module Prelude(Read(..)) where
instance (Read a) => Read (Maybe a) where
readsPrec p = \ r -> readParen False ( \r -> [(Nothing,t) | ("Nothing",t) <- lex r]) r
++
readParen (p > 9) ( \r -> [(Just a,v) | ("Just",t) <- lex r,
(a,v) <- readsPrec 10 t]) r
|