[Haskell-beginners] newtype with a typclass

Răzvan Rotaru razvan.rotaru at gmail.com
Mon Mar 18 16:43:10 CET 2013


It seems that type constructors don't allow usage of typeclasses. Is it not
possible to create polymorphic types in Haskell by declaration?

For example I want a map with String keys and anything that is Showable as

newtype MyMap = Map String Show

How can I do that?

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