> > In this file, the current behaviour is the following, > > > o Try to establish the answer (yes or no). > > o If this doesn't work, throw an exception. > > > although the actual behaviour is down to the inheriting classes. > > > From the point of view of the ring, this might seem sensible. But I > > think the case where this is used is something like this: One has > > various algorithms at hand for computing with a given ring, and the > > computation would be done much better if one knew the ring was a > > field, say. I think the code would be a lot cleaner if the following > > behaviour was offered: > > > o Try to find out whether the ring is a field, say. > > o If the positive answer can be established, return yes. Otherwise, > > return false. > > If R is a ring that is in fact a field, I'm sure that many people will be > very unhappy if we have: > > sage: R.is_field() > False > > This would be more acceptable: > > sage: R.is_field(unknown_returns_false=True) > True or False > > So why not just add a flag that is off by default to the "is_field", etc. > functions, so they do what you want? It makes the code very easy to > read, will be easy to document, since it will be easy to learn about if you > get frustrated and type "R.is_field?". Then much of the library code code > use it. > > William
I am sorry if my post wasn't very clear; by "I think the code would be a lot cleaner if the following behaviour was offered" I did not mean that the default behaviour of the current implementations of "is_field" etc should be changed. Instead, that is why I included the methods "is_certainly_field" etc. However, I think your suggestion of adjusting the current implementation of "is_field" etc by including an optional parameter looks much cleaner. If other people agree with this approach, I guess I can just leave a short note explaining this behaviour in the generic method in sage/ rings/ring.pyx and then go through all inheriting classes overwriting the method to make the adjustments, right? Sebastian --~--~---------~--~----~------------~-------~--~----~ 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 URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
