You want a variable? Then pass a variable, and not an atom:
iex(1)> defmodule Revive do
...(1)> defmacro revive(key, val) do
...(1)> quote do
...(1)> var!(unquote(key)) = unquote(val)
...(1)> end
...(1)> end
...(1)> end
{:module, Revive,
<<70, 79, 82, 49, 0, 0, 4, 132, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 140,
0, 0, 0, 15, 13, 69, 108, 105, 120, 105, 114, 46, 82, 101, 118, 105, 118,
101, 8, 95, 95, 105, 110, 102, 111, 95, 95, ...>>, {:revive, 2}}
iex(2)> require Revive
Revive
iex(3)> user
** (CompileError) iex:4: undefined function user/0
iex(3)> Revive.revive(user, "Aku")
"Aku"
iex(4)> user
"Aku"
