Hi Christian,
On Fri, May 20, 2011 at 10:10:37AM +0200, Christian Nassau wrote:
> I would like to create a new category that's derived from
> AlgebrasWithBasis, but I get an infinite recursion when I ask for the
> CartesianProducts:
>
> Here's a simple example:
>
> class MyAlgebrasWithBasis(AlgebrasWithBasis):
> def __init__(self,R):
> AlgebrasWithBasis.__init__(self,R)
Is your intention to create a subcategory of AlgebrasWithBasis? That
is a category whose objects are algebras with basis, possibly endowed
with more structure? If yes, the idiom is:
class AlgebrasWithBasis(Category_over_base_ring):
@cached_method
def super_categories(self):
return [AlgebrasWithBasis(self.base_ring())]
...
Otherwise, please describe precisely your use case to see what we
should do with it (fix the issue, raise a better warning, ...). Note
that at this point, the hierarchy of classes for categories is
basically flat:
Category
- Sets
- Semigroups
- Fields
- ...
- Category_over_base_ring
- Modules
- Algebras
- ...
Best,
Nicolas
--
Nicolas M. Thiéry "Isil" <nthi...@users.sf.net>
http://Nicolas.Thiery.name/
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