That's a clever routine. It should be faster than mine since it only makes a single pass though the list. Thanks for all the suggestions from everyone that responded. Here is a link to some more info on the project I'm working on if anyone is interested:
http://ehaskell.blogspot.com/
-Eric
On 2/5/07, ihope <ihope127@gmail.com
> wrote:On 2/4/07, Eric Olander <olandere@gmail.com
> wrote:
> Hi,
> I'm still somewhat new to Haskell, so I'm wondering if there are better
> ways I could implement the following functions, especially shiftl:
>
> >> moves the last element to the head of the list
> shiftl :: [a] -> [a]
> shiftl [] = []
> shiftl x = [last x] ++ init x
Well, you could try this, though I'm actually sure it's any faster:
> shiftl (x1:x2:xs) = last:x1:init
> where last:init = shiftl (x2:xs)
> shiftl [x] = [x]
> shiftl [] = error "shiftl: empty list"
Or, if you don't want to give an error on [], omit the last line and
replace both of the [x] with xs.
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