fantomas-tool 5.0.0-alpha-002

.NET 6.0
Suggested Alternatives

fantomas

This is a prerelease version of fantomas-tool.
dotnet tool install --global fantomas-tool --version 5.0.0-alpha-002
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-tool --version 5.0.0-alpha-002
This package contains a .NET tool you can call from the shell/command line.
#tool dotnet:?package=fantomas-tool&version=5.0.0-alpha-002&prerelease
nuke :add-package fantomas-tool --version 5.0.0-alpha-002

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-tool

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-tool 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-tool 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 "(%s -> %s)" (t1.ToString()) (t2.ToString())
                 | 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 "(%s -> %s)" (t1.ToString()) (t2.ToString())
             | 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
5.0.0-alpha-002 928 4/4/2022
5.0.0-alpha-001 454 3/19/2022
4.7.9 51,145 5/2/2022
4.7.8 2,579 4/25/2022
4.7.7 5,668 4/20/2022
4.7.6 20,386 4/4/2022
4.7.5 6,064 3/27/2022
4.7.4 716 3/25/2022
4.7.3 7,498 3/12/2022
4.7.2 10,485 3/11/2022
4.7.1 7,628 3/8/2022
4.7.0 4,741 3/4/2022
4.6.6 445 3/4/2022
4.6.5 49,142 2/18/2022
4.6.4 3,947 2/11/2022
4.6.3 4,415 2/8/2022
4.6.2 1,434 2/6/2022
4.6.1 7,438 2/1/2022
4.6.0 23,786 1/14/2022
4.6.0-beta-001 468 1/8/2022
4.6.0-alpha-011 1,397 12/29/2021
4.6.0-alpha-010 1,197 12/4/2021
4.6.0-alpha-009 3,223 11/24/2021
4.6.0-alpha-008 739 11/19/2021
4.6.0-alpha-007 951 11/7/2021
4.6.0-alpha-006 1,044 11/3/2021
4.6.0-alpha-005 478 10/27/2021
4.6.0-alpha-004 37,911 10/20/2021
4.6.0-alpha-003 389 10/5/2021
4.6.0-alpha-002 328 9/7/2021
4.6.0-alpha-001 228 8/11/2021
4.5.12 759 1/8/2022
4.5.11 2,041 12/29/2021
4.5.10 8,121 12/4/2021
4.5.9 6,918 11/24/2021
4.5.8 2,200 11/19/2021
4.5.7 1,219 11/7/2021
4.5.6 1,279 11/3/2021
4.5.5 897 10/27/2021
4.5.4 10,014 10/5/2021
4.5.3 8,241 9/7/2021
4.5.2 11,383 8/11/2021
4.5.1 5,006 7/24/2021
4.5.0 12,640 7/7/2021
4.5.0-beta-005 294 7/6/2021
4.5.0-beta-004 236 7/5/2021
4.5.0-beta-003 292 7/5/2021
4.5.0-beta-002 681 6/27/2021
4.5.0-beta-001 2,328 6/5/2021
4.5.0-alpha-020 310 5/26/2021
4.5.0-alpha-019 671 5/22/2021
4.5.0-alpha-018 249 5/21/2021
4.5.0-alpha-017 540 5/15/2021
4.5.0-alpha-016 307 5/9/2021
4.5.0-alpha-015 479 5/8/2021
4.5.0-alpha-014 490 4/30/2021
4.5.0-alpha-013 389 4/27/2021
4.5.0-alpha-012 304 4/23/2021
4.5.0-alpha-011 510 4/20/2021
4.5.0-alpha-010 549 4/14/2021
4.5.0-alpha-009 258 4/11/2021
4.5.0-alpha-008 499 4/8/2021
4.5.0-alpha-007 287 4/8/2021
4.5.0-alpha-006 272 4/5/2021
4.5.0-alpha-005 698 4/3/2021
4.5.0-alpha-004 293 4/2/2021
4.5.0-alpha-003 600 3/28/2021
4.5.0-alpha-002 433 3/22/2021
4.5.0-alpha-001 4,849 2/26/2021
4.4.0 27,359 2/25/2021
4.4.0-beta-008 638 2/19/2021
4.4.0-beta-007 279 2/12/2021
4.4.0-beta-006 523 2/12/2021
4.4.0-beta-005 327 2/9/2021
4.4.0-beta-004 487 2/5/2021
4.4.0-beta-003 537 1/30/2021
4.4.0-beta-002 427 1/23/2021
4.4.0-beta-001 305 1/22/2021
4.4.0-alpha-008 378 1/15/2021
4.4.0-alpha-007 2,675 12/26/2020
4.4.0-alpha-006 352 12/25/2020
4.4.0-alpha-005 330 12/23/2020
4.4.0-alpha-004 304 12/22/2020
4.4.0-alpha-003 369 12/18/2020
4.4.0-alpha-002 345 12/17/2020
4.4.0-alpha-001 365 12/17/2020
4.3.0 6,053 12/17/2020
4.3.0-beta-002 372 12/11/2020
4.3.0-beta-001 334 12/7/2020
4.3.0-alpha-007 375 11/21/2020
4.3.0-alpha-006 384 11/20/2020
4.3.0-alpha-005 341 11/16/2020
4.3.0-alpha-004 337 11/12/2020
4.3.0-alpha-003 331 11/10/2020
4.3.0-alpha-002 368 10/26/2020
4.3.0-alpha-001 1,278 10/23/2020
4.2.0 6,152 9/25/2020
4.2.0-alpha-004 473 9/23/2020
4.2.0-alpha-003 378 9/21/2020
4.2.0-alpha-002 417 9/19/2020
4.2.0-alpha-001 388 9/18/2020
4.1.1 1,894 9/17/2020
4.1.0 987 9/10/2020
4.1.0-beta-004 455 9/5/2020
4.1.0-beta-003 433 9/4/2020
4.1.0-beta-002 399 9/4/2020
4.1.0-beta-001 412 9/3/2020
4.1.0-alpha-001 419 9/1/2020
4.0.0 2,903 8/27/2020
4.0.0-beta-003 373 8/21/2020
4.0.0-beta-002 952 8/7/2020
4.0.0-beta-001 646 7/20/2020
4.0.0-alpha-014 436 7/14/2020
4.0.0-alpha-013 382 7/11/2020
4.0.0-alpha-012 696 7/6/2020
4.0.0-alpha-011 372 6/25/2020
4.0.0-alpha-010 367 6/18/2020
4.0.0-alpha-009 363 6/12/2020
4.0.0-alpha-008 383 6/2/2020
4.0.0-alpha-007 356 6/1/2020
4.0.0-alpha-006 424 5/23/2020
4.0.0-alpha-005 586 5/16/2020
4.0.0-alpha-004 887 5/4/2020
4.0.0-alpha-003 416 5/3/2020
4.0.0-alpha-002 368 4/26/2020
4.0.0-alpha-001 360 4/20/2020
3.3.0 13,183 2/28/2020
3.3.0-beta-002 966 2/21/2020
3.3.0-beta-001 469 2/18/2020
3.2.0 2,047 2/3/2020
3.2.0-beta-002 660 1/7/2020
3.2.0-beta-001 437 12/26/2019
3.1.0 11,904 11/27/2019
3.0.0 1,115 10/11/2019
3.0.0-beta-006 407 10/2/2019
3.0.0-beta-005 395 9/27/2019
3.0.0-beta-004 407 9/18/2019
3.0.0-beta-003 418 9/13/2019
3.0.0-beta-002 772 7/20/2019
3.0.0-beta-001 552 7/12/2019
2.9.2 6,068 2/2/2019
2.9.1 1,449 11/20/2018
2.9.0 1,081 10/17/2018
2.8.1 1,042 9/12/2018
2.8.0 1,158 7/7/2018

### Changed
* Target net6.0 for fantomas-tool.