I'm trying to make a binary tree object which uses a recursively called new() method to create a tree n nodes deep. The problem is that whenever i try to assign new nodes to the object branch variables from within the object methods it doesn't work, but whenever I assign a node to a branch outside of the object method functions, it works perfectly.

That's probably a bad explanation of the problem, but hopefully my code is self explanatory. For those of you who are going to point me to modules which implement a binary tree, I'm doing this as an excercise in preparation for a larger project involving complex objects and data structures, etc. Thanks for your help, this one's driving me mad.

package bin_tree;

#create a new instance of the bin_tree object, taking #$depth as an ar
+gument... Create a binary tree,
#recursively calling new() in order to create a node with #the desired
+ depth.
sub new{
    $class=shift;
    $depth=shift; #pull the class values and the depth beneath the nod
+e desired, 0 for no lower nodes
    $self={value,a,b}; #make our object as an anonymous hash with keyw
+ords but no values yet, that way the a and b keys (our branches) defa
+ult evaluate to null
    $self->{value}=0;
    print $self->{value},"\n"; #just a debugging statement to try to f
+igure out whats going on
    while ($depth >= 1){ #if we need to get deep, recursively call the
+ new() method, assigning the created objects to our a and b branches
        $depth--;
        $self->{a} = bin_tree->new($depth); #problem is here... the ne
+w binary tree node never gets returned
        $self->{b} = bin_tree->new($depth);
        print $self->{a},"\n"; #debugging statement, this still evalua
+tes to null, even though it should be set as an object reference now
    }
    bless $self, $class; #make object
    return $self; #return object
}

#5 minute depth test function, recursively runs down the "a" side of a
+ binary tree, returns the depth eventually
sub depth_test{
    $self=shift;
    print $i++,"\n";
    if (defined $self->{a}){
    $depth=$self->{a}->depth_test();
    }
    return $depth+1;
}
#try to create a three node deep binary tree
$bintree = bin_tree->new(3);
print "Before:",$bintree->{a},"\n";
$deep = $bintree->depth_test();
print "Depth:",$deep,"\n"; #prove that new() call is just creating the
+ first level node)
$bintree->{a} = bin_tree->new();
$bintree->{a}->{a} = bin_tree->new();
print "After:",$bintree->{a},"\n";
$deep = $bintree->depth_test();
print "Depth:",$deep,"\n"; #prove that when the code is outside of the
+ object methods, i can use my technique to build a tree
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