On Tuesday, May 19, 2015 at 1:20:55 AM UTC+5:30, Ian wrote: > It may be possible that lists in CPython could be made to share their > internal arrays with other lists on a copy-on-write basis, which could > allow slicing to be O(1) as long as neither list is modified while the > array is being shared. I expect this would be a substantial piece of > work, and I don't know if it's something that anybody has looked into.
One fundamental difference/choice in language semantics is copy vs reference C#/.Net call it value-type and reference-type. [The names may be a bit odd...] Functional languages OTOH tend to the philosophy: - maximise sharing internally - mutability taboo which has its own costs -- eg 'obvious' data structures like arrays become hard/impossible Its quite likely that your proposal - slices as COW-views -- will have significant penalties in other usage scenarios. Imagine plastering more and more complex slice-views on an array inter-mixed with updates. I must say I am impressed by C#/.Net for making the value/object distinction first-class all the way from language to VM. -- https://mail.python.org/mailman/listinfo/python-list
