Noble Monks,

I seek your wisdom to guide me to understand this cool code I found in StackOverflow https://stackoverflow.com/questions/4156483/perl-create-a-hash-from-an-array

while I was translating a python script found on reddit (I find this kind of exercise very engaging and useful) https://www.reddit.com/r/ProgrammerHumor/comments/6mkac8/found_this_in_the_comment_on_rtinder/

The code creates an hash from an array, using as keys the elements of the array and as values their position in the array

my @header_line = ('id', 'name', 'age');
my %fields;
@fields{@header_line} = (0 .. $#header_line);
#result: %fields = { id => 0, name => 1, age => 2};

[download]

I skimmed the Camel book to no avail.


Here is the finished script, I'd also like to know your opinion on its quality

#!/usr/bin/env perl
use strict;
use warnings;
use Algorithm::Permute;

my @people = qw(Brian Carlos Dana Evan Farra);
my $iter = new Algorithm::Permute(\@people);
while (my @perm = $iter->next) {
 my %positions;
 @positions{@perm} = (0..$#perm);
 my $test =
   #Brian next to Dana
   abs($positions{Brian} - $positions{Dana}) == 1
   #Dana not next to Evan
   && abs($positions{Dana} - $positions{Evan}) > 1
   #Carlos on Dana's right
   && $positions{Carlos} - $positions{Dana} == 1
   #one seat between Brian and Farra
   && abs($positions{Brian} - $positions{Farra}) == 2;
 if ($test) {
   print "@perm\n";
 }
}

[download]

In reply to Help me understand this idiomatic hash from array code by adhrain

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