Original bug ID: 1064
Reporter: administrator
Status: closed
Resolution: fixed
Priority: normal
Severity: minor
Category: ~DO NOT USE (was: OCaml general)

Bug description

Full_Name: Jacek Chrzaszcz
Version: 3.04
OS: Linux
Submission from: fw-gw-atm.mimuw.edu.pl (193.0.96.15)

Hello,

One of my first-year student found this bug during a "TP" session:

If you have your own qinterface file map.cmi in your current directory and then
start ocaml and (forgetting about #load "map.cmo") try to use your module, like

    Objective Caml version 3.04

let a=Map.empty_map in Map.update a 7 "a";;

• you get a Segmentation fault

I would guess the toplevel finds the interface in the current directory and the
implementation in memory (stdlib) and ....they do not match...

I do not suppose Set or List modules would behave any better, but I include
map.mli below just in case.

Jacek Chrzaszcz

PS. I remember I found a similar bug a while ago. It is fixed/43
PS2. I hope you don't mind the comments in Polish below. The guy who wrote it is
a good student. He writes a lot of comments :)

---------cut----------
type ('a, 'b) map;;
(* mapa ma dwa typy abstrakcyjne:
'a - typ wspolrzednej
'b - typ przechowywanych danych *)

val empty_map: ('a, 'b) map;;
(* [empty_map] daje pusta mape *)

val dom: ('a, 'b) map -> 'a -> bool;;
(* [dom m x] odpowiada na pytanie "czy do mapy [m] byl wkladany element o
wspolrzednych [x] ?" *)

val apply: ('a, 'b) map -> 'a -> 'b;;
(* [apply m x] zwraca dane przechowywane w mapie [m] na wspolrzednych [x].
Jesli element o tych wspolrzednych nie istnieje, podnosi wyjatek
Not_found *)

val update: ('a, 'b) map -> 'a -> 'b -> ('a, 'b) map;;
(* [update m x d] wstawia do mapy [m] dane [d] w miejscu o wspolrzednych
[x]. Jesli w miejscu [x] jest juz przechowywany jakis element, to
zostanie
on zamieniony na [d]. Zwraca tak zmodyfikowana mape. *)