From: Michael Garriss <mgarriss@...>
Date: 2003-09-18T08:23:59+09:00
Subject: going over two interators

I often find that I need to go over two enumerables in parallel.  I have 
used a little method called 'both' for this:

irb
arr1 = [1,2,3,4,5]
--> [1, 2, 3, 4, 5]
arr2 = [6,7,8,9,10]
--> [6, 7, 8, 9, 10]
def both( enum1, enum2 )
  enumC = enum2.dup
  enum1.each do |e1|
    yield e1, enumC.shift
  end
end
--> nil
both( arr1, arr2 ) do |a,b|
  puts "#{a} : #{b}"
end
1 : 6
2 : 7
3 : 8
4 : 9
5 : 10
--> [1, 2, 3, 4, 5]


It assumes that enum1 is at least at big as enum2.

Is there a way someone can think of that's more efficient then this?  
Namely getting rid of the 'dup'.  Or maybe I'm missing some rubyism that 
would make this easier.

TIA,
Michael