I agree with your proposal. Would it be too ambiguous to also allow Q(x) as synonymous for x.lift()?
On Wed, Apr 20, 2011 at 10:34 AM, Simon King <simon.k...@uni-jena.de> wrote: > Hi! > > Working at #9138 and #11068, I'd like to put as many rings as possible > into both the new coercion model and the category framework. > > One question arose for quotient rings. > > Let Q be a quotient ring with ambient ring R, and let x be an element > of x. You meant: x is an element of Q. In order to "lift" x, i.e., return a representative of x in R, > one can do x.lift(). Fine, and certainly justified by the object > oriented mantra. > > However, the current category framework requests the possibility to > ask Q to lift x, with the syntax Q.lift(x). The problem is that the > class sage.rings.quotient_ring.QuotientRing provides Q.lift() with a > different meaning: It returns the lifting morphism, i.e., for lifting > x one would do Q.lift()(x). > > Nicolas suggested to ask here how we should resolve the conflict. > > My personal feeling is that the syntax should be as follows: > * x.lift() is fine. > * Q.lifting_morphism() should return the lifting morphism (better use > explicit method names!). > * Q.lift(x) should be removed, and the category framework for > quotient rings should request a parent method "lifting_morphism" > instead of "lift". > > Apparently, Q.lift in whatever meaning is not very commonly used, so, > it probably doesn't matter. > > However: What do you think? > > Best regards, > Simon > > -- > 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 > -- 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
