> Sure. So we have 4 (?) possible outcomes:
>
> 1. Inverse exists and we can compute it: return the inverse
> 2. We can compute that the inverse does not exist: ZeroDivisionError
> 3. We can compute that the inverse exists but cannot find the inverse:
> NotImplementedError
> 4. We cannot determ
Is there any Parent that has generators in Sage? It seems that all parents
with generators use the old ParentWithGens. Also,
CategoryObject._populate_generators_() contains a isinstance(.., Sequence)
which will always raise an error (it should be Sequence_generic). So there
can't be anybody usi
On Fri, Nov 2, 2012 at 3:10 PM, Volker Braun wrote:
> Is there any Parent that has generators in Sage? It seems that all parents
> with generators use the old ParentWithGens.
This is because in order to move, e.g. Rings off of ParentWithGens,
all its descendants must be moved to the new coercion
I think I'm to blame: we had plans for implementing generators in a certain
way with the transition to the new coercion model. I'll work on #5768 this
weekend and report back. In the mean time, manually implementing a gens()
method is fine: if I get sage.structure.generators working correctly the
