use strict;
use warnings;
my %Entry;
$Entry{-1} = '';
my @list;
my $id;
while(<DATA>){
  chomp;
  last if /OUTPUT/;
  my $entry = $1 if /\b(\w+)$/;
  my $level = () = $_ =~ m[\-]g;
  my $item;
  $Entry{$level} = $entry; #Remember the last entry
  $item->{id} = ++$id;
  $item->{name} = $entry;
  $item->{parent} = $Entry{$level-1};
  $item->{level} = $level;
  push @list,$item;
}
foreach my $item (@list){
  print join "|", map { $item->{$_} } qw(id level name parent);
  print "\n";

}

__DATA__
foo
->bar
-->troz
->narf
__OUTPUT__
1|0|foo|
2|1|bar|foo
3|2|troz|bar
4|1|narf|foo