1No::Worries::Export(3)User Contributed Perl DocumentationNo::Worries::Export(3)
2
3
4
6 No::Worries::Export - symbol exporting without worries
7
9 use No::Worries::Export qw(export_control);
10
11 sub foo () { ... }
12
13 our $bar = 42;
14
15 sub import : method {
16 my($pkg, %exported);
17 $pkg = shift(@_);
18 grep($exported{$_}++, qw(foo $bar));
19 export_control(scalar(caller()), $pkg, \%exported, @_);
20 }
21
23 This module eases symbol exporting by providing a simple yet powerful
24 alternative to the Exporter module.
25
26 The symbols that can be imported are defined in a hash (the third
27 argument of export_control()), the key being the symbol name and the
28 value being:
29
30 • a scalar: indicating a normal symbol
31
32 • a code reference: to be called at import time
33
34 The normal symbols can be functions (such as "foo"), scalars (<$foo>),
35 arrays (<@foo>) or hashes (<%foo>).
36
37 All the normal symbols can be imported at once by using an asterisk in
38 the import code:
39
40 use Foo qw(*);
41
42 Alternatively, a regular expression can be given to filter what to
43 import:
44
45 # import "foo" and all the normal symbols starting with "bar"
46 use Foo qw(foo /^bar/);
47
48 The special symbols can be used to execute any code. For instance:
49
50 # exporting module
51 our $backend = "stdout";
52 sub import : method {
53 my($pkg, %exported);
54 $pkg = shift(@_);
55 $exported{syslog} = sub { $backend = "syslog" };
56 export_control(scalar(caller()), $pkg, \%exported, @_);
57 }
58
59 # importing code
60 use Foo qw(syslog);
61
62 Finally, anything looking like a number will trigger a version check:
63
64 use Foo qw(1.2);
65 # will trigger
66 Foo->VERSION(1.2);
67
68 See UNIVERSAL for more information on the VERSION() mthod.
69
71 This module provides the following function (not exported by default):
72
73 export_control(CALLERPKG, PKG, EXPORT, NAMES...)
74 control the symbols exported by the module; this should be called
75 from an "import" method
76
78 Exporter, No::Worries.
79
81 Lionel Cons <http://cern.ch/lionel.cons>
82
83 Copyright (C) CERN 2012-2019
84
85
86
87perl v5.38.0 2023-07-21 No::Worries::Export(3)