On Mon, Oct 17, 2005 at 11:52:56AM +0200, Bill Allombert wrote:
> It looks like hugs segfault if you instance Show but not define a
> show method and then implicitly use it:
>
> Let foo.hs =
> --->8-----
> module Fibo where
> type Quad = (Integer,Integer)
> newtype Gauss = Karl Quad
> instance Eq Gauss where
> Karl (a,b) == Karl (c,d) = a == c && b == d
> instance Show Gauss where
> ---8<-----
> in
> $ hugs fibo3.hs
> Type :? for help
> Fibo> Karl (1,2)
> zsh: segmentation fault hugs fibo3.hs
This is an instance of Hugs segfaulting on some infinite computations
(here show -> showsPrec -> show). You can do the same thing with an
empty Eq instance or just
let f x = g x + 1; g x = f x + 2 in f 3
The general problem is documented in the User's Guide, but I believe
it's fixed in CVS version (src/machine.c 1.25 and src/prelude.h 1.79
if anyone's interested in backporting).
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
