Re: Re: Optimizing the bejeezus out of a sub

My goal was to speed things up by avoiding copying each value from @_ to $section. While foreach is certainly more aesthetic, some benchmarking shows it to be about the same speed as my loop.

I'm a little surprised by this, actually; I expected using @_ directly to always be faster, since it would avoid copying values.

Comment on Re: Re: Optimizing the bejeezus out of a sub

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Re: Re: Re: Optimizing the bejeezus out of a sub by IlyaM (Parson) on Jun 24, 2003 at 08:55 UTC
`foreach my $section ( @_ ) { ... }` doesn't copy value from @_ to $section. In the loop the variable $section is merely an alias to a currently selected element in @_ array. You can even modify @_ array by assigning a new value to $section. Example: `# adds 1 to all elements of array foreach my $elem (@arr) { $elem ++; }` [download] -- Ilya Martynov, ilya@iponweb.net CTO IPonWEB (UK) Ltd Quality Perl Programming and Unix Support UK managed @ offshore prices - http://www.iponweb.net Personal website - http://martynov.org	[reply] [d/l] [select]

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Re: Re: Re: Optimizing the bejeezus out of a sub
by IlyaM (Parson) on Jun 24, 2003 at 08:55 UTC

foreach my $section ( @_ ) { ... }

# adds 1 to all elements of array
foreach my $elem (@arr) {
    $elem ++;
}
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--
Ilya Martynov, ilya@iponweb.net
CTO IPonWEB (UK) Ltd
Quality Perl Programming and Unix Support UK managed @ offshore prices - http://www.iponweb.net
Personal website - http://martynov.org

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