Haskell：（+1）和（\ x-> x + 1）有什麼區別？

這兩個函數有區別嗎？Haskell：（+1）和（ x-> x + 1）有什麼區別？

ghct說：

Prelude> :t (+1) 
(+1) :: Num a => a -> a 
Prelude> :t \x->x+1 
\x->x+1 :: Num a => a -> a

但是

當我使用（1）的語法在這段代碼：

data B = B { 
    pos :: Int, 
    cells :: [Int] 
} deriving (Show) 

createB :: Int -> B 
createB n = B 0 (take n $ repeat 0) 

size :: B -> Int 
size b = length $ cells b 

get_curr :: B -> Int 
get_curr b = (cells b) !! (pos b) 

apply :: (Int -> Int) -> B -> B 
apply f b = let n = pos b 
       h = take n $ cells b  -- head 
       t = drop (n + 1) $ cells b -- tail 
       in B n $ h ++ [f (get_curr b)] ++ t 

-- ... 
eval :: [Char] -> StateT B IO() 
eval [] = return() 
eval (x:xs) = do 
       b <- get 

       put $ case x of 
         '+'   -> apply (+1) b 
         '-'   -> apply (-1) b 
         '>'   -> fwd b 
         '<'   -> back b 
         otherwise -> b 
       -- ...

前奏（以及編譯器），所述：

> :load BrainFuck.hs 
[1 of 1] Compiling BrainFuck  (BrainFuck.hs, interpreted) 

BrainFuck.hs:49:40: 
    No instance for (Num (Int -> Int)) 
     arising from the literal `1' 
    Possible fix: add an instance declaration for (Num (Int -> Int)) 
    In the expression: 1 
    In the first argument of `apply', namely `(- 1)' 
    In the expression: apply (- 1) b 
Failed, modules loaded: none.

我在做什麼錯？對不起，如果代碼是不那麼酷（完整源在這裏：https://github.com/nskeip/bf/blob/a755b2d27292593d63fe1e63c2a6e01cebc73520/BrainFuck.hs）

來源

2012-02-29 Nikita Hismatov