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missingfaktor/blabber.hs

Last active May 31, 2016 23:42
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blabber.hs
Prelude> newtype Dyn a = Dyn a deriving Show
Prelude> data Book = Book (Dyn String) Int deriving Show
Prelude> :{
Prelude| class Serialise a where
Prelude| serialise :: a -> String
Prelude| :}
Prelude> instance Serialise Book where serialise (Book (Dyn s) i) = s ++ ":" ++ show i
Prelude>
Prelude> let serialisedBook = fmap serialise (\s -> Book s 32)
Prelude> -- apply dynamic value when available
Prelude> serialisedBook (Dyn "isbn")
"isbn:32"
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