Package MyBaseClass; sub new { my $class = shift; my $self = {}; bless($self,$class); $self->_init(); return $self; } sub _init { my $self = shift; @{$self->{things}} = qw(thing_0.1 thing_0.2 thing_0.3 thing_11.0 thing_11.1); # etc,etc return $self; } # $a and $b don't seem to exist within this context sub specialSort { my $self = shift; my @aParts = split(/[_.]/, $a); my @bParts = split(/[_.]/, $b); return 1 if (int $a_parts[1] > int $b_parts[1] || ($a_parts[1] eq $b_parts[1] && (int $a_parts[2]) > (int $b_parts[2]))); return -1 if (int $a_parts[1] < int $b_parts[1] || ($a_parts[1] eq $b_parts[1] && (int $a_parts[2]) < (int $b_parts[2]))); return 0 if ($a eq $b); die((caller(0))[3] . " LOGIC error."); } 1;