From: dagbrown@... (Dave Brown)
Date: 2003-12-06T02:52:03+09:00
Subject: Re: Dumb question to which I ought to know the answer by now

In article <20031205141744.GA18597@mulan.thereeds.org>,
Mark J. Reed <markjreed@mail.com> wrote:
: On Fri, Dec 05, 2003 at 11:03:07PM +0900, Austin Ziegler wrote:
: > What you can do is:
: > 
: > 	hash = nil; keys.zip(value) { |k, v| (hash ||= {})[k] = v }
: 
: Now that is handy.  I assume there's a historical reason for the
: name 'zip'?  Because I would never have thought it meant 
: "iterate in parallel with". :)

That's not quite what zip does.

The reason it's called "zip" is that it's stolen directly from
Python, which has a function by that name which does just that.
It takes corresponding elements from two arrays and groups them
together:

    irb(main):001:0> [1,2,3,4].zip([5,6,7,8])
    => [[1, 5], [2, 6], [3, 7], [4, 8]]

Another thing you could use would be "transpose", which is a
more-general method to do similar things:

    irb(main):002:0> [[1,2,3,4],[5,6,7,8]].transpose
    => [[1, 5], [2, 6], [3, 7], [4, 8]]

--Dave