strings are lists :S

me llevo un rato encontrar este bug

2> lists:suffix(".fn", io_lib:format("~p-~p-~p.~s", [1,2,3,"fn"])).
false
3> lists:suffix(".fn", lists:flatten(io_lib:format("~p-~p-~p.~s", [1,2,3,"fn"]))).
true

la razon es que

1> io_lib:format("~p-~p-~p.~s", [1,2,3,"fn"]).
["1",45,"2",45,"3",46,"fn"]

y no lo que uno esperaria

4> lists:flatten(io_lib:format("~p-~p-~p.~s", [1,2,3,"fn"])).                     
"1-2-3.fn"