[Haskell-beginners] About monad

[Trung Quang Nguyen]

Hi all,

I saw this


   1. instance Monad Maybe where
   2.     return x = Just x
   3.     Nothing >>= f = Nothing
   4.     Just x >>= f  = f x
   5.     fail _ = Nothing


I am wondering about the implementation of function (>>=). Why don't
it be *Just
x >>= f = Just (f x)*?

Any body knows about this?

--Trung
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