# Haskelly

**Repository Path**: mirrors_ndmitchell/Haskelly

## Basic Information

- **Project Name**: Haskelly
- **Description**: Haskelly is a VS Code extension that provides complete support for casual and expert Haskell development.
- **Primary Language**: Unknown
- **License**: GPL-3.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-09-25
- **Last Updated**: 2026-04-12

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Haskelly

Haskelly is a VS Code extension that provides complete support for casual and expert Haskell development. This includes:
* Code highlight
* Code snippets
* Type hovers
* Code completion
* Running Haskell inside the editor using either GHCi, runHaskell or Stack build
* Testing all the prop functions in a file with QuickCheck or Stack test


## Features

### Code highlight
Proper code highlight for Haskell code based on [Haskell TextMate](https://github.com/textmate/haskell.tmbundle) and for Cabal files thanks to [Justus Adam](https://github.com/JustusAdam/language-haskell/blob/master/syntaxes/cabal.tmLanguage).

### Code snippets
Snippets for the most popular functions such as `map` or `fold` and other structures like `data` or `newtype`. 
For the tokens which have a snippets, Haskelly will show both the suggestion and the snippet. If you want to disable this behaviour and force Haskelly to only provide the snippet, set the configuration `haskelly.snippets.important` to `true`. Go to the [Extension Settings](## Extension Settings) section to learn how to add your own snippets.

### Type hovers
Hover on top of an identifier and Haskelly will tell you what's its type.

![hover](resources/hover.gif) 

### Code completion
Intelligent code completion which takes into account functions and constants defined in the opened file as well as the Haskell standard library and any imported modules.

![completion](resources/completion.gif)

### Running Haskell
The extension allows three ways of executing Haskell using the integrated terminal inside VS Code:
* GHCi: you can call all the functions declared in the file providing the arguments. The extension calls `stack ghci` in the background.

* Run file: looks for a main function and executes it. The extension uses `stack runhaskell` under the hood.

* Stack run: runs the Stack project defined in the root folder. The extension runs `stack run` which uses the [stack-run](https://hackage.haskell.org/package/stack-run) package.

![bulding](resources/build.gif)

### Testing Haskell
Easily run [QuickCheck](https://hackage.haskell.org/package/QuickCheck) on all the functions that start with the prefix `prop_` in the currently opened file. If working in a Stack project, Haskelly will run `stack test`.

## Demo 

Watch a demo [here](https://www.youtube.com/watch?v=r3x64iz5xDk).

## Requirements
* [Stack](https://www.haskellstack.org). If you don't know about it, Stack is the best Haskell package manager. If you still use Cabal, check out Stack. After installing Stack and adding it to your `PATH`, run `$ stack setup`. This will install the GHC (Glasgow Haskell Compiler) and GHCi.

* Stack packages (installed locally if working inside a Stack project):
    * Intero package for code completion. To install it globally: `$ stack install intero` or `$ stack build intero` if working on a Stack project.
    * QuickCheck package for running `QuickCheck`. To install it: `$ stack install QuickCheck`.
    * stack-run package for running `stack run`. To install it: `$ stack install stack-run`.


## Extension Settings

Haskelly is fully customizable. Just add any of these properties in the preferences file (Code -> Preferences -> Workspace Settings (settings.json))
* `haskelly.codeCompletion`: set to `false` to disable code completion
* `haskelly.buttons.ghci`: set to `false` to hide the `GHCi` button in the bottom bar
* `haskelly.buttons.runfile`: set to `false` to hide the `Run file` button in the bottom bar
* `haskelly.buttons.quickcheck`: set to `false` to hide the `QuickCheck` button in the bottom bar
* `haskelly.buttons.stackRun`: set to `false` to hide the `Stack run` button in the bottom bar
* `haskelly.buttons.stackTest`: set to `false` to hide the `Stack test` button in the bottom bar
* `haskelly.snippets.important` set to `true` to hide code completion for which there's a snippet.
* `haskelly.snippets.custom` add your custom snippets following the structure of this [file](https://github.com/haskelly-dev/Haskelly/tree/master/languages/snippets/haskell.json).


## Road map

 Check out the next features and development of Haskelly in this [public board](https://trello.com/b/vsMlLU4h/haskelly-features).


## Contributing

If you'd like to contribute to Haskelly, this is what you can do:

* Bugs: This extension is in alpha, so some bugs might be present. We would really appreciate if you
could post any issue on the Github repository [issues section](https://github.com/haskelly-dev/Haskelly/issues) or contact us at: [zcabmse@ucl.ac.uk](mailto:zcabmse@ucl.ac.uk?Subject=Haskelly%20feedback).
* Ideas and feature requests: We want to get everyone's opinion on what we're building so feel free to use the two mentioned channels for any comment or suggestion.
* Documentation: Found a typo or strangely worded sentences? Submit a PR!
* Code: Contribute bug fixes, features or design changes.

## Release notes

Check out the release notes [here](https://github.com/haskelly-dev/Haskelly/releases).

## Intero

Haskelly uses the [Intero](https://github.com/commercialhaskell/intero) package in order to provide code completion and type hovers.

## License

[GNU 3](https://github.com/haskelly-dev/Haskelly/blob/master/License.txt)