module Ast

  class ArrayExpression < Expression
    attr_reader :values
    def attributes
      [:values]
    end
    def initialize vals
      @values = vals
    end
    def to_s
      values.to_s
    end
  end

  class AssociationExpression < Expression
    attr_reader :key , :value

    def initialize key , value
      @key , @value = key , value
    end

    def attributes
      [:key , :value]
    end

    def to_s
      key.inspect + " , " + value.inspect
    end

  end
  class HashExpression < ArrayExpression
  end
end