From: Peter Szinek <peter@...>
Date: 2006-10-17T18:20:45+09:00
Subject: Re: Array.new question

> a = (0..3).collect{[]} # => [[], [], [], []]
> a[0][0] = 1
> a # => [[1], [], [], []]

Thx!

>> 2) Is there an idiomatic way to do this (in a generic way, of course):
>>
>> some_func(
>> [1,2,3]
>> [4,5,6]
>> [7,8,9] )
>>
>> => [ [1,4,7], [2,5,8], [3,6,9] ]
> [1,2,3].zip([4,5,6],[7,8,9]) # => [[1,4,7], [2,5,8], [3,6,9]]

Sorry, I did not describe the scenario properly.
The thing is that I am iterating over an array (of arrays)
and I don't have the all the arrays at once (the inner arrays are 
generated on the fly). Let me illustrate it:

input = [ [1,2,3], [4,5,6], [7,8,9] ]
result = []

input.each { |i| do_something_with(result, i) }

and the result should be

[ [1,4,7], [2,5,8], [3,6,9] ]

The question sounds: how is do_something_with implemented?
I have already implemented it but I don't think so it's a state-of-the 
art solution ;)

Thanks,
Peter
http://www.rubyrailways.com