On 1/28/2010 6:30 PM, Josiah Carlson wrote:
I would also point out that the way these things are typically done is that programmers/engineers have use-cases that are not satisfied by existing structures, they explain the issues they have with existing structures, and they propose modifications. So far, Steve has not offered any use-cases for why his proposed change is necessary; merely
Use of a list as a queue rather than as a stack, as in breadth-first search, where one only needs to pop off the front but never push to the front. That is not to say that this is common or that a deque or other options may no be pretty satisfactory. But it would certainly be easier, when presenting such algorithms, to just be able to use a list, which has already been taught, than to introduce another structure. Currently a deque is not a drop-in replacement for a list in that one cannot use all list methods with a deque.
As I understand it, his proposal is simpler than the one rejected a couple of years ago is that it does not include intentional over-allocation at the front of the list, as would be needed for guaranteed O(1) behavior for deque-like insertion at the front. I may consider a Python version of his idea for one of my needs, where speed is not an issue.
I agree that the discussion has gone on too long here and that some of Steve's rhetoric has been unnecessarily abrasive and off-putting. He has been told this and acknowledged it once on Python-list, but habits die hard. For both reasons, I suggested a few days ago that further discussion should focus on the patch and be moved to the issue on the tracker. So I will not say more here.
Terry Jan Reedy _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
