power_of_perl.pl

package Test {
    use Keyword::Declare;

    my $vars = {};

    keyword let (Str $name, Block $block) {
        $name =~ s/^("|')(.*)("|')$/$2/;

        "my sub $name { \$vars->{$name} //= do $block }"
    }

    let 'foo' {
        int(rand 10);
    }

    sub boo {
        print "Run 1 = " .  foo() . "\n";
        print "Run 2 = " .  foo() . "\n";
        $vars = {};
        print "Run 3 = " .  foo() . "\n";
        print "Run 4 = " .  foo() . "\n";
    }


};

Test::boo('doo!');


1;