On Sunday, August 24, 2014 3:04:33 AM UTC+1, Travis Scrimshaw wrote: > > Another (and broader) example would be graded modules, where we have > morphism which preserve grading and those with a grading shift. >
In that case I would go with the construction that Simon proposed, have completely different parents. And define a coercion from grading-preserving morphisms to shift-by-0. No need to have a single parent for perhaps-shifted morphisms, and you can leverage the existing framework instead of figuring out yourself how to compose morphisms. IMHO its fine to have a _repr_ with many branches, that only proves that you are trying to make the notation concise. The more important question is can you implement the operations without lots of special casing. -- 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 sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
