Front page | perl.perl5.porters |
Postings from June 2022
On Wed, Jun 8, 2022 at 3:45 PM Felipe Gasper <felipe@felipegasper.com>
wrote:
>
> > On Jun 8, 2022, at 13:38, Dan Book <grinnz@gmail.com> wrote:
> >
> > As was shown in the example, you don't actually use the proposed
> variable yourself in try/catch as it sets up a lexical variable for the
> scope of catch.
>
> That would certainly encourage adoption of try/catch.
>
> > As an alternative: what if, under `use feature 'errorobject'`, $@ were
> the object, but without the feature itâd be the string? So the feature
> would only change how eval populates $@.
> >
> > This is not possible, because it is not populated lexically.
>
> I donât think that matters:
>
> -----
> {
> use feature 'errorobject';
>
> eval { 9 / 0 };
> }
>
> say blessed $@; # prints something
>
> {
> no feature 'errorobject';
>
> eval { 9 / 0};
> }
>
> say blessed $@; # prints nothing
> -----
>
> Whenever $@ is populated, the relevant logic would check to see if the
> active feature set dictates putting the object or the string into $@.
>
This is exactly the problem. The lexical feature would have an effect on
the exact problematic code we are discussing (which is by the way not
"esoteric" in any useful sense of the word, we simply cannot break it),
which is not in the scope of the feature.
-Dan
Thread Previous
|
Thread Next