Re: A plague on all your features

Interesting. You can maybe figure out why 'c' and 'd' differ so much using this:

use strict;
use warnings;
no strict 'refs';

use Data::Dumper;
$Data::Dumper::Sortkeys = 1;
$Data::Dumper::Deparse = 1;
print Dumper( { map { $_ => $_->() } 'a' .. 'g' } );

sub dumphints {
    my @caller = caller(0);
    $caller[10];
}
                                         sub a {dumphints()}
{use feature ':5.10';                    sub b {dumphints()}}
{use 5.010;                              sub c {dumphints()}}
{no feature ':all'; use feature ':5.10'; sub d {dumphints()}}

{use feature 'say';                   sub e {dumphints()}}
{                   no feature 'say'; sub f {dumphints()}}
{use feature 'say'; no feature 'say'; sub g {dumphints()}}
[download]

I find the output for 'c' honestly surprising.

Hire me at Toby Ink Ltd or Join my OnlyFans

Comment on Re: A plague on all your features Download Code

Replies are listed 'Best First'.
Re^2: A plague on all your features by ikegami (Patriarch) on Mar 07, 2023 at 00:43 UTC
$VAR1 = { 'a' => undef, 'b' => { 'feature_bareword_filehandles' => 1, 'feature_indirect' => 1, 'feature_multidimensional' => 1, 'feature_say' => 1, 'feature_state' => 1, 'feature_switch' => 1 }, 'c' => undef, 'd' => { 'feature_bareword_filehandles' => 1, 'feature_indirect' => 1, 'feature_multidimensional' => 1, 'feature_say' => 1, 'feature_state' => 1, 'feature_switch' => 1 }, 'e' => { 'feature_bareword_filehandles' => 1, 'feature_indirect' => 1, 'feature_multidimensional' => 1, 'feature_say' => 1 }, 'f' => { 'feature_bareword_filehandles' => 1, 'feature_indirect' => 1, 'feature_multidimensional' => 1 }, 'g' => { 'feature_bareword_filehandles' => 1, 'feature_indirect' => 1, 'feature_multidimensional' => 1 } }; [download]	[reply] [d/l]
Re^3: A plague on all your features by ikegami (Patriarch) on Mar 07, 2023 at 00:58 UTC
I don't know why the hints are undef for `c`, but I can confirm it's accurate. `$ diff -u \ <( perl -MO=Concise,b b.pl 2>&1 ) \ <( perl -MO=Concise,c b.pl 2>&1 ) --- /dev/fd/63 2023-03-06 20:59:39.932888013 -0400 +++ /dev/fd/62 2023-03-06 20:59:39.932888013 -0400 @@ -1,8 +1,8 @@ b.pl syntax OK -main::b: +main::c: 5 <1> leavesub[1 ref] K/REFC,1 ->(end) - <@> lineseq KP ->5 -1 <;> nextstate(main 1252 b.pl:15) v:%,,&,x,x&,x$,fea=15 ->2 +1 <;> nextstate(main 1257 b.pl:16) v:,&,x,x&,x$,fea=1 ->2 4 <1> entersub KS ->5 - <1> ex-list K ->4 2 <0> pushmark s ->3` [download] Note the different value of the hints (`fea=` for "feature") for the two lines.	[reply] [d/l] [select]
Re^4: A plague on all your features by ikegami (Patriarch) on Mar 07, 2023 at 01:04 UTC
Actually, the whole `v:` thing is the hints, not just the `fea=` portion. And we see another difference: The `%`. Not sure what it means, but it relates to `%^H`. Presumably the presence of `%^H`. Again, present for `b` but not `c`.	[reply] [d/l] [select]
Re^5: A plague on all your features by ikegami (Patriarch) on Mar 07, 2023 at 01:17 UTC


Think about Loose Coupling
	PerlMonks