package DeepCopy;
require Exporter;
@ISA=qw/Exporter/;
@EXPORT=qw/copy/;

sub copy {
  # copy $_[0] and return a freshly-reffed version.
  my ($out,$bless);
  my $orig = shift;
  my $type = ref $orig;
  return $orig unless $type;
  unless ($type =~ /SCALAR|REF|CODE|ARRAY|HASH|GLOB/) {
    $bless = $type;
    if (UNIVERSAL::isa($orig,'SCALAR')) {
      $type = 'SCALAR';
    } elsif (UNIVERSAL::isa($orig,'REF')) {
      $type = 'REF';
    } elsif (UNIVERSAL::isa($orig,'CODE')) {
      $type = 'CODE';
    } elsif (UNIVERSAL::isa($orig,'ARRAY')) {
      $type = 'ARRAY';
    } elsif (UNIVERSAL::isa($orig,'HASH')) {
      $type = 'HASH';
    } elsif (UNIVERSAL::isa($orig,'GLOB')) {
      $type = 'GLOB';
    } else {
      warn 'I am now deeply lost.';
      return $orig;
    }
  }
  if ($type eq 'SCALAR' or 
      $type eq 'REF' or
      $type eq 'CODE') {
    my $foo = $orig;
    $out = \$foo;
  } elsif ($type eq 'ARRAY') {
    push @$out, copy($_) for @$orig;
  } elsif ($type eq 'HASH') {
    $out->{$_} = copy($orig->{$_}) for keys %$orig;
  } elsif ($type eq 'GLOB') {
    warn 'GLOB copy unimplemented';
    my $foo = $orig;
    $out = \$foo;
  } else {
    warn 'I am now deeply lost.';
  }
  bless $out, $bless if $bless;
  return $out;
}

1;