From: Gunther Diemant <g.diemant@...>
Date: 2011-03-16T05:24:00+09:00
Subject: Re: Array#rotate fails in a simple program

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If upgrading isn't an option you could use each_slice from the enumerator
stdlib.

require 'enumerator'

[2,3,5,7,11,13,17].each_slice(2) do |pair|
  puts pair.join(',')
end

#output
2,3
5,7
11,13
17

2011/3/15 RichardOnRails <RichardDummyMailbox58407@uscomputergurus.com>

> I'm runing Ruby 1.8.6 over WinXP-Pro/SP3
>
> I'm writing a program to illustrate prime numbers and Ruby programming
> for my teenage granddaughter.  Unfortunately, I've got a problem:
>
> On line 54, I've got the statement:
> $primes.rotate!(group_size)
>
> That results in the error:
> Adrienne01.rb:54: undefined method `rotate!' for [2, 3, 5, 7]:Array
> (NoMethodError)
>
> However, http://www.ruby-doc.org/core/ defines "ary.rotate!(cnt=1) -->
> ary"
> Also, "rotate" (without the bang) is defined in Ruby/core and fails in
> the same manner.
>
> I've posted the program and its output in http://www.pastie.org/1674687
>
> Is Array#rotate! only defined in a Ruby version later than mine?  Or
> is there something I'm missing here?
>
> Any guidance offered will be gratefully received.
>
> Best wishes,
> Richard
>
>

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