use strict;

use Benchmark qw(cmpthese);

use constant NUM_OF_VARS => 10000;
use constant NUM_OF_TESTS => 1000;

my @names = ();

# Meaningless, getting rid of warning
*NULL = *NULL;
open(NULL, '>/dev/null') or die "Couldn't open /dev/null: $!; stopped";

## Initialize a bunch of variables to interpolate
{
  no strict 'refs';
  my $var_name = 'aa';
  for ( 0 .. NUM_OF_VARS ) {
    $ {"Q::$var_name" } = "Name is '$var_name', number $_";
    push(@names, "\$Q::$var_name");
    $var_name++;
  }
}

# Build up two subroutine strings to eval
my $list_print = "print NULL ";
$list_print .= join(",\n", map( qq{'$_ is ', $_, "\\n"}, @names) );
$list_print .= ';';


my $build_print = "my \$string = '';\n";
foreach my $name (@names) {
  $build_print .= qq{\$string .= '$name is ';\n};
  $build_print .= qq{\$string .= $name;\n};
  $build_print .= qq{\$string .= "\\n";\n};
}
$build_print .= "print NULL \$string;\n";


# Benchmark the subs
cmpthese(NUM_OF_TESTS, {
                        'build_print' => $build_print,
                        'list_print' => $list_print,
                       });

##</code><code>##

Benchmark: timing 1000 iterations of build_print, list_print...
build_print: 120 wallclock secs (119.84 usr +  0.04 sys = 119.88 CPU) @  8.34/s (n=1000)
list_print: 92 wallclock secs (91.23 usr +  0.11 sys = 91.34 CPU) @ 10.95/s (n=1000)
              Rate build_print  list_print
build_print 8.34/s          --        -24%
list_print  10.9/s         31%          --