devel::beginlift(3pm) [debian man page]

Devel::BeginLift(3pm)					User Contributed Perl Documentation				     Devel::BeginLift(3pm)

NAME

       Devel::BeginLift - make selected sub calls evaluate at compile time

SYNOPSIS

	 use Devel::BeginLift qw(foo baz);

	 use vars qw($i);

	 BEGIN { $i = 0 }

	 sub foo { "foo: $_[0]
"; }

	 sub bar { "bar: $_[0]
"; }

	 for (1 .. 3) {
	   print foo($i++);
	   print bar($i++);
	 }

	 no Devel::BeginLift;

	 print foo($i++);

       outputs -

       foo: 0 bar: 1 foo: 0 bar: 2 foo: 0 bar: 3 foo: 4

DESCRIPTION

       Devel::BeginLift 'lifts' arbitrary sub calls to running at compile time - sort of a souped up version of "use constant". It does this via
       some slightly insane perlguts magic.

   import
	 use Devel::BeginLift qw(list of subs);

       Calls Devel::BeginLift->setup_for(__PACKAGE__ => @list_of_subs);

   unimport
	 no Devel::BeginLift;

       Calls Devel::BeginLift->teardown_for(__PACKAGE__);

   setup_for
	 Devel::BeginLift->setup_for($package => @subnames);

       Installs begin lifting magic (unless already installed) and registers "${package}::$name" for each member of @subnames to be executed when
       parsed and replaced with its output rather than left for runtime.

   teardown_for
	 Devel::BeginLift->teardown_for($package);

       Deregisters all subs currently registered for $package and uninstalls begin lifting magic is number of teardown_for calls matches number of
       setup_for calls.

   setup_for_cv
	 $id = Devel::BeginLift->setup_for_cv(&code);

       Same as "setup_for", but only registers begin lifting magic for one code reference. Returns an id to be used in "teardown_for_cv".

   teardown_for_cv
	 Devel::BeginLift->teardown_for_cv($id);

       Deregisters begin lifting magic referred to by $id.

AUTHOR

       Matt S Trout - <mst@shadowcatsystems.co.uk>

       Company: http://www.shadowcatsystems.co.uk/ Blog: http://chainsawblues.vox.com/

LICENSE

       This library is free software under the same terms as perl itself

perl v5.14.2							    2012-04-22						     Devel::BeginLift(3pm)

Devel::Dwarn(3) 					User Contributed Perl Documentation					   Devel::Dwarn(3)

NAME

       Devel::Dwarn - return Dwarn @return_value

SYNOPSIS

	 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(...)

       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 Devel::Dwarn;

	 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 Devel::Dwarn;

	 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 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' };

TIPS AND TRICKS

   global usage
       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.

   method chaining
       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;

SEE ALSO

       This module is really just a shortcut for Data::Dumper::Concise::Sugar, check it out for more complete documentation.

perl v5.18.2							    2013-12-31							   Devel::Dwarn(3)