Rails - return all values for nested-attributes, instead of just the 'pointer'

Question

So, I've been banging my head against the wall for the past couple of hours trying to get this. Also, I'll change the name of the question when I know the name of the thing below.

First question, what is this called? #<Comment:0x007fda3aaeb7c8> which is returned from the database.

Secondly, I'm trying to return (render json) a comment that contains child comments.

Something like this:

[
  {
   id: 1,
   title:'title',
   body:'body'
  },
  {
   "#< Comment:0x007fda3b3517f0>": {},
   "#< Comment:0x007fda3b3517f0>": {},
  }
]

How do I return the values of those comments? When I puts them in the console it shows their attributes and values, like so:

puts comments[0][1]

{#<Comment id: 17, body: "Another Reply Test", created_at: "2016-08-20 04:05:16", updated_at: "2016-08-20 04:05:16", parent_id: 13, user_id: 54>=>{}, #<Comment id: 18, body: "Another Reply Test", created_at: "2016-08-20 04:05:16", updated_at: "2016-08-20 04:05:16", parent_id: 13, user_id: 54>=>{}}

but if I try to modify them at all - like to_a or to_json - it just blows up (for a lack of a better term) like such:

puts comments[0][1].to_a
#<Comment:0x007fda3b1911b8>
{}
#<Comment:0x007fda3b190fd8>
{}

I'm using Postgres, and I'm using closure_tree's hash_tree to sort the comments.

Any advice would be very much appreciated, especially with the first question.

EDIT: The def index that returns the comments:

def index
        if request.headers["type"] == 'music'
            comments = Comment.where("song_id = ?", request.headers["id"]).hash_tree.to_a
            comments.each do |comment|
                puts comment[1] #shows all attributes and values
                puts comment[1].to_a #blows up
                puts comment[1].to_s #works
            end
        end
        if comments
            render json: {status:200, success:true, comments:comments}
        else
            render json: {status:404, success:false}
        end
end

Answer 1

The answer to my strugle was to use .as_json.merge!(children=>[]) then push all underlying comments into the above, then push the above into the comment

Here's the repo for anyone interested: https://github.com/jrothrock/comments/