If the name of a function is an action or an imperative command,the function should return an error-code integer.(-Exxx=failure,0=success)
If the name is a predicate, the function should return a "succeeded" boolean.(0 = failure,non-zero = success).
這一則比較算是 common sense 了

沒有像上一則酸一下匈牙利表示法那麼兇 XDDD