Installation

The Quick Way

The rest of this document explains how to install pa_ppx the hard way. Here, we’ll explain the easy way, which is to use opam:

opam install camlp5 pa_ppx

That’s it. You’ll want to get the sources, so you can look at the tests (as samples).

For those who wish to do things “manually” or hack on camlp5/pa_ppx, there are somewhat strict version-constraints that limit which versions of camlp5 and pa_ppx are compatible with each version of OCaml (due to the fact that OCaml’s AST changes from version-to-version). This is why it is easiest to just install via opam, but we describe below the steps of manual installation. Consult the opam files to see what the version-requirements are for prerequisites.

Prerequisites

1. Ocaml

To install pa_ppx you’ll need Ocaml (version >= 4.10.0) and Camlp5 (version >= 8.00).

You can install both Ocaml and Camlp5 in the usual way, typically via opam.

2. ocamlfind and not-ocamlfind

ocamlfind is unavoidable, and I’ve written a little wrapper, not-ocamlfind that provides some useful extra commands, which I’ll refer to throughout this documentation:

opam install ocamlfind not-ocamlfind

3n. Various other ocaml packages:

``pa_ppx`` has tests to verify that things work with both ``pa_ppx``

and the standard PPX rewriters, so there are a ton of extra packages needed. The best way to get them all is to let opam do the work:

opam install --deps-only -t .

Building and Installing

Once having installed camlp5, you can build and install pa_ppx via:

make && make install

and you can run (copious) tests (some of which fail – I’m working on that!):

make -k test