From: "Skye Shaw!@#$" <skye.shaw@...>
Date: 2007-07-24T12:45:06+09:00
Subject: Re: Newbie Question: irb

On Jul 23, 3:32 pm, Mike Halloran <mike.hallo...@gmail.com> wrote:
> How can I access the previous result of an evaluation in the irb
> debugger.

You must enable EVAL_HISTORY. Once you do so, you can access the
return value of the last expression via "_".
See http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/102888

The token "__" (2 underscores) will give you access to the currrent
IRB::History object. Unfortunatley, it's not a full fledged array.

irb(main):001:0> 1+1
=> 2
irb(main):002:0> 2+2
=> 4
irb(main):003:0> __[-2]+1
=> 3
irb(main):004:0> __[-1]*3
=> 9