Common data transform patterns - please add yours!

[peerreynders]

input = %{person: %{first: "Jose", last: "valim"}, age: 100}
output = update_in(input, [:person, :last], &String.upcase(&1))
IO.inspect(output)

iex(1)> input = %{person: %{first: "Jose", last: "valim"}, age: 100}
%{age: 100, person: %{first: "Jose", last: "valim"}}
iex(2)> output = update_in(input, [:person, :last], &String.upcase(&1))
%{age: 100, person: %{first: "Jose", last: "VALIM"}}
iex(3)> IO.inspect(output)
%{age: 100, person: %{first: "Jose", last: "VALIM"}}
%{age: 100, person: %{first: "Jose", last: "VALIM"}}
iex(4)>