#!/usr/local/bin/perl -w
use strict;

my $d = " #";
my $t = " +";
my $l = " \\";
my $p = " |";
my $s = "  ";

my $tree = {
    'one' => {
        'two' => {
            'five' => {
                'boo' => {
                    'baz' => { },
                },
            },
        },
        'three' => {
            'four' => { },
            'yak' => { },
            'six' => {
                'foo' => {
                    'yuk' => { },
                },
                'ggg' => { },
            },
        },
    },
};

print "with pipes...\n" . &render_node($tree->{'one'}, 'one');
print "no pipes...\n" . &render_node_tab($tree->{'one'}, 'one');

sub render_node {
    my ($tree, $node, $tok, $pad, $last) = @_;
    $tok  = $s unless defined $tok;
    $pad  = "" unless defined $pad;
    $last = 1  unless defined $last;
    
    my $out = $pad . $tok . $d . $node . "\n";

    my @kids = sort keys %{$tree};
    for (my $i = 0; $i < scalar @kids; $i++) {
        my $knode = $kids[$i];
        my $ktree = $tree->{$knode};
        my $klast = ($i+1 == scalar @kids);
        my $ktok  = ($klast ? $l : $t);
        my $kpad  = $pad . ($last ? $s : $p);
        
        $out .= &render_node($ktree, $knode, $ktok, $kpad, $klast);
    }
    return $out;
}

sub render_node_tab {
    my ($tree, $node, $tok, $indent) = @_;
    $tok    = $s unless defined $tok;
    $indent = 0  unless defined $indent;

    my $out = ($s x $indent) . $tok . $d . $node . "\n";

    my @kids = sort keys %{$tree};

    for (my $i = 0; $i < scalar @kids; $i++) {
        my $knode   = $kids[$i];
        my $ktree   = $tree->{$knode};
        my $ktok    = ($i+1 == scalar @kids) ? $l : $t;
        my $kindent = $indent+1;
        
        $out .= &render_node_tab($ktree, $knode, $ktok, $kindent);
    }
    
    return $out;
}
__END__
with pipes...
   #one
   + #three
   | + #four
   | + #six
   | | + #foo
   | | | \ #yuk
   | | \ #ggg
   | \ #yak
   \ #two
     \ #five
       \ #boo
         \ #baz
no pipes...
   #one
   + #three
     + #four
     + #six
       + #foo
         \ #yuk
       \ #ggg
     \ #yak
   \ #two
     \ #five
       \ #boo
         \ #baz