RCR 235: anArray.rekursive_index

Add a new instance method to Array to allow a more powerfull way to search for a key.

It isn't currently trivially possible to search for a key in an array that contains subarrays.

 Add a new instance method rekursive_index to the Array class.

Interface:

   rekursive_index(key) -> anArray<br>

This method would return an array, that contains the indexes of the arrays necessary to reach the key.
example:
a=[9, 7, 5, [1, 2], 3]
a.rekursive_index(1) -> [3, 0]
a.rekursive_index(7) -> [1]
a.rekursive_index(0) -> nil
a.rekursive_index([1,2]) -> [3]

It isn't possible to just reimplement the index method to achieve this, because rekursive.index will return an Array with one element, where index would just return the element. And for consistencies sake, it has to be that way.

class Array

  def rekursive_index(key)
    rIndex=nil
    each_with_index do |element, index|
      if element==key
        rIndex=[index]
        break
      end
      if element.kind_of?(Array)
        rIndex=element.rekursive_index(key)
        if rIndex
          rIndex=[index]+rIndex
          break
        end
      end
    end
    rIndex
  end

end