How to balance parenthesis recursively

Question

I\'m working on some code to balance parenthesis, this question proved most useful for the algorithm.

I implemented it in my first language (PHP) but I\'m learning Scala

Answer 1

  val myStack = new Stack[Char]

  def balance(chars: List[Char]): Boolean = {
    def processParanthesis(x: Char, a: List[Char]): Stack[Char] = {
      if (x == '(') {
        myStack.push('(');
      } else if (x == ')') {
        if (!myStack.empty())
          myStack.pop();
        else
          myStack.push(')');
      }
      if (a.length == 0)
        return myStack;
      else
        return processParanthesis(a.head, a.tail);
    }
    return processParanthesis(chars.head, chars.tail).empty();
  }