Re: @array elements multiplication with another array elements.

Here's another example using pairwise from the lovely List::MoreUtils package...

use List::MoreUtils qw( pairwise );

my @array1 = (3,4,6,5,8);
my @array2 = (2,2,4,5,1);

my @mults = pairwise { $a * $b } @array1, @array2;
print "@mults\n";
[download]

perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

Comment on Re: @array elements multiplication with another array elements. Select or Download Code

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Re^2: @array elements multiplication with another array elements. by grizzley (Chaplain) on Oct 31, 2012 at 07:39 UTC
Wow, how can `pairwise` tell where the end of 1st array is? There was always the ~~problem~~ feature that regardless whether you write `my @array1 = (3,4,6,5,8); my @array2 = (2,2,4,5,1);` [download] or `my @array1 = (3,4,6,5,8,2,2,4); my @array2 = (5,1);` [download] using it with coma always results in flattened list: `@array1,@array2` [download] is equivalent to `(3,4,6,5,8,2,2,4,5,1)` [download] and yet `pairwise` deals with it: `c:\>perl -le "use List::MoreUtils qw/pairwise/; @a=(1..5);@b=(11..15); + print for pairwise {$a+$b} @a, @b" 12 14 16 18 20 c:\>perl -le "use List::MoreUtils qw/pairwise/; @a=(1..5, 11,12);@b=(1 +3..15); print for pairwise {$a+$b} @a, @b" 14 16 18 4 5 11 12` [download]	[reply] [d/l] [select]
Re^3: @array elements multiplication with another array elements. by tobyink (Canon) on Oct 31, 2012 at 07:51 UTC
It uses a prototype of `&\@\@`. That means the two arrays get implicitly turned into arrayrefs by the Perl parser. The body of the sub just sees a coderef and two arrayrefs - not a flattened list. See perlsub. `perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'`	[reply] [d/l]
Re^4: @array elements multiplication with another array elements. by grizzley (Chaplain) on Oct 31, 2012 at 08:31 UTC
That's true! Wow, thanks, first example of prototypes being useful `c:\>perl -le "sub f(\@\@) { print 'array ', ++$cnt ,': ', join ' ', @$ +_ for @_ } @a=(1..5, 11,12);@b=(13..15); f @a, @b" array 1: 1 2 3 4 5 11 12 array 2: 13 14 15` [download]	[reply] [d/l]