On Mon, Jun 22, 2015 at 1:40 PM, Jeroen Demeyer <jdeme...@cage.ugent.be> wrote: > Hello, > > for about 2 weeks in the history in Sage (8 years ago), Sage had optimized > in-place operations. Essentially, if you did > > A += B > > then this might actually *mutate* the object A in-place if the refcount of A > was low enough such that we knew that no other pointers to A existed. See > #624. > > This gave impressive speed improvements, but it broke stuff (in numpy in > particular), so it was disabled in #1038. Essentially, the problem is that, > in C code (maybe also Cython?), we cannot count on the refcount of an object > to determine how many pointers it has. > > Currently in Sage, there are still some hooks in the coercion framework for > these disabled in-place operations. > > There is a ticket #1069 to revive this functionality, but it hasn't shown > any activity at all in 8 years. Since I also don't see how we could deal > with in-place operations in a safe way,
What about something explicit, e.g., A.add_inplace(B) which would mutate A and be very clear and explicit. I actually expected something like that to exist, but found it doesn't. > I propose to close that ticket as > "wontfix" and instead remove the parts of Sage which still refer to these > in-place operations. +1 > I am interested to hear any objections... > > Jeroen. > > -- > 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 post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- William (http://wstein.org) -- 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 post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
