On 4/18/07, Nick Alexander <[EMAIL PROTECTED]> wrote: > Martin Albrecht <[EMAIL PROTECTED]> writes: > > Almost, done. Exception: > > This list of exceptions is interesting. Is it possible that is_zero > is in the wrong place in the hierarchy?
It's in the only place it can go. Putting it in SageObject wouldn't make sense. Possibly there should be another is_zero in the base module or ring class. I have some comments below about each exceptional case, by the way. > And the precision issues are more widespread; is_zero for reals, etc, > has the same issues. Reals and complexes do not have this issue because in SAGE they are all fixed precision fields -- there are no lazy reals in SAGE (not yet, at least). > Other than that, +1 include from me. Many thanks for looking it over!! > > ./libs/ntl/ntl.pyx: def is_zero(self): > > ./libs/ntl/ntl.pyx: def is_zero(self): > > ./libs/ntl/ntl.pyx: def is_zero(ntl_GF2E self): > > ./libs/ntl/ntl.pyx: def is_zero(self): > > > > Does not inherit from Element. When I wrote the ntl interface I viewed it as attempting to model as close as possible the actual C++ interface to the NTL library. The idea was not to make something that behaved like other SAGE rings, but to provide an easier path to quickly use NTL in implementing other SAGE rings and objects. > > ./modular/hecke/module.py: def is_zero(self): > > > > Does not inherit from Element. That thing inherits from Module, which is defined in module.pyx. I think here we either don't have an is_zero method in modulear/hecke/module.py or we move it to modules/module.pyx, and define __nonzero__ -- i.e., the same as was done for elements. > > ./structure/element.pyx: def is_zero(self): > > > > Does not inherit from Element. Um -- that is element ?? Huh? It doesn't inherit from itself ? > > ./rings/morphism.py: def is_zero(self): > > > > Does not inherit from Element. That's bad. Ring morphisms are elements so should inherit from element. That they don't is a mistake. > > ./rings/number_field/number_field_ideal.py: def is_zero(self): > > ./rings/number_field/number_field_ideal.py: def is_zero(self): > > > > Does not inherit from Element. I think ideals should also be elements of a group of fraction ideals, or at least of something. > > ./rings/padics/padic_lazy_element.py: def is_zero(self, prec): > > ./rings/padics/padic_capped_relative_element.py: def is_zero(self, prec = > > None): > > ./rings/padics/padic_extension_generic_element.py: def is_zero(self, > > prec): > > ./rings/padics/padic_ring_fixed_mod_element.py.orig: def is_zero(self, > > prec > > = None): > > ./rings/padics/local_generic_element.py: def is_zero(self, prec): > > ./rings/padics/padic_ring_fixed_mod_element.py: def is_zero(self, prec = > > None): > > > > Require additional prec parameter which doesn't fit into the __nonzero__ > > concept, so I left it as is. Ideas? I think that should be left as is. At least I don't have any better ideas. William --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
