use Benchmark qw/:all/;

sub regex {
	return ($_[1] =~ m/^$_[0]/) ? 1 : 0;
}

sub index_func {
	return (index($_[1], $_[0]) == 0) ? 1 : 0;
}

cmpthese ( 500000, {
	'regex match' => sub { regex('abbr', 'abbreviation') or die },
	'index match' => sub { index_func('abbr', 'abbreviation') or die },
	'regex miss'  => sub { regex('anna', 'abbreviation') and die },
	'index miss'  => sub { index_func('anna', 'abbreviation') and die },
});

__END__
                 Rate regex match  regex miss  index miss index match
regex match  680272/s          --        -13%        -36%        -38%
regex miss   781250/s         15%          --        -27%        -29%
index miss  1068376/s         57%         37%          --         -3%
index match 1101322/s         62%         41%          3%          --