use strict;
use warnings;
use Data::Dump qw(pp);
use feature qw(say);

my @points = map { pp($_) } (
    [ 0,           0 ],
    [ -1,          -2 ],
    [ 1,           2 ],
    [ -1,          2 ],
    [ 1,           -2 ],
    [ 0,           1 ],
    [ 1,           0 ],
    [ -1,          0 ],
    [ 0,           -1 ],
    [ 2147483647,  2147483647 ],
    [ 2147483647,  -2147483647 ],
    [ -2147483647, 2147483647 ],
    [ -2147483647, -2147483647 ],
);

kgb_str_look( kgb_str_hash() );

sub kgb_str_hash {
    my %cells = map { $_ => undef } @points;
    \%cells;
}

sub kgb_str_look {
    my $cells = shift;
    for (@points) {
        ( exists $cells->{$_} ) ? say $_ : die;
    }
}