Devel::Dwarn - Combine warns and Data::Dumper::Concise
use Devel::Dwarn; return Dwarn some_call(...)
is equivalent to:
use Data::Dumper::Concise; if (wantarray) { my @return = some_call(...); warn Dumper(@return); return @return; } else { my $return = some_call(...); warn Dumper($return); return $return; }
but shorter. If you need to force scalar context on the value,
use Devel::Dwarn; return DwarnS some_call(...)
use Data::Dumper::Concise; my $return = some_call(...); warn Dumper($return); return $return;
If you need to force list context on the value,
use Devel::Dwarn; return DwarnL some_call(...)
use Data::Dumper::Concise; my @return = some_call(...); warn Dumper(@return); return @return;
If you want to label your output, try DwarnN
use Devel::Dwarn; return DwarnN $foo
use Data::Dumper::Concise; my @return = some_call(...); warn '$foo => ' . Dumper(@return); return @return;
If you want to output a reference returned by a method easily, try $Dwarn
$foo->bar->{baz}->$Dwarn
my $return = $foo->bar->{baz}; warn Dumper($return); return $return;
If you want to immediately die after outputting the data structure, every Dwarn subroutine has a paired Ddie version, so just replace the warn with die. For example:
DdieL 'foo', { bar => 'baz' };
Instead of always just doing:
use Devel::Dwarn; Dwarn ...
We tend to do:
perl -MDevel::Dwarn foo.pl
(and then in the perl code:)
::Dwarn ...
That way, if you leave them in and run without the use Devel::Dwarn the program will fail to compile and you are less likely to check it in by accident. Furthmore it allows that much less friction to add debug messages.
use Devel::Dwarn
One trick which is useful when doing method chaining is the following:
my $foo = Bar->new; $foo->bar->baz->Devel::Dwarn::DwarnS->biff;
which is the same as:
my $foo = Bar->new; (DwarnS $foo->bar->baz)->biff;
This module is really just a shortcut for Data::Dumper::Concise::Sugar, check it out for more complete documentation.
To install Data::Dumper::Concise, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Data::Dumper::Concise
CPAN shell
perl -MCPAN -e shell install Data::Dumper::Concise
For more information on module installation, please visit the detailed CPAN module installation guide.