bull-or-cow.yml

---
- name: Reinitialise variables.
  set_fact:
    bulls: 0
    cows: 0
    not_bulls: []
    pegs_without_bulls: []
    guesses_without_bulls: []

- name: Check for bulls.
  set_fact:
    bulls: "{{ bulls|int + (guesses[n] == pegs[n])|ternary(1, 0) }}"
    not_bulls: "{{ not_bulls + (guesses[n] != pegs[n])|ternary([ n ], [])  }}"
  loop: "{{ guesses }}"
  loop_control:
    index_var: n
    label: peg

- name: Remove bulls from pegs and guesses.
  set_fact:
    guesses_without_bulls: "{{ not_bulls | map('extract', guesses) | list }}"
    pegs_without_bulls: "{{ not_bulls | map('extract', pegs) | list }}"

- name: Check for cows.
  include_tasks: cow.yml
  loop: "{{ guesses_without_bulls }}"
  loop_control:
    index_var: n
    loop_var: guess
    label: peg