[Haskell-cafe] Re: Re: Re: Full strict functor by abusing Haskell exceptions

Román González wrote:

On Thu, Sep 16, 2010 at 2:12 PM, Ben Franksen wrote:

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Sjoerd Visscher wrote:

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But StrictIncl can't be a pointed functor, only endofunctors can be pointed.

Could someone tell me what exactly a pointed functor is? I googled but did not find a definition.

Here you will find what a Pointed Functor would be => http://haskell.org/sitewiki/images/8/85/TMR-Issue13.pdf

Look up for the Typeclassopedia, start reading functor, next thing you will find is the Pointed typeclass

Thanks for the link. What I actually wanted was a mathematical definition, though. From the TMR article I gather that a pointed functor could be defined as an endo-functor F: C -> C together with a natural transformation pure: Id -> F where Id: C -> C is the identity functor. No additional laws (beside naturality of pure) are imposed. Right so far? Why is this an interesting structure? Cheers Ben