%Struct{} vs %{__struct__: Struct}

Questions & Help Questions
3

I prefer the previous answer, but another option would get a list of keys expected in the struct and take them from the map.

Building on the other example:

iex> Map.take(m, Map.keys(%URI{}))
%URI{
  authority: "forum.elixirforum.com",
  fragment: nil,
  host: "forum.elixirforum.com",
  path: nil,
  port: 80,
  query: nil,
  scheme: "http",
  userinfo: nil
}

Two downsides to this approach compared to the previous:

  1. This solution won’t replace any missing keys.
  2. This approach doesn’t let you create the struct dynamically (not without wrapping it in struct/0 at least, which at that point you might as well do the other).