From: Tom Werner <tom@...>
Date: 2006-07-29T04:42:25+09:00
Subject: Re: What to use binding for?

Gene Tani wrote:
> Daniel N wrote:
>   
>> Hi everyone,
>>
>> There was a post a couple of days ago that included a call to binding
>>
>> I was interested in this and went to look up the binding docs.  All good, it
>> seems simple enough, but I can't think of how to use it.
>>
>> Could anyone provide a simple explaination/code of an example of how it
>> might be used.
>>
>>     
> Google say:
>
> http://extensions.rubyforge.org/rdoc/classes/Binding.html
> http://groups.google.com/group/comp.lang.ruby/browse_frm/thread/1d08d0cdb3b53d11
>
> http://onestepback.org/index.cgi/Tech/Ruby/RubyBindings.rdoc/style/print
>   

Looking at Jim Weirich's article on writing a local variable swap method 
using binding, I couldn't help but think that the following would reduce 
code size, complexity, and call keystrokes in the final embodiment of 
the method:

def swap(a, b, bind)
    eval "#{a}, #{b} = #{b}, #{a}", bind
end

a = Object.new     #=> #<Object:0x2c64540>
b = Object.new     #=> #<Object:0x2c617c8>

swap(:a, :b, binding)

a     #=> #<Object:0x2c617c8>
b     #=> #<Object:0x2c64540>

Not that I have any delusions about this pedagogical method having any 
relevance in the real world, but there it is just the same.

Tom

-- 
Tom Werner
Helmets to Hardhats
Software Developer
tom@helmetstohardhats.org
www.helmetstohardhats.org