gistfile1.txt

# £1.54 discount on 3 or more Strawberries

grammar PricingRules

  rule discount
    amount / item
  end

  rule item
    "Fruit Tea" / "Coffee" / "Strawberries"
  end

  rule amount
    # Must match: http://www.rubular.com/regexes/9480
    ("free" / [\d+\.\d{2}|free|\d\dp]) {
      def eval
        (text_value == 'free' ? 0.00 : text_value.to_i)
      end
    }
  end
  
end