From: kapheine@... (Zachary P. Landau)
Date: 2003-07-24T04:47:32+09:00
Subject: Re: RegExp outermost ()

> s = 'a group ( stuff ( other )) (( hey ( you ) (there) ) stuff )'
> 
> magic_re = # ?
> s.scan(magic_re) { |match| puts match }
> 
> output:
> ( stuff ( other ))
> (( hey ( you ) (there) ) stuff )

I think the easiest way to do this is with a stack. You push when you
see a ( and pop when you see a ). The first entry on the stack is the
start of a parens. Keep pushing and popping (kinky) until the stack is
empty again. That would be the end of one group. Rinse and repeat.