From: Gavin Kistner <gavin@...>
Date: 2005-08-04T08:39:01+09:00
Subject: Re: Combination of two arrays

On Jul 28, 2005, at 8:09 AM, Jim Freeze wrote:
>   irb(main):004:0>  foo.collect { |f| f * bar }.inject([]) { |a,e|  
> a.concat e }
>   => [["a", 1], ["a", 2], ["a", 3], ["b", 1], ["b", 2], ["b", 3],  
> ["c", 1],
>   ["c", 2], ["c", 3]]
>
> There, that's better, but ugly. Anyone got a cleaner way to flatten?

require 'flattenx'
foo.collect { |f| f * bar }.flatten_once

(Given http://www.wobblini.net/ruby/flattenx.html )