def update_existing(map, key, fun) do
case map do
%{^key => old} -> %{map | key => fun.(old)}
_ -> map
end
end
def update_indifferent(map, key, fun) when is_atom(key) do
map
|> update_existing(key, fun)
|> update_existing(Atom.to_string(key), fun)
end
And then
params
|> update_indifferent(:start_time, &CalendarUtils.from_iso8601/1)
|> update_indifferent(:end_time, &CalendarUtils.from_iso8601/1)
