On 2009-Oct-4, at 2:07 pm, Moritz Lenz wrote:
Michael Zedeler wrote:
It doesn't, because succ should always give the next, smallest
element given some ordering relation.
Where's that definition from?
The dictionary. =) It would be confusing to have a "successor"
method for something that isn't orderable and discrete. An ordered
continuous type like Real could have .inc and .dec; it just happens
that in the common case of Ints, .succ and .inc mean the same thing.
Complex could have an .inc method, but I don't think there's any
especially obvious choice (because .inc probably wants an ordered
type). Would it add 1? or 1+i? Better to spell it out explicitly.
Well, Real implies ordering (at least to me ;-), I don't think we
class or role for countability.
A Discrete role would be useful, but is Set good enough for that?