bird and dog

categorical x^n in scala

  /**
   * Builds a degree object (x^n) for a given object.
   *
   * @param x the source object
   * @param n degree to which to raise object x
   * @return x^n and its projections to x
   * @TODO(vpatryshev): write good unitests
   */
  def degree(x: O, n: Int): Option[(O, List[A])] = {
    require(n >= 0, "Degree should be positive, we have " + n)
    if (n == 0) {
      terminal map(x => (x, List[A]()))
    }
    else {
      degree(x, n - 1) flatMap (
        value => {
          val (x_n_1, previous_projections) = value
          product(x, x_n_1) flatMap(
            xn => {
              val (p1, p_n_1) = xn
              val projections = p1 :: previous_projections map (m(p_n_1, _)) 
              Some((d0(p1), projections))
            }
          )
        }
      )
    }
  }

Seems like I am still learning to write code.

85 and kicking

video (10x alzheimer)