In this course we use VS Code and Docker to set up a development environment with everything you need (compiler, interpreter, package manager and packages) for using Haskell in this course. Alternatively, you can install Haskell by yourself using ghcup (https://www.haskell.org/ghcup/), see the bottom of this page.

If you run into issues, send us a message over at the #tech-support channel on Slack, and we'll do our best to resolve your issue!

Getting started with VS Code and Docker

There are three steps: (1) installing VS Code (2) Installing Docker, and (3) Running Haskell in a Docker Container

1. Installing VS Code

VS Code is a recent editor from Microsoft that has everything you need to effectively develop Haskell programs, with Language Server integration, optional modal editing (for the vimmers out there), and nice remote development interfaces for compiling and running on remote machines. Most importantly, VS Code allows you to easily integrate a small VM-like service (Docker) to automatically set up a development environment, which we use in this course.

Windows

Go to https://code.visualstudio.com/
Click the 'Download for Windows' button
Run the installer and follow the instructions

MacOS

Go to https://code.visualstudio.com/
Click the 'Download for macOS' button
Run the installer and follow the instructions

Alternatively, follow the instructions here: https://code.visualstudio.com/docs/setup/mac

Linux

Ubuntu

Go to https://code.visualstudio.com/#alt-downloads
Download the .deb file
Run sudo apt install ./<file>.deb

Alternatively, follow the instructions on https://code.visualstudio.com/docs/setup/linux to add it via apt.
Nix

Run nix-env -i vscode

Note: you might run into issues on Nix with the node exectuable linked in the
.vscode-server directory not linking to the right one, so you'll have to go to
./vscode-server/bin/<hash> and link it to one on your system with ln -s $(which node) node

Other

You probably know how to install it already, otherwise reach out to us in #tech-support

2. Installing Docker

Docker is a virtualization tool that allows you to containerize applications, essentially defining a small virtual machines with everything needed to run a tool or an app. In this course, we use it to run a small Linux container with all the tools and packages needed for the course, though Docker is widely used in industry to run apps and servers in production environments (often in combination with an orchestrator). Most importantly, Docker and VS Code allow us to define an environment to get started, without having to rely too heavily on system specific settings.

Windows

Go to https://docs.docker.com/desktop/windows/install/ and click the 'Download Desktop Docker for Windows' button.
Launch the installer and follow the instructions. This can take a few minutes, so go hydrate in the meantime.
(Might not be required) Restart your computer to enable the service and login
Open the Docker Desktop application to start the backend (Press the Windows key and write Docker, and then Enter on Docker Desktop). You'll have to accept the terms and conditions in the pop-up on the first launch, so you might have to hunt for that window when it pops up.

MacOS

For macOS it's a bit weird, since there are two versions: one for the old Intel chip and one for the new M1 chip.

Follow the instructions here https://docs.docker.com/desktop/mac/install/

Make sure to pick the right version. In general, older Macs are Intel, while newer ones (M1, M2) are Apple Silicon.

Note: if it is running very slow, you might want to consider running it locally instead of via Docker (see below).

On some machines, you might also have to increase the memory of the virtual machines. You do this by going into the Docker Deskt op App > Preferences (gear wheel) > Resources and moving the Memory slider to 4gb (or even 8gb if 4gb doesn't work).

Linux

Using Docker on Linux is a bit of an overkill, since you're already running Linux. But it helps with making sure that compiler and libraries are all the same.

Ubuntu
Follow the instructions at https://docs.docker.com/engine/install/ubuntu/
Nix
Follow the instructions at https://nixos.wiki/wiki/Docker
Other

You can probably figure it out yourselves, otherwise talk to us in `#tech-support`.

3. Running In A Container

After installing VS Code and Docker, development is a breeze:

Note that you can re-use the container from this course in other projects: simply copy the .devcontainer directory to a new folder.

Getting started with ghcup

An alternative way to install is not using docker at all, and installing the necessary Haskell packages as you need them. The best way to do this is using ghcup. Go to https://www.haskell.org/ghcup/ and follow the instructions for your platform. This will install recommended versions of ghc and cabal. You will also get prompted to install stack and the Haskell language serer (HLS). Stack is a build tool for Haskell while HLS can be used to provide some Haskell support for your code editor. You will not need either in this course but you are free to install them if you wish.

In order to complete the labs you will need to install a few packages (if you are using the Docker image they are already installed). You can install the necessary packages for the first couple of labs by running cabal install --lib QuickCheck random.