Yclept Nemo <orbisvi...@gmail.com> added the comment: > max and min for a range object are already O(1) one-liners:
true; dropping > As for __and__, it doesn't feel like a particularly natural operation to me, > given that a range object represents an *ordered* sequence of integers rather > than just a subset. True, there is no canonical sorting. However, the concept of the intersection of ordered sets is commonplace and implemented in other libraries, for example: http://www.swi-prolog.org/pldoc/doc_for?object=section%282,%27A.17%27,swi%28%27/doc/Manual/ordsets.html%27%29%29 http://hackage.haskell.org/packages/archive/containers/0.4.1.0/doc/html/Data-Set.html#v:intersection http://hackage.haskell.org/packages/archive/data-ordlist/0.2/doc/html/Data-List-Ordered.html#v:isect My implementation inherets the ordering of the first range: R(1) R(2) R(F) p p p n p n p n p n n n key: p === positive === increasing key: n === negative === decreasing Haskell documentation has an apt paradigm for the ordering: "Elements of the result come from the first set"; similary my implementation selects elements from the first set common to the second. >From a programming persepctive this is quite natural too: lcm = (a*b)/gcd(a,b) where lcm determines the ordering. Basically, the behavior of the attached __and__ implementation is driven by python's gcd function. ---------- Added file: http://bugs.python.org/file26214/Range.py _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue15224> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
