Re: TIMTOWTDI - printing an array

Anonymous subroutine perhaps?

knoppix@Microknoppix:~$ perl -E '
> @arr = qw{ 11 22 33 44 };
> sub { say shift while @_ }->( @arr );'
11
22
33
44
knoppix@Microknoppix:~$
[download]

Cheers,

JohnGG

Comment on Re: TIMTOWTDI - printing an array Download Code

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Re^2: TIMTOWTDI - printing an array by choroba (Cardinal) on Jun 20, 2012 at 23:43 UTC
or `sub { print @_ }->($_) for @arr;` [download]	[reply] [d/l]
Re^3: TIMTOWTDI - printing an array by johngg (Canon) on Jun 21, 2012 at 08:29 UTC
That also works but you are incurring the expense of creating and invoking the subroutine for each and every element of the array rather than just once. This might have an impact on performance. Cheers, JohnGG	[reply]
Re^3: TIMTOWTDI - printing an array by johngg (Canon) on Jun 21, 2012 at 10:54 UTC
I think this benchmark code confirms my point regarding the expense of continually creating and invoking anonymous subroutines. `use strict; use warnings; use Benchmark qw{ cmpthese }; my @arr = ( 1 .. 1e6 ); my $rcOneElement = sub { my $aref = shift; sub { my $var = shift }->( $_ ) for @$aref; }; my $rcAllElements = sub { my $aref = shift; sub { my $var = shift while @_ }->( @$aref ); }; cmpthese ( -5, { OneElement => sub { $rcOneElement->( \ @arr ) }, AllElements => sub { $rcAllElements->( \ @arr ) }, } );` [download] The output. `Rate OneElement AllElements OneElement 2.59/s -- -58% AllElements 6.16/s 138% --` [download] However, I am good at cocking up benchmarks so I could be deluding myself :-/ Cheers, JohnGG	[reply] [d/l] [select]