Haskellリハビリ

適当に。parser作りまでGW中に行け…ないかな。。。

list = [1,2,3,4,5]

main = do print $ mySum list
          print $ mean list
          print $ var list

-- sumはすでにあるけど、実装してみた
mySum :: [Double] -> Double
mySum list = foldl (+) 0 list

mean :: [Double] -> Double
mean list = (mySum list) / fromIntegral (length list)

var :: [Double] -> Double
var list = (mean $ map (^2) list) - (mean list)^2