From: "David A. Black" <dblack@...>
Date: 2008-08-15T08:59:28+09:00
Subject: Re: tricky hash initialization

I should add: the same-variable-name version works in Ruby 1.9.


David

On Fri, 15 Aug 2008, David A. Black wrote:

> Hi --
>
> On Fri, 15 Aug 2008, Ray Pereda wrote:
>
>> Sebastian Hungerecker wrote:
>>> Hash.new {|h,k| h[k] = Hash.new(&h.default_proc)}
>> 
>> Thanks for the attempt.  Seems on the right track but not quite.
>> 
>>>> h = Hash.new {|h,k| h[k] = Hash.new(&h.default_proc)}
>> => {}
>>>> h["a"]["b"]["c"]
>> => {}
>>>> h
>> => {"c"=>{}}
>> 
>> After h["a"]["b"]["c"]
>> what needs to happen is h is equal to
>> {"a"=>{"b"=>{"c"=>{}}}}
>
> I think it's a variable clobbering issue. Try this:
>
> hash = Hash.new {|h,k| h[k] = Hash.new(&h.default_proc) }
>
>
> David
>
> -- 
> Rails training from David A. Black and Ruby Power and Light:
> *  Advancing With Rails    August 18-21    Edison, NJ
> * Co-taught by D.A. Black and Erik Kastner
> See http://www.rubypal.com for details and updates!
>

-- 
Rails training from David A. Black and Ruby Power and Light:
  *  Advancing With Rails    August 18-21    Edison, NJ
  * Co-taught by D.A. Black and Erik Kastner
See http://www.rubypal.com for details and updates!