On Fri, Jul 17, 2009 at 12:41 PM, Cristiano Paris<[email protected]> wrote: > ... > Now, to confirm my hypothesis, I wrote a slight different version of > fib, like follows: > > fib' n = 1:1:(fib' n) `plus` (tail $ fib' n) where plus = zipWith (+) > > i.e. I inserted a fictious argument n in the definition of fib'. > > Now, if I try "take 30 $ fib' 100", it takes significntly longer than > "take 30 fib": specifically, the latter is instantaneous, while the > former takes about 5 seconds to complete on my MacBook Pro. Is this an > evidence that the "tying the knot" process is going on in the first > version?
BTW, after a -O2 compilation, fib' is apparently as fast a fib. Cristiano _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
