Comments on: Patterns in Haskell revisited http://yaxu.org/patterns-in-haskell-revisited/ Making music with text Thu, 04 Apr 2013 04:14:46 +0000 hourly 1 http://wordpress.org/?v=3.5.1 By: Alex http://yaxu.org/patterns-in-haskell-revisited/comment-page-1/#comment-103896 Alex Tue, 06 Mar 2012 19:19:32 +0000 http://yaxu.org/?p=917#comment-103896 Great tip, thanks Noah!

]]> By: Noah Easterly http://yaxu.org/patterns-in-haskell-revisited/comment-page-1/#comment-103893 Noah Easterly Tue, 06 Mar 2012 19:00:13 +0000 http://yaxu.org/?p=917#comment-103893 Cool stuff. I’d note that both `length xs` and `xs !! x` are O(n), so that makes `toPattern :: [a] -> Pattern a` O(n^2), but it doesn’t have to be. You can look the length up once, and use `zipWith` to iterate through your elements

    instance Patternable [] where
        toPattern xs = Cycle ps
          where
            n = length xs
            ps = zipWith mkArc xs [0..]
            mkArc x i = Arc  x ((fromIntegral i) / (fromIntegral n)) Nothing
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