$ ./3.sscce.pl 
1..1
number is 1
number is 8
["abcdef", "abcdef", "abcde ", " bcdef"]
inside first anonymous block
index 1 out of range at ./3.sscce.pl line 34.
# Looks like your test exited with 255 before it could output anything
+.
$ cat 3.sscce.pl
[download]

#!/usr/bin/perl -w
use 5.011;
use Path::Tiny;
use lib "lib";
use Data::Dump;

my $path_to_file = path( "lib", "1.txt" );

### counterexample

my @array = $path_to_file->slurp;
my $number = scalar @array;
say "number is $number";

## read data into arrays properly
my @better_array = $path_to_file->lines;
my $number2 = scalar @better_array;
say "number is $number2";

# moving forward with slurp method
my $input = $path_to_file->slurp;
$input=~ s/\t/ /g;
my @lines = split /\n/, $input;
my $out = make_rectangular( \@lines, 4, 6 );
dd $out;


## tests
use crossword2;
use Test::More;

{
  say "inside first anonymous block";
  my $subset = getsubset( $out, "R1" );
  is_deeply $subset, [ [ 'a' .. 'f' ] ];
  say "exiting first anonymous block";
}
dd $out;

sub make_rectangular {
    my ( $lines, $maxrows, $maxlength ) = @_;
    my @out;
    my $rowcount=1;
    for my $line (@$lines) {
        my $trimmed = substr $line, 0, $maxlength;
        push @out, sprintf "%-*s", $maxlength, $trimmed;
        last if ++$rowcount>$maxrows;
    }
    return \@out;
}


__END__
[download]

What is being tested is whether the first row is a .. f . The getsubset subroutine is from Selecting Ranges of 2-Dimensional Data. I was able to replicate those results at the time. Other tests looked like:

{
  my $subset = getsubset( $data, "R2C5:R4C8" );
  print_aoa $subset;
  is_deeply $subset, [ [ 'e' .. 'h' ], [ 15, 66, 17, 18 ], [ 55, 56, 5
+7, 58 ] ];
  $subset->[1][2] += 5;
  say "added 5 to a value";
}
say "----------";
print_aoa $data;
say "----------";
{
  my $subset = getsubset( $data, "C8:Cn" );
  print_aoa $subset;
  is_deeply $subset,
    [ [ 8 .. 10 ], [ 'h' .. 'j' ], [ 18 .. 20 ], [ 58 .. 60 ] ];
  $subset->[1][2] = 'X';
  say "substitutes X";
}
[download]

So, Athanasius, when you ask what I desire...what I would like is to pass similar tests, but not with cyrillic, just nice plain ascii a, b, c's. I'm only looking for vectors, although some puzzles require only adjacency. Anyways, the crossword module is 204 lines: listing for xword pm. The function make_russian_crossword shows the pitiful and incomprehensible demoralization that prompted the need to get back to first principles.