/usr/share/perl5/Class/C3/Adopt/NEXT.pm is in libclass-c3-adopt-next-perl 0.12-1.
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 | use strict;
use warnings;
package Class::C3::Adopt::NEXT;
use NEXT;
use MRO::Compat;
use List::MoreUtils qw/none/;
use warnings::register;
our $VERSION = '0.12';
{
my %c3_mro_ok;
my %warned_for;
my @no_warn_regexes;
{
my $orig = NEXT->can('AUTOLOAD');
no warnings 'redefine';
*NEXT::AUTOLOAD = sub {
my $class = ref $_[0] || $_[0];
my $caller = caller();
# 'NEXT::AUTOLOAD' is cargo-culted from C::P::C3, I have no idea if/why it's needed
my $wanted = our $AUTOLOAD || 'NEXT::AUTOLOAD';
my ($wanted_class) = $wanted =~ m{(.*)::};
unless (exists $c3_mro_ok{$class}) {
eval { mro::get_linear_isa($class, 'c3') };
if (my $error = $@) {
warn "Class::C3::calculateMRO('${class}') Error: '${error}';"
. ' Falling back to plain NEXT.pm behaviour for this class';
$c3_mro_ok{$class} = 0;
}
else {
$c3_mro_ok{$class} = 1;
}
}
if (length $c3_mro_ok{$class} && $c3_mro_ok{$class}) {
unless ($warned_for{$caller}) {
$warned_for{$caller} = 1;
if (!@no_warn_regexes || none { $caller =~ $_ } @no_warn_regexes) {
warnings::warnif("${caller} uses NEXT, which is deprecated. Please see "
. "the Class::C3::Adopt::NEXT documentation for details. NEXT used ");
}
}
}
unless ($c3_mro_ok{$class}) {
$NEXT::AUTOLOAD = $wanted;
goto &$orig;
}
goto &next::method if $wanted_class =~ /^NEXT:.*:ACTUAL/;
goto &maybe::next::method;
};
*NEXT::ACTUAL::AUTOLOAD = \&NEXT::AUTOLOAD;
}
sub import {
my ($class, @args) = @_;
my $target = caller();
for my $arg (@args) {
$warned_for{$target} = 1
if $arg eq '-no_warn';
}
}
sub unimport {
my $class = shift;
my @strings = grep { !ref $_ || ref($_) ne 'Regexp' } @_;
my @regexes = grep { ref($_) && ref($_) eq 'Regexp' } @_;
@c3_mro_ok{@strings} = ('') x @strings;
push @no_warn_regexes, @regexes;
}
}
1;
__END__
=head1 NAME
Class::C3::Adopt::NEXT - make NEXT suck less
=head1 SYNOPSIS
package MyApp::Plugin::FooBar;
#use NEXT;
use Class::C3::Adopt::NEXT;
# or 'use Class::C3::Adopt::NEXT -no_warn;' to suppress warnings
# Or use warnings::register
# no warnings 'Class::C3::Adopt::NEXT';
# Or suppress warnings in a set of modules from one place
# no Class::C3::Adopt::NEXT qw/ Module1 Module2 Module3 /;
# Or suppress using a regex
# no Class::C3::Adopt::NEXT qr/^Module\d$/;
sub a_method {
my ($self) = @_;
# Do some stuff
# Re-dispatch method
# Note that this will generate a warning the _first_ time the package
# uses NEXT unless you un comment the 'no warnings' line above.
$self->NEXT::method();
}
=head1 DESCRIPTION
L<NEXT> was a good solution a few years ago, but isn't any more. It's slow,
and the order in which it re-dispatches methods appears random at times. It
also encourages bad programming practices, as you end up with code to
re-dispatch methods when all you really wanted to do was run some code before
or after a method fired.
However, if you have a large application, then weaning yourself off C<NEXT>
isn't easy.
This module is intended as a drop-in replacement for NEXT, supporting the same
interface, but using L<Class::C3> to do the hard work. You can then write new
code without C<NEXT>, and migrate individual source files to use C<Class::C3>
or method modifiers as appropriate, at whatever pace you're comfortable with.
=head1 WARNINGS
This module will warn once for each package using NEXT. It uses
L<warnings::register>, and so can be disabled like by adding C<no warnings
'Class::C3::Adopt::NEXT';> to each package which generates a warning, or adding
C<use Class::C3::Adopt::NEXT -no_warn;>, or disable multiple modules at once by
saying:
no Class::C3::Adopt::NEXT qw/ Module1 Module2 Module3 /;
somewhere before the warnings are first triggered. You can also setup entire
name spaces of modules which will not warn using a regex, e.g.
no Class::C3::Adopt::NEXT qr/^Module\d$/;
=head1 MIGRATING
=head2 Current code using NEXT
You add C<use MRO::Compat> to the top of a package as you start converting it,
and gradually replace your calls to C<NEXT::method()> with
C<maybe::next::method()>, and calls to C<NEXT::ACTUAL::method()> with
C<next::method()>.
Example:
sub yourmethod {
my $self = shift;
# $self->NEXT::yourmethod(@_); becomes
$self->maybe::next::method();
}
sub othermethod {
my $self = shift;
# $self->NEXT::ACTUAL::yourmethodname(); becomes
$self->next::method();
}
On systems with L<Class::C3::XS> present, this will automatically be used to
speed up method re-dispatch. If you are running perl version 5.9.5 or greater
then the C3 method resolution algorithm is included in perl. Correct use of
L<MRO::Compat> as shown above allows your code to be seamlessly forward and
backwards compatible, taking advantage of native versions if available, but
falling back to using pure perl C<Class::C3>.
=head2 Writing new code
Use L<Moose> and make all of your plugins L<Moose::Roles|Moose::Role>, then use
method modifiers to wrap methods.
Example:
package MyApp::Role::FooBar;
use Moose::Role;
before 'a_method' => sub {
my ($self) = @_;
# Do some stuff
};
around 'a_method' => sub {
my $orig = shift;
my $self = shift;
# Do some stuff before
my $ret = $self->$orig(@_); # Run wrapped method (or not!)
# Do some stuff after
return $ret;
};
package MyApp;
use Moose;
with 'MyApp::Role::FooBar';
=head1 CAVEATS
There are some inheritance hierarchies that it is possible to create which
cannot be resolved to a simple C3 hierarchy. In that case, this module will
fall back to using C<NEXT>. In this case a warning will be emitted.
Because calculating the MRO of every class every time C<< ->NEXT::foo >> is
used from within it is too expensive, runtime manipulations of C<@ISA> are
prohibited.
=head1 FUNCTIONS
This module replaces C<NEXT::AUTOLOAD> with it's own version. If warnings are
enabled then a warning will be emitted on the first use of C<NEXT> by each
package.
=head1 SEE ALSO
L<MRO::Compat> and L<Class::C3> for method re-dispatch and L<Moose> for method
modifiers and L<roles|Moose::Role>.
L<NEXT> for documentation on the functionality you'll be removing.
=head1 AUTHORS
Florian Ragwitz C<rafl@debian.org>
Tomas Doran C<bobtfish@bobtfish.net>
=head1 COPYRIGHT AND LICENSE
Copyright (c) 2008, 2009 Florian Ragwitz
You may distribute this code under the same terms as Perl itself.
=cut
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