How to convert nested property list ( having string keys ) to Elixir nested map?

Questions / Help
,
1

Hi, how to convert a list like this to nested map in elixir ?

[
  {"_id", "idhere"},
  {"App-Version", "version_here"},
  {"TX-ID", "tx-id-here"},
  {"Method", "method-here"},
  {"Body",
   {[
      {"Identification",
       [
         {"A", "A-Val"},
         {"B", "B-Val"},
         {"C", "C-Val"},
         {"D", "D-Val"}
       ]},
      {"CurrentTime", "2023-02-23T16:40:13+05:30"},
      {"Names", ["Name1", "Name2"]}
    ]}}
]
2

I would do it something like this:

  def transform([{_, _}|_] = list) do
    Enum.reduce(list, %{}, fn {key, val}, map ->
      Map.put(map, key, transform(val))
    end)
  end
  def transform({[{_, _}|_] = list}), do: transform(list)

  def transform(val), do: val

And then call it with just

transform/1

And the result would be something like:

%{
  "App-Version" => "version_here",
  "Body" => %{
    "CurrentTime" => "2023-02-23T16:40:13+05:30",
    "Identification" => %{
      "A" => "A-Val",
      "B" => "B-Val",
      "C" => "C-Val",
      "D" => "D-Val"
    },
    "Names" => ["Name1", "Name2"]
  },
  "Method" => "method-here",
  "TX-ID" => "tx-id-here",
  "_id" => "idhere"
}
3 Likes
3

Thanks, solution is concise

4

May I offer an alternative:

def transform([_ | _] = list) do
  Map.new(list, fn
    {k, [{_, _} | _] = v} -> {k, transform(v)}
    {k, {[_ | _] = v}} -> {k, transform(v)}
    {k, v} -> {k, v}
  end)
end
4 Likes
5

Map.new with fn method is more concise . Thanks
I tried this initially, but didn’t complete successfully.

1 Like