Hi Robert, >> In order to sanitize the behavior of objects, parents and elements in >> sage, >> I'm about to add some tests to the framework. I think they are all >> reasonable >> but I may be asking to much. Please comment about the following: >> >> 1 - Any SageObject must have an equality methods such that >> self == self and self != None >> >> 2 - Element construction should be idempotent. More precisely, for any >> element e within parent P, the equality P(e) == e must hold. >> This is for example needed by the constructor of many Parent with a >> base >> ring, such as matrices. > > Elements of real interval fields don't satisfy the above two constraints > (the notion of equality for intervals being that every element of the first > interval is equal to every element in the second).
You get the point. As far as I understand a RIF only return True if the interval are reduced to a single point. Is it right ? It would be better to return a special value like Unknown than False. But that's another question... Anyway, I'm strongly info favor of giving 1- and 2- a general rule with an explicit exception for RIF. As I said, the test framework allows such exceptions. Is there an agreement on * Making 1- and 2- below a general rule >> 1 - Any SageObject must have an equality methods such that >> self == self and self != None >> >> 2 - Element construction should be idempotent. More precisely, for any >> element e within parent P, the equality P(e) == e must hold. * Making explicit exception for particular cases such as RIF. Cheers, Florent -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
