(define (R) (reload-module (current-module)))
-(define gc-size 20)
-(define the-cars (make-vector gc-size))
-(define the-cdrs (make-vector gc-size))
+(define gc-size 10)
+(define the-cars (make-vector gc-size '(* . *)))
+(define the-cdrs (make-vector gc-size '(* . *)))
(define gc-free 0)
(define (show-gc)
- (display "free:") (display gc-free) (newline)
- (display "cars:") (display the-cars) (newline))
+ (display "\nfree:") (display gc-free) (newline)
+ (display "cars:") (display the-cars) (newline)
+ (display "cdrs:") (display the-cdrs) (newline))
(show-gc)
+(define cell-type car)
+(define cell-index cdr)
+
(define (make-cell type . x)
- (cons type (if (pair? x) (car x))))
+ (cons type (if (pair? x) (cell-type x) '*)))
(define (gc-alloc)
((lambda (index)
(set! gc-free (+ gc-free 1))
- ;;(cons 'cell index)
- (make-cell *unspecified* index)
- )
+ (make-cell '* index))
gc-free))
(define (gc-make-number x)
((lambda (cell)
- (vector-set! the-cars (cdr cell) (make-cell 'number x))
+ (vector-set! the-cars (cell-index cell) (make-cell 'n x))
cell)
(gc-alloc)))
-(display (gc-make-number 3)) (newline)
+(define (gc-cons x y)
+ ((lambda (cell)
+ ((lambda (pair)
+ (vector-set! the-cars (cell-index cell) pair)
+ (vector-set! the-cars (cell-index cell) (make-cell 'p (cell-index x)))
+ (vector-set! the-cdrs (cell-index cell) (make-cell 'p (cell-index y)))
+ pair)
+ (make-cell 'p (cell-index cell))))
+ (gc-alloc)))
+
+(define (gc-car c)
+ (if (eq? (cell-type c) 'p) (vector-ref the-cars
+ (cell-index
+ (vector-ref the-cars (cell-index c))))))
+
+(define (gc-cdr c)
+ (if (eq? (cell-type c) 'p) (vector-ref the-cars
+ (cell-index
+ (vector-ref the-cdrs (cell-index c))))))
+
+(display (gc-make-number 7)) (newline)
+(define first (gc-make-number 8)) (newline)
+(show-gc)
+(define second (gc-make-number 9)) (newline)
(show-gc)
+(define pair (gc-cons first second))
+(show-gc)
+(display "pair:") (display pair) (newline)
+
+(display "car:") (display (gc-car pair)) (newline)
+(display "cdr:") (display (gc-cdr pair)) (newline)