Bryan O'Sullivan wrote:
Andrew Coppin wrote:
On the other hand, this is the anti-theisis of Haskell. We start with a high-level, declarative program, which performs horribly, and end up with a manually hand-optimised blob that's much harder to read but goes way faster.
Buh? This is hard to read?
Look closer: it's hardER to read. mean xs = sum xs / fromIntegral (length xs) mean = go 0 0 n where go s l x | x > m = s / fromIntegra l | otherwise = go (s+x) (l+1) (x+1 One version makes it instantly clear, at a glance, what is happening. The other requires you to mentally walk round a look, imperative style, to figure out what's happening. It's not a *big* deal, but it's unfortunate. I'm more worried about what happens in less trivial examples. [Let's face it, who wants to compute the sum of the numbers from 1 to N?]