fooxy_wat.rb

class Foo
  class XY
    def initialize x, y
      @x, @y = x, y
    end
    attr :x, :y

    def limit *args
      [x, y].max
    end
  end

  def initialize *args
    case
    when args.count == 1 && args[0].is_a?(Fixnum)
      x, y, z = resolve(args[0]) 
    when args.count == 3 
      x, y, z = args
    end

    @xy = XY.new(x, y)

    raise ArgumentError, 'z cannot be converted to an integer' unless z.respond_to?(:to_i)
    raise 'x does not exist' unless (1..@xy.limit).cover? z.to_i

    @number = z.to_i
  end
end

begin
  Foo.new
rescue => error
  puts "RESCUING from: #{error.class}::#{error.message}"
  binding.pry
end