[Caml-list] Pippo: a pretty interesting pre-processor that uses OCaml

[Jonathan Protzenko <jonathan.protzenko@gmail.com>]

Hi,

Following yesterday's discussion, and using that as a pretext for 
writing my own tool, here's yet another pre-processor-sort-of.

https://github.com/protz/pippo

It requires OCaml 4.01.0rc1. The documentation for it is, of course, 
pre-processed using Pippo. It is distributed with a Makefile that 
allows you to recompile the documentation and thus play with the tool.

It works as described in yesterday's thread: anything found between {% 
and %} is fed to an OCaml interactive session. Therefore, the output of 
the OCaml commands is interleaved with the non-OCaml parts of the file. 
Basically, the tool allows you to script your documents easily.

The tool also contains a special "inject_value" facility, that allows 
you to make any OCaml value (constant, function) available in the 
top-level session. For instance, running:

  inject_value
    "__version"
    "unit -> unit"
    (fun () ->
      print_endline "This is pippo v0.1");

will allow you to write, in the to-be-pre-processed document :

{%
  __version ();
%}

For the record, the question (how do I use Toploop.setvalue) was asked 
a few years ago but left unanswered 
<http://caml.inria.fr/pub/ml-archives/caml-list/2009/03/7e9085b8601142024108e254df9dfb1e.en.html>. 
The OCaml maintainers should probably not look at the implementation, 
by the way.

Cheers,

~ jonathan

PS: My warmest thanks go to Thomas Braibant for helping me find a name 
with a pun (in French)