yary wrote:
> Is this a known issue, or my misunderstanding?
>
>> subset non-Nil where * !=== Nil;
> (non-Nil)
>> sub out-check($out) returns non-Nil { return $out }
> &out-check
>> out-check(44)
> 44
>> out-check(Nil)
> Nil
>
> ^ Huh, I expected an exception on "out-check(Nil)" saying the return
After writing that email, I remembered a bit of logic from a class long
ago, that any assertion made on the empty set is true. Since Nil is a
representation of no results, it would make sense to have assertions about
it return true. I think this example shows an optimization to skip return
type che
Nil is always a valid return value regardless of any check.
This is because it is the base of all failures.
On Sat, Dec 19, 2020, 8:17 PM yary wrote:
> Is this a known issue, or my misunderstanding?
>
> > subset non-Nil where * !=== Nil;
> (non-Nil)
> > sub out-check($out) returns non-Nil { ret
