On 9/27/07, Fernando Perez wrote: > > On 9/27/07, Robert Bradshaw wrote: > > > I agree with your caution, but don't see how the examples above mess > > anything up. If an object B wants to pretend to be immutable, it > > merely has to check that nothing points to it before mutating itself > > (and, in mutating itself, don't mutate objects that have other > > pointers to them). > > Yup, I was just trying to illustrate the issues that could arise if > one uses the assumption that refcount==1 <==> no side effects on > in-place operations. But with the proper care, it's a perfectly valid > approach for optimizing expressions involving immutable objects. > Given Bill's surprise, it probably wasn't totally useless to provide > these examples :) >
Very useful indeed, thanks! :-) Regards, Bill Page. --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
