[Fwd: Re: [Haskell-cafe] Implicit newtype unwrapping]

Holger Siegel holgersiegel74 at yahoo.de
Wed Dec 2 19:25:37 EST 2009

Am Donnerstag, den 03.12.2009, 01:16 +0100 schrieb Martijn van
> So here's a totally wild idea Sjoerd and I came up with.
> What if newtypes were unwrapped implicitly?
> What advantages and disadvantages would it have?
> In what cases would this lead to ambiguous code?

instance Monoid a => Monoid (Dual a)

instance Monoid (Endo a)
instance Monoid b => Monoid (a -> b)

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