From: Kenosis <kenosis@...>
Date: 2007-02-24T06:00:10+09:00
Subject: Re: enum_cons with tail

On Feb 23, 11:50 am, "S. Robert James" <srobertja...@gmail.com> wrote:
> enum_cons chops off the tail of the collection, if it isn't evenly
> divisble:
>
> e.g.:
>     (1..10).each_cons(3) {|a| p a}
>     # outputs below
>     [1, 2, 3]
>     [2, 3, 4]
>     [3, 4, 5]
>     [4, 5, 6]
>     [5, 6, 7]
>     [6, 7, 8]
>     [7, 8, 9]
>     [8, 9, 10]
>
> I'd also like to get:
> [9, 10, nil]
> [10, nil, nil]
>
> Is there anyway to do this?  (The collection is an opened File, too
> large to load entirely in memory.)
>
> I don't have a clear grasp as to how internally Ruby treats a File as
> Enumerable.

Not that I am aware of.  Two things come to mind.  1) You could append
nil items to your array to make it evenly divisable, 2) you could
extend arrary with your own each_cons that does what you want.  Hope
this is at least some help.  Perhaps others will know a more direct
way to accomplish what you seek.

Ken