This file is indexed.

/usr/share/perl5/Rose/Object/MixIn.pm is in librose-object-perl 0.860-1.

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
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
package Rose::Object::MixIn;

use strict;

use Carp;

our $Debug = 0;

our $VERSION = '0.856';

use Rose::Class::MakeMethods::Set
(
  inheritable_set => 
  [
    '_export_tag' =>
    {
      list_method    => '_export_tags',
      clear_method   => 'clear_export_tags',
      add_method     => '_add_export_tag',
      delete_method  => 'delete_export_tag',
      deletes_method => 'delete_export_tags',
    },

    '_pre_import_hook',
    {
      clear_method   => 'clear_pre_import_hooks',
      add_method     => 'add_pre_import_hook',
      adds_method    => 'add_pre_import_hooks',
      delete_method  => 'delete_pre_import_hook',
      deletes_method => 'delete_pre_import_hooks',    
    },
  ],
);

sub import
{
  my($class) = shift;

  my $target_class = (caller)[0];

  my($force, @methods, %import_as);

  foreach my $arg (@_)
  {
    if(!defined $target_class && $arg !~ /^-/)
    {
      $target_class = $arg;
      next;
    }

    if($arg =~ /^-?-force$/)
    {
      $force = 1;
    }
    elsif($arg =~ /^-?-target[-_]class$/)
    {
      $target_class = undef; # set on next iteration...lame
      next;
    }
    elsif($arg =~ /^:(.+)/)
    {
      my $methods = $class->export_tag($1) or
        croak "Unknown export tag - '$arg'";

      push(@methods, @$methods);
    }
    elsif(ref $arg eq 'HASH')
    {
      while(my($method, $name) = each(%$arg))
      {
        push(@methods, $method);
        $import_as{$method} = $name;
      }
    }
    else
    {
      push(@methods, $arg);
    }
  }

  foreach my $method (@methods)
  {
    my $code = $class->can($method) or 
      croak "Could not import method '$method' from $class - no such method";

    my $import_as = $import_as{$method} || $method;

    if($target_class->can($import_as) && !$force)
    {
      croak "Could not import method '$import_as' from $class into ",
            "$target_class - a method by that name already exists. ",
            "Pass a '-force' argument to import() to override ",
            "existing methods."
    }

    if(my $hooks = $class->pre_import_hooks($method))
    {
      foreach my $code (@$hooks)
      {
        my $error;

        TRY:
        {
          local $@;
          eval { $code->($class, $method, $target_class, $import_as) };
          $error = $@;
        }

        if($error)
        {
          croak "Could not import method '$import_as' from $class into ",
                "$target_class - $error";
        }
      }
    }

    no strict 'refs';      
    $Debug && warn "${target_class}::$import_as = ${class}->$method\n";
    *{$target_class . '::' . $import_as} = $code;
  }
}

sub export_tag
{
  my($class, $tag) = (shift, shift);

  if(index($tag, ':') == 0)
  {
    croak 'Tag name arguments to export_tag() should not begin with ":"';
  }

  if(@_ && !$class->_export_tag_value($tag))
  {
    $class->_add_export_tag($tag);
  }

  if(@_ && (@_ > 1 || (ref $_[0] || '') ne 'ARRAY'))
  {
    croak 'export_tag() expects either a single tag name argument, ',
          'or a tag name and a reference to an array of method names';
  }

  my $ret = $class->_export_tag_value($tag, @_);

  croak "No such tag: $tag"  unless($ret);

  return wantarray ? @$ret : $ret;
}

sub export_tags
{
  my($class) = shift;
  return $class->_export_tags  unless(@_);
  $class->clear_export_tags;
  $class->add_export_tags(@_);
}

sub add_export_tags
{
  my($class) = shift;

  while(@_)
  {
    my($tag, $arg) = (shift, shift);
    $class->export_tag($tag, $arg);
  }
}

sub pre_import_hook
{
  my($class, $method) = (shift, shift);

  if(@_ && !$class->_pre_import_hook_value($method))
  {
    $class->add_pre_import_hook($method);
  }

  if(@_ && (@_ > 1 || (ref $_[0] && (ref $_[0] || '') !~ /\A(?:ARRAY|CODE)\z/)))
  {
    croak 'pre_import_hook() expects either a single method name argument, ',
          'or a method name and a code reference or a reference to an array ',
          'of code references';
  }

  if(@_)
  {
    unless(ref $_[0] eq 'ARRAY')
    {
      $_[0] = [ $_[0] ];
    }
  }

  my $ret = $class->_pre_import_hook_value($method, @_) || [];

  return wantarray ? @$ret : $ret;
}

sub pre_import_hooks { shift->pre_import_hook(shift) }

1;

__END__

=head1 NAME

Rose::Object::MixIn - A base class for mix-ins.

=head1 SYNOPSIS

  package MyMixInClass;

  use Rose::Object::MixIn(); # Use empty parentheses here
  our @ISA = qw(Rose::Object::MixIn);

  __PACKAGE__->export_tag(all => [ qw(my_cool_method my_other_method) ]);

  sub my_cool_method  { ... }
  sub my_other_method { ... }
  ...

  package MyClass;
  # Import methods my_cool_method() and my_other_method()
  use MyMixInClass qw(:all);
  ...

  package MyOtherClass;  
  # Import just my_cool_method()
  use MyMixInClass qw(my_cool_method);
  ...

  package YetAnotherClass;
  # Import just my_cool_method() as cool()
  use MyMixInClass { my_cool_method => 'cool' }

=head1 DESCRIPTION

L<Rose::Object::MixIn> is a base class for mix-ins.  A mix-in is a class that exports methods into another class.  This export process is controlled with an L<Exporter>-like interface, but L<Rose::Object::MixIn> does not inherit from L<Exporter>.

When you L<use|perlfunc/use> a L<Rose::Object::MixIn>-derived class, its L<import|/import> method is called at compile time.  In other words, this:

    use Rose::Object::MixIn 'a', 'b', { c => 'd' };

is the same thing as this:

    BEGIN { Rose::Object::MixIn->import('a', 'b', { c => 'd' }) }

To prevent the L<import|/import> method from being run, put empty parentheses "()" after the package name instead of a list of arguments.

    use Rose::Object::MixIn();

See the L<synopsis|/SYNOPSIS> for an example of when this is handy: using L<Rose::Object::MixIn> from within a subclass.  Note that the empty parenthesis are important.  The following is I<not> equivalent:

    # This is not the same thing as the example above!
    use Rose::Object::MixIn;

See the documentation for the L<import|/import> method below to learn what arguments it accepts.

=head1 CLASS METHODS

=over 4

=item B<import ARGS>

Import the methods specified by ARGS into the package from which this method was called.  If the current class L<can|perlfunc/can> already perform one of these methods, a fatal error will occur.  To override an existing method, you must use the C<-force> argument (see below).

Valid formats for ARGS are as follows:

=over 4

=item * B<A method name>

Literal method names will be imported as-is.

=item * B<A tag name>

Tags names are indicated with a leading colon.  For example, ":all" specifies the "all" tag.  A tag is a stand-in for a list of methods.  See the L<export_tag|/export_tag> method to learn how to create tags.

=item * B<A reference to a hash>

Each key/value pair in this hash contains a method name and the name that it will be imported as.  Use this feature to import methods under different names in order to avoid conflicts with existing methods.

=item * C<-force>

The special literal argument C<-force> will cause the specified methods to be imported even if the calling class L<can|perlfunc/can> already perform one or more of those methods.

=item * C<-target_class CLASS>

The special literal argument C<-target-class> followed by a class name will cause the specified methods to be imported into CLASS rather than into the calling class.

=back

See the L<synopsis|/SYNOPSIS> for several examples of the L<import|/import> method in action.  (Remember, it's called implicitly when you L<use|perlfunc/use> a L<Rose::Object::MixIn>-derived class with anything other than an empty set of parenthesis "()" as an argument.)

=item B<clear_export_tags>

Delete the entire list of L<export tags|/export_tags>.

=item B<export_tag NAME [, ARRAYREF]>

Get or set the list of method names associated with a tag.  The tag name should I<not> begin with a colon.  If ARRAYREF is passed, then the list of methods associated with the specific tag is set.

Returns a list (in list context) or a reference to an array (in scalar context) of method names.  The array reference return value should be treated as read-only.  If no such tag exists, and if an ARRAYREF is not passed, then a fatal error will occur.

=item B<export_tags>

Returns a list (in list context) and a reference to an array (in scalar context) containing the complete list of export tags.  The array reference return value should be treated as read-only.

=back

=head1 AUTHOR

John C. Siracusa (siracusa@gmail.com)

=head1 LICENSE

Copyright (c) 2010 by John C. Siracusa.  All rights reserved.  This program is
free software; you can redistribute it and/or modify it under the same terms
as Perl itself.