Travis Scrimshaw wrote: > We need to be very careful about defining "not knowing". I (stongly) > believe when the objects/types are incomparable (say the rings ZZ and > QQ), then == should return False and != should return True.
Sorry, I don't understand your example: I think everyone agrees that ZZ == QQ should be False, but many people think that ZZ(1) == QQ(1) should be True (though I personally disagree), and my post only was about Elements. > Subsequently, when there is no coercion between the parents, they > should not raise an error. Regarding ==, I believe it is a matter of convenience and consistency. Raising an error makes it easier to catch bugs, while returning False when there is no coercion allows things like [a for a in [1, "banana"] if a == 1]. Regarding !=, I am less convinced. Returning True would imply that the objects are known to be different (as opposed to: not known to be equal, in the case of ==), while the coercion may not be implemented but otherwise make perfect sense. And in any case, I don't see what else than raising an error we could do in the case of <, <=, >, >=. -- Marc -- 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 https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
