;; prisond.scm: iterated prisoner's dilemma simulation ;; by matt ;; this program is in the public domain (define strategies '()) (define add-strategy (lambda (x y) (set! strategies (cons (cons x y) strategies)))) (define angel (lambda (x y) 0)) (define devil (lambda (x y) 1)) (define tat-for-tit (lambda (x y) (if (null? x) 1 (if (= (car x) 0) 1 0)))) (define tit-for-tat (lambda (x y) (if (null? x) 0 (car x)))) (define time-machine (lambda (x y) (if (> 3 (length x)) 0 (caddr x)))) (define random-choice (lambda (x y) (random 2))) (define grudger (lambda (x y) (if (memq 1 x) 1 0))) (define angry-tit-for-tat (lambda (x y) (if (null? x) 1 (car x)))) (define apl (lambda (x y) (if (null? x) 1 (if (= ( car y) 0) 1 0)))) (load-shared-object "/usr/lib/libc.so.6") (define fork (foreign-procedure #f "fork" () unsigned)) ;(define waitpid (foreign-procedure #f "waitpid" (unsigned uptr unsigned) integer-32)) (define wait (foreign-procedure #f "wait" (uptr) integer-32)) (define mmap (foreign-procedure #f "mmap" (uptr unsigned integer-32 integer-32 integer-32 unsigned) uptr)) (define shmem (mmap 0 8 3 33 -1 0)) (define tt-run (lambda (pid) (if (> pid 0) (begin (wait 0) (foreign-ref 'integer-64 shmem 0) ) 'temporary-timeline))) (define tt-send (lambda (x) (begin (foreign-set! 'integer-64 shmem 0 3) (exit)))) (define tt-recv (lambda () (tt-run (fork)))) (set! strategized 0) (set! running 0) (define apiomemetics (lambda (x y) (if (null? x) (if (= running 0) (let ((ttr (tt-recv))) (if (eq? ttr 'temporary-timeline) (begin (set! running 1) (display "temporary TL\n") 0) (begin (set! running 1) (display "primary TL, got result ") (display ttr) (newline) (set! strategized 1) 0))) 0) (if (= (length x) 99) (if (= strategized 0) (begin (display "end of game, reversing\n") (tt-send 3) ) (begin (set! running 0) (display "end of game in primary\n") 0 )) (car x))))) (define prisond (lambda (x y) (if (= x y) (if (= x 1) '(-2 -2) '(-1 -1)) (if (= x 1) '(0 -3) '(-3 0))))) (define iter-prisond (lambda (x y z) (define scores '(0 0)) (define moves-x '()) (define moves-y '()) (define current-moves '()) (define helper (lambda (x y z) (if (= z 0) scores (begin (set! current-moves (list (x moves-x moves-y) (y moves-y moves-x))) (set! moves-x (cons (cadr current-moves) moves-x)) (set! moves-y (cons (car current-moves) moves-y)) (set! scores (map + scores (prisond (car current-moves) (cadr current-moves)))) (helper x y (- z 1)))))) (helper x y z))) (define get-strategy-scores (lambda (x) (define score 0) (define helper (lambda (y) (if (eqv? (car x) (car y)) 0 (set! score (+ score (car (iter-prisond (cdr x) (cdr y) 100))))))) (map helper strategies) score)) (define get-all-scores (lambda () (define helper (lambda (x) (write (list (car x) (get-strategy-scores x))) (newline))) (map helper strategies))) (add-strategy 'angel angel) (add-strategy 'devil devil) (add-strategy 'tit-for-tat tit-for-tat) (add-strategy 'tat-for-tit tat-for-tit) (add-strategy 'time-machine time-machine) (add-strategy 'random-choice random-choice) (add-strategy 'grudger grudger) (add-strategy 'angry-tit-for-tat angry-tit-for-tat) (add-strategy 'apl apl) (add-strategy 'apiomemetics apiomemetics) (random-seed (time-second (current-time))) (get-all-scores) (exit)