require 'arc-furnace/node'

module ArcFurnace
  class Source < Node
    extend Forwardable

    def prepare

    end

    # Advance this source by one, returning the row as a hash
    def row
      result = value
      advance
      result
    end

    # Is this source empty?
    def empty?

    end

    # The current value this source points at
    # This is generally the only method required to implement a source.
    def value

    end

    # Close the source
    def close

    end

    # Advance this source by one. #advance specifies no return value contract
    def advance

    end

  end
end