(λx.x) Ben Hanna

Software Engineer and Functional Programming Enthusiast

Setting up a Haskell Environment in Ubuntu


These instructions have been tested against Kubuntu 18.04 LTS.

In the process of learning Haskell, I've recently gone through the various editors to try and see which one has the ideal tooling. There's many different opinions on the matter, but for me I've settled on Emacs with intero. I went with intero because it has solid type-checking, an interactive REPL, and doesn't require a whole lot of configuration to get going. With that said, I'll show you how to setup this environment in the context of an Ubuntu system.

Install Stack

The first thing we need to install is stack. If you come from a Node.js background then stack is somewhat akin to the functionality nvm and npm provide. Some of the most prominent features stack provides are dependency installation, scaffolding for new projects, and GHC version management.

To install stack, run the following command.

wget -qO- https://get.haskellstack.org/ | sh

Once installed, the stack binary will be available to use in your terminal.

Install Emacs

Installing Emacs in Ubuntu is a fairly trivial task that can be performed with the following command.

sudo apt-get install emacs

After installation, startup emacs at least once so that it initializes your emacs.d folder.

Install Intero

Now before we install intero we also need install libtinfo-dev, without this package intero will fail to build with stack lts-11.

sudo apt-get install libtinfo-dev

Next place the following into ~/.emacs.d/init.el.

;; If you don't have MELPA in your package archives:
(require 'package)
(add-to-list
  'package-archives
  '("melpa" . "http://melpa.org/packages/") t)
(package-initialize)
(package-refresh-contents)

;; Install Intero
(package-install 'intero)
(add-hook 'haskell-mode-hook 'intero-mode)

With that file place, just open emacs in a terminal and intero should start installing.

Create a Test Project

To verify that everything is working, create a new project with stack.

stack new test-project
cd test-project
stack setup

Now open src/Lib.hs and modify the code. You should see type errors come up as you change the file.

For more information on the rest of the features intero provides see the repository.