[Haskell-cafe] Pointed, but not Applicative

Tony Morris tonymorris at gmail.com
Sun Aug 28 12:41:30 CEST 2011


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On 28/08/11 01:41, Sönke Hahn wrote:
> Hi!
> 
> I was reading through the Typeclassopedia ([1]) and I was wondering which 
> type could be an instance of Pointed, but not of Applicative. But I can't 
> think of one. Any ideas?
> 
> Sönke
> 
> [1] http://www.haskell.org/haskellwiki/Typeclassopedia
> 
> 
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Pointed f => Pointed (StateT s f)

but not

Applicative f => Applicative (StateT s f)

- -- 
Tony Morris
http://tmorris.net/

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