%Struct{} vs %{__struct__: Struct}

Questions & Help Questions
5

you can also use map cons, if you would like for your code to crash when you try to assign a nonexistent field, lets you catch errors in tests (how good is your test coverage? lol)

defmodule S do
  defstruct [x: 0]
  def do_something(val = %S{}) do
     %{val | y: "oops"}
  end
end

will crash on do_something. Whenever it’s a struct, I prefer using map cons for that bailout behaviour.