virtual instance variables

virtual instance variables

[Jeremy Yallop]

Should this be considered a bug?

    # (object val virtual c : float method m = c end) # m;;
    Segmentation fault

Re: [Caml-list] virtual instance variables

[Jon Harrop]

On Thursday 28 June 2007 14:34:20 Jeremy Yallop wrote:
> Should this be considered a bug?
>
>     # (object val virtual c : float method m = c end) # m;;
>     Segmentation fault

Yes:

$ ocaml
        Objective Caml version 3.09.1

# (object val virtual c : float method m = c end) # m;;
Syntax error

$ ocaml
        Objective Caml version 3.10.0

# (object val virtual c : float method m = c end) # m;;
Signal -10

and what is signal -10?! :-)

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
The OCaml Journal
http://www.ffconsultancy.com/products/ocaml_journal/?e

Re: [Caml-list] virtual instance variables

[Vincent Hanquez]

On Thu, Jun 28, 2007 at 02:47:59PM +0100, Jon Harrop wrote:
> $ ocaml
>         Objective Caml version 3.10.0
> 
> # (object val virtual c : float method m = c end) # m;;
> Signal -10
> 
> and what is signal -10?! :-)

$ ocaml
        Objective Caml version 3.10.0

# Sys.sigsegv;;
- : int = -10
# 


-- 
Vincent Hanquez

Re: [Caml-list] virtual instance variables

[Jacques Garrigue]

From: Jeremy Yallop <jeremy.yallop@ed.ac.uk>

> Should this be considered a bug?
> 
>     # (object val virtual c : float method m = c end) # m;;
>     Segmentation fault

Any segmentation fault using no unsafe features is clearly a bug, and
should go in the bug database.
Should be fixed soon.

Jacques Garrigue

virtual instance variables

[micha]

entering in the toplevel: 

class virtual c = object val virtual d : int end;;

then:

class d = object inherit c val d = 9 end;;

gives me: Exception: Not_found.
What is not found?  (compiling works)

if I define:
 class virtual c = object val d = 0 end;;
 class d = object inherit c val d = 9 end;;

gives the warning:
Warning V: the instance variable d is overriden.
The behaviour changed in ocaml 3.10 (previous behaviour was hiding.)

I thought that  without the virtual declaration the behaviour is the
same as before?

cheers,
 Michael