There was something quite similar yesterday...

my $tree = 'Foo::Bar::Baz';
my %pkg;

my $ref = \%pkg;
for(split /::/,$tree){
   $ref = exists $ref->{$_} ?
        # we don't need no autivivification
       ( $ref->{$_} = {} ) : $ref->{$_}
}

use Data::Dumper;
warn Dumper(\%pkg);
[download]

Sometimes it's usefull if you've done linked lists in Pascal at school :)

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