NAME

List::AssignRef - assign an arrayref to an array sensibly

SYNOPSIS

        # You can't do this in Perl...
        
        my \@array = $arrayref;
        
        # But you can do this...
        
        use List::AssignRef;
        deref my @array = $arrayref;

DESCRIPTION

OK, so you might ask yourself, why would you want to do this:

        my \@array = $arrayref;

When you can just do this:

        my @array = @{ $arrayref };

Well, in that simple case List::AssignRef is overkill.

However, what about cases when you have a function that returns a list of arrayrefs, such as part from List::MoreUtils. For example:

        my ($staff, $managers) = part { $_->title =~ /Manager/ } @employees;

If you want @staff and @managers arrays (as against arrayrefs), you need to dereference each separately. Something like:

        my @parted = part { $_->title =~ /Manager/ } @employees;
        my @staff    = @{$parted[0]};
        my @managers = @{$parted[1]};

List::AssignRef makes this slightly prettier:

        (deref my @staff, deref my @managers)
                = part { $_->title =~ /Manager/ } @employees;

List::AssignRef exports exactly one function...

deref ARRAY|HASH|SCALAR

deref must be given a (non-reference) array, hash or scalar. It acts as an lvalue, allowing a reference array, hash or scalar respectively to be assigned to it.

This module uses Exporter::Shiny which means that you can rename the exported function easily:

        use List::AssignRef deref => { -as => 'dereference' };

LEGACY PERL SUPPORT

The examples above rely on a parsing improvement in Perl 5.14. Although this module does support earlier versions of Perl (5.6 and above), prior to 5.14 you may need to add additional parentheses:

        (deref(my @staff), deref(my @managers))
                = part { $_->title =~ /Manager/ } @employees;

BUGS

Please report any bugs to http://rt.cpan.org/Dist/Display.html?Queue=List-AssignRef.

SEE ALSO

List::Util, List::MoreUtils.

Ref::List is not dissimilar but without the prototype trickery and lvalue stuff, so doesn't satisfy this module's use case.

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

This software is copyright (c) 2012 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.

cpanm List::AssignRef

perl -MCPAN -e shell
install List::AssignRef