]> OK, this is my new polynom parser, it seems to work OK, thanks to your explanations. let rec parse s = let parse_puissance = parser | [< ''^'; e = parse_int >] -> e | [< >] -> 1 in let parse_x = parser | [< ''X'; e = parse_puissance >] -> e | [< >] -> 0 in let parse_coeff = parser | [< n = R.parse >] -> n | [< >] -> R.one in let parse_monome = parser | [< n = parse_coeff; e = parse_x >] -> monome n e | [< e = parse_x >] -> monome R.one e in let rec parse_suite = parser | [< ''+'; m = parse_monome; p = parse_suite >] -> m ++ p | [< ''-'; m = parse_monome; p = parse_suite >] -> (opp m) ++ p | [< >] -> zero in match s with parser | [< m = parse_monome >] -> match parse_suite s with | p -> m ++ p and the results : # print (P.parse (Stream.of_string "-1+3X+4X^2"));; [3: -1, 3, 4]- : unit = () # print (P.parse (Stream.of_string ""));; [1: 1]- : unit = () Oups !! What do you think about this ? \bye -- Nicolas FRANCOIS http://nicolas.francois.free.fr A TRUE Klingon programmer does NOT comment his code ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners