这两个实现在功能上是否等同?如果是这样,哪个更好? # from a model
WIDGET_COLORS = %w(red yellow green)
validates :widget_color,
inclusion: {in: WIDGET_COLORS, allow_nil: true}
或 # from a model
WIDGET_C
abstract class FinSet[T] protected() {
// given a set other, it returns true iff every element of this is an element of other
def <=(other:FinSet[T]): Boolean =
// ????
这就是我给的目前为止。我对如