$HASH_LIMIT = 1024;

##  myhash (key:string) : int
#
#   calculate a checksum
#
sub myhash {
    my $key = shift;
    my $h = 0;

    for $c (unpack ('c*', $key)) {  ##  break the key into chars

        $h *= 2;            ##  shift the hash value left one bit
        $h ^= $c;           ##  and XOR it with the next char
    }
    
    $h %= $HASH_LIMIT;      ##  trim to fit the defined range
    return ($h);            ##  and return the result
}

for $k (qw( testing the hash function )) {
    printf ("%10s - %s\n", $k, &myhash($k));
}

##</code><code>##

@MY_HASH = (0) x $HASH_LIMIT;

##  put (key:string, val:string) : nil
#
#   store a value in a hash
#
sub put {
    my $key = shift;
    my $val = shift;

    $MY_HASH[ &myhash($key) ] = $val;
    return;
}

##  get (key:string) : string
#
#   get a value from the hash
#
sub get {
    my $key = shift;

    return ($MY_HASH[ &myhash($key) ]);
}