On 9/27/07, Robert Bradshaw <[EMAIL PROTECTED]> 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 :) Cheers, f --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
