NAME Exporter::LexicalVars - export lexical variables SYNOPSIS BEGIN { package MyVars; use Exporter::LexicalVars -setup => { '$pi' => 3.14159, '$foo' => sub { my $ref = shift; $$ref = "Hello world"; }, }; }; use Data::Dumper; my $pi = 3; { use MyVars; print Dumper($pi); # 3.14159 print Dumper($foo); # Hello world } print Dumper($pi); # 3 { use MyVars qw( $foo ); print Dumper($pi); # 3 print Dumper($foo); # Hello world } DESCRIPTION Exports lexical (`my`) variables. In the setup hashref, you can provide either non-reference values to define in the caller's lexical context, or you can provide initializers as coderefs. Initializers are called with a reference to the variable which has been defined in the caller's lexical context. You can use that reference to not just assign it a value, but potentially mark the variable as read-only, or tie the variable, or whatever. Lexical scalar, array and hash variables are each supported. In the case of arrays and hashes, providing `undef` in the setup hashref will initialize them to empty, but otherwise you must initialize them with an initializer coderef; not a non-reference scalar value. Exporter-style "tags" may also be defined: BEGIN { package MyVars; use Exporter::LexicalVars -setup => { '$pi' => sub { ... }, '$e' => sub { ... }, ':maths' => [qw( $pi $e )], }; }; use MyVars qw( :maths ); use MyVars -maths; # this works too A tag called `:all` will be automatically set up for you. If your exporter is called without any arguments, then it will export a tag called `:default` if it exists, or `:all` otherwise. BUGS Please report any bugs to . SEE ALSO Exporter::Tiny, Exporter, Sub::Exporter, perldata. . AUTHOR Toby Inkster . COPYRIGHT AND LICENCE This software is copyright (c) 2014 by Toby Inkster. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. DISCLAIMER OF WARRANTIES THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.