gistfile1.hs

asInt :: String -> Int
asInt xs = loop 0 xs

loop acc [] = acc
loop acc (x:xs) = let acc' = acc * 10 + digitToInt x
                  in loop acc' xs

loopF :: Double -> String -> Double
loopF acc [] = acc
loopF acc (x:xs) = let acc' = (acc + fromIntegral (digitToInt x))*0.1
                   in loopF acc' xs

asDecimal :: String -> Double
asDecimal xs = loopF 0 (reverse xs)

asDouble :: String -> Double
asDouble xs = 
    if null (filter (=='.') xs)
    then fromIntegral $ asInt xs
    else let (intPart, '.':decPart) = break (=='.') xs
         in (fromIntegral $ asInt intPart) + (asDecimal decPart)