Merge pull request #115 from yuanw/doom-emacs-doc

Add emacs/doom-emacs integration sub-section

Author: fendor

README.md

@@ -25,6 +25,9 @@ This is *very* early stage software.
         - [Install via cabal](#install-via-cabal)
         - [Install specific GHC Version](#install-specific-ghc-version)
   - [Project Configuration](#project-configuration)
+  - [Editor Integration](#editor-integration)
+    - [With emacs](#using-haskell-language-server-with-emacs)
+    - [With doom emacs](#using-haskell-language-server-with-doom-emacs)
   - [Contributing](#contributing)
     - [It's time to join the project!](#its-time-to-join-the-project)
 
@@ -267,6 +270,56 @@ dependencies:
   - someDep
 ```
 
+## Editor Integration
+
+Note to editor integrators: there is now 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 binary in your path (usually `~/.local/bin` or `~/.cabal/bin` on linux and macOS).
+
+### Using haskell-language-server with Emacs
+
+Install HLS along with the following emacs packages:
+
+[lsp-mode](https://github.com/emacs-lsp/lsp-mode)
+[lsp-ui](https://github.com/emacs-lsp/lsp-ui)
+[lsp-haskell](https://github.com/emacs-lsp/lsp-haskell)
+
+Make sure to follow the instructions in the README of each of these packages.
+
+``` emacs-lisp
+(use-package lsp-haskell
+ :ensure t
+ :config
+ (setq lsp-haskell-process-path-hie "haskell-language-server-wrapper")
+ ;; Comment/uncomment this line to see interactions between lsp client/server.
+ ;;(setq lsp-log-io t)
+)
+```
+
+
+
+### Using haskell-language-server with [doom-emacs](https://github.com/hlissner/doom-emacs/tree/develop/modules/lang/haskell#module-flags)
+
+Install haskell-language-server, and then enable haskell lang module with lsp flag in `.doom.d/init.el`
+``` emacs-lisp
+:lang
+(haskell +lsp)
+```
+
+in your `.doom.d/config.el` file
+
+``` emacs-lisp
+(use-package lsp-haskell
+ :ensure t
+ :config
+ (setq lsp-haskell-process-path-hie "haskell-language-server-wrapper")
+ ;; Comment/uncomment this line to see interactions between lsp client/server.
+ ;;(setq lsp-log-io t)
+)
+```
+
+then do `$HOME/.emacs.d/bin/doom refresh`
+
 ## Contributing
 
 ### It's time to join the project!