foreach my $letter (split( //, $list_order )) {
my $r;
- $r = &{$map_funcs->{$letter}[1]}($b) <=> &{$map_funcs->{$letter}[1]}($a) if $map_funcs->{$letter}[0] eq '<->';
- $r = &{$map_funcs->{$letter}[1]}($a) <=> &{$map_funcs->{$letter}[1]}($b) if $map_funcs->{$letter}[0] eq '<=>';
- $r = &{$map_funcs->{$letter}[1]}($a) cmp &{$map_funcs->{$letter}[1]}($b) if $map_funcs->{$letter}[0] eq 'cmp';
+ $r = (&{$map_funcs->{$letter}[1]}($b)//0 ) <=> (&{$map_funcs->{$letter}[1]}($a)//0 ) if $map_funcs->{$letter}[0] eq '<->';
+ $r = (&{$map_funcs->{$letter}[1]}($a)//0 ) <=> (&{$map_funcs->{$letter}[1]}($b)//0 ) if $map_funcs->{$letter}[0] eq '<=>';
+ $r = (&{$map_funcs->{$letter}[1]}($a)//"") cmp (&{$map_funcs->{$letter}[1]}($b)//"") if $map_funcs->{$letter}[0] eq 'cmp';
return $r if $r != 0;
}
return 0;