$ perl -Mstrict -Mwarnings -E '
    use Benchmark qw{cmpthese};

    {
        my %op_func1 = (
            "+" => sub { $_[0] + $_[1] },
            "-" => sub { $_[0] - $_[1] },
            "*" => sub { $_[0] * $_[1] },
            "/" => sub { $_[0] / $_[1] },
        );

        sub expr1 {
            my ($lhs, $op, $rhs) = split " ", shift;
            $op_func1{$op}->($lhs, $rhs);
        }
    }

    sub expr2 {
        state $op_func2 = {
            "+" => sub { $_[0] + $_[1] },
            "-" => sub { $_[0] - $_[1] },
            "*" => sub { $_[0] * $_[1] },
            "/" => sub { $_[0] / $_[1] },
        };

        my ($lhs, $op, $rhs) = split " ", shift;
        $op_func2->{$op}->($lhs, $rhs);
    }

    my @ops = ("+","-","*","/");

    cmpthese(-1, {
        with_my    => sub { expr1("4 $_ 5") for @ops },
        with_state => sub { expr2("4 $_ 5") for @ops },
    });
'
               Rate with_state    with_my
with_state 112733/s         --        -2%
with_my    114840/s         2%         --