Le Fri, 2 Feb 2007 18:29:56 -0800, Bob Williams <a6b37331@telus.net> a
écrit :
> My first impulse was to suggest that toplevel disallow the
> redefinition of anything.  But Daniel has convinced me that reloading
> an object file can be useful during development.  So how about this:
> when toplevel redefines an exception, the exception's tag number
> should not change.
> 
> Daniel mentioned a related problem, with similar pitfalls:
> 
> 	type t = C;;
> 	... define function Foo using t ...
> 	type t = D;;
> 	... what should we do about Foo? ...
> 
> Foo is now clearly obsolete, as are any blocks on the heap that were
> constructed by C.  What should be done here?

As you said, redefinition can be useful sometimes. But in most of the
cases, it's a bug. So why not make the compiler issue a (possibly
optional) warning on redefinitions ? 

Sincerely,
-- 
Gabriel Kerneis