DOKK / manpages / debian 11 / libdata-dumper-concise-perl / Data::Dumper::Concise::Sugar.3pm.en

User Contributed Perl Documentation

NAME

Data::Dumper::Concise::Sugar - return Dwarn @return_value

SYNOPSIS

  use Data::Dumper::Concise::Sugar;
  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 Data::Dumper::Concise::Sugar;
  return DwarnS some_call(...)

is equivalent to:

  use Data::Dumper::Concise;
  my $return = some_call(...);
  warn Dumper($return);
  return $return;

If you need to force list context on the value,

  use Data::Dumper::Concise::Sugar;
  return DwarnL some_call(...)

is equivalent to:

  use Data::Dumper::Concise;
  my @return = some_call(...);
  warn Dumper(@return);
  return @return;

If you want to label your output, try DwarnN

  use Data::Dumper::Concise::Sugar;
  return DwarnN $foo

is equivalent to:

  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

is equivalent to:

  my $return = $foo->bar->{baz};
  warn Dumper($return);
  return $return;

If you want to format the output of your data structures, try DwarnF

 my ($a, $c) = DwarnF { "awesome: $_[0] not awesome: $_[1]" } $awesome, $cheesy;

is equivalent to:

  my @return = ($awesome, $cheesy);
  warn DumperF { "awesome: $_[0] not awesome: $_[1]" } $awesome, $cheesy;
  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' };

DESCRIPTION

  use Data::Dumper::Concise::Sugar;

will import Dwarn, $Dwarn, DwarnL, DwarnN, and DwarnS into your namespace. Using Exporter, so see its docs for ways to make it do something else.

Dwarn

  sub Dwarn { return DwarnL(@_) if wantarray; DwarnS($_[0]) }

$Dwarn

  $Dwarn = \&Dwarn

$DwarnN

  $DwarnN = \&DwarnN

DwarnL

  sub Dwarn { warn Data::Dumper::Concise::Dumper @_; @_ }

DwarnS

  sub DwarnS ($) { warn Data::Dumper::Concise::Dumper $_[0]; $_[0] }

DwarnN

  sub DwarnN { warn '$argname => ' . Data::Dumper::Concise::Dumper $_[0]; $_[0] }

Note: this requires Devel::ArgNames to be installed.

DwarnF

  sub DwarnF (&@) { my $c = shift; warn &Data::Dumper::Concise::DumperF($c, @_); @_ }

TIPS AND TRICKS

global usage

Instead of always just doing:

  use Data::Dumper::Concise::Sugar;
  Dwarn ...

We tend to do:

  perl -MData::Dumper::Concise::Sugar foo.pl

(and then in the perl code:)

  ::Dwarn ...

That way, if you leave them in and run without the "use Data::Dumper::Concise::Sugar" 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.

method chaining

One trick which is useful when doing method chaining is the following:

  my $foo = Bar->new;
  $foo->bar->baz->Data::Dumper::Concise::Sugar::DwarnS->biff;

which is the same as:

  my $foo = Bar->new;
  (DwarnS $foo->bar->baz)->biff;