[Haskell-cafe] Thinking about an unlistN

Michael Feathers mfeathers at mindspring.com
Sun Aug 10 14:47:20 EDT 2008


I wrote this function the other day, and I was wondering if I'm missing 
something.. whether there is already a function or idiom around to do this.


unlist3 :: (a -> a -> a -> b) -> [a] -> b
unlist3 f (x:y:z:xs) = f x y z


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.


Thanks,

Michael





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