Michael Foord wrote: > How great is the complication? Making list.pop(0) efficient sounds like > a worthy goal, particularly given that the reason you don't use it is > because you *know* it is inefficient (so the fact that you don't use it > isn't evidence that it isn't wanted - merely evidence that you had to > work around the known inefficiency).
The implementation must be changed in at least four places: * The PyListObject struct gets an additional pointer that stores a reference to the head. I would keep the head (element 0) of the list in **ob_item and the reference to the malloc()ed array in a new pointer *ob_allocated. * PyList_New() stores the pointer to the allocated memory in op->ob_allocated and sets op->ob_item = op->ob_allocated * listpop() moves the op->ob_item pointer by one for the special case of pop(0) * list_resize() should occasionally compact the free space before the head with memcpy() if it gets too large. listinsert() could be optimized for 0 if the list has some free space in front of the header, too. I favor this approach over an integer offset because doesn't change the semantic of ob_item. Christian _______________________________________________ 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
