On Sun, 19 Dec 2021 12:45:18 +0000 (UTC), Ovid via perl5-porters <perl5-porters@perl.org> wrote:
> On Sunday, 19 December 2021, 13:28:23 CET, Oodler 577 <oodler577@sdf-eu.org> wrote:
>
>
> > Thank you, this is super helpful. My final comment is just to
> > reiterate what I most recently said; as long as this doesn't
> > affect how things currently work with undef/q{}/0 and existing
> > built-ins/ops; and we get a C<unknown> built-in that does for
> > unknown values what C<defined> does for undef'd values,
>
> For interpolation, I would suggest it behave like undef, but with a
> warning. I would (only half-joking here), also consider it to
> stringify to U+FFFD REPLACEMENT CHARACTER.
100% joking: 016844 ???? BAMUM LETTER PHASE-A UNKNOWN
> my $name = unknown;
> say "Hello, $name!";
>
> Output:
>
> Use of unknown value $name in say at ...
> Hello, ?!
>
> > As an exercise, I wonder how many use cases for undef would remain
> > if unknown was available. If the answer is "not many", then maybe
> > the answer would be a compatible tweak to undef and not the
> > creation of a new special value. Just a thought...
>
> I would not recommend changing current behavior of undef. That would
> be widespread carnage.
>
> Ovid
--
H.Merijn Brand https://tux.nl Perl Monger http://amsterdam.pm.org/
using perl5.00307 .. 5.33 porting perl5 on HP-UX, AIX, and Linux
https://tux.nl/email.html http://qa.perl.org https://www.test-smoke.org
> On Sunday, 19 December 2021, 13:28:23 CET, Oodler 577 <oodler577@sdf-eu.org> wrote:
>
>
> > Thank you, this is super helpful. My final comment is just to
> > reiterate what I most recently said; as long as this doesn't
> > affect how things currently work with undef/q{}/0 and existing
> > built-ins/ops; and we get a C<unknown> built-in that does for
> > unknown values what C<defined> does for undef'd values,
>
> For interpolation, I would suggest it behave like undef, but with a
> warning. I would (only half-joking here), also consider it to
> stringify to U+FFFD REPLACEMENT CHARACTER.
100% joking: 016844 ???? BAMUM LETTER PHASE-A UNKNOWN
> my $name = unknown;
> say "Hello, $name!";
>
> Output:
>
> Use of unknown value $name in say at ...
> Hello, ?!
>
> > As an exercise, I wonder how many use cases for undef would remain
> > if unknown was available. If the answer is "not many", then maybe
> > the answer would be a compatible tweak to undef and not the
> > creation of a new special value. Just a thought...
>
> I would not recommend changing current behavior of undef. That would
> be widespread carnage.
>
> Ovid
--
H.Merijn Brand https://tux.nl Perl Monger http://amsterdam.pm.org/
using perl5.00307 .. 5.33 porting perl5 on HP-UX, AIX, and Linux
https://tux.nl/email.html http://qa.perl.org https://www.test-smoke.org