clone::pp(3pm) [debian man page]

PP(3pm) 						User Contributed Perl Documentation						   PP(3pm)

NAME

       Clone::PP - Recursively copy Perl datatypes

SYNOPSIS

	 use Clone::PP qw(clone);

	 $item = { 'foo' => 'bar', 'move' => [ 'zig', 'zag' ]  };
	 $copy = clone( $item );

	 $item = [ 'alpha', 'beta', { 'gamma' => 'vlissides' } ];
	 $copy = clone( $item );

	 $item = Foo->new();
	 $copy = clone( $item );

       Or as an object method:

	 require Clone::PP;
	 push @Foo::ISA, 'Clone::PP';

	 $item = Foo->new();
	 $copy = $item->clone();

DESCRIPTION

       This module provides a general-purpose clone function to make deep copies of Perl data structures. It calls itself recursively to copy
       nested hash, array, scalar and reference types, including tied variables and objects.

       The clone() function takes a scalar argument to copy. To duplicate arrays or hashes, pass them in by reference:

	 my $copy = clone(@array);    my @copy = @{ clone(@array) };
	 my $copy = clone(\%hash);     my %copy = %{ clone(\%hash) };

       The clone() function also accepts an optional second parameter that can be used to limit the depth of the copy. If you pass a limit of 0,
       clone will return the same value you supplied; for a limit of 1, a shallow copy is constructed; for a limit of 2, two layers of copying are
       done, and so on.

	 my $shallow_copy = clone( $item, 1 );

       To allow objects to intervene in the way they are copied, the clone() function checks for a couple of optional methods. If an object pro-
       vides a method named "clone_self", it is called and the result returned without further processing. Alternately, if an object provides a
       method named "clone_init", it is called on the copied object before it is returned.

BUGS

       Some data types, such as globs, regexes, and code refs, are always copied shallowly.

       References to hash elements are not properly duplicated. (This is why two tests in t/dclone.t that are marked "todo".) For example, the
       following test should succeed but does not:

	 my $hash = { foo => 1 };
	 $hash->{bar} = { $hash->{foo} };
	 my $copy = clone( \%hash );
	 $hash->{foo} = 2;
	 $copy->{foo} = 2;
	 ok( $hash->{bar} == $copy->{bar} );

       To report bugs via the CPAN web tracking system, go to "http://rt.cpan.org/NoAuth/Bugs.html?Dist=Clone-PP" or send mail to
       "Dist=Clone-PP#rt.cpan.org", replacing "#" with "@".

SEE ALSO

       For a faster implementation in XS, see "clone" in Clone, "clone" in Util, or <Storable/dclone>.

CREDITS AND COPYRIGHT

       Developed by Matthew Simon Cavalletto at Evolution Softworks.  More free Perl software is available at "www.evoscript.org".

       Copyright 2003 Matthew Simon Cavalletto. You may contact the author directly at "evo@cpan.org" or "simonm@cavalletto.org".

       Code initially derived from Ref.pm. Portions Copyright 1994 David Muir Sharnoff.

       Interface based by Clone by Ray Finch with contributions from chocolateboy.  Portions Copyright 2001 Ray Finch. Portions Copyright 2001
       chocolateboy.

       You may use, modify, and distribute this software under the same terms as Perl.

perl v5.8.8							    2008-03-27								   PP(3pm)

Template::Stash(3)					User Contributed Perl Documentation					Template::Stash(3)

NAME

       Template::Stash - Magical storage for template variables

SYNOPSIS

	   use Template::Stash;

	   my $stash = Template::Stash->new(\%vars);

	   # get variable values
	   $value = $stash->get($variable);
	   $value = $stash->get(@compound);

	   # set variable value
	   $stash->set($variable, $value);
	   $stash->set(@compound, $value);

	   # default variable value
	   $stash->set($variable, $value, 1);
	   $stash->set(@compound, $value, 1);

	   # set variable values en masse
	   $stash->update(\%new_vars)

	   # methods for (de-)localising variables
	   $stash = $stash->clone(\%new_vars);
	   $stash = $stash->declone();

DESCRIPTION

       The "Template::Stash" module defines an object class which is used to store variable values for the runtime use of the template processor.
       Variable values are stored internally in a hash reference (which itself is blessed to create the object) and are accessible via the get()
       and set() methods.

       Variables may reference hash arrays, lists, subroutines and objects as well as simple values.  The stash automatically performs the right
       magic when dealing with variables, calling code or object methods, indexing into lists, hashes, etc.

       The stash has clone() and declone() methods which are used by the template processor to make temporary copies of the stash for localising
       changes made to variables.

PUBLIC METHODS

   new(\%params)
       The "new()" constructor method creates and returns a reference to a new "Template::Stash" object.

	   my $stash = Template::Stash->new();

       A hash reference may be passed to provide variables and values which should be used to initialise the stash.

	   my $stash = Template::Stash->new({ var1 => 'value1',
					      var2 => 'value2' });

   get($variable)
       The "get()" method retrieves the variable named by the first parameter.

	   $value = $stash->get('var1');

       Dotted compound variables can be retrieved by specifying the variable elements by reference to a list.  Each node in the variable occupies
       two entries in the list.  The first gives the name of the variable element, the second is a reference to a list of arguments for that
       element, or 0 if none.

	   [% foo.bar(10).baz(20) %]

	   $stash->get([ 'foo', 0, 'bar', [ 10 ], 'baz', [ 20 ] ]);

   set($variable, $value, $default)
       The "set()" method sets the variable name in the first parameter to the value specified in the second.

	   $stash->set('var1', 'value1');

       If the third parameter evaluates to a true value, the variable is set only if it did not have a true value before.

	   $stash->set('var2', 'default_value', 1);

       Dotted compound variables may be specified as per get() above.

	   [% foo.bar = 30 %]

	   $stash->set([ 'foo', 0, 'bar', 0 ], 30);

       The magical variable '"IMPORT"' can be specified whose corresponding value should be a hash reference.  The contents of the hash array are
       copied (i.e. imported) into the current namespace.

	   # foo.bar = baz, foo.wiz = waz
	   $stash->set('foo', { 'bar' => 'baz', 'wiz' => 'waz' });

	   # import 'foo' into main namespace: bar = baz, wiz = waz
	   $stash->set('IMPORT', $stash->get('foo'));

   clone(\%params)
       The "clone()" method creates and returns a new "Template::Stash" object which represents a localised copy of the parent stash. Variables
       can be freely updated in the cloned stash and when declone() is called, the original stash is returned with all its members intact and in
       the same state as they were before "clone()" was called.

       For convenience, a hash of parameters may be passed into "clone()" which is used to update any simple variable (i.e. those that don't
       contain any namespace elements like "foo" and "bar" but not "foo.bar") variables while cloning the stash.  For adding and updating complex
       variables, the set() method should be used after calling "clone()."  This will correctly resolve and/or create any necessary namespace
       hashes.

       A cloned stash maintains a reference to the stash that it was copied from in its "_PARENT" member.

   declone()
       The "declone()" method returns the "_PARENT" reference and can be used to restore the state of a stash as described above.

AUTHOR

       Andy Wardley <abw@wardley.org> <http://wardley.org/>

COPYRIGHT

       Copyright (C) 1996-2007 Andy Wardley.  All Rights Reserved.

       This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

       Template, Template::Context

perl v5.12.1							    2009-05-20							Template::Stash(3)