Balanced String?

gistfile1.rb

module BalancedString
  OPENERS = ['(','[','{']
  CLOSERS = [')',']','}']

  def self.matching_pair?(opener,closer)
    OPENERS.index(opener) == CLOSERS.index(closer)
  end

  def self.is_balanced?(string)
    mystack = Array.new

    string.each_char do |c|
      if OPENERS.include? c
        mystack.push c
      elsif CLOSERS.include? c
        return false unless matching_pair? mystack.pop, c
      end
    end
    mystack.size == 0 ? true : false
  end
end

t       = ['{}','{[]}','{5}','a']
f       = ['([)]','{[]']
strings = t + f
strings.each { |s| puts "Is #{s} balanced? #{BalancedString.is_balanced?(s)}" }