cast = [
  %{
    character: "Buttercup",
    actor: %{
      first: "Robin",
      last: "Wright"
    },
    role: "princess"
  },
  %{
    character: "Westley",
    actor: %{
      first: "Cary",
      last: "Elwes"
    },
    role: "farm boy"
  }
]

# returns character fields from all structs
IO.inspect get_in(cast, [Access.all(), :character])

# role of element with index 1
IO.inspect get_in(cast, [Access.at(1), :role])

# return new dict, but with uppercased actor.last
IO.inspect get_and_update_in(cast, [Access.all(), :actor, :last], fn (val) -> {val, String.upcase(val)} end)