# File: alternation.rb

require_relative 'polyadic_expression' # Access the superclass

module Regex # This module is used as a namespace
  # Abstract class. A n-ary matching operator.
  # It succeeds when one child expression succeeds to match the subject text
  class Alternation < PolyadicExpression
    # Constructor.
    def initialize(*theChildren)
      super(theChildren)
    end

    protected

    # Conversion method re-definition.
    # Purpose: Return the String representation of the concatented expressions.
    def text_repr()
      result_children = children.map(&:to_str)
      result = '(?:' + result_children.join('|') + ')'

      return result
    end
  end # class
end # module

# End of file