Thank you Robert, Jean-Pierre and Simon. I see what I can do from your suggestions.
2013/11/8, Simon King <[email protected]>: > Hi Vincent, > > On 2013-11-08, Vincent Delecroix <[email protected]> wrote: >> I was working with #15378 and I wondered why SchemeMorphism inherits >> from Element and not from Morphism as they should. > > It *should* in fact inherit from both. In fact, some time ago, I tried > to provide both Morphism and Element as base classes for SchemeMorphism. > > The problem is: Python allows you to use both base classes (it believes > that both base classes have a compatible layout), but then some cdef > attribute of Element gets confused with some cdef attribute of Morphism. > > Hence, in fact these two base classes do *not* have compatible layout, > and it is a bug that Python does not raise an error when you try to > create a class that uses both base classes at the same time. > > So, in this case, multiple inheritance is a no-op, and thus the category > framework is your friend... > > Best regards, > Simon > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
