Dear Enrique, No, that would just duplicate functionality and make things more complicated.
To Cython and/or Python experts, It would be great if someone could give some comments about this. This feels like a very natural thing to do, but it might lead to a very subtle breakage in the wild. If there is anything additional I can provide, please just ask. Thank you, Travis On Monday, March 18, 2024 at 1:15:18 AM UTC+9 enriqu...@gmail.com wrote: > Is there any sense to define a new class of UniqueRepresentation with the > same characteristics and other name with the switch of order? > > El miércoles, 13 de marzo de 2024 a las 16:58:49 UTC+1, Travis Scrimshaw > escribió: > >> Hi everyone, >> On https://github.com/sagemath/sage/pull/37128, we find it useful to >> swap the order of the base classes for UniqueRepresentation. Thus, it >> becomes >> >> class UniqueRepresentation(WithEqualityById, CachedRepresentation): >> >> I believe this is very reasonable since we want to have objects' >> (typically parents, but not limited to them) comparison and hashing be >> first in the MRO. In particular, this is important if we have the following >> setup: >> >> class Foo(CachedRepresentation): >> pass >> >> class Bar(UniqueRepresentation, Foo): >> pass >> >> That way Bar gets the main benefits of being a UR (fast equality and >> hashing). With the current way, there is no way (that I know) to simply >> have the corresponding methods at the Cython level (at best, there is a >> Python redirect that has to be manually implemented) since WithEqualityById >> is a Cython cdef class. >> >> However, we then have a problem with unpickling, but I suspect it is a >> bigger issue. From combinat/root_system/cartan_type.py, the last line fails >> with an incompatible class order: >> >> sage: pg_CartanType_simple_finite = >> unpickle_global('sage.combinat.root_system.cartan_type', >> 'CartanType_simple_finite') >> sage: si1 = unpickle_newobj(pg_CartanType_simple_finite, ()) >> sage: from sage.misc.fpickle import unpickleModule >> sage: pg_make_integer = unpickle_global('sage.rings.integer', >> 'make_integer') >> sage: si2 = pg_make_integer('4') >> sage: unpickle_build(si1, >> {'tools':unpickleModule('sage.combinat.root_system.type_A'), 't':['A', >> si2], 'letter':'A', 'n':si2}) >> >> Mainly, the last line does a self.__class__ = UR.__class__, where UR is >> an instance of a UniqueRepresentation. Granted, this is a very old pickle, >> but I am worried it isn't a problem with this specific pickle. >> >> This is beyond my knowledge of Cython. Any thoughts or advice about this >> issue would be appreciated. >> >> Thank you, >> Travis >> >> -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/0966e7ed-6875-4e4a-89bc-eb043f3d9efbn%40googlegroups.com.
