my $foo = [('') x 9];
format =
+-----------------------+
| @ @ @ | @ @ @ | @ @ @ |~~ 
@{ shift @f1 || $foo }
|-------+-------+-------|
| @ @ @ | @ @ @ | @ @ @ |~~ 
@{ shift @f2 || $foo } 
|-------+-------+-------|
| @ @ @ | @ @ @ | @ @ @ |~~ 
@{ shift @f3 || $foo } 
+-----------------------+
.
write;

##</code><code>##

my $foo = [('') x 9];
push @$_, $foo for \@f1,\@f2,\@f3;
format =
+-----------------------+
| @ @ @ | @ @ @ | @ @ @ |~~
@{shift @f1}
|-------+-------+-------|
| @ @ @ | @ @ @ | @ @ @ |~~
@{shift @f2}
|-------+-------+-------|
| @ @ @ | @ @ @ | @ @ @ |~~
@{shift @f3}
+-----------------------+
.
write;