* Steve Howell:
On Jan 23, 12:13 am, Terry Reedy <tjre...@udel.edu> wrote:
Challenge yes, mock no.

Part of writing good basic data structures is not adding needless
complication from featuritis and not penalizing 99.99% of access to
satify a .01% need better satisfied another way.


I would like to challenge your assertion that advancing ob_item
instead of doing memmove during list_ass_slice would impact the
performance of list accesses in any way.  It would only slow down
operations that add/insert items into the list by, and then only by a
single conditional statement, and those add/insert operations are
already O(N) to begin with.

I'm sorry, no, the last part is incorrect.

Appending to a 'list' can currently be constant time, if OS reallocation is constant time (as the string '+' optimization relies on).

With the pop optimization it can no longer be constant time without risking an accumulation of unused memory, a memory leak, although it can be amortized constant time, at the cost of wasting some percentage of memory.


Cheers & hth.,

- Alf

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