#!/usr/bin/env perl
use strict;
use warnings;
use Parse::RecDescent;
use Data::Dumper;

$::RD_ERRORS = 1;
$::RD_WARN = 1;
$::RD_HINT = 1;
#$::RD_TRACE = 1;
#$::RD_AUTOACTION = q { print Dumper \@item };

my $grammar = q{
{
    use Data::Dumper;
    sub unroll {
        my @list = @{$_[0]};
        my $unrolled;
        for my $href (@list) {
            for my $key (keys %{$href}) {
                $unrolled->{$key} = $href->{$key};
            }
        }
        return $unrolled;
    };
}

Expression: Object(s)  { $return = unroll($item[1]) }

Object: String  '{' Param(s) '}' 
        {
            $return  = { $item[1] => unroll($item[3]) }
        }

Param: String '=' String
       {
           $return = { $item[1] => $item[3] }

       } 
       | Object(s)
       {
           $return = unroll($item[1])
       }

String: /[\w\d]+/ { $return = $item[1] }
};

my $parser = Parse::RecDescent->new($grammar);
my $text = do { undef $/; <DATA> };
my $tree = $parser->Expression($text) or die $!;
$tree->{ObjectType1}{NestedObject}{DeeplyNested}{Param60} = 'tuna';
print Dumper $tree;

__DATA__
ObjectType1
{
   Param1 = 8
   Param2 = SomeText
   NestedObject
   {
      Param1 = 3
      Param2 = MoreText
      DeeplyNested
      {
          Param50 = 500
          Param60 = squid
      }
   }
}

ObjectType2
{
    Param1 = 3
    Param2 = 40
}