On Thu, Oct 02, 2008 at 02:55:34PM -0400, Sean Allen wrote: > > On Oct 2, 2008, at 1:18 PM, Bert Freudenberg wrote: > > >> If you wanted to take a mutable object and make it immutable and be > >> able to go back again to mutable, > >> how could you do that? > > > > What is your use case? > > use case. > > system needs to track changes to itself. > > one option that has come up is... > > linked list of different 'versions' of same object. > head is the live object. everything else past versions. > > want to mutate object? you have to 'unlock'. > unlocking gives you a new copy and updates the linked list, > allowing all the accessors that mutate state to work. > > when locked, calling one of those accessors would result in > an error. but when locked, read access still needed. > > if i can find a way to put this in a superclass and have > children get the functionality w/o doing anything else, > then i really like it.
heh. I'm making something that creates a new object version whenever an ivar is changed. I'm using tweak's fields and compiler to do it, so it will only work in a Croquet image. Not to mention that I've just barely started. The code is at http://croquet-src-01.oit.duke.edu:8886/RayTracing/Quansi-Core-mtf.10.mcz -- Matthew Fulmer -- http://mtfulmer.wordpress.com/ _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
