From: Tim Pease <tim.pease@...>
Date: 2009-01-31T05:19:33+09:00
Subject: Re: binding in ruby1.9


On Jan 30, 2009, at 12:56 PM, Charles Oliver Nutter wrote:

> Tim Pease wrote:
>> Could someone explain why this code does not work in ruby1.9 and  
>> possibly provide a workaround. The end goal is to be able to pass a  
>> binding to an ERb result method that provides a limited set of  
>> variables to the ERb template evaluation.
>> > cat a.rb
>> obj = Object.new
>> class << obj
>>  attr_accessor :foo
>> end
>> obj.foo = 'the foo method'
>> eval "puts foo", obj.__send__(:binding)
>
> What an unusual feature to keep coming up.
>
> The contract of binding is that it returns a reification of the  
> caller's binding. Under 1.8, however, the behavior acted a bit  
> differently, using the "self" that binding was actually called  
> against. 1.9 has largely remedied this by always returning the  
> binding of the caller, even if you __send__(:binding) to another  
> object.
>

Okay, that explanation makes sense. My new implementation (following  
along with the Kernel docs)

 > cat a.rb
obj = Object.new
class << obj
   attr_accessor :foo
   def get_binding() binding; end
end
obj.foo = 'the foo method'
eval "puts foo", obj.get_binding

 > ruby1.9 a.rb
the foo method


Thanks for the insight.

Blessings,
TwP