+/* translates key_t to keycode */
+uint8_t keymap_key_to_keycode(uint8_t layer, key_t key);
+/* translates keycode to action */
+action_t keymap_keycode_to_action(uint8_t keycode);
+/* translates Fn keycode to action */
+action_t keymap_fn_to_action(uint8_t keycode);
+
+
+/* action for key */
+// TODO: should use struct key_t? move to action.h?