Re: [Haskell-cafe] turning an imperative loop to Haskell

On 9/6/07, Dougal Stanton <[EMAIL PROTECTED]> wrote: > On 06/09/07, Sebastian Sylvan <[EMAIL PROTECTED]> wrote: > [2,3,4,9,16,29,54,99,182,335] -- what's this? Two times this: http://www.research.att.com/~njas/sequences/A000213 plus this: http://www.research.att.com/~njas/sequences/A001590 plus tw

Re: [Haskell-cafe] turning an imperative loop to Haskell

On Thu, 6 Sep 2007, Axel Gerstenberger wrote: Thanks to all of you. The suggestions work like a charm. Very nice. I still need to digest the advices, but have already one further question: How would I compute the new value based on the 2 (or even more) last values instead of only the last on

Re: [Haskell-cafe] turning an imperative loop to Haskell

On 06/09/07, Sebastian Sylvan <[EMAIL PROTECTED]> wrote: > > foo = 2 : 3 : zipWith f (drop 1 foo) foo > > There's also zipWith3 etc. for functions with more arguments. I think this is called taking a good thing too far, but cool too: f1 u = u + 1 f2 u v = u + v f3 u v w = u + v + w -- functions

Re: [Haskell-cafe] turning an imperative loop to Haskell

When you get to more than two arguments, it will probably be nicer to do something like this: fibs = map (\(a,b) -> a) $ iterate (\(a,b) -> (b, a+b)) (0,1) or fibs = unfoldr (\(a,b) -> Just (a, (b, a+b))) (0,1) -- this uses unfoldr to get rid of the map This is essentially a translation of the imp

Re: [Haskell-cafe] turning an imperative loop to Haskell

On 06/09/07, Axel Gerstenberger <[EMAIL PROTECTED]> wrote: > however,I don't get it this to work. Is it possible to see the > definition of the iterate function? The online help just shows it's usage... The Haskell 98 report includes source for the standard prelude. Check 'em out...

Re: [Haskell-cafe] turning an imperative loop to Haskell

On 06/09/07, Axel Gerstenberger <[EMAIL PROTECTED]> wrote: > Thanks to all of you. The suggestions work like a charm. Very nice. > > I still need to digest the advices, but have already one further > question: How would I compute the new value based on the 2 (or even > more) last values instead of

Re: [Haskell-cafe] turning an imperative loop to Haskell

Axel Gerstenberger wrote: Thanks to all of you. The suggestions work like a charm. Very nice. I still need to digest the advices, but have already one further question: How would I compute the new value based on the 2 (or even more) last values instead of only the last one? [ 2, 3 , f 3 2, f

Re: [Haskell-cafe] turning an imperative loop to Haskell

Thanks to all of you. The suggestions work like a charm. Very nice. I still need to digest the advices, but have already one further question: How would I compute the new value based on the 2 (or even more) last values instead of only the last one? [ 2, 3 , f 3 2, f((f 3 2) 3), f ( f((f 3 2)

Re: [Haskell-cafe] turning an imperative loop to Haskell

On 06/09/07, Axel Gerstenberger <[EMAIL PROTECTED]> wrote: > module Main where > > import System.IO > import Text.Printf > > main :: IO () > main = do > let all_results1 = take 2 $ step [1] > --print $ length all_results1 -- BTW: if not commented out, >

Re: [Haskell-cafe] turning an imperative loop to Haskell

On Thu, 6 Sep 2007, Axel Gerstenberger wrote: module Main where import System.IO import Text.Printf main :: IO () main = do let all_results1 = take 2 $ step [1] --print $ length all_results1 -- BTW: if not commented out, -- all values of all_res