{-# LANGUAGE CPP #-}
module Data.Text.Internal.Builder.RealFloat.Functions
(
roundTo
) where
roundTo :: Int -> [Int] -> (Int,[Int])
#if MIN_VERSION_base(4,6,0)
roundTo d is =
case f d True is of
x@(0,_) -> x
(1,xs) -> (1, 1:xs)
_ -> error "roundTo: bad Value"
where
b2 = base `quot` 2
f n _ [] = (0, replicate n 0)
f 0 e (x:xs) | x == b2 && e && all (== 0) xs = (0, [])
| otherwise = (if x >= b2 then 1 else 0, [])
f n _ (i:xs)
| i' == base = (1,0:ds)
| otherwise = (0,i':ds)
where
(c,ds) = f (n-1) (even i) xs
i' = c + i
base = 10
#else
roundTo d is =
case f d is of
x@(0,_) -> x
(1,xs) -> (1, 1:xs)
_ -> error "roundTo: bad Value"
where
f n [] = (0, replicate n 0)
f 0 (x:_) = (if x >= 5 then 1 else 0, [])
f n (i:xs)
| i' == 10 = (1,0:ds)
| otherwise = (0,i':ds)
where
(c,ds) = f (n-1) xs
i' = c + i
#endif