Why is this blowing the stack, thought it was tail-recursive...

[Scott David Daniels]

ssecorp wrote:
  <a recursive Fibonacci generator thast demonstrates no tail recursion 
used>
> and can memoization speed up this even more? ....

Generators get you to an even clearer Fibonacci expression.

     def _Fibonacci_gen():
         a, b = 1, 0
         while True:
             a += b
             yield a
             b += a
             yield b

Here's how to use it to avoid redundant comutation:

     _next_entry = _Fibonacci_gen().next
     _sofar = []

     def fib(n):
         while len(_sofar) <= n:
             _sofar.append(_next_entry())
         return _sofar[n]


--Scott David Daniels
Scott.Daniels at Acm.Org