d:
Regarding the Fannkuch Shootout Entry:
If we are willing to specialize flop in the way shown on the wiki, another 8% can be gained by similarly specializing rotate:
rotate 2 (x1:x2:xs) = x2:x1:xs rotate 3 (x1:x2:x3:xs) = x2:x3:x1:xs ...
Cheers, I've updated the proposed entry on the wiki. It now runs 40% faster than Bertram's original entry, and its within 25% of an imperative version I wrote yesterday translating from the currently fastest C version. Note that the imperative version is unoptimised so far though, so there could be room to move here, and it may be worth while translating some of the other C entries, to submit a fast, alongside an elegant entry. Entries that may currently be worth submitting: takfp - http://www.haskell.org/hawiki/TakfpEntry pidigits (currently 2nd!) - http://www.haskell.org/hawiki/PidigitsEntry mandelbrot - http://www.haskell.org/hawiki/MandelbrotEntry harmonic - http://www.haskell.org/hawiki/HarmonicEntry fannkuch (pure and impure) - http://www.haskell.org/hawiki/FannkuchEntry Chris, would you like to submit these? -- Don