Alexteslin wrote:
Hello,
I just came across with this question on the exam and can not think of implementing it.
mapPair :: (a -> a -> a) -> [a] -> [a]
such that mapPairs f [x1, x2, x3, x4...] = [f x1 x2, f x3 x4,...]
and if the list contains an odd number of elements, the last one is kept unchanged, for example
mapPairs f [x1, x2, x3] = [f x1 x2, x3]
Any ideas will be appreciated, thanks
Oh, I think i just defined it - seems to work. I spent some time on the exam and made silly mistakes: mapPairs :: (a -> a -> a) -> [a] -> [a] mapPairs f [x] = [x] mapPairs f [] = [] mapPairs f (x:xs) = f x (head xs) : mapPairs f (tail xs) I was concing f x to (head xs) as well and mapPairs f [x] = x - this is very silly mistake. Does anyone think this is the right answer? -- View this message in context: http://www.nabble.com/defining-mapPairs-function-tf4350356.html#a12395696 Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.