The Parenthesis Matched?

 def parentmatched(inputstring)  
  while inputstring != nil  
   p inputstring  
   break if (inputstring.gsub!(/\(\)/, '')==nil)  
  end  
  if inputstring.eql?('')  
   puts "matched"  
  else  
   puts "non-matched"  
  end  
 end  

 parentmatched("((())(())()(()))()");