1Package::Anon(3) User Contributed Perl Documentation Package::Anon(3)
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6 Package::Anon - Anonymous packages
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9 my $stash = Package::Anon->new;
10 $stash->add_method(get_answer => sub { 42 });
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12 my $obj = $stash->bless({});
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14 $obj->get_answer; # 42
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17 This module allows for anonymous packages that are independent of the
18 main namespace and only available through an object instance, not by
19 name.
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21 # Declare an anonymous package using new()
22 my $stash = Package::Anon->new;
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24 # Add behavior to the package
25 $stash->add_method('get_answer', sub{ return 42; });
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27 # Create an instance of the anonymous package
28 my $instance = $stash->bless({});
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30 # Call the method
31 $instance->get_answer(); # returns 42
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33 In "$my_object->do_stuff()" Perl uses a the name of the class
34 $my_object is blessed into to resolve the function "do_stuff()".
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36 Packages created using Package::Anon exist outside of the "main::"
37 namespace and cannot be referenced by name. These packages are defined
38 within stashes that are only accessible through a reference rather than
39 using a name.
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41 Previous attempts to allow for anonymous packages in Perl use
42 workarounds that still ultimately result in references by named
43 packages. Because Package::Anon allows method dispatching without a
44 name lookup, packages are truly anonymous.
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47 new ($name?)
48 my $stash = Package::Anon->new;
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50 my $stash = Package::Anon->new('Foo');
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52 Create a new anonymous package. The optional $name argument sets the
53 stash's name. This name only serves as an aid for debugging. The stash
54 is not reachable from the global symbol table by the given name.
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56 $name defaults to "__ANON__".
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58 bless ($reference)
59 my $instance = $stash->bless({});
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61 Bless a $reference into the anonymous package.
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63 add_method ($name, $code)
64 $stash->add_method(foo => sub { return 42; });
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66 Register a new method in the anonymous package. "add_method()" is
67 provided as a convenience method for adding code symbols to slots in
68 the anonymous stash. For additional symbol table manipulation, see
69 "SYMBOL TABLE MANIPULATION".
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71 blessed ($obj)
72 my $stash = Package::Anon->blessed($obj);
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74 Returns a Package::Anon instance for the package the given $obj is
75 blessed into, or undef if $obj isn't an object.
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77 install_glob ($name)
78 my $gv = $stash->install_glob('foo');
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80 Create a glob with the given $name and install it under that $name
81 within the $stash. The returned glob can be used to install symbols
82 into the $stash. See "SYMBOL TABLE MANIPULATION" for examples.
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85 These methods interact with the symbol table in ways that could cause
86 unexpected results in your programs. Please use them with caution.
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88 create_glob ($name)
89 my $gv = $stash->create_glob('foo');
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91 Creates a new glob with the name $name, pointing to $stash as its
92 stash. The created glob is not installed into the $stash.
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94 This method implements functionality similar to Symbol::gensym, but
95 allows you to specify the name of the glob.
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98 This module is intended to create anonymous packages with behavior, not
99 data members. Support for data members has been documented because the
100 Glob API supports the addition of data types besides coderefs. Please
101 use this module with caution when creating data members in your
102 anonymous packages.
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104 add_method('get_answer', sub {return 42});
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106 is the same as:
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108 my $gv = install_glob('get_answer');
109 *$gv = sub { return 42 };
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111 For other data types:
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113 *$gv = \$foo # scalar
114 *$gv = \@foo # array
115 *$gv = \%foo # hash
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117 Currently, "Package::Anon" instances are blessed stash references, so
118 the following is possible:
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120 $stash->{$symbol_name} = *$gv;
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122 However, the exact details of how to get a hold of the actual stash
123 reference might change in the future.
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126 · Florian Ragwitz <rafl@debian.org>
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128 · Ricardo Signes <rjbs@cpan.org>
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130 · Jesse Luehrs <doy@tozt.net>
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132 · Augustina Blair <auggy@cpan.org>
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135 This software is copyright (c) 2012 by Florian Ragwitz.
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137 This is free software; you can redistribute it and/or modify it under
138 the same terms as the Perl 5 programming language system itself.
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142perl v5.28.1 2012-08-29 Package::Anon(3)