Passing a function is so usual, that there is this & &1 notation, but it does not mean that Map.get is anonymous.
You can do like something like this with a more complex function
do_what_you_want = fn x -> # do some stuff end
map |> Enum.map(&do_what_you_want.(&1))
Otherwise, You should have done
map |> Enum.map(fn x -> # do some stuff end)
And note that
&Map.get(&1, key)
is equivalent to
fn x → Map.get(x, key) end
It is not equivalent to Map.get(x, key)
