1Sub::Exporter::Lexical(U3s)er Contributed Perl DocumentatSiuobn::Exporter::Lexical(3)
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NAME

6       Sub::Exporter::Lexical - to export lexically-available subs with
7       Sub::Exporter
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VERSION

10       version 0.092292
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SYNOPSIS

13       Achtung!  I don't know why I wrote this.  I don't use it and never
14       have.  Originally, it was not lexical, but dynamic, despite the name.
15       What was I thinking?  Clearly this was a bad brain day.  I have
16       rewritten the code now to use Lexical::Sub, which should make the
17       behavior actually lexical, but I have not expanded the test suite.  To
18       continue...
19
20       In an exporting library:
21
22         package Some::Toolkit;
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24         use Sub::Exporter -setup => {
25           exports   => [ qw(foo bar baz) ],
26         };
27
28         sub foo { ... }
29         sub bar { ... }
30         sub baz { ... }
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32       In an importing library:
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34         package Vehicle::Autobot;
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36         use Sub::Exporter::Lexical lexical_installer => { -as => 'lex' };
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38         ...;
39
40         {
41           use Some:::Toolkit { installer => lex }, qw(foo bar);
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43           foo(1,2,3);
44           my $x = bar;
45
46           ...
47         };
48
49         # ... and here, foo and bar are no longer available ...
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DESCRIPTION

52       Sub::Exporter::Lexical provides an alternate installer for
53       Sub::Exporter.  Installers are documented in Sub::Exporter's
54       documentation; all you need to know is that by using
55       Sub::Exporter::Lexical's installer, you can import routines into a
56       lexical scope that will be cleaned up when that scope ends.
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58       There are two places it makes sense to use the lexical installer: when
59       configuring Sub::Exporter in your exporting package or when importing
60       from a package that uses Sub::Exporter.  For the first case, do
61       something like this:
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63         package Some::Toolkit;
64         use Sub::Exporter::Lexical ();
65         use Sub::Exporter -setup => {
66           exports   => [ ... ],
67           installer => Sub::Exporter::Lexical::lexical_installer,
68         };
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70       For the second:
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72         package My::Library;
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74         use Sub::Exporter::Lexical ();
75         use Some::Toolkit
76           { installer => Sub::Exporter::Lexical::lexical_installer },
77           qw(foo bar baz);
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EXPORTS

80       Sub::Exporter::Lexical offers only one routine for export, and it may
81       also be called by its full package name:
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83   lexical_installer
84       This routine returns an installer suitable for use as the "installer"
85       argument to Sub::Exporter.  It installs all requested routines as
86       usual, but marks them to be removed from the target package as soon as
87       the block in which it was called is complete.
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89       It does not affect the behavior of routines exported into scalar
90       references.
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92       More importantly, it does not affect scopes in which it is invoked at
93       runtime, rather than compile time.  This is important!  It means that
94       this works:
95
96         {
97           use Some::Toolkit { installer => lexical_installer }, qw(foo);
98           foo(1,2,3);
99         }
100
101         foo(); # this dies
102
103       ...but this does not...
104
105         {
106           require Some::Toolkit;
107           Some::Toolkit->import({ installer => lexical_installer }, qw(foo));
108           foo(1,2,3);
109         }
110
111         foo(); # this does not die, even though you might expect it to
112
113       Finally, you can't supply a "-as => \$var" install destination yet.
114

AUTHOR

116       Ricardo Signes <rjbs@cpan.org>
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119       This software is copyright (c) 2013 by Ricardo Signes.
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121       This is free software; you can redistribute it and/or modify it under
122       the same terms as the Perl 5 programming language system itself.
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126perl v5.28.0                      2013-11-24         Sub::Exporter::Lexical(3)
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