(First off, is it OK to continue polling the NumPy list now and then on Cython language decisions? Or should I expect that any interested Cython users follow the Cython list?)
In Python, if I write "-1 % 5", I get 4. However, in C if I write "-1 % 5" I get -1. The question is, what should I get in Cython if I write (a % b) where a and b are cdef ints? Should I
[ ] Get 4, because it should behave just like in Python, avoiding surprises when adding types to existing algorithms (this will require extra logic and be a bit slower)
[ ] Get -1, because they're C ints, and besides one isn't using Cython if one doesn't care about performance
Whatever we do, this also affects the division operator, so that one in any case will have a==(a//b)*b+a%b.
(Orthogonal to this, we can introduce compiler directives to change the meaning of the operator from the default in a code blocks, and/or make special functions for the semantics that are not chosen as default.)