This project aims to be the universal interface to a growing number of Haskell tools, providing a full-featured and easy to query backend for editors and IDEs that require Haskell-specific functionality.
We are currently focusing on using the Language Server Protocol as the interface via which we talk to clients.
Supports plain GHC projects, cabal projects(sandboxed and non sandboxed) and stack projects
Fast due to caching of compile info
Uses LSP, so should be easy to integrate with a wide selection of editors
Diagnostics via hlint and GHC warnings/errors
Code actions and quick fixes via apply-refact
Type information and documentation(via hoogle) on hover
Jump to definition
List all top level definitions
Highlight references in document
Formatting via brittany
Renaming via HaRe
To install HIE
git clone https://github.com/haskell/haskell-ide-engine cd haskell-ide-engine stack install
Using HIE with vscode
Make sure HIE is installed (see above) and directory stack put the
hie binary in is in your path
~/.local/bin on linux)
git clone https://github.com/alanz/vscode-hie-server cd vscode-hie-server npm install .
vscode-hie-server/ in Visual Studio Code and press
F5 to open a new window with the extension loaded.
Hoogle Docs on hover
HIE supports fetching docs from hoogle on hover. It can use the Hoogle database for your user, or a project specific database.
To generate a global hoogle database for your user from hackage, run
$ hoogle generate
To generate a project specific database for a stack project, run
$ stack hoogle $ stack build
To generate a project specific database for a sandboxed cabal project, run
$ cabal install --enable-documentation --haddock-hoogle $ hoogle generate --database=hiehoogledb.hoo --local=.
in the root dir of your cabal project
If you don't have the dependencies built with haddock/documentation enabled, you need to remove the sandbox and build everything again before running the commands given above
$ cabal sandbox delete $ cabal sandbox init
To generate a project specific database for a non-sandboxed cabal project, run
$ cabal install $ hoogle generate --local --database=hiehoogledb.hoo
If HIE detects a project specific hoogle DB, it will use it over the global db.
- Multiproject support
- Project wide references
- Cross project find definition
- New-build support
- HaRe refactorings
- More code actions
- Cross project/dependency Find Definition
- Case splitting, type insertion etc.
This is not yet another
Both the ghc-mod and ide-backend maintainers have agreed to contribute code to this new repository and then rebase the old repos on this. The reason we're using a new repo instead of modifying one of the existing ones is so that the existing projects experience no disruption during this migration process. If this was a new set of people starting a new project without support from existing projects, I'd agree with you. But Alan's reached out to existing players already, which is an important distinction.
This project is not started from scratch:
- See why we should supersede previous tools
- Check the list of existing tools and functionality
- See more other tools and IDEs for inspiration
It's time to join the project!
- Register in our google group mailing list.
- Join our IRC channel at
- Fork this repo and hack as much as you can.
- Ask @alanz or @hvr to join the project.
Apart from stack you need cask for the emacs tests. You can install it using
curl -fsSL https://raw.githubusercontent.com/cask/cask/master/go | python
Below you find a short overview of the main architectural layers of
For more info have a look in the docs folder at the root of this project, especially:
1. BIOS layer
ghc-mod stays an AGPL project,
and is used for its "awesome sauce" in terms of
the BIOS functions that it does so well. This interface is
straightforward to use,
and if a license-constrained user wants to do something else it is also easy to
replace, if there is strong control of the operating environment.
2. Plugin layer
A layer providing a point to integrate tools and existing functions, probably including ghci.
3. IDE interfacing layer
The focus is currently on LSP as the protocol we use to interface with IDEs.
Existing transports are still functional for the time being.
All the documentation is in the docs folder at the root of this project.