On May 24, 2007, at 1:53 PM, Michel wrote:
> > My apologies if I have misunderstood things. I am doing some pyrex > programming and I see there are many pitfalls (like writing !=None :-) > > I encountered the following problem: > If I understand correctly then rings have a _zero_element attribute > but not a _unit_element > attribute. Since you often want to initialize something to 1, not > having a unit element is inconvenient. > > Of course you can create the unit element as R(1) but this seems to be > expensive and has > unpredicable performance (it depends on the implementation of the > __call__ method of R). > Furthermore you want there to be a unique unit element for efficiency > of testing. > > So unless I have misunderstood things (which is quite likely) I would > propose to give > rings a _unit_element attribute which is initialized in the > constructor. Strong +1 for this. I can't believe we don't already have it :-) Not sure I would want it called _unit_ though, makes me think rather of invertible elements. How about _one_, or _unity_? david --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
