#! /bin/perl -w

# Copyright © 2001-2003 Joe Puliadi. No part
# may be reproduced without prior consent. To
# get permission, email joe@agatya.com

# Name:   hoh
# URL:    /training/bio3/2ndClass/hoh
# Author: Joe Puliadi (joe@agatya.com)
# Date:   Wed Apr 10 15:40:11 PDT 2002
# Syntax:
#    hoh
#
# Description:
# This program describes how to work with
# hash of hashes.
#

use strict;
print "\n";

my %aa_count =
    (
	A => {
		   pos => 3,
		   count => 7
	     },
	B => {
		   pos => 7,
		   count => 1
	     },
    );

# add a new aminoacid to the %aa_count
$aa_count{C} = {
		   pos => 4,
		   count => 0
	        };

# add another aminoacid to %aa_count
$aa_count{D}{pos}   = 5;
$aa_count{D}{count} = 2;

# add a new attribute to the aa_count
$aa_count{A}{line_no} = 0;
$aa_count{B}{line_no} = 1;
$aa_count{C}{line_no} = 2;
$aa_count{D}{line_no} = 3;

print 'Aminoacids of %aa_count: ',
	join(' ', keys(%aa_count)), "\n";
my @loh = values(%aa_count);
print 'Attributes of the aa_count: ',
	join(' ', keys(%{$loh[0]})), "\n";

# you can access vals with the arrow notation
print q/$aa_count{C}->{pos}: /,
	"$aa_count{C}->{pos}\n";
print "\n";

__END__

Aminoacids of %aa_count: A B C D
Attributes of the aa_count: count pos line_no
$aa_count{C}->{pos}: 4