TA貢獻(xiàn)1946條經(jīng)驗(yàn) 獲得超4個(gè)贊
$
putStrLn (show (1 + 1))
putStrLn (show $ 1 + 1)putStrLn $ show (1 + 1)putStrLn $ show $ 1 + 1
.
putStrLn (show (1 + 1))
(1 + 1)
.
show
Int
String.
putStrLn
String
IO ().
showputStrLn
(putStrLn . show) (1 + 1)
$
putStrLn . show $ 1 + 1
TA貢獻(xiàn)1825條經(jīng)驗(yàn) 獲得超6個(gè)贊
infixr 9 .(.) :: (b -> c) -> (a -> b) -> (a -> c)(f . g) x = f (g x)infixr 0 $($) :: (a -> b) -> a -> b f $ x = f x
($)(.)
f $ g $ h $ x
==>
f . g . h $ x
$.
TA貢獻(xiàn)2041條經(jīng)驗(yàn) 獲得超4個(gè)贊
($)
id :: a -> a id x = x
($)
($) :: (a -> b) -> (a -> b)($) = id
($)f $ g xf (g x).
(.)
f = g . h
f x = (g . h) x
f x = g (h x)
舉報(bào)