;;; allergies.el --- Allergies Exercise (exercism)

;;; Commentary:

;;; Code:

(require 'seq)

(setq allergens
      '(eggs
        peanuts
        shellfish
        strawberries
        tomatoes
        chocolate
        pollen
        cats))

(defun allergen-list (n)
  (let* ((index 0)
         (pred (lambda (item)
                 (let ((r (< 0 (logand (ash 1 index) n))))
                   (setq index (1+ index))
                   (when r item)))))
    (mapcar 'symbol-name
            (seq-filter pred allergens))))

(defun allergic-to-p (n item)
  (seq-contains-p (allergen-list n) item))

(provide 'allergies)
;;; allergies.el ends here