From: Logan Capaldo <logancapaldo@...>
Date: 2006-08-06T04:27:38+09:00
Subject: Re: Iterating over an array n element at a time


On Aug 5, 2006, at 3:20 PM, Trans wrote:

>
> Kim Pedersen wrote:
>> Is there an elegant way to iterate over an array n elements at a  
>> time?
>> e.g. something like...
>>
>> a = [1,1,1,2,2,2,3,3,3]
>>
>> a.each(3) do |x,y,z|
>>     print x,y,z,"\n"
>> end
>>
>> prints...
>> 111
>> 222
>> 333
>>
>> //kim
>
> enumerator is probably better since it is built-in, but...
>
>   require 'facet/enumerable/each_by'
>   a = [1,1,1,2,2,2,3,3,3]
>   a.each_by(3) { |x,y,z| print x,y,z,"\n" }
>   111
>   222
>   333
>
> But why not have Ruby fill those arguments out automatically? This
> already does:
>
>   a = [[1,1,1],[2,2,2],[3,3,3]]
>   a.each { |x,y,z| print x,y,z,"\n" }
>
> So couldn't some "slurping" indicator be used?
>
>   a = [1,1,1,2,2,2,3,3,3]
>   a.each { |(x,y,z)| print x,y,z,"\n" }
>
> Or something.
>
( ) already have meaning in block arguments though
e.g.:

{ :a => 1, :b => 2 }.inject({}) { |h, (k, v)| h[k] = v + 1; h }
#=> {:b=>3, :a=>2}

> T.
>
>