Kurt Hutchinson wrote:
On 8/15/07, Alexteslin <[EMAIL PROTECTED]> wrote:
I am really sorry, but i still can't define the function. The chapter the
exercise is in precedes algebraic types or Maybe a types. And is seems that
must being easy to define.
I answered some exercises on using foldr such as summing for example, but
this one i am trying:
myLast :: [Int] -> Int
myLast (x:xs) = foldr (some function) x xs.
With summing as i understood foldr goes through the list and sums up by (+)
operator and one argument like 0. Like: foldr (+) 0 xs
I don't think you can do it directly using just foldr. However, you
can use foldr to build up a function that, when applied to the list,
will evaluate to the last element. foldr will be acting like a
function composition engine that evaluates to a function to process
the list.
Something like this? (spoiler warning)
http://hpaste.org/2283
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