while ($text =~ m/\G([\w-]+|.)/sg) { my $tok = $1; if ($tok eq '{' or $tok =~ /^\w/) { push @stack, $tok; } elsif ($tok eq '}') { my $arr = []; my $allScalar = 1; my $allHash = 1; while ($stack[-1] ne '{') { my $val = pop @stack; $allScalar &&= ! ref $val; $allHash &&= 'HASH' eq ref $val; unshift @$arr, $val; } pop @stack; # '{' if ($allScalar) { if (@$arr != 2) { push @stack, $arr; } else { push @stack, { shift @$arr, shift @$arr }; } } elsif ($allHash) { my $hash = {}; for my $h (@$arr) { @$hash{keys %$h} = values %$h; } my $n = keys%$hash; my @nSlice; for my $i (1..$n) { push @nSlice, $hash->{$i} if exists $hash->{$i} } if (@nSlice == $n) { # keys are 1 .. n push @stack, [@nSlice]; } else { push @stack, $hash; } } elsif (!ref(my $key = shift @$arr)) { $arr = $arr->[0] if @$arr == 1; push @stack, { $key => $arr }; } else { die Dumper(\@stack); } } }