<Perl> 
Package MyAppConfig;
my $cfg = {
    DBMpath => '/foo/bar/quux',
    salt    => 'NaCl',
    baseDir => '/baz/bar/foo',
};
sub salt {
    my ($class,$salt) = @_;

    $cfg->{salt} = $salt if $salt;

    return $cfg->{salt};
}
# Write accessors/mutators as desired for the other elements too.
</Perl>