Re: Re: returning arrays from a sub

I thought your benchmark was pretty good, but I thought it'd be interesting to see the performance of each in scalar and array context by themselves. So without further ado, here is the benchmark code I used:

#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw(cmpthese);   

my $count = 8000;
my @array = (3.14) x 1000;

sub want {
    return wantarray ? @array : scalar @array;
}

sub nowant {
    return @array;
}

cmpthese($count*50, {
    "scalar_want"   => sub { my $test = want()   },
    "scalar_nowant" => sub { my $test = nowant() },
} );
cmpthese($count, {
    "array_want"    => sub { my @test = want()   },
    "array_nowant"  => sub { my @test = nowant() },
} );
[download]

And here are the results:

                  Rate   scalar_want scalar_nowant
scalar_want   740741/s            --          -15%
scalar_nowant 869565/s           17%            --
               Rate   array_want array_nowant
array_want   2778/s           --          -1%
array_nowant 2797/s           1%           --
[download]

To me these are interesting for several reasons. They are fairly consistent with your results -- for the array context, at least. They also show the version without explicit context check to be faster in scalar context. Note the extremely high rate makes the results somewhat useless, but interesting nonetheless.

Comment on Re: Re: returning arrays from a sub - how clever is Perl? Select or Download Code

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Re: Re: Re: returning arrays from a sub - how clever is Perl? by mildside (Friar) on Oct 22, 2003 at 03:55 UTC
... show the version without explicit context check to be faster in scalar context Ahhh! So maybe Perl is clever after all. I thought that it should be. Cheers!	[reply]