[Haskell-cafe] Thinking about an unlistN

Justin Bailey jgbailey at gmail.com
Mon Aug 11 15:06:40 EDT 2008

On Sun, Aug 10, 2008 at 11:47 AM, Michael Feathers
<mfeathers at mindspring.com> wrote:
> unlist3 :: (a -> a -> a -> b) -> [a] -> b
> unlist3 f (x:y:z:xs) = f x y z

Oleg has written about this. Be careful, its easy to overdose on:

"Functions with the variable number of (variously typed) arguments"

> I was also wondering whether the function can be generalized to N or whether
> this is just one of those edges in the type system that you can't abstract
> over.

With template haskell I don't think that exists.


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