Programming Elixir 1.3

Nested Dictionary Structures

The various dictionary types let us associate keys with values. But those values can themselves be dictionaries. For example, we may have a bug-reporting system. We could represent this using the following:

maps/nested.exs

defmodule Customer do
  defstruct name: "", company: ""
end

defmodule BugReport do
  defstruct owner: %Customer{}, details: "", severity: 1
end

Let’s create a simple report:

iex> report = %BugReport{owner: %Customer{name: "Dave", company: "Pragmatic"},
...>                     details: "broken"}
%BugReport{details: "broken", severity: 1,
           owner: %Customer{company: "Pragmatic", name: "Dave"}}

The owner attribute of the report is itself a Customer struct. ...