Haskeletor

Haskeletor is a Haskell plugin for IntelliJ-based IDEs.

It supports code highlighting, code completion, compilation error highlighting — everything you need from an IDE for Haskell.

This plugin is based on the work of Rik van der Kleij and intellij-haskell contributors.

Installation

From JetBrains Marketplace

1. Open the IDE Plugins settings page.
2. Search for Haskeletor in the search bar.
3. Click Install to install the plugin.

Alternatively, download the plugin from the Marketplace in the browser.

From the Releases Page

1. Download the latest release from the Releases page.
2. Use the Install Plugin from Disk action to install it into your IDE.

From Sources

Read the contributor guide. Short version:

1. To run the debug version of the IDE with the installed plugin, run the following shell command:

   $ ./gradlew runIde

2. To build a local version of the plugin for subsequent installation into a compatible IDE, run the following shell command:

   $ ./gradlew buildPlugin

   Then, grab a plugin distribution from the build/distributions directory, and use the Install Plugin from Disk action to install it into your IDE.

Usage

Prerequisites

• Obtain the latest version of Stack.
  • The recommended installation is via GHCup.

Importing An Existing Project

By default, Haskeletor will use the stack executable in the PATH.

If you have stack somewhere else, you can specify its path in the IDE Settings. See the Languages and Frameworks → Haskell page: if required, set up the Stack path to the custom executable.

When set up, open your project folder in an IntelliJ-based IDE. It is expected that all the setup actions will be performed automatically. You will see several progress bars (can take several minutes for initial one-time setup); afterward, the project will be ready to use: you'll see code highlighting and completion in .hs files.

Remarks

1. IntelliJ's Build action is not (yet) implemented. Project is built when the project is opened and when needed, e.g. when library code is changed and the user navigates to test code;
2. About Haskell Project in Help menu shows which Haskell GHC/tools are used by the plugin for the project;
3. GHC depends on libtinfo-dev. On Ubuntu you can install it with sudo apt-get install libtinfo-dev;
4. Haskell tools depend on libgmp3-dev zlib1g-dev. On Ubuntu you can install them with sudo apt-get install libgmp3-dev zlib1g-dev;
5. Cabal's internal libraries are not (yet) supported;
6. Cabal's common stanzas are not (yet) supported;
7. The Haskell tools are built in an IntelliJ sandbox with LTS-19. So they have no dependency on Stackage resolvers in your projects. After Stackage LTS-13 minor updates one can use Haskell>Update Haskell tools;
8. Stack REPLs are running in the background. You can restart them by Haskell>Update Settings and Restart REPLs.

Plugin Features

• Syntax highlighting;
• Error/warning highlighting;
• Haskell Problems View. This tool window displays GHC messages for the currently edited files;
• Find usages of identifiers;
• Resolve references to identifiers;
• Code completion;
• In-place rename identifiers;
• View type info from (selected) expression;
• View sticky type info;
• View expression info;
• View quick documentation;
• View quick definition;
• Structure view;
• Goto to declaration (called Navigate>Declaration in IntelliJ menu);
• Navigate to declaration (called Navigate>Class in IntelliJ menu);
• Navigate to an identifier (called Navigate> Symbol in IntelliJ menu);
• Goto instance declaration (called Navigate>Instance Declaration in IntelliJ menu);
• Navigate to declaration or identifier powered by Hoogle (called Navigate>Navigation by Hoogle in IntelliJ menu);
• Inspection by HLint;
• Quick fixes for HLint suggestions;
• Show error action to view formatted messages. Useful in case message consists of multiple lines (Ctrl-F10, Meta-F10 on Mac OSX);
• Intention actions to add language extension (depends on compiler error), add top-level type signature (depends on compiler warning);
• Intention action to select which module to import if the identifier is not in scope;
• Code formatting by ormolu.
• Code completion for project module names, language extensions, and package names in Cabal file;
• Running REPL, tests, and executables via Run Configurations;
• Smart code completion on typed holes (since GHC 8.4);

Folders

Haskeletor stores tooling packages in a special cache folder, shared by all the projects. This directory might get large, especially if you have several versions of tooling used by Haskeletor, so periodic cleanup is recommended (at least after you update or uninstall Haskeletor).

The cache is stored in a per-OS location:

• Linux: $XDG_CACHE_HOME/haskeletor or $HOME/.cache/haskeletor,
• macOS: ~/Library/Caches/me.fornever.haskeletor,
• Windows: %LOCALAPPDATA%\haskeletor.

Documentation

• Contributor Guide
• Maintainer Guide

License

The project is distributed under the terms of the Apache 2.0 license (unless a particular file states otherwise).

The license indication in the project's sources is compliant with the REUSE specification v3.3.

Copyright holders:

• 2000-2015 JetBrains s.r.o.
• 2012-2014 Sergey Ignatov
• 2014-2022 intellij-haskell contributors https://github.com/rikvdkleij/intellij-haskell
• 2014-2022 Rik van der Kleij
• 2024-2026 Friedrich von Never friedrich@fornever.me
• 2024-2026 haskeletor contributors https://github.com/ForNeVeR/haskeletor