perl-Contextual-Return

Usually, when you need to create a subroutine that returns different values
in different contexts (list, scalar, or void), you write something like:
sub get_server_status {
    my ($server_ID) = @_;


    my %server_data = _ascertain_server_status($server_ID);



    if (wantarray()) {
        return @server_data{ qw(name uptime load users) };
    }
    if (defined wantarray()) {
        return $server_data{load};
    }
    if (!defined wantarray()) {
        carp 'Useless use of get_server_status() in void context';
        return;
    }
    else {
        croak q{Bad context! No biscuit!};
    }
}


That works okay, but the code could certainly be more readable. In its
simplest usage, this module makes that code more readable by providing
three subroutines--'LIST()', 'SCALAR()', 'VOID()'--that are true only when
the current subroutine is called in the corresponding context:
use Contextual::Return;

sub get_server_status {
    my ($server_ID) = @_;


    my %server_data = _ascertain_server_status($server_ID);



    if (LIST)   { return @server_data{ qw(name uptime load users) } }
    if (SCALAR) { return $server_data{load}                         }
    if (VOID)   { print "$server_data{load}\n"                      }
    else        { croak q{Bad context! No biscuit!}                 }
}


          

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License: Artistic-1.0 or GPL-1.0+
URL: http://search.cpan.org/dist/Contextual-Return/