On Tue, Sep 13, 2016 at 1:35 AM, Guido van Rossum <gu...@python.org> wrote: > Couldn't we use the order in the actual hash table (which IIUC now > contains just indexes into the ordered vector of key/value/hash > structs)? That would probably simulate the pre-3.6 order quite > effectively.
Maybe, it can. But current implementation may be faster on iteration, thanks to hardware prefetch of CPU. When sizeof(entry) is 24 (amd64), only 2.66... entries can be on cache line. > But we'd have to add a new API to reveal the order (in effect just > what Nick wanted). How much of the OrderedDict can be implemented just > by adding new methods (IOW without changing the data structure)? Current data structure uses fixed capacity, mostly append only array for entries. To implement `OrderedDict.move_to_end(last=False)`, OrderedDict should be implement more hack. (e.g. use the array as ring.) _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
