On Fri, 29 Apr 2011 23:45:30 -0500, harrismh777 <harrismh...@charter.net> wrote: : There is much debate about this generally, but general wisdom is that : recursion is to be avoided when possible.
That is context dependent at best. You have given reasons to avoid recursion in /executable code/, but that's a compiler issue. You have only given reason /for/ recursion in source code. It generally gives little and very reaadble code. In almost every non-trivial software project, the programmers will be more overworked than the computer, and therefore they are the once to consider when optimising. : Recursion is very tempting to young artists because its a ~cool trick, : and because sometimes it requires very little coding (although huge : amounts of memory!), or as in your case, recursion depth errors. Waste of memory happens only with some types of recursion, and even then it is usually negligible. The recursion depth issue is the result of a flawed base case, and nothing to do with a weakness of recursion. : Anyway, the better way to build a Fibonacci sequence generator is the : following... I have expanded things a bit so that someone not knowing : what the sequence is can see what is happening... you will notice simple : 'for' iterations, and no recursion: And surprisingly difficult to read for such a well-known operation as Fibonacci numbers. If you want to promote iteration, you had better at least try to make it legible. Your code is obviously more efficient in being O(n) whereas OP had (I think) O(2^n), but that's not a property of iteration. You can make a recursive implementation which is O(n). Any undergraduate textbook teaching recursion in any depth is likely to give it as an example; see e.g. Simon Thompson's Haskell book. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
