F# Interactive Plugin for Notepad++

Usage

Default shortcut	Command
Alt + Shift + F12	open/close the FSI console window
Alt + Enter (with text selected)	evaluate the active selection in FSI
none	pass the current file to FSI's #load directive 1

F# Syntax Highlighting

Notepad++ 8.4.3 and later

Opening any file with the extension *.fs, *.fsx, *.fsi or *.fsscript will activate Lexilla's F# lexer.

Older Notepad++ versions

For dark themes, copy the Obsidian theme F# UDL into %AppData%\Notepad++\userDefineLangs (system-wide Notepad++ installation), or the userDefineLangs folder of a portable Notepad++ installation.

For the default or a light theme, use the default F# UDL.

How to configure tab settings for F# source files

Notepad++ 8.8.1 and later

With the plugin loaded, modify your indentation preferences for F# (or "fsharp", if using version 0.2.2.0 and older).

Older Notepad++ versions

F# Interactive v0.2.3.1 and later

• Open the plugin options dialog:

  

• To indent using spaces, check the box beside Convert tabs to spaces

• To indent using hard tabs, un‌check the box beside Convert tabs to spaces

• Set the number of spaces (or tab size) using the Tab length edit control

  

Older plugin versions

XML configuration file

To make 4 spaces the default tab setting for F# files when Notepad++ starts, do the following:

• Open NPPFSIPlugin.xml in %AppData%\Notepad++\plugins\Config or $(PORTABLE_NPP_DIR)\plugins\Config

• Add the attribute tabSettings="132" to the node /NotepadPlus/Languages/Language[@name="F#"] (or /NotepadPlus/Languages/Language[@name="fsharp"], if using version 0.2.2.0 and older)

  For example:

  - <Language name="F#" ext="fs fsi fsx fsscript" commentLine="//" commentStart="(*" commentEnd="*)">
  + <Language name="F#" ext="fs fsi fsx fsscript" tabSettings="132" commentLine="//" commentStart="(*" commentEnd="*)">
  

  The "magic" number 132 is explained here.

Installation

Plugins Admin

A builtin plugin manager is available in Notepad++ versions 7.6 and newer.

Find Plugins on the main menu bar and select Plugins Admin. Check the box beside F# Interactive and click Install.

Manual installation

• Download a release archive

• Extract the NPPFSIPlugin.dll module and subfolders (Doc, Config)

• Right-click on NPPFSIPlugin.dll and select Properties:

  

• If the Unblock option is shown, click the checkbox and click Apply, then OK:

  

• System-wide Notepad++ installation

  • Create a folder named NPPFSIPlugin under %ProgramFiles%\Notepad++\plugins (64-bit), or %ProgramFiles(x86)%\Notepad++\plugins (32-bit)

• Portable Notepad++

  • Locate the plugins folder where notepad++.exe is installed
  • Create a folder named NPPFSIPlugin

• Move the NPPFSIPlugin.dll module and Config subfolder into the NPPFSIPlugin folder:

  

• Restart Notepad++ if it’s already running

Acknowledgements

Original source code © 2010 Prapin Peethambaran, MIT License

The FpcPipes unit is adapted from source code believed to be in the Public Domain: https://github.com/marsupilami79/DelphiPipes#licensing

The F# Software Foundation logo for F# is an asset of the F# Software Foundation: https://foundation.fsharp.org/logo

License

Distributed under the terms of the GNU General Public License, Version 3 or later, in addition to the rights of past contributors mentioned in Copyright.txt.

Footnotes

1. Also starts a new FSI session if one is not currently active. ↩