Re: How to compare hash value

I don't think your code is doing what you want. Examine the following:

LIAM:~$ perl
push(@a, 'a');
push(@a, 'b');
$foo{stuff} = @a;
print $foo{stuff} . "\n";
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gives the result of 2. This is because you're assigning into the hash value the result of (scalar @a). If you really want to go with a hash of lists, your code should look more like

$myhash{$key1}=\@value1
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Instead, you probably should be using a hash of hashes, e.g.

$myhash{$key1} = {'abd' => 1, 'bcd' => 2, ...};
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This will prevent duplicate elements from messing up your set. Then, you can use sort and keys together to do the compare. Here's a subroutine that does what I think you're looking for:

sub add_set
{ # adds a set if it's unique, otherwise does nothing.
my ($mhash, $new_hashid, @elements) = @_;
my %endhash;
foreach my $element (@elements)
  {$endhash{$element} = 1;}
my @matched_keys = grep
    {
    my $truth = 1;
    foreach my $cand_element (keys %endhash)
        {$truth *= defined $mhash{$_}{$cand_element}; }
    }
    (keys %$mhash); # This only ensures that we have a subset
my $magic_key;
foreach my $matched_key (@matched_keys)
  {
  my $match_ok = 1;
  foreach my $c_elem (keys %{$mhash{$matched_key}} )
    {
    if(! defined($endhash{$c_elem}) )
      {$match_ok = 0;}
    }
  if($match_ok) {$magic_key = $matched_key;last;}
  }
if(defined($magic_key) )
  {
  # Our set is already in here, so just return
  print "Set already found, returning\n";
  return;
  }
$$mhash{$new_hashid} = \%endhash; # Otherwise, add it
}
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Note that this code is very untested. Here's some minimal test code:

my %foo;
$foo{set1} = {a=>'beta', 'c'=>'gamma'};
add_set(\%foo, "set2", 'beta','gamma');
add_set(\%foo, "set3", 'moo', 'cow');
print join("\n", keys %foo);
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Thinking about it, Quantum::Superpositions might be a better way to do this. There also might be a fairly obvious better way to do this that I'm not seeing. Anyhow, I hope this helps.

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