use Benchmark;

use Set::Scalar;
my $stopwords = Set::Scalar->new;
$stopwords->insert( qw(a i at be do to or is not no the
               that they then these them who where
               why can find on an of and it by));

my %stopwords;
@stopwords{qw(a i at be do to or is not no the
               that they then these them who where
               why can find on an of and it by)} = ();

@word = split /\s+/, "Oh say can you see by the dawn's early light";

sub withSetScalar {
    my @salient_word = grep { not $stopwords->has($_) } @word;
}

sub byHash {
    my @salient_word = grep { not exists $stopwords{$_} } @word;
}

timethese 100000, {
    withSetScalar => \&withSetScalar,
    byHash => \&byHash,
};
__END__
Benchmark: timing 100000 iterations of byHash, withSetScalar...
    byHash:  1 wallclock secs ( 1.06 usr +  0.00 sys =  1.06 CPU) @ 94
+161.96/s (n=100000)
withSetScalar:  9 wallclock secs ( 8.05 usr +  0.01 sys =  8.06 CPU) @
+ 12403.87/s (n=100000)
[download]

I don't think the "nicer" syntax is worth the price. (If the sentence/text was longer the difference would be even bigger.)

Edit by castaway: Closed small tag in signature