From: dblack@...
Date: 2006-03-07T07:28:57+09:00
Subject: Re: What is the best way to iterate through two containers of the same length?

Hi --

On Tue, 7 Mar 2006, William James wrote:

> Mark  Watson wrote:
>> If I have two containers c1 and c2 of the same length, what is the
>> proper "Ruby way" to do this:
>>
>> c1.length.times {|i|
>>   # access c1[i], c2[i]
>> }
>>
>> I like that Ruby container classes provide their own iterators, but
>> what I would like to have is something like:
>>
>> (c1,c2).each {|x1,x2| .... }
>>
>> I thought of writing my own iterator class so that I could do something
>> like:
>>
>> Iterator.new(c1,c2).each {|x1,x2| .... }
>>
>> but that looks clumsy and inefficient.
>>
>> I am transitioning to using mostly Ruby (moving away from Java, Lisp,
>> and Smalltalk) and I would like to use the proper Ruby idioms.
>
> foo = %w(x y z) ; bar = [2,4,6]
> [foo, bar].transpose.each{|a,b| print a, b, $/ }
>  --->
> x2
> y4
> z6

I don't think $/ is very idiomatic.  See the ToDo file in the source;
it includes:

* discourage use of symbol variables (e.g. $/, etc.) in manual

:-)


David

-- 
David A. Black (dblack@wobblini.net)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

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