dkubb/axiom

# encoding: utf-8

module Axiom
  class Relation

    # A class that represents a base relation
    class Base < Relation
      include Equalizer.new(:header, :to_set, :name)

      # The base relation name
      #
      # @example
      #   name = base.name
      #
      # @return [Symbol]
      #
      # @api public
      attr_reader :name

      # Initialize a base relation
      #
      # @param [#to_sym] name
      #   the relation name
      # @param [Header, #to_ary] header
      #   the relation header
      # @param [Enumerable] tuples
      #   the relation tuples
      #
      # @return [undefined]
      #
      # @api private
      def initialize(name, header, tuples = Empty::ZERO_TUPLE)
        super(header, tuples)
        @name = name.to_sym
      end

      # Compare the base relation with other relation for equivalency
      #
      # @example
      #   base == other  # => true or false
      #
      # @param [Relation] other
      #   the other relation to compare with
      #
      # @return [Boolean]
      #
      # @api public
      def ==(other)
        super && (!other.respond_to?(:name) || name == other.name)
      end

    end # class Base
  end # class Relation
end # module Axiom