Both are excellent suggestions. We have to think a bit about the consequences.
Still, both would not solve the problem of what to return when the collection is empty. > On 23 Mar 2020, at 15:47, Konrad Hinsen <konrad.hin...@fastmail.net> wrote: > > Am 23.03.20 um 14:45 schrieb James Foster: > >>> On Mar 23, 2020, at 6:06 AM, Sven Van Caekenberghe <s...@stfx.eu> wrote: >>> >>> What you found out now is that the clever trick used to avoid picking an >>> additive identity (picking an element, counting it twice and then >>> subtracting it) leads to a loss of precision when floating point numbers >>> are involved. This is an important issue. >> If this approach is to be preserved, then each class should have an additive >> identity so instead of adding and subtracting an object, we let the object >> tell us its zero. > > Or define a singleton class "Zero" with a + method that returns the other > operand, and use that Zero object for the additive identity. > > Konrad. > >
