IHaskell

You can now try IHaskell directly in your browser at CoCalc or mybinder.org.

Alternatively, watch a talk and demo showing off IHaskell features.

IHaskell is a kernel for the Jupyter project, which allows you to use Haskell inside Jupyter frontends (including the console and notebook). It currently supports GHC 8.4 through 9.10.

For a tour of some IHaskell features, check out the demo Notebook. More example notebooks are available on the wiki. The wiki also has more extensive documentation of IHaskell features.

Interactive In-Browser Notebook

Installation

Linux

Some prerequisites; adapt to your distribution.

sudo apt-get install -y python3-pip git libtinfo-dev libzmq3-dev libcairo2-dev libpango1.0-dev libmagic-dev libblas-dev liblapack-dev

Install stack, clone this repository, install Python requirements, install ihaskell, and install the Jupyter kernelspec with ihaskell.

These instructions assume you don't already have Stack or a Jupyter installation, please skip the relevant steps if this is not the case.

curl -sSL https://get.haskellstack.org/ | sh
git clone https://github.com/gibiansky/IHaskell
cd IHaskell
pip3 install -r requirements.txt
stack install --fast
ihaskell install --stack

Run Jupyter.

stack exec jupyter -- notebook

Mac

You need to have Homebrew installed. If you do not have it yet run /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" in your terminal.

You also need the Xcode command line tools. You can install them by running xcode-select --install in the terminal and following the prompts.

These instructions assume you don't already have Stack or a Jupyter installation, please skip the relevant steps if this is not the case.

brew install python3 zeromq libmagic cairo pkg-config haskell-stack pango
git clone https://github.com/gibiansky/IHaskell
cd IHaskell
pip3 install -r requirements.txt
stack install --fast
ihaskell install --stack

If you have Homebrew installed to a location that stack does not expect (e.g. /opt/homebrew), you'd need to specify --extra-include-dirs ${HOMEBREW_PREFIX}/include --extra-lib-dirs ${HOMEBREW_PREFIX}/lib to the stack command.

Run Jupyter.

stack exec jupyter -- notebook

Tested on macOS Sierra (10.12.6)

Windows

IHaskell does not support Windows, however it can be used on Windows 10 via Windows Subsystem for Linux (WSL). If WSL is not installed, follow the Installation Guide for Windows 10. The following assumes that Ubuntu is picked as the Linux distribution.

In the Ubuntu app, follow the steps above for Linux.

Jupyter Notebook is now ready to use. In the Ubuntu app, launch a Notebook Server, without opening the notebook in a browser:

jupyter notebook --no-browser

Returning to Windows 10, open a browser and copy and paste the URL output in the step above (the token will differ).

Or copy and paste one of these URLs:
     http://localhost:8888/?token=9ca8a725ddb1fdded176d9e0e675ba557ebb5fbef6c65fdf

Tested on Windows 10 (build 18362.175) with Ubuntu 18.04 on WSL

Alternatively, install Virtualbox, install Ubuntu or another Linux distribution, and proceed with the install instructions.

Docker

To quickly run a Jupyter notebook with the IHaskell kernel, try the Dockerfile in the top directory.

docker build -t ihaskell:latest .
docker run --rm -p 8888:8888 ihaskell:latest

Or use the continuously updated Docker image on Docker Hub.

docker run --rm -p 8888:8888 gibiansky/ihaskell

In order to mount your own local files into the Docker container use following command:

docker run --rm -p 8888:8888 -v "$PWD":/home/jovyan/src gibiansky/ihaskell

Be aware that the directory you're mounting must contain a stack.yaml file. A simple version would be:

resolver: lts-16.23
packages: []

It's recommended to use the same LTS version as the IHaskell image is using itself (as can be seen in its stack.yaml). This guarantees that stack doesn't have to first perform a lengthy installation of GHC before running your notebook.

You can also use the following script to run IHaskell in Docker: https://gist.github.com/brandonchinn178/928d6137bfd17961b9584a8f96c18827

Nix

If you have the nix package manager installed, you can create an IHaskell notebook environment with one command. For example:

$ nix-build -I nixpkgs=https://github.com/NixOS/nixpkgs/tarball/nixos-23.05 release.nix --argstr compiler ghc928 --arg packages "haskellPackages: [ haskellPackages.lens ]"
<result path>
$ <result path>/bin/jupyter notebook

It might take a while the first time, but subsequent builds will be much faster. You can use the https://ihaskell.cachix.org cache for prebuilt artifacts.

The IHaskell display modules are not loaded by default and have to be specified as additional packages:

$ nix-build -I nixpkgs=https://github.com/NixOS/nixpkgs/tarball/nixos-23.05 release.nix --argstr compiler ghc928 --arg packages "haskellPackages: [ haskellPackages.ihaskell-blaze haskellPackages.ihaskell-charts ]"

For more examples of using IHaskell with Nix, see https://github.com/vaibhavsagar/notebooks.

Developing

IHaskell is regularly updated to work with the latest version of GHC. To read how this is done, and how the development environment is set up, please see this blog post.

Nix flake

There is also a Nix flake that provides a developer environment. For details on Nix flakes, please see the documentation at https://wiki.nixos.org/wiki/Flakes.

After this, IHaskell can be compiled as follows:

nix develop # This opens a new shell with all dependencies installed
cabal update # Make sure Cabal's package index is up-to-date
cabal build # Builds IHaskell

Note that this shell also provides haskell-language-server, which can be used in your editor if it supports it. Opening your editor from within the nix develop shell should allow it to see haskell-language-server.

Troubleshooting

Where are my packages? (IHaskell + Stack)

Stack manages separate environments for every package. By default your notebooks will only have access to a few packages that happen to be required for IHaskell. To make packages available add them to the stack.yaml in the IHaskell directory and run stack install --fast.

Packages should be added to the packages: section and can take the following form (reproduced here from the stack documentation). If you've already installed a package by stack install you can simply list its name even if it's local.

- package-name
- location: .
- location: dir1/dir2
- location: https://example.com/foo/bar/baz-0.0.2.tar.gz
- location: http://github.com/yesodweb/wai/archive/2f8a8e1b771829f4a8a77c0111352ce45a14c30f.zip
- location:
    git: git@github.com:commercialhaskell/stack.git
    commit: 6a86ee32e5b869a877151f74064572225e1a0398
- location:
    hg: https://example.com/hg/repo
    commit: da39a3ee5e6b4b0d3255bfef95601890afd80709

The kernel keeps dying (IHaskell + Stack)

The default instructions globally install IHaskell with support for only one version of GHC. If you've e.g. installed an lts-10 IHaskell and are using it with an lts-9 project the mismatch between GHC 8.2 and GHC 8.0 will cause this error. Stack also has the notion of a 'global project' located at ~/.stack/global-project/ and the stack.yaml for that project should be on the same LTS as the version of IHaskell installed to avoid this issue.