Front page | perl.perl5.porters |
Postings from October 2021
Den 08.10.2021 21:24, skrev Ricardo Signes:
> Porters,
>
> On today's PSC call, we were discussing the state of the "use v5.36"
> bundle, and whether it should turn off the "indirect" and
> "multidimensional" features. Our consensus was that this
> *should* happen. For those who want a refresher:
>
> "no feature 'indirect'" disables "indirect object syntax" meaning you
> can no longer write this:
> my $object = new Class (1, 2);
>
> This is useful as a footgun remover, converting a mistake from runtime
> to compile time. For example, say you're like me and often forget to
> load Try::Tiny…
> dinah:~$ perl -c -e 'try {1 };'
> -e syntax OK
>
> dinah:~$ perl -e 'try {1 };'
> Can't locate object method "try" via package "1" (perhaps you forgot to load "1"?) at -e line 1.
>
> dinah:~$ perl -c -e 'no feature "indirect"; try {1 };'
> syntax error at -e line 1, near "try {"
> -e had compilation errors.
>
> The first two stanzas show the current behavior: the code compiles but
> won't run.
>
> The third shows the behavior without indirect: it fails to compile.
>
> This syntax has long been discouraged. Existing code will continue to
> work, and this will only affect code that disables the syntax. Some
> example code in documentation may now be "wrong" when put into place
> with use v5.36.0 in place, but that's a risk we're already taking with
> other features.
>
> My take: indirect syntax will be around more or less forever.
>
+1 on removing default indirect support, but I hope we can alter the
current behaviour of 'no indirect' – as written in Neil Bower's Perl
Quirks document (whic isn't public anymore)
[quote]
Note that using 'no indirect' basically just is what one would expect
"use warnings 'indirect'" would've done.
I just realized I can't ensure all "indirect"-like syntax is treated as
function calls (or other fitting syntax), which was what I really
expected from the pragma/module.
Example code from a bug report I didn't submit now since I recalled the
"indirect" chapter here:
Expected output is a silent:
```
foo
bar
baz
```
```
$ cat /tmp/no_no_indirect.t
#!/usr/bin/env perl
use v5.30;
no indirect;
use Path::Tiny;
sub p {
say shift;
}
say Path::Tiny->new("foo");
p "bar";
p Path::Tiny->new("baz");
```
```
$ perl /tmp/no_no_indirect.t
Indirect call of method "p" on object "Path::Tiny" at
/tmp/no_no_indirect.t line 14.
foo
bar
Can't locate object method "p" via package "Path::Tiny" at
/tmp/no_no_indirect.t line 14.
``
[/quote]
--
Nicolas Mendoza
Thread Previous
|
Thread Next