/usr/share/perl5/Clone/Choose.pm is in libclone-choose-perl 0.008-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 | package Clone::Choose;
use strict;
use warnings;
use Carp ();
our $VERSION = "0.008";
$VERSION = eval $VERSION;
our @BACKENDS = (
Clone => [0.10, "clone"],
Storable => "dclone",
"Clone::PP" => "clone",
);
my $use_m;
BEGIN
{
unless ($use_m)
{
eval "use Module::Runtime (); 1;"
and $use_m = Module::Runtime->can("use_module")
unless $ENV{CLONE_CHOOSE_NO_MODULE_RUNTIME};
$use_m ||= sub {
my ($pkg, @imports) = @_;
my $use_stmt = "use $pkg";
@imports and $use_stmt = join(" ", $use_stmt, @imports);
eval $use_stmt;
$@ and die $@;
1;
};
}
}
sub backend
{
my $self = shift;
my @backends = @BACKENDS;
if ($ENV{CLONE_CHOOSE_PREFERRED_BACKEND})
{
my $favourite = $ENV{CLONE_CHOOSE_PREFERRED_BACKEND};
my %b = @backends;
Carp::croak "$favourite not found" unless $b{$favourite};
@backends = ($favourite => $b{$favourite});
}
while (my ($pkg, $rout) = splice @backends, 0, 2)
{
eval { $use_m->($pkg, ref $rout ? ($rout->[0]) : ()); 1; } or next;
my $fn = $pkg->can(ref $rout ? $rout->[1] : $rout);
$fn or next;
return $pkg;
}
return;
}
sub can
{
my $self = shift;
my $name = shift;
my @backends = @BACKENDS;
return __PACKAGE__->SUPER::can($name) unless $name eq "clone";
if ($ENV{CLONE_CHOOSE_PREFERRED_BACKEND})
{
my $favourite = $ENV{CLONE_CHOOSE_PREFERRED_BACKEND};
my %b = @backends;
Carp::croak "$favourite not found" unless $b{$favourite};
@backends = ($favourite => $b{$favourite});
}
my $fn;
while (my ($pkg, $rout) = splice @backends, 0, 2)
{
eval { $use_m->($pkg, ref $rout ? ($rout->[0]) : ()); 1; } or next;
$fn = $pkg->can(ref $rout ? $rout->[1] : $rout);
$fn or next;
last;
}
return $fn;
}
sub import
{
my ($me, @params) = @_;
my $tgt = caller(0);
my @B = @BACKENDS;
local @BACKENDS = @B;
push @params, "clone" unless grep { /^clone$/ } @params;
while (my $param = shift @params)
{
if ($param =~ m/^:(.*)$/)
{
my $favourite = $1;
$ENV{CLONE_CHOOSE_PREFERRED_BACKEND}
and $ENV{CLONE_CHOOSE_PREFERRED_BACKEND} ne $favourite
and Carp::croak
"Environment CLONE_CHOOSE_PREFERRED_BACKEND($ENV{CLONE_CHOOSE_PREFERRED_BACKEND}) not equal to imported ($favourite)";
my %b = @BACKENDS;
Carp::croak "$favourite not found" unless $b{$favourite};
@BACKENDS = ($favourite => $b{$favourite});
}
elsif ($param eq "clone")
{
my $fn = __PACKAGE__->can("clone");
$fn or Carp::croak "Cannot find an apropriate clone().";
no strict "refs";
*{"${tgt}::clone"} = $fn;
@params
and Carp::croak "Parameters left after clone. Please see description.";
return;
}
else
{
Carp::croak "$param is not exportable by " . __PACKAGE__;
}
}
}
sub get_backends
{
my $self = shift;
my %backends = @BACKENDS;
if ($ENV{CLONE_CHOOSE_PREFERRED_BACKEND})
{
my $favourite = $ENV{CLONE_CHOOSE_PREFERRED_BACKEND};
Carp::croak "$favourite not found" unless $backends{$favourite};
%backends = ($favourite => $backends{$favourite});
}
return keys %backends;
}
1;
__END__
=head1 NAME
Clone::Choose - Choose appropriate clone utility
=head1 SYNOPSIS
use Clone::Choose;
my $data = {
value => 42,
href => {
set => [ 'foo', 'bar' ],
value => 'baz',
},
};
my $cloned_data = clone $data;
# it's also possible to use Clone::Choose and pass a clone preference
use Clone::Choose qw(:Storable);
=head1 DESCRIPTION
C<Clone::Choose> checks several different modules which provides a
C<clone()> function and selects an appropriate one. The default preference
is
Clone
Storable
Clone::PP
This list might evolve in future. Please see L</EXPORTS> how to pick a
particular one.
=head1 EXPORTS
C<Clone::Choose> exports C<clone()> by default.
One can explicitly import C<clone> by using
use Clone::Choose qw(clone);
or pick a particular C<clone> implementation
use Clone::Choose qw(:Storable clone);
The exported implementation is resolved dynamically, which means that any
using module can either rely on the default backend preference or choose
a particular one.
It is also possible to select a particular C<clone> backend by setting the
environment variable CLONE_CHOOSE_PREFERRED_BACKEND to your preferred backend.
This also means, an already chosen import can't be modified like
use Clone::Choose qw(clone :Storable);
When one seriously needs different clone implementations, our I<recommended>
way to use them would be:
use Clone::Choose (); # do not import
my ($xs_clone, $st_clone);
{ local @Clone::Choose::BACKENDS = (Clone => "clone"); $xs_clone = Clone::Choose->can("clone"); }
{ local @Clone::Choose::BACKENDS = (Storable => "dclone"); $st_clone = Clone::Choose->can("clone"); }
Don't misinterpret I<recommended> - modifying C<@Clone::Choose::BACKENDS>
has a lot of pitfalls and is unreliable beside such small examples. Do
not hesitate open a request with an appropriate proposal for choosing
implementations dynamically.
The use of C<@Clone::Choose::BACKENDS> is discouraged and will be deprecated
as soon as anyone provides a better idea.
=head1 PACKAGE METHODS
=head2 backend
C<backend> tells the caller about the dynamic chosen backend:
use Clone::Choose;
say Clone::Choose->backend; # Clone
This method currently exists for debug purposes only.
=head2 get_backends
C<get_backends> returns a list of the currently supported backends.
=head1 AUTHOR
Jens Rehsack <rehsack at cpan dot org>
Stefan Hermes <hermes at cpan dot org>
=head1 BUGS
Please report any bugs or feature requests to
C<bug-Clone-Choose at rt.cpan.org>, or through the web interface at
L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Clone-Choose>.
I will be notified, and then you'll automatically be notified of progress
on your bug as I make changes.
=head1 SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Clone::Choose
You can also look for information at:
=over 4
=item * RT: CPAN's request tracker
L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Clone-Choose>
=item * AnnoCPAN: Annotated CPAN documentation
L<http://annocpan.org/dist/Clone-Choose>
=item * CPAN Ratings
L<http://cpanratings.perl.org/d/Clone-Choose>
=item * Search CPAN
L<http://search.cpan.org/dist/Clone-Choose/>
=back
=head1 LICENSE AND COPYRIGHT
Copyright 2017 Jens Rehsack
Copyright 2017 Stefan Hermes
This program is free software; you can redistribute it and/or modify it
under the terms of either: the GNU General Public License as published
by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.
=head1 SEE ALSO
L<Clone>, L<Clone::PP>, L<Storable>
=cut
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