How to set up your development environment

This section explains how to set up a development environment on your local machine. At the end of this tutorial, you will be able to follow the tutorial howto-write-an-exercise.md. For the moment, only GNU/Linux and MacOS X are supported.

An alternative to following the instructions below is to use a pre-built Docker container. Assuming you have an exercise repository in directory $REPOSITORY (absolute path), and a recent enough version of Docker installed, use:

docker version # If this fails, find out how to run Docker, first
docker login
docker run --rm \
  -v $REPOSITORY:/repository:ro \
  -v learn-ocaml-sync:/sync \
  -p 80:8080 --name learn-ocaml-server \

This will start an instance of the learn-ocaml server on port 80 (ignore the message about 8080, this is the port used internally). An example repository can be obtained in the demo-repository directory of learn-ocaml.

Software requirements

Please make sure that the following tools are available on your machine:

To install opam, please follow the instructions described on the Official OPAM website.

The other dependencies are installed automatically by opam.

Step 0: What we are about to do

We will install in directory $DIR a fresh copy of learn-ocaml source tree as well as a source directory into which you will develop your exercises.

Step 1: Install the learn-ocaml platform locally

We assume that the current directory is $DIR.

First, clone the current learn-ocaml source tree:

git clone git@github.com:ocaml-sf/learn-ocaml.git && cd learn-ocaml

If you do not have a GitHub account, do instead:

git clone https://github.com/ocaml-sf/learn-ocaml.git && cd learn-ocaml

Get an opam environment (a.k.a “switch”) with the learn-ocaml dependencies ready:

opam switch create . --deps-only --locked
opam install opam-installer
eval $(opam env)

(Alternatively, use opam install . --deps-only to install the dependencies in your current opam switch, without creating a dedicated one.)

Second, compile and install the platform:

make && make opaminstall

At this point, you should get a working learn-ocaml program in your path. Try:

learn-ocaml --help

This should open the manpage of the command-line tool to interact with the platform.

Note for developers: An API documentation could be partially generated with the make doc command. Currently, the only two supported modules are Test_lib and Learnocaml_report.

Step 2: Set up a work directory

Now, let us go back to $DIR and create a root for the source tree of exercises:

cd $DIR && cp -fr learn-ocaml/demo-repository my-learn-ocaml-repository

Step 3: Sanity check

Check that your installation works:

learn-ocaml build --repo my-learn-ocaml-repository
learn-ocaml serve

This should output several lines in your terminal ending with:

Starting server on port 8080

At this point, browsing http://localhost:8080 should get you to the homepage of the learn-ocaml instance that is running on your local machine.

You are now ready to write your first exercise! Please proceed to the next tutorial How to write exercises?