GODI – The source code Objective Caml distribution

Via its homepage:

GODI provides an advanced programming environment for the Objective Caml (O’Caml) language.

From INRIA (who created O’Caml) you can get the O’Caml compiler and runtime system, but this is usually not enough to develop applications. You also need libraries, and there are many developers all over the world providing them; you can go and pick them up. But it is a lot of work to build and install them.

GODI is a system that simplifies this task: It is a framework that automatically builds the O’Caml core system, and additionally installs a growing number of pre-packaged libraries. For a number of reasons GODI is a source-code based system, and there are no precompiled libraries, but it makes it very simple for everybody to compile them.

GODI is available for O’Caml-3.10 and 3.11. It runs on Linux, Solaris, FreeBSD, NetBSD, Windows (Cygwin and MinGW), HP-UX, MacOS X.

Enhanced Ocaml Documentation Version 3.12

The Enhanced Ocaml Documentation is provided by Hendrik Tews; basically it visually highlights any difference between the previous and current version of the documentation. Here is how he does it:

I diff the txt versions of the reference manual and change the html version by hand. For the grammar rule index I use a tool and manual editing.

–Hendrik Tews

Wow. What a labor of love. Be sure to give him a hand!

(via Caml-list)

Resources for Learning CamlP4

For an accessible introduction to modern (>= 3.10) Camlp4, you may be interested in Jake Donham’s blog post series “Reading Camlp4” : http://ambassadortothecomputers.blogspot.com/search/label/camlp4
You will also find valuable (though incomplete) information on the camlp4 wiki : http://brion.inria.fr/gallium/index.php/Camlp4

The older version of camlp4 (< 3.10, now called camlp5) also provides a documentation http://caml.inria.fr/pub/docs/tutorial-camlp4/index.html , and you can also use to Martin Jambon’s tutorial
http://martin.jambon.free.fr/extend-ocaml-syntax.html (for the older camlp4).

— bluestorm

You can also see the articles in sequence at


which I recommend since later articles depend on earlier material.

— Jake Donham

Shameless self-plug, but I wrote a blog post this summer about my experience figuring out how to do it. I provide a walk-through and explanation of a minimal syntax extension which adds lazy list pattern matching support based on Batteries. The URL:


I do assume a basic knowledge of parsing context-free grammars, but a generic tutorial on parsing with a tool such as Yacc can fill in that gap. The Wikipedia article[1] may also be helpful.

Once you’ve lept the hurdle of figuring out what pieces you need to write and build a syntax extension, the remaining tricky part is to figure out what pieces of the grammar you need to extend to accomplish your objective. For that, I consult the definition of the OCaml parser in Camlp4OCamlParser.ml in the OCaml source tree.
1. http://en.wikipedia.org/wiki/Context-free_grammar

— Michael Ekstrand

If you consider yourself as a n00b, don’t start by camlp4. This is probably the most difficult part of OCaml — and to program camlp4 you need to use OCaml standard syntax (or revised syntax, it depends if you
use antiquotations).

If you still want to follow the hard path, as suggested elsewhere, Jake Donham’s blog posts are very good:


Or if you are around, there is a tutorial session at CUFP:
(but you need to subscribe).

— Sylvain Le Gall

(via Caml-list)