Yclept Nemo <orbisvi...@gmail.com> added the comment: >> None of those are specific to arithmetic progressions (i.e., range-like >> lists / sets), as far as I can tell.
Does this (the data-type involved) really matter? >> I could see more use for general list-intersection functionality. The way to implement generic functionality is to define a protocol and override inherited behavior when necessary. Generic intersection (when semantics can be agreed upon) can computed using the iterator protocol, but __and__ of the range class should be overridden to provide O(1) behavior. So, perhaps a proposal for implementing __and__ for lists as well ? >> I'm still -1 on this; it seems too specialised a need to belong in the core >> language. While I do see several arguments against the inclusion of __and__: . it would require the inclusion of union and difference operations . vague definition of intersection with regard to ranges. Do you treat range like a linear equation, so only consider intersections at the same index. Also the issue regarding ordering. . re issue1766304, it may be pointless providing an O(1) __and__ for range if it can only work for ints(??) I don't think that complexity or specialisation should matter. A range is already a specialised data type (do any other languages have a range class - separate from slices?) Python's data model provides __and__. Conceptually, why not bring range to its full potential using facilities that python already provides. By the way, I don't have anything at stake in this - just arguing for argument's sake - so you can close this if you feel strongly enough about not implementing it. ---------- _______________________________________ 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
