A  do BLOCK also forms a closure without the need for either a named or anonymous secondary subroutine.

>perl -wMstrict -le
"my $param = 'param is foo';
 my $coderef = do {
  my $sub_param = $param;
  sub { print $sub_param }
  };
 $coderef->();
 $param = 'param now bar';
 $coderef->();
"
param is foo
param is foo
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