In sage/structure/parent_base.pyx there is a function "check_old_coerce" with the following definition:
cdef inline check_old_coerce(parent.Parent p): if p._element_constructor is not None: raise RuntimeError, "%s still using old coercion framework" % p This function is called from a few methods in class ParentWithBase (e.g. from _richcmp, from _coerce_c_impl, and from base_extend). In my class (which inherits from ParentWithBase) I've defined _element_constructor_ instead, but the init for ParentWithBase insist on copying this method onto _element_constructor -- thus the "check_old_coerce" function always fails... It's impossible to avoid!!! What is the base class that one is supposed to use instead of ParentWithBase? The only reference for the coercion model that I was able to find is http://www.sagemath.org/doc/reference/coercion.html#example, which even shows an example, but the example inherits from Ring, which ultimately inherits from ParentWithBase anyway. Gonzalo -- 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
