Learned Monks,

I build a data structure as I parse a file. The gist of it is in the code below. I am using Perl 5.8.5 if that matters.

I go round and round. Sometimes I read information on one line and that sets the "context" for the data on the lines that immediately follow. When I want to actually store something, I'm left with a number of state variables to index to where I need to put the data. Instead, I hope to use this "context" to just set a pointer into the data structure that I assemble and keep this as one state variable.

I then hope to collect the data into an anonymous array aliased by the hashref pointer.

Everything looks okay at first. My first call to "Dumper" prints what I expect. When I get to the end however, I see that the data was never placed into the main data structure. If I make multiple passes that should "push" to the same array, they don't show up either.

My pointer/alias is not working...

use strict;
use warnings;
use Data::Dumper;

my $data;

my $fsm = 1;
my $m = '';
my $i = '';

while(<DATA>) {
  our   $pointer;
  local *pointer;

  chomp;
  if (/^INSTANCE:\s+(\S+)/) {
    $m = '';
    $i = $1;
  } elsif (/^MODULE:\s+(\S+)/) {
    $m = $1;
    $i = '';
  } elsif (/^Fsm\s+(\S+)/) {
    next if !$fsm;
    if ($m) {
      *pointer = \$data->{'module'}->{$m}->{$1};
    } else {
      *pointer = \$data->{'instance'}->{$i}->{$1};
    }
  } elsif (/^State\s+(\S+)/) {
    next if !$fsm;
    push(@{ $pointer->{'state'} }, "$1");
    print "A: " . Dumper( $pointer );  #DEBUG
  } elsif (/^Transition\s+(\S+)/) {
    next if !$fsm;
    push(@{ $pointer->{'transition'} }, "$1");
    print "B: " . Dumper( $pointer );  #DEBUG
  }
}

print "C: " . Dumper($data);

__DATA__
INSTANCE: i_name
Fsm f_name
State s_name1
# Transition t_name
# State s_name2

[download]
Output looks like this...

A: $VAR1 = {
          'state' => [
                        's_name1'
                     ]
        };
C: $VAR1 = {
          'instance' => {
                      'i_name' => {
                                    'f_name' => undef
                                  }
                        }
        };

[download]
Given the data above, the final expected data should look like this...

C: $VAR1 = {
          'instance' => {
                      'i_name' => {
                                    'f_name' => {
                                                'state' => [
                                                              's_name1
+'
                                                           ]
                                                }
                                  }
                        }
        };

[download]
If you uncomment the commented lines in the __DATA__ section, then I'd expect data like this...

C: $VAR1 = {
          'instance' => {
                      'i_name' => {
                                    'f_name' => {
                                                'state' => [
                                                              's_name1
+'
                                                              's_name2
+'
                                                           ]
                                                }
                                                'transition' => [
                                                                  't_n
+ame'
                                                                ]
                                                }
                                  }
                        }
        };

[download]
Re: Grouping an array of hashrefs by similar key values was helpful. Searching for "*" is a tricky thing to do!

Your help is always appreciated!

Update: added the "expected results"

In reply to pointer/alias question by shoness

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