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Ocaml 3.01 and camlp4 syntax?
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Date: 2008-11-12 (23:22)
From: Erik de Castro Lopo <mle+ocaml@m...>
Subject: Ocaml 3.01 and camlp4 syntax?
Hi all,

Mostly out of curiosity, I'm having a look at the efuns Emacs
clone written in Ocaml:


and trying to compile it with a recent Ocaml compiler like 3.10.2.

>From the files, it seems that the last version of Ocaml this code
compiled with was 3.01 (around the year 2000?). I've managed to find
fixes for a bunch of problems.

One of those problems was that one of the files (common/options.ml)
had code like this:

    open Genlex
    let lexer = make_lexer [ "=" ; "{" ; "}"; "["; "]"; ";" ; "("; ")"; ","; "."]
    let rec parse_gwmlrc = parser
        [< id = parse_id; 'Kwd "="; v = parse_option ; 
          eof = parse_gwmlrc >] -> (id, v) :: eof
    | [< >] -> []

which the current compiler complained about "[<". A bit of googling
suggested that this was in fact camlp4 source code. Sure enough,
renaming that file to pa_options.ml and running it throught camlp4
resulted in a file that the standard compiler digested quite happily.

I've now come to another file gwml/afterstep.mll that seems to be
ocamllex source code but again has these camlp4 like extensions.
Unfortunately camlp4 doesn't like this file, probably because it
has ocamllex syntax instead of ocaml syntax.

So, I have two questions :

 1) Did early versions of ocaml (say up to and including 3.01) handle
    constructs like those above that were later removed and and added
    to camlp4 instead?

 2) Any suggestions on how to handle the camlp4 syntax stuff in an
    ocamllex source file? Obviously, this code could be extracted
    and placed in its own file but I'm open to other suggestions.

Erik de Castro Lopo
Seen on comp.lang.python:
Q : If someone has the code in python for a buffer overflow,
    please post it.
A : Python does not support buffer overflows, sorry.