Unless i am missing something (which i usually am), why not just sort the results?
@union = sort grep { not $seen{$_}++ } (@union, @array3);
UPDATE: i think i see what you want now ... let's try using CHARS instead of INTS. In order
to have "intelligent" sorting, you have to provide the "intelligence" ... in this case, let's
give weights to each of the items we are dealing with:
my @array1 = ([b=>1], [d=>3], [z=>4], [e=>5]);
my @array2 = ([a=>2], [b=>1], [z=>4]);
my @array3 = ([d=>3], [e=>5]);
The rest of the code is mostly the same (i did not bother to see if this could be refactored
for efficiency), but since our arrays hold more arrays, we need to code appropriately:
my %seen;
my @union = grep { not $seen{$_->[0]}++ } (@array1, @array2);
undef %seen;
@union =
map { $_->[0] }
sort { $a->[1] <=> $b->[1] }
grep { not $seen{$_->[0]}++ } (@union, @array3);
use Data::Dumper;
print Dumper \@union;
Hope this helps. :)
