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.

• Haskell IDE Engine (HIE)
  • Features
  • Installation
    • Installation with Nix
    • Installation on ArchLinux
    • Installation from source
      • Linux pre-requirements
      • Windows: long paths (optional)
      • Download the source code
      • Choose your GHC version
      • Install a specific GHC version 8.2.1 - 8.6.3
      • For GHC 8.0.2
      • Install all available GHC versions
    • Installation with Shake
      • Install specific GHC Version with Shake
      • Install all available GHC versions with Shake
  • Configuration
  • Editor Integration
    • Using HIE with VS Code
      • Using VS Code with Nix
    • Using HIE with Sublime Text
    • Using HIE with Vim or Neovim
      • vim-plug
      • Vim 8.0
      • Sample ~/.vimrc
    • Using HIE with Atom
    • Using HIE with Emacs
    • Using HIE with Spacemacs
    • Using HIE with Spacemacs on Nix Based Projects
    • Using HIE with Oni
  • Docs on hover/completion
  • Contributing
    • Planned Features
    • It's time to join the project!
  • Documentation
    • Architecture
  • Troubleshooting
    • DYLD on macOS
    • macOS: Got error while installing GHC 8.6.1 or 8.6.2 - dyld: Library not loaded: /usr/local/opt/gmp/lib/libgmp.10.dylib
    • macOS: Got error while processing diagnostics: unable to load package integer-gmp-1.0.2.0
    • cannot satisfy -package-id <package>
      • Is <package> base-x?
      • Is there a hash (#) after <package>?
      • Otherwise

• 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 haddock) on hover

  

• Jump to definition

  

• List all top level definitions

  

• Highlight references in document

  

• Completion

  

• Formatting via brittany

  

• Renaming via HaRe

  

• Add packages to cabal and hpack package files

  

• Typo quick fixes

  

• Add missing imports (via hsimport)

  

Follow the instructions at https://github.com/domenkozar/hie-nix

An haskell-ide-engine-git package is available on the AUR.

Using Aura:

# aura -A haskell-ide-engine-git

To install HIE, you need stack version >= 1.7.1.

HIE builds from source code, so there's a couple of extra steps.

On Linux you will need install a couple of extra libraries (for Unicode (ICU) and NCURSES):

Debian/Ubuntu:

sudo apt install libicu-dev libtinfo-dev libgmp-dev

Fedora:

sudo dnf install libicu-devel ncurses-devel

ArchLinux: see below.

In order to avoid problems with long paths on Windows you can do the following:

1. Edit the group policy: set "Enable Win32 long paths" to "Enabled" (Works only for Windows 10).

2. Clone the haskell-ide-engine to the root of your logical drive (e.g. to C:\hie)

git clone https://github.com/haskell/haskell-ide-engine --recurse-submodules
cd haskell-ide-engine

The GHC version you are going to install HIE for depends on which version of GHC you are using for your project. If you don't have a current project there are two potential options:

1. The Nightly GHC version (currently 8.6.3)
2. The LTS GHC version (which is currently 8.4.4)

By default in a stack project you will get the LTS version.

You can check which version of ghc you are using in your project by running the following at the root of your project:

stack ghc -- --version

You can install an specific version or all available GHC versions.

We will use the make tools here to wrap stack install. The preferred installation mechanism is via make, as it makes sure the repo is synced, installs the required cabal libraries if missing, and makes copies of the executables with suffixes to be able to tell them apart.

Install Nightly (and hoogle docs):

make hie-8.6.3
make build-doc-8.6.3

Install LTS (and hoogle docs):

make hie-8.4.4
make build-doc-8.4.4

This step can take more than 30 minutes, so grab a coffee and please be patient!

The available versions depend on the stack-*.yaml config files in the haskell-ide-engine directory.

This is no longer supported on the HIE master branch, so you must switch to the hie-0.1.0.0 branch:

git checkout hie-0.1.0.0
git submodule update --init

Then you can run stack install:

stack --stack-yaml=stack-8.0.2.yaml install

This is the simplest approach as it will install all GHC versions to match against any project versions you might have.

Warning: Requires 20+ GB of space and potentially more than 2 hours to install, so please be patient!

This will:

• install all supported GHC versions (8.2.1 - 8.6.3)
• name them as expected by the VS Code plugin
• build local hoogle docs for each version

On non-Windows platforms use the command:

make build-all

On Windows use: PowerShell:

./build-all.ps1

or

cmd.exe:

powershell -ExecutionPolicy RemoteSigned -c ./build-all.ps1

Then add

"languageServerHaskell.useCustomHieWrapper": true,
"languageServerHaskell.useCustomHieWrapperPath": "hie-wrapper",

to VS Code user settings.

Experimental build script for HIE. Feedback is appreciated. Uses the shake build system for predictable builds. The build script is platform independent and the only prerequisites are that git and stack are installed. The dependency on make and other linux specific commands has been dropped. It is also required, that the directory output of stack path --local-bin is on the path before installation, otherwise the installation of cabal will fail and hie executables may not be found. The installation path is usually ~/.local/bin on UNIX systems and C:\Users\User\AppData\Roaming\local\bin on windows.

Note, on first invocation of the build script, a GHC is being installed for execution. However, if you build HIE for every GHC, no GHC is downloaded twice. The GHC used for the install.hs can be adjusted in shake.yaml by using a different resolver.

Available commands can be seen with:

stack ./install.hs help

Remember, this will take time to download a Stackage-LTS and an appropriate GHC. However, afterwards all commands should work as expected.

Install Nightly (and hoogle docs):

stack ./install.hs hie-8.6.3
stack ./install.hs build-doc-8.6.3

Install LTS (and hoogle docs):

stack ./install.hs hie-8.4.4
stack ./install.hs build-doc-8.4.4

The Haskell IDE Engine can also be built with cabal new-build instead of stack build. This has the advantage that you can decide how the GHC versions have been installed. However, this approach does currently not work for windows due to a missing feature upstream. To see what GHC versions are available, the command stack install.hs cabal-ghcs can be used. It will list all GHC versions that are on the path and their respective installation directory. If you think, this list is incomplete, you can try to modify the PATH variable, such that the executables can be found. Note, that the targets cabal-build, cabal-build-docs and cabal-build-all depend on the found GHC versions. They install Haskell IDE Engine only for the found GHC versions.

An example output is:

> stack install.hs cabal-ghcs
******************************************************************
Found the following GHC paths:
ghc-8.4.4: /opt/bin/ghc-8.4.4
ghc-8.6.2: /opt/bin/ghc-8.6.2

******************************************************************

If your desired ghc has been found, you use it to install Haskell IDE Engine.

stack install.hs cabal-hie-8.4.4
stack install.hs cabal-build-doc-8.4.4

In general, targets that use cabal instead of stack are prefixed with cabal-* and are identical to their counterpart, except they do not install a GHC if it is missing but fail.

Warning: Requires 20+ GB of space and potentially more than 2 hours to install, so please be patient!

This will:

• install all supported GHC versions (8.2.1 - 8.6.3)
• name them as expected by the VS Code plugin
• build local hoogle docs for each version

stack ./install.hs build-all

Then add

"languageServerHaskell.useCustomHieWrapper": true,
"languageServerHaskell.useCustomHieWrapperPath": "hie-wrapper",

to VS Code user settings.

To install HIE only for those GHC versions that are present on your system, you use:

stack ./install.hs cabal-build-all

This will:

• install Haskell Ide Engine for GHC versions that have been found on your path
• name them as expected by the VS Code plugin
• build local hoogle docs for each version

There are some settings that can be configured via a settings.json file:

{
    "languageServerHaskell": {
        "hlintOn": Boolean,
        "maxNumberOfProblems": Number
        "diagnosticsDebounceDuration" : Number
        "liquidOn"                    : Bool (default False)
        "completionSnippetsOn"        : Bool (default True)
        "formatOnImportOn"            : Bool (default True)
        "formattingProvider"          : String (default "brittany",
                                                alternate "floskell")
    }
}

• VS Code: These settings will show up in the settings window
• LanguageClient-neovim: Create this file in $projectdir/.vim/settings.json or set g:LanguageClient_settingsPath

Note to editor integrators: there is now a hie-wrapper executable, which is installed alongside the hie executable. When this is invoked in the project root directory, it attempts to work out the GHC version used in the project, and then launch the matching hie executable.

All of the editor integrations assume that you have already installed HIE (see above) and that stack put the hie binary in your path (usually ~/.local/bin on linux and macOS).

Install from the VSCode marketplace, or manually from the repository vscode-hie-server.

.config/nixpkgs/config.nix sample:

with import <nixpkgs> {};

let
  hie = (import (fetchFromGitHub {
                   owner="domenkozar";
                   repo="hie-nix";
                   rev="e3113da";
                   sha256="05rkzjvzywsg66iafm84xgjlkf27yfbagrdcb8sc9fd59hrzyiqk";
                 }) {}).hie84;
in
{
  allowUnfree = true;
  packageOverrides = pkgs: rec {

    vscode = pkgs.vscode.overrideDerivation (old: {
      postFixup = old.postFixup + ''
        wrapProgram $out/bin/code --prefix PATH : ${lib.makeBinPath [hie]}
      '';
    });

  };
}

• Make sure HIE is installed (see above) and that the directory stack put the hie binary in is in your path
  • (usually ~/.local/bin on unix)
• Install LSP using Package Control
• From Sublime Text, press Command+Shift+P and search for Preferences: LSP Settings
• Paste in these settings. Make sure to change the command path to your hie

{
"clients": {
  "haskell-ide-engine": {
    "command": ["hie"],
    "scopes": ["source.haskell"],
    "syntaxes": ["Packages/Haskell/Haskell.sublime-syntax"],
    "languageId": "haskell",
  },
},
}

Now open a haskell project with Sublime Text. You should have these features available to you:

1. Errors are underlined in red
2. LSP: Show Diagnostics will show a list of hints and errors
3. LSP: Format Document will prettify the file

As above, make sure HIE is installed. These instructions are for using the LanguageClient-neovim client.

If you use vim-plug, then you can do this by e.g. including the following line in the Plug section of your init.vim:

Plug 'autozimu/LanguageClient-neovim', {
    \ 'branch': 'next',
    \ 'do': './install.sh'
    \ }

and issuing a :PlugInstall command within neovim.

Clone LanguageClient-neovim into ~/.vim/pack/XXX/start/, where XXX is just a name for your "plugin suite".

set rtp+=~/.vim/pack/XXX/start/LanguageClient-neovim
let g:LanguageClient_serverCommands = { 'haskell': ['hie-wrapper'] }

You'll probably want to add some mappings for common commands:

nnoremap <F5> :call LanguageClient_contextMenu()<CR>
map <Leader>lk :call LanguageClient#textDocument_hover()<CR>
map <Leader>lg :call LanguageClient#textDocument_definition()<CR>
map <Leader>lr :call LanguageClient#textDocument_rename()<CR>
map <Leader>lf :call LanguageClient#textDocument_formatting()<CR>
map <Leader>lb :call LanguageClient#textDocument_references()<CR>
map <Leader>la :call LanguageClient#textDocument_codeAction()<CR>
map <Leader>ls :call LanguageClient#textDocument_documentSymbol()<CR>

Use Ctrl+xCtrl+o (<C-x><C-o>) to open up the auto-complete menu, or for asynchronous auto-completion, follow the setup instructions on LanguageClient.

If you'd like diagnostics to be highlighted, add a highlight group for ALEError/ALEWarning/ALEInfo, or customize g:LanguageClient_diagnosticsDisplay:

hi link ALEError Error
hi Warning term=underline cterm=underline ctermfg=Yellow gui=undercurl guisp=Gold
hi link ALEWarning Warning
hi link ALEInfo SpellCap

If you're finding that the server isn't starting at the correct project root, it may also be helpful to also specify root markers:

let g:LanguageClient_rootMarkers = ['*.cabal', 'stack.yaml']

Make sure HIE is installed, then install the two Atom packages atom-ide-ui and ide-haskell-hie,

$ apm install language-haskell atom-ide-ui ide-haskell-hie

Install HIE along with the following emacs packages:

lsp-mode lsp-ui lsp-haskell

Make sure to follow the instructions in the README of each of these packages.

Install HIE, and then add the following to your .spacemacs config,

(defun dotspacemacs/layers ()
  "..."
  (setq-default
   ;; ...
   dotspacemacs-configuration-layers
   '(
     lsp
     (haskell :variables ;; Or optionally just haskell without the variables.
              haskell-completion-backend 'ghci
              haskell-process-type 'stack-ghci)
     )
   dotspacemacs-additional-packages '(
      (lsp-haskell :location (recipe :fetcher github :repo "emacs-lsp/lsp-haskell"))
      )
    ;; ...
    ))

and then activate lsp-haskell in your user-config section,

(defun dotspacemacs/user-config ()
  "..."
  (require 'lsp-haskell)
  (add-hook 'haskell-mode-hook #'lsp-haskell-enable)
  )

Now you should be able to use HIE in Spacemacs. I still recommend checking out lsp-ui and lsp-mode.

If you use HIE with spacemacs on nix-built haskell projects, you may want to try out this spacemacs layer. It has installation instructions which includes a nix expression to install everything that hie needs in your environment. It wraps the hie binary calls to use nix-sandbox to find the closest ancestor directory that has nixfiles.

It is still pretty new and may change drastically as the author understands the lsp, lsp-ui, lsp-haskell, hie stack a bit better. PRs and feedback are very welcome on the layer's repo if you find it useful and/or lacking in some way.

Oni (a Neovim GUI) added built-in support for HIE, using stack, in #1918. If you need to change the configuration for HIE, you can overwrite the following settings in your ~/.config/oni/config.tsx file (accessible via the command palette and Configuration: Edit User Config),

export const configuration = {
  "language.haskell.languageServer.command": "stack",
  "language.haskell.languageServer.arguments": ["exec", "--", "hie"],
  "language.haskell.languageServer.rootFiles": [".git"],
  "language.haskell.languageServer.configuration": {},
}

HIE supports fetching docs from haddock on hover. It will fallback on using a hoogle db(generally located in ~/.hoogle on linux) if no haddock documentation is found.

To generate haddock documentation for stack projects:

$ cd your-project-directory
$ stack haddock --keep-going

To enable documentation generation for cabal projects, add the following to your ~/.cabal/config

documentation: True

To generate a hoogle database that hie can use

$ cd haskell-ide-engine
$ stack --stack-yaml=<stack.yaml you used to build hie> exec hoogle generate

Or you can set the environment variable HIE_HOOGLE_DATABASE to specify a specific database.

• 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 project is not started from scratch:

1. See why we should supersede previous tools
2. Check the list of existing tools and functionality
3. See more other tools and IDEs for inspiration

❤️ Haskell tooling dream is near, we need your help! ❤️

• Register in our google group mailing list.
• Join our IRC channel at #haskell-ide-engine on freenode.
• Fork this repo and hack as much as you can.
• Ask @alanz or @hvr to join the project.

All the documentation is in the docs folder at the root of this project.

Have a look at

• the Architecture discussion,
• Protocol discussion and
• Design discussion.

If you hit a problem that looks like can't load .so/.DLL for: libiconv.dylib (dlopen(libiconv.dylib, 5): image not found), it means that libraries cannot be found in the library path. We can hint where to look for them and append more paths to DYLD_LIBRARY_PATH.

export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:/usr/lib:/usr/local/lib"

On practice /usr/local/lib is full of dylibs linked by brew. After you amend DYLD_LIBRARY_PATH, some of the previously compiled application might not work and yell about incorrect linking, for example, dyld: Symbol not found: __cg_jpeg_resync_to_restart. You may need to look up where it comes from and remove clashing links, in this case it were clashing images libs:

$ brew unlink libjpeg
$ brew unlink libtiff
$ brew unlink libpng

Recompile.

These builds have a dependency on homebrew's gmp library. Install with brew: brew install gmp. Should be fixed in GHC 8.6.3.

Rename the file at ~/.stack/programs/x86_64-osx/ghc-8.4.3/lib/ghc-8.4.3/integer-gmp-1.0.2.0/HSinteger-gmp-1.0.2.0.o to a temporary name. Should be fixed in GHC 8.8.1.

Make sure that you are running the correct version of hie for your version of ghc, or check out hie-wrapper.

Delete any .ghc.environment* files in your project root and try again. (At the time of writing, cabal new-style projects are not supported with ghc-mod)

Try running cabal update.