.0-alpha-015 275 5/8/2021
4.5.0-alpha-014 272 4/30/2021
4.5.0-alpha-013 249 4/27/2021
4.5.0-alpha-012 227 4/23/2021
4.5.0-alpha-011 306 4/20/2021
4.5.0-alpha-010 251 4/14/2021
4.5.0-alpha-009 245 4/11/2021
4.5.0-alpha-008 280 4/8/2021
4.5.0-alpha-007 272 4/8/2021
4.5.0-alpha-006 243 4/5/2021
4.5.0-alpha-005 246 4/3/2021
4.5.0-alpha-004 275 4/2/2021
4.5.0-alpha-003 288 3/28/2021
4.5.0-alpha-002 234 3/22/2021
4.5.0-alpha-001 1,844 2/26/2021
4.4.0 9,876 2/25/2021
4.4.0-beta-008 285 2/19/2021
4.4.0-beta-007 276 2/12/2021
4.4.0-beta-006 277 2/12/2021
4.4.0-beta-005 273 2/9/2021
4.4.0-beta-004 277 2/5/2021
4.4.0-beta-003 713 1/30/2021
4.4.0-beta-002 274 1/23/2021
4.4.0-beta-001 710 1/22/2021
4.4.0-alpha-008 497 1/15/2021
4.4.0-alpha-007 993 12/26/2020
4.4.0-alpha-006 384 12/25/2020
4.4.0-alpha-005 445 12/23/2020
4.4.0-alpha-004 495 12/22/2020
4.4.0-alpha-003 486 12/18/2020
4.4.0-alpha-002 420 12/17/2020
4.4.0-alpha-001 352 12/17/2020
4.3.0 2,911 12/17/2020
4.3.0-beta-002 424 12/11/2020
4.3.0-beta-001 359 12/7/2020
4.3.0-alpha-007 414 11/21/2020
4.3.0-alpha-006 372 11/20/2020
4.3.0-alpha-005 329 11/16/2020
4.3.0-alpha-004 818 11/12/2020
4.3.0-alpha-003 362 11/10/2020
4.3.0-alpha-002 370 10/26/2020
4.3.0-alpha-001 404 10/23/2020
4.2.0 3,971 9/25/2020
4.2.0-alpha-004 563 9/23/2020
4.2.0-alpha-003 378 9/21/2020
4.2.0-alpha-002 418 9/19/2020
4.2.0-alpha-001 485 9/18/2020
4.1.1 822 9/17/2020
4.1.0 1,048 9/10/2020
4.1.0-beta-004 524 9/5/2020
4.1.0-beta-003 422 9/4/2020
4.1.0-beta-002 831 9/4/2020
4.1.0-beta-001 422 9/3/2020
4.1.0-alpha-001 409 9/1/2020
4.0.0 2,976 8/27/2020
4.0.0-beta-003 438 8/21/2020
4.0.0-beta-002 510 8/7/2020
4.0.0-beta-001 840 7/20/2020
4.0.0-alpha-014 682 7/14/2020
4.0.0-alpha-013 446 7/11/2020
4.0.0-alpha-012 892 7/6/2020
4.0.0-alpha-011 330 6/25/2020
4.0.0-alpha-010 716 6/18/2020
4.0.0-alpha-009 354 6/12/2020
4.0.0-alpha-008 488 6/2/2020
4.0.0-alpha-007 341 6/1/2020
4.0.0-alpha-006 1,305 5/23/2020
4.0.0-alpha-005 1,207 5/16/2020
4.0.0-alpha-004 785 5/4/2020
4.0.0-alpha-003 415 5/3/2020
4.0.0-alpha-002 440 4/26/2020
4.0.0-alpha-001 329 4/20/2020
3.3.0 11,414 2/28/2020
3.3.0-beta-002 1,299 2/21/2020
3.3.0-beta-001 461 2/18/2020
3.2.0 20,056 2/3/2020
3.2.0-beta-002 1,059 1/7/2020
3.2.0-beta-001 602 12/26/2019
3.1.0 9,740 11/27/2019
3.0.0 4,145 10/11/2019
3.0.0-beta-006 1,178 10/2/2019
3.0.0-beta-005 372 9/27/2019
3.0.0-beta-004 972 9/18/2019
3.0.0-beta-003 502 9/13/2019
3.0.0-beta-002 14,195 7/20/2019
3.0.0-beta-001 5,135 7/12/2019
2.9.2 23,301 2/2/2019
2.9.1 3,657 11/20/2018
2.9.0 8,467 10/17/2018
2.8.1 1,706 9/12/2018
2.8.0 4,937 7/7/2018
2.7.1 3,820 5/2/2018
2.7.0 1,433 5/2/2018
2.6.1 44,697 4/22/2017
2.5.0 2,024 2/19/2017
2.4.0 2,128 10/24/2016
2.3.0 1,801 7/9/2016
2.2.0 1,535 4/24/2016
2.1.0 1,404 4/1/2016
2.0.2 8,141 11/15/2015
1.11.0 1,979 9/12/2015
1.10.0 1,335 8/29/2015
1.9.0 1,737 8/10/2015
1.8.0-beta 1,161 7/19/2015
1.7.0 1,485 6/10/2015
1.6.0 2,321 10/25/2014
1.5.0 1,747 9/18/2014
1.4.0 2,098 7/1/2014
1.3.0 1,639 5/17/2014
1.2.0 1,635 4/21/2014
1.1.0 1,506 3/29/2014
1.0.7 1,506 3/12/2014
1.0.5.1 1,566 1/15/2014
1.0.5 1,306 1/7/2014
1.0.4 1,364 11/16/2013
1.0.3 1,383 10/6/2013
1.0.2 1,358 8/16/2013
1.0.1 1,506 7/22/2013
1.0.0 2,566 7/16/2013
0.9.9.2 1,700 7/2/2013
0.9.9.1 1,528 6/22/2013
0.9.8 1,488 6/14/2013
0.9.7 1,458 6/7/2013
0.9.6 1,419 5/31/2013
0.9.5 1,530 5/23/2013
0.9.4 1,423 5/19/2013
0.9.3 1,395 5/9/2013
0.9.2 1,408 5/3/2013
0.9.1 1,686 4/26/2013
0.9.0 1,462 4/19/2013
0.8.9 1,474 4/12/2013
0.8.8 1,410 4/11/2013
0.8.7 1,393 4/9/2013
0.8.6 1,403 4/4/2013
0.8.5 1,479 4/2/2013
0.8.4 1,415 4/1/2013
0.8.3 1,431 4/1/2013
0.8.2 1,392 4/1/2013
0.8.1 1,461 3/31/2013
0.8.0 1,455 3/31/2013

### Fixed
* List of functions misaligned and breaks (Elmish). [#2158](https://github.com/fsprojects/fantomas/issues/2158)
* Idempotency problem when Elmish Html. [#2195](https://github.com/fsprojects/fantomas/issues/2195)
* Splitting list results in code that doesn't compile. [#2201](https://github.com/fsprojects/fantomas/issues/2201)
* Idempotency problem when using a list with interpolated strings. [#2242](https://github.com/fsprojects/fantomas/issues/2242)
* Idempotency problem when using set and spread syntax. [#2392](https://github.com/fsprojects/fantomas/issues/2392)
* Formatting (*) returns ( * ). [#2452](https://github.com/fsprojects/fantomas/issues/2452)
* Comment after last case of function with operator is removed.[#2454](https://github.com/fsprojects/fantomas/issues/2454)
* Trailing whitespace in block comments should be preserved. [#2450](https://github.com/fsprojects/fantomas/issues/2450)