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

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

NAME

       Devel::ArgNames - Figure out the names of variables passed into subroutines.

SYNOPSIS

	       use Devel::ArgNames;

	       sub foo {
		       warn "foo() called with arguments: "
			       . join(", ", map { defined() ? $_ : "<unknown>" } arg_names(@_) );
	       }

	       foo($bar, $gorch, $blah[4]);

DESCRIPTION

       When print-debugging code, you will often ind yourself going:

	       print "$foo is $foo, $bar is $bar"

       With this module, you can write a reusable subroutine easily:

	       sub my_print_vars {
		       my %vars;

		       @vars{arg_names()} = @_;

		       foreach my $var ( keys %vars ) {
			       warn "$var is $vars{$var}
";
		       }
	       }

	       my_print_vars($foo, $bar);

       This module doesn't provide dumping facilities because there are too many to choose from. This is a DIY kit ;-)

EXPORTS

       arg_names [ $level ]
	   This function will return the names associated with the variables found on @_, at the level $level. If $level is not provided
	   "arg_names"'s caller's caller will be used ("$level == 2" in that case).

VERSION CONTROL

       This module is maintained using Darcs. You can get the latest version from <http://nothingmuch.woobling.org/Devel-ArgNames/>, and use
       "darcs send" to commit changes.

SEE ALSO

       Data::Dumper::Simple, DB, Devel::Caller, Devel::Caller::Perl, PadWalker.

AUTHORS

       Ran Eilam

       Yuval Kogman <nothingmuch@woobling.org>

COPYRIGHT

	       Copyright (c) 2007 Yuval Kogman. All rights reserved
	       This program is free software; you can redistribute
	       it and/or modify it under the same terms as Perl itself.

perl v5.10.1							    2008-01-02						      Devel::ArgNames(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)