Map a nested JSON payload to a struct in Elixir - json

Question

I am attempting to port the Golang tutorial geddit to Elixir. I have done so successfully with Dartlang, but Elixir's operations on maps & lists are confusing for me.
Using HTTPoison and JSEX, I have the following code:
defmodule Redditex do
use HTTPoison.Base
def process_url(url) do
"http://www.reddit.com/r/#{url}.json"
end
def process_response_body(body) do
json = JSEX.decode! body
json = Enum.map json, fn ({k, v}) -> {String.to_atom(k), v } end
json
end
end
My difficulty is parsing the JSON body into an appropriate struct where the JSON contains nested data. Jazz has some allusion to mapping to a structure but not with nested data.
Is there an example or a common practice to decode JSON in Elixir similar to Go's usage:
type Response struct {
Data struct {
Children []struct {
Data Item
}
}
}
type Item struct {
Title string
URL string
Comments int `json:"num_comments"` #mapping to another field label
}

Answer 1

Using the Poison JSON library I was able to get partly there for handling the nesting:
def handle_response(%{status_code: 200, body: body}) do
json = Poison.decode!(body, as: %{"data" => %{"children" => [%{"data" => Redditex.Item}]}})
items = Enum.map( json["data"]["children"], fn (x) -> x["data"] end )
end
Enumertion is necessary to remove the anonymous structs and the remapping of the field names has not shown as a native solution. A work path forward nonetheless.