From: Asfand Yar Qazi <ay1204@...2s.com>
Date: 2005-02-18T06:04:53+09:00
Subject: Re: Evaluating a string of Ruby code within an anonymous module:   done correctly?

Joel VanderWerf wrote:
> Joel VanderWerf wrote:
> 
>> Here's an even simpler way, just wrapping the code in a proc, which 
>> may be suitable for small snippets of code:
>>
>> def eval_string(s, *args_to_pass)
>>     pr = eval("proc do |*args| #{s.to_str} end")
>>     pr[*args_to_pass]
>> end
>>
>> eval_string(<<EOL, [1, 2, 3, 4, 5])
>>   b = args.collect {|i| i*3}
>>   c = b.join("||")
>>   puts(c)
>> EOL
>>
>> Warning: the binding of the "pr" local variable and the two arg 
>> variables is still in effect wthin the proc, so this may not be 
>> suitable. Or you could use very obscure names and hope.
> 
> 
> Just realized how to fix that:
> 
> def empty_binding
>   binding
> end
> 
> def eval_string(s, *args_to_pass)
>     pr = eval("proc do |*args| #{s.to_str} end", empty_binding)
>     pr[*args_to_pass]
> end
> 
> eval_string(<<EOL, [1, 2, 3, 4, 5])
>   b = args.collect {|i| i*3}
>   c = b.join("||")
>   puts(c)
>   #p pr #<-- now this fails
> EOL
> 
> 

I think I like this method best.  very nice!

Thanks