Peñá, Botp wrote:

>On their case, they like the @@ solution, except that they want the @@
>removed. I thought i was so close here. I was looking for something like
>var_missing or whatever and do what like debuggers do in reflection to get
>into the local var...
>
>I guess i made a mistake in that i was trying to _lure_ them rather than
>educate them. 
>  
>
Good observation. Unfortunately, in order to get them over, it sounds 
like you'd have to teach them good programming practices, as Ruby's 
syntax/semantics encourage good practices and discourages bad ones. For 
example, in the problem you provided, the best solution (ignoring other 
factors such as deadlines) would have been to refactor the code to pass 
'foo' as a parameter (in that case, no @ or $), or to objectize the 
code, and make it an instance variable of some object (a single @).

This works just fine, for example, and looks quite pretty to me:

#prints each member. takes any object that responds to #each,
#and whose elements respond to #inspect.
def print_each(arr)
    arr.each {|f| p f}
end

letters=["a","b","c"]
print_each letters
__END__

But I could be alone.

This is with an instance variable, but it's overkill in this example, since we're not modifying foo:

#prints each member. constructor takes any object that responds to #each,
#and whose elements respond to #inspect.
class EachPrinter
  def initialize(arr)
    @arr = arr
  end
  def print
    @arr.each {|f| p f}
  end
end

letters=%w{a b c}
EachPrinter.new(letters).print
__END__

Here's another way possible in Ruby:

class Enumerable
  #prints each element using Kernel#p
  def p_each
    self.each {|f| p f}
  end
end

letters=%w{a b c}
letters.p_each #possible since letters.is_a? Enumerable

But decide for yourself whether you want to pollute the Enumerable method namespace. Since this is a general functionality that has nothing specifically to do with your problem domain, I'd opt for throwing it in.

Are any of these solutions valid for you? Is there something I'm missing?

Devin