On 10/3/10 1:45 PM, Dominique Devriese wrote:
Additionally, you can't combine the functions (blowup . allButLast)
and lastToTheLength into a function that returns a pair like you seem
to attempt. You need a function like the following for that:
comma :: (a -> b) -> (a -> c) -> a -> (b,c)
comma f g x = (f x, g x)
Then you could say:
blowup = (uncurry (++)) . comma (blowup . allButLast) lastToTheLength
It is worth noting that such a function already exists in the standard
libraries; it is the &&& operator in Control.Arrow:
blowup = uncurry (++) . (blowup . allButLast &&& lastToTheLength)
Cheers,
Greg
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
