Re: misc SEGV's

[Ilya Zakharevich <ilya@math.ohio-state.edu>]

On Mon, Jul 01, 2002 at 10:58:11PM +0200, Karim BELABAS wrote:
> > ? elltors(%1)
> >   ***   bug in GP (Segmentation Fault), please report
> 
> We need new types to prevent forgeries as above.

Exactly my sentiment.  We need new types to implement a typed-object
system, implement efficient embedding of external objects, implement
new user-installable types (e.g., a complex algebraic number as a pair
of [t_POL, t_COMPLEX(t_REAL)] - the second one being a "good enough"
approximation to the particular root) etc.

All these easily solved by installing *one* new type, with a dispatch
table of methods.  And the first step in this is to allow
destruction-from-stack (in these rarely needed cases) via something
like RESTORE_STACKPOS(av) macro I introduced in my other message.

Ilya