gistfile1.cl

(defclass rock ()())
(defclass paper ()())
(defclass scissors ()())

(defgeneric r-p-s (a b))

(defmethod r-p-s ((r rock) (p paper)) 'paper)
(defmethod r-p-s ((r rock) (s scissors)) 'rock)
(defmethod r-p-s ((p paper) (s scissors)) 'scissors)

gistfile2.txt

rock ← list clone()
paper ← list clone()
scissors ← list clone()

(rock, paper) compete ← routine
  result(`select { @isa paper })
(paper, scissors) compete ← routine
  result(`select { @isa scissors })
(scissors, rock) compete ← routine
  result(`select { @isa rock })


“--- Usage:”
john’s ← rock clone()
bob’s ← paper clone()

(john’s, bob’s) compete()