From: matz@... (Yukihiro Matsumoto)
Date: 2000-12-09T23:48:01+09:00
Subject: [ruby-talk:6968] Re: parallel array traversal

Hi,

In message "[ruby-talk:6956] parallel array traversal"
    on 00/12/09, Raja S. <raja@cs.indiana.edu> writes:

|Is there a way to do a parallel traversal of a group of arrays in Ruby?
|Or more generally move a collection of index variables in lock-step?

Hmm.

|Python has come recently added the 'zip' facility.  Reasonable, but it also
|creates unnecessary garbage by creating an object that in most situations gets
|discarded once one is out of the loop.

IIRC, Python's zip creates [[a1, b1, c1], [a2, b2, c2],...] from
[a1,a2,...], [b1, b2,...] and [c1, c2,...].

How about something like

  [a1, a2, a3].zip do |x, y, z|
     ...
  end

which do not create unnecessary objects?  There might be better name
for this method.

							matz.