SaturatingNum Bit

[gergoerdi]

I have a use case where Overflowing Bit, and thus a SaturatingNum Bit instance, would be useful. I see no reason Bit couldn't be made into SaturatingNum. Sketch(y) implementation:

instance SaturatingNum Bit where
    satAdd = \case
        SatWrap -> addOr 0
        SatBound -> addOr maxBound
        SatZero ->  addOr 0
        SatSymmetric -> addOr maxBound
        SatError -> addOr $ errorX "satAdd"
      where
        addOr ext = \x y -> if x == 1 && y == 1 then ext else x + y

    satSub = \case
        SatWrap -> subOr 1
        SatBound -> subOr minBound
        SatZero ->  subOr 0
        SatSymmetric -> subOr maxBound
        SatError -> subOr $ errorX "satSub"
      where
        subOr ext = \x y -> if x == 0 && y == 1 then ext else x - y

    satMul = \case
        _ -> (*)