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

# read text from DATA
my $text = do { local $/; <DATA> };

# parse text and convert to AoA
my @stack;
while ($text =~ m/\G([\w-]+|.)/sg) {
	my $tok = $1;
	if ($tok eq '{' or $tok =~ /^\w/) {
		push @stack, $tok;
	}
	elsif ($tok eq '}') {	# stack: ... '{' key val(s)
		my $arr = [];
		while ($stack[-1] ne '{') {
			unshift @$arr, pop @stack;
		}
		pop @stack; # '{'
		push @stack, $arr;
	}
}
print Dumper(\@stack);
__DATA__
{chart { {1 { {title title_1} {xlable X-lab} {ylable Y-lab}
{description desc1} {type line} {series { {1 { {x_data {1 2 3 4 5} }
{y_data {20 90 60 50 30}} } } } } } } } }