Basically, it allows you to inline C in OCaml code, in a very fashionable way. Type conversion between OCaml and C is (almost always) automatically dealt with for base types (int, float, bool, string, etc.) and you can register and unregister custom converters. A few examples are shown in the test.ml.

The idea behind all this syntaxic sugar for inlining C code in OCaml is to provide a natural way of using C and OCaml together to whoever wants to bind C libraries to OCaml. Of course, this is still under developement, and any ideas to improve it are welcome.

Here is what one can write:

The ext keyword is the equivalent of let to define external functions. All types must be specified (for the arguments and for the return value. Camlp4 the generates the C function, the external declaration etc.

Using camlp4, we extract the quotations containing C code and we dump that in a temporary .c file, and compile it. Here is an example:

The thing we would like to do is the following:

Which would be converted to:

There is nothing difficult to understand (it was actually difficult to do). An object is just a hashtable and a parent object. Typing is bypassed using Obj.magic

Let's have a little fun:

The result:

Note : This is only a proof of concept, never use this in OCaml, it is not at all compliant with OCaml philosophy. It's funny, however

I started by modifying Thumper which I slightly modified (in order to deal with post queries). Then I added OCaml CGI to encode and decode queries, SpiderCaml which includes SpiderMonkey in OCaml and OCaml Mysql to use MySQL. Actually this was more like doing Lego than coding…

What can it do ?
URIs are parsed as : /module/action/arg1/arg2/arg3. This will execute Module.action(arg1, arg2, arg3), where Module is defined in the file modules/module.js. The default module being home and the default action, index.

This being said, their is a Joo object in the global namespace which contains useful stuff:

Note : the print function just adds text to the output buffer, their is no control on the flushing, sorry. Everything is sent at the end.
Moreover, I have added the MIME types only for html and jpeg files, you may want to add other MIME types in main.ml

First, what does it look like ?

I bet most of you have already played to those games where you have to click on colored boxes on a grid to make them disappear. Sandclick is exactly this king of game, the only difference is in the way it deals with falling boxes.

Usually, in those games, when a colored block is above and empty space, it falls into it. In Sandclick, blocks fall like sand : grains can fall on the side, here is what happens when there is an empty space:

• if there is something above, this something falls down
• if not, then the content of what is on the top left or top right falls

And it goes on and on until it stabilizes.

Basically a zipper is a list which has a cursor, thus reading and moving through is non destructive.

A simple example :

Its result :

It is however absent from OCaml… Of course, it can be emulated:

But this is really too much… Wouldn't it be nice to write something like that :

The [+ (* ... *)] indicates that this is a list comprehension. This actually is possible using camlp4

Tout d'abord, il faut savoir qu'en caml, les choses suivantes sont équivalentes :
# 0xf;;
- : int = 15
# 0o17;;
- : int = 15
# 0b1111;;
- : int = 15
# 15;;
- : int = 15
Le premier est écrit en hexadécimal, le second en ocal, le troisième en binaire, et le dernier en décimal. Donc la gestion de l'hexadécimal en OCaml est native.

Une des utilisations courantes de l'hexadécimal est pour représenter les couleurs en 65536 couleurs. Pour convertir un entier en tuple r,g,b on peut utiliser la fonction suivante :

Dans l'autre sens, c'est un peu plus compliqué : en effet, en mémoire tous les entiers sont stockés de la même manière (int31 à la caml), et on s'en fiche de savoir sous quelle forme ils sont entrés. Mais ce n'est pas un drame ; effectivement, on a besoin d'avoir un entier sous forme hexadécimale principalement pour l'affichage, donc on utilise les fonctions du module Printf :

Je vous renvoie à la documentation du module Pervasives pour plus de détails.

Espérons que maintenant ceux qui passeront ici en cherchant ocaml hexadécimal repartirons heureux