sub global_sum {
  state $sum = 0;
  $sum += $_[0];
  $sum;
}

##</code><code>##

$ perl -e '
> use strict;
> use warnings;
> use v5.10;
>
> sub somefunc
> {
>    state $var = do {
>      say "Heavy calculations";
>      42+$_[0];
>    };
> }
>
> say somefunc(0);
> say somefunc(10);
> '
Heavy calculations
42
42

##</code><code>##

$ perl -e '
> use strict;
> use warnings;
> use v5.10;
> { my $var = 42;
>      sub somefunc
>      {
>         $var + shift;
>      }
> }
> say somefunc(5);
> say somefunc(10);
> '
47
52