From: lasitha <lasitha.ranatunga@...>
Date: 2009-03-09T02:54:40+09:00
Subject: Re: how to un-ragged a 2D array?

On Sun, Mar 8, 2009 at 10:38 PM, Phlip <phlip2005@gmail.com> wrote:
> lasitha wrote:
>
>> needs.map {|x, y| [x, y ||= x] }
>
> You win! But try just:
>
>  needs.map{|x, y| [x, y || x] }

Doh!  And i was feeling so clever just a minute ago :)


> (And would needs.map{|*x| [*x, *x].first(2) } work on Ruby 1.9? 1.8.7?)

Neither.

Doesn't compile on 1.8.7

On 1.9 the splat wraps arrays in another array so we end up with:
[[1, 1], [[2, 3], [2, 3]], [4, 4], ...]
         ~~~~~~~~~~~~~~~~

Best i could manage with explicit use of splat was:
needs.map{|x| [*x] }.each {|x| x[1] ||= x[0] }

Which, combined with Sebastian's earlier solution, generalises to any
target length:
needs.map{|x| [*x] }.map {|x| x + [x.last] * (legth - x.length) }


> However, I ain't gonna edit my gist just to put it in - you missed the
> deadline! (-:

pfft.

cheers :)
lasitha