From: Sammy Larbi <sam@...>
Date: 2007-09-20T21:28:15+09:00
Subject: Idiomatic Ruby for Array#extract / Range#length?

------=_Part_27336_30112547.1190291295390
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

During the monthly meeting of our code dojo, we were surprised by a couple
of things in Ruby, so I had a couple of questions I'd like to ask the
community:

1) Would it make sense to talk about a Range having a length, as in:

class Range
      def length
           self.end - self.begin
      end
end


2) What about a 2 dimensional slice (you want a submatrix, for example)?

def test_extract_submatrix
  assert_equal [[1,2,3],[4,5,6],[7,8,9]].extract_submatrix(1..2,1..2)
, [[5,6],[8,9]]
end

class Array
  def extract_submatrix(row_range, col_range)
    self[row_range].transpose[col_range].transpose
  end
end


3)  Are the better/more idiomatic ways to do these?

4) Excuse my ignorance, as I've yet to use Facets, but are these the type of
things it adds (and more)?  Are they already in there?

Thanks and kind regards,
Sam

------=_Part_27336_30112547.1190291295390--