From: Eero Saynatkari <eero.saynatkari@...>
Date: 2006-08-28T01:18:03+09:00
Subject: Re: Nuby with instance_eval question

Geoff Barnes wrote:
> Wondering why this works the way it does:
> 
>       1 class Klass
>       2
>       3  attr_accessor :attr1
>       4
>       5  def initialize (&block)
>       6          chum = "chum_in_Klass"
>       7          instance_eval(&block) # Why does instance_eval pick up 
> self.attr1 from Klass but not 'chum'??
>       8          eval_attr1
>       9  end
>      10  def eval_attr1
>      11          @ok = self.attr1.call
>      12  end
>      13 end
>      14
>      15 chum = "chum_in_main"
>      16
>      17 foo=Klass.new {
>      18         self.attr1 = proc { chum }
>      19 }

You are creating a closure here and, since 'chum' exists in
this scope (you would get an error otherwise), it is bound
here.

>      20
>      21 puts foo.inspect # -> foo.ok = "chum_in_main"
>      22
>      23 chum="chum_in_main_again"
>      24 foo.eval_attr1
>      25
>      26 puts foo.inspect # -> foo.ok = "chum_in_main_again"
> 
> <snip />
>
> Thanks


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