Integration point for [ghcide](https://github.com/digital-asset/ghcide) and [haskell-ide-engine](https://github.com/haskell/haskell-ide-engine). One IDE to rule
For now only installation from source is supported.
### Installation from source
#### Common pre-requirements
-`stack` or `cabal` must be in your PATH
- You need stack version >= 2.1.1 or cabal >= 2.4.0.0
-`git` must be in your PATH
- The directory where `stack`or `cabal` put the binaries must be in you PATH:
- For stack you can get it with `stack path --local-bin`
- For cabal it is by default `$HOME/.cabal/bin` in linux and `%APPDATA%\cabal\bin` in windows.
Tip: you can quickly check if some command is in your path by running the command.
If you receive some meaningful output instead of "command not found"-like message
then it means you have the command in PATH.
#### Linux-specific pre-requirements
On Linux you will need install a couple of extra libraries (for Unicode ([ICU](http://site.icu-project.org/)) and [NCURSES](https://www.gnu.org/software/ncurses/)):
sudo dnf install libicu-devel ncurses-devel # also zlib-devel if not already installed
```
#### Windows-specific pre-requirements
In order to avoid problems with long paths on Windows you can do either one of the following:
1. Clone the `haskell-language-server` to a short path, for example the root of your logical drive (e.g. to
`C:\hls`). Even if you choose `C:\haskell-language-server` you could hit the problem. If this doesn't work or you want to use a longer path, try the second option.
2. If the `Local Group Policy Editor` is available on your system, go to: `Local Computer Policy -> Computer Configuration -> Administrative Templates -> System -> Filesystem` set `Enable Win32 long paths` to `Enabled`. If you don't have the policy editor you can use regedit by using the following instructions [here](https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#enable-long-paths-in-windows-10-version-1607-and-later). You also need to configure git to allow longer paths by using unicode paths. To set this for all your git repositories use `git config --system core.longpaths true` (you probably need an administrative shell for this) or for just this one repository use `git config core.longpaths true`.
In addition make sure `haskell-language-server.exe` is not running by closing your editor, otherwise in case of an upgrade the executable can not be installed.
**For a full explanation of possible configurations, refer to [hie-bios/README](https://github.com/mpickering/hie-bios/blob/master/README.md).**
haskell-language-server has some limited support via hie-bios to detect automatically
your project configuration and set up the environment for GHC.
The plan is to improve it to handle most use cases.
However, for now, the more reliable way is using a `hie.yaml` file in the root
of the workspace to **explicitly** describe how to setup the environment.
For that you need to know what *components* have your project and the path
associated with each one. So you will need some knowledge about
[stack](https://docs.haskellstack.org/en/stable/build_command/#components) or [cabal](https://cabal.readthedocs.io/en/latest/cabal-commands.html?#cabal-v2-build) components.
Note to editor integrators: there is a `haskell-language-server-wrapper` executable, which is installed alongside the `haskell-language-server` 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 `haskell-language-server` executable.
All of the editor integrations assume that you have already installed `haskell-language-server` (see above) and that the installation script put the `haskell-language-server` and `haskell-language-server-wrapper` binaries in your `PATH` (usually `~/.local/bin` or `~/.cabal/bin` on Linux and macOS, `%APPDATA%\local\bin` or `%APPDATA%\cabal\bin` on Windows).
[the VSCode marketplace](https://marketplace.visualstudio.com/items?itemName=alanz.vscode-hie-server), or manually from the repository [vscode-hie-server](https://github.com/alanz/vscode-hie-server).
Choose `haskell-language-server` in the extension setting `languageServerHaskell.hieVariant`.
### Using Haskell Language Server with Sublime Text
- Install [LSP](https://packagecontrol.io/packages/LSP) using [Package Control](https://packagecontrol.io/)
and issuing a `:PlugInstall` command within Neovim or Vim.
##### Clone the LanguageClient-neovim repo
As an alternative to using [vim-plug](https://github.com/junegunn/vim-plug) shown above, clone [LanguageClient-neovim](https://github.com/autozimu/LanguageClient-neovim)
into `~/.vim/pack/XXX/start/`, where `XXX` is just a name for your "plugin suite".
##### Sample `~/.vimrc`
```vim
set rtp+=~/.vim/pack/XXX/start/LanguageClient-neovim
let g:LanguageClient_serverCommands = { 'haskell': ['haskell-language-server-wrapper', '--lsp'] }
```
You'll probably want to add some mappings for common commands:
The plugin ide-haskell-hie is designed to work with haskell-ide-engine by default, so you will have to put the path to haskell-language-server-wrapper in the configuration option `Absolute path to hie executable`.
The developers tend to hang out at [our IRC channel](https://webchat.freenode.net/?channels=haskell-ide-engine) at `#haskell-ide-engine` on `freenode`.
