Le mardi 26 octobre 2010 à 17:55 +0200, Emmanuel Dieul a écrit :
> let format_date =
>    let format_valeur = function valeur ->
>      (if valeur < 10 then "0" else "") ^ (string_of_int valeur)
>    in
>    function date ->
>      Printf.sprintf "%s/%s/%l %s:%s:%s"
>        format_valeur(date.Unix.tm_mday)
>        (format_valeur(date.Unix.tm_mon + 1) : string)
>        (date.Unix.tm_year + 1900)
>        (format_valeur(date.Unix.tm_hour) : string)
>        (format_valeur(date.Unix.tm_min) : string)
>        (format_valeur(date.Unix.tm_sec) : string)
> ;;
> 

Here, the argument to the Printf.sprintf function are : 
"%s/%s/%l %s:%s:%s", format_valeur, date.Unix.tm_mday, ...

Just add parenthesis around (format_valeur date.Unix.tm_mday) (but
without any type annotation) to pass the _result_ of this application to
the sprintf function. You don't need parenthesis around the argument of
the function though.

Mathias