[Haskell-cafe] Ultra-newbie Question
ctauss1 at gmail.com
Sat Sep 18 14:01:11 EDT 2010
Thanks you Ivan and David for clarifying this.
On Sat, Sep 18, 2010 at 3:55 AM, Ivan Lazar Miljenovic <
ivan.miljenovic at gmail.com> wrote:
> On 18 September 2010 17:51, Christopher Tauss <ctauss1 at gmail.com> wrote:
> > Hello Haskell Community -
> > I am a professional programmer with 11 years experience, yet I just do
> > seem to be able to get the hang of even simple things in Haskell. I am
> > trying to write a function that takes a list and returns the last n
> > elements.
> > There may be a function which I can just call that does that, but I am
> > trying to roll my own just to understand the concept.
> > Let's call the function n_lastn and, given a list [1,2,3,4,5], I would
> > n_lastn 3 = [3,4,5]
> > Seems like it would be something like:
> > n_lastn:: [a]->Int->[a]
> > n_lastn 1 (xs) = last(xs)
> > n_lastn n (x:xs) = ????
> > The issue is I do not see how you can store the last elements of the
> Easiest way I can think of:
> n_lastn n = reverse . take n . reverse
> n_lastn n xs = drop (len - n) xs
> len = length xs
> Ivan Lazar Miljenovic
> Ivan.Miljenovic at gmail.com
> IvanMiljenovic.wordpress.com <http://ivanmiljenovic.wordpress.com/>
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