Elixir has a great feature in its Enumerable,group_by/3 function where you can pass 2 functions to it. The first being what to group by (called a key_fun). The second being a function that returns the val (called the value_fun). See: https://hexdocs.pm/elixir/Enum.html#group_by/3
By default the value_fun is a function that does nothing ie. fn x -> x end (making its default behaviour the same as Ruby/Rails group_by method)
I would like this functionality in Rails. What do you think, dear community?
(Apologies if this has been brought up before. I did a quick search but found nothing)