Re (4): Simple Switch statement

Ah, but why not:

for($switch_me) {
    /bob/   && do { print "Got 'bob'!\n"; break };
    /frnak/ && do { print "Got 'frnak'!\n"; break };
    $_ == 1 && do { print "Got 1!\n"; break };

    print "Got nuttin'!\n";
}
[download]

You can have your cake AND eat it too.

Alakaboo

Comment on Re (4): Simple Switch statement Download Code

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Re: Re (4): Simple Switch statement by Roger (Parson) on Sep 14, 2003 at 02:42 UTC
I have constructed the following test case to compare the performance of simple regular expression and simple eq test: `use Benchmark; @switch_me = qw / bob frnak 1 roger james /; timethese (1000000, { 'test_regex' => ' &test_regex; ', 'test_eq' => ' &test_eq; ' }); sub test_regex() { for(@switch_me) { /bob/ && do { break }; /frnak/ && do { break }; $_ == 1 && do { break }; } } sub test_eq() { for(@switch_me) { $_ eq "bob" && do { break }; $_ eq "frnak" && do { break }; $_ == 1 && do { break }; } }` [download] The two subroutines are identical except for the string testing bit. The following are the test results: `Benchmark: timing 1000000 iterations of test_eq, test_regex... test_eq: 8 wallclock secs ( 8.45 usr + 0.01 sys = 8.46 CPU) @ 118161.41/s (n=1000000) test_regex: 10 wallclock secs ( 9.22 usr + 0.01 sys = 9.23 CPU) @ 108307.16/s (n=1000000)` [download] It's about (118161.41-108307.16)/108307.16 = 10% speed increase in using eq than using regular expression. It's not a great increase, but it's nevertheless faster to use eq than regular expression.	[reply] [d/l] [select]

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Re: Re (4): Simple Switch statement
by Roger (Parson) on Sep 14, 2003 at 02:42 UTC

use Benchmark;
@switch_me = qw / bob frnak 1 roger james /;

timethese (1000000, {
    'test_regex' => ' &test_regex; ',
    'test_eq' => ' &test_eq; '
});

sub test_regex()
{
    for(@switch_me) {
        /bob/   && do { break };
        /frnak/ && do { break };
        $_ == 1 && do { break };
    }
}

sub test_eq()
{
    for(@switch_me) {
        $_ eq "bob" && do { break };
        $_ eq "frnak" && do { break };
        $_ == 1 && do { break };
    }
}
[download]

Benchmark: timing 1000000 iterations of test_eq, test_regex...
   test_eq:  8 wallclock secs ( 8.45 usr +  0.01 sys =  8.46 CPU)
             @ 118161.41/s (n=1000000)
test_regex: 10 wallclock secs ( 9.22 usr +  0.01 sys =  9.23 CPU)
            @ 108307.16/s (n=1000000)
[download]

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