1,gm,saturn
1,gm,chevy
1,gm,caddy
2,ford,taurus
2,ford,escort
3,vw,bug
3,vw,jetta
3,vw,phaeton
..

1. gm
	- saturn
	- chevy
	- caddy
2. ford
	- taurus
	- escort
..

#!/usr/bin/perl -w

use strict;

my $seen = 0;

while (<DATA>) {
  chop;
  my ($id, $maker, $make) = split(",", $_);
  if ($id != $seen) {
    print "$id. $maker\n";
    print "   - $make\n";
    $seen = $id;
  } else {
    print "   - $make\n";
  }
}

__DATA__
1,gm,saturn
1,gm,chevy
1,gm,caddy
2,ford,taurus
2,ford,escort
3,vw,bug
3,vw,jetta
3,vw,phaeton
[download]

So, I really need an array of hashrefs. I really need something like --

my @carmakers = (
  \%thismaker,
  \%thismaker,
  \%thismaker
);
[download]

where

my %thismaker = ('thismaker' => 'gm', 'makes' => \@makes);
[download]

where

my @makes = (\%thismake, \%thismake, \%thismake);
[download]

where

my %thismake = ('thismake' => 'saturn');
my %thismake = ('thismake' => 'chevy');
my %thismake = ('thismake' => 'caddy');
[download]

in turn for each maker and within each maker for each make.

This will allow me to display the following --

<tmpl_loop carmakers>
    <tmpl_var thismaker>
    <tmpl_loop makes>
        <tmpl_var thismake>
    </tmpl_loop>
</tmpl_loop>
[download]

Applying my logic as above doesn't work

my $seen = 0;

my @carmakers;
while (<DATA>) {
  chop;
  my ($id, $maker, $make) = split(",", $_);
  if ($id != $seen) {
    my %maker;
    $maker{'thismaker'} = $maker;
      my @makes;
      my %make = ('thismake' => $make);
      push(@makes, \%make);
    $maker{'makes'} = \@makes;
    push(@carmakers, \%maker);  # problem1
    $seen = $id;
  } else {   
      my %make = ('thismake' => $make);
      push(@makes, \%make);  # problem2
    $maker{'makes'} = \@makes;
  }
}
[download]

But, this is where I run into my logic problem. The line marked "# problem1" should not occur unless a new car maker is encountered. And the line marked "# problem2" fails because it does not see the @makes declared in the same block but in the first conditional.

Which brings me to a more general problem. Under "use strict" how do I access a variable declared in a block that is at the same level as the current block? In other words, if I have

while (looping over something) {
  if (cond1) {
    create @foo if a certain condition is met
    do a bunch of things
  } else {
    do something to foo already declared
    do a bunch of other things
  }
}
[download]