Re: when and unless

[David Kastrup <dak@gnu.org>]

Andy Wingo <wingo@pobox.com> writes:

> On Tue 06 Dec 2011 12:17, David Kastrup <dak@gnu.org> writes:
>
>> I've actually wondered if it would not make sense to return
>> *unspecified* in the case of the plain else-less if even if the
>> condition is true, namely when you write (if #t #t).
>
> I have wondered this too.
>
>> There is probably code relying on this to be #t, but frankly, this
>> appears like a recipe for breakage.
>
> Yeah.  A first (and probably worthwhile) step would be to warn if such
> a statement is processed for value.

Well, is it being processed for value if what I do with the value is
calling unspecified? on it in order to find out whether I should warn
about a function returning a value when it shouldn't?

I am working on a language where returning values in certain contexts
might at one point of time might lead to the values being used.  So I
need to implement warnings to that effect in order to find out calls
_not_ returning *unspecified*...

-- 
David Kastrup