From: "Eric I." <rubytraining@...>
Date: 2007-11-23T03:30:13+09:00
Subject: Re: How to give depth to arrays?

Others, including Chris Morales, have interpreted the task as follows:

> p [2,3,3,5,4,4].depthen => [2,[3,3,[[5],4,4]]]

But that doesn't seem right to me, since the element 2 is at a depth
of 1 and not 2.  I would think the result should be:

     [[2,[3,3,[[5],4,4]]]]

Anyway, here's a solution which handles my interpretation:

class Array
  def depthen
    result = []

    self.each do |depth|
      array_end = result
      (depth - 1).times do
        array_end << [] unless array_end.last.kind_of? Array
        array_end = array_end.last
      end
      array_end << depth
    end

    result
  end
end

And here's what it does:

p [2, 3, 3, 5, 4, 1, 4, 6, 10, 2].depthen
  # => [[2, [3, 3, [[5], 4]]], 1, [[[4, [[6, [[[[10]]]]]]]], 2]]

To change it to the other interpretation, just change "depth - 1" to
"depth - 2".  And then, presumably, the array depthen is called on
shouldn't have any "1"s in it (although even they're handled
"gracefully" with the depthen method provided).

Eric

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