note
ikegami
<p>I recommend that you use the <c>perlbug</c> command line tool to ask p5p to explain the outcome of the following cleaned up version of your program. Include the output.
<c>
use strict;
use warnings;
use feature qw( say );
use Data::Dumper qw( Dumper );
BEGIN {
package str;
use strict;
use warnings;
use feature qw( say );
use overload
'""' => \&stringify,
'.' => \&concat;
sub new { my $class = shift; bless([ @_ ], $class) }
sub stringify { join '', @{ $_[0] } }
sub concat {
my ($s1, $s2, $inverted) = @_;
return ref($s1)->new( $inverted ? ($s2,$s1) : ($s1,$s2) );
}
$INC{"str.pm"} = 1;
}
sub _dump {
local $Data::Dumper::Indent = 0;
local $Data::Dumper::Terse = 1;
local $Data::Dumper::Sortkeys = 1;
return Dumper(@_);
}
{
my $str = str->new('foo');
my $good = "a $str a";
say "good: "._dump($good);
my $bad; $bad = "a $str a";
say "bad: "._dump($bad);
}
</c>
<p>Output:
<c>
good: bless( [bless( ['a ',bless( ['foo'], 'str' )], 'str' ),' a'], 'str' )
bad: 'a foo a'
</c>
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