From: Harry <list.push@...>
Date: 2007-04-28T22:36:55+09:00
Subject: Re: cyclic array

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On 4/28/07, Josselin <josselin@wanadoo.fr> wrote:
>
> I would like to print  n elements from an Array in a cyclic way.
>
> I mean :
>
> using anArray = [ "a", "b", "c", "d", "e", "f", "g"], I should do :
>
> anArray.print_cyclic(4, 0) => "a", "b", "c", "d"   (first print  4
> elements starting with the first one)
>
> anArray.print_cyclic_next => "b", "c", "d", "e"
> anArray.print_cyclic_next => "c", "d", "e", "f"
> anArray.print_cyclic_next => "d", "e", "f", "g"
> anArray.print_cyclic_next => "e", "f", "g", "a"
> anArray.print_cyclic_next =>  "f", "g", "a", "b"
> anArray.print_cyclic_next => "g", "a", "b", "c"
> .....
> also in reverse cycle
> anArray.print_cyclic(4, 0) => "a", "b", "c", "d"
> anArray.print_cyclic_previous => "g", "a", "b", "c"
> anArray.print_cyclic_previous => "f", "g", "a", "b",
>
> what could be the simplest way to do it ?  no simple way using Array
> class methods only  ,
> should I define a class and methods to loop into the array ?  any
> existing lib ?  if it has been already done why should I rewrite it ....
>
>
> tfyh
>
> joss
>
>
>
This will do the shifting but I'm not sure about wrapping around.

require 'enumerator'
(1..25).each_cons(5) do |x|
p x
end


Harry

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