99 lines
2.6 KiB
Scheme
99 lines
2.6 KiB
Scheme
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(define-module (guile gc))
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(define (R) (reload-module (current-module)))
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(define gc-size 10)
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(define the-cars (make-vector gc-size '(* . *)))
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(define the-cdrs (make-vector gc-size '(* . *)))
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(define gc-free 0)
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(define (show-gc)
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(display "\nfree:") (display gc-free) (newline)
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(display "cars:") (display the-cars) (newline)
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(display "cdrs:") (display the-cdrs) (newline))
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(show-gc)
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(define (cell-type c) (car (gc-cell c)))
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(define cell-index cdr)
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(define (cell-value c) (cdr (gc-cell c)))
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(define (make-cell type . x)
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(cons type (if (pair? x) (car x) '*)))
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(define (gc-alloc)
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((lambda (index)
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(set! gc-free (+ gc-free 1))
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(make-cell '* index))
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gc-free))
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(define (make-number x)
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((lambda (cell)
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(vector-set! the-cars (cell-index cell) (make-cell 'n x))
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cell)
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(gc-alloc)))
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(define (make-symbol x)
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((lambda (cell)
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(vector-set! the-cars (cell-index cell) (make-cell 's x))
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cell)
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(gc-alloc)))
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(define (gc-cons x y)
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((lambda (cell)
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(vector-set! the-cars (cell-index cell) (make-cell 'p (cell-index x)))
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(vector-set! the-cdrs (cell-index cell) y)
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cell)
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(gc-alloc)))
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(define (gc-car c)
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(vector-ref the-cars (cell-index c)))
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(define (gc-cdr c)
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(vector-ref the-cdrs (cell-index c)))
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(define gc-cell gc-car)
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(define (gc-pair? c)
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(eq? (cell-type c) 'p))
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(define (gc-set-car! c x)
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(if (gc-pair? c) (vector-set! the-cars (cell-index c) x)))
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(define (gc-set-cdr! c x)
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(if (gc-pair? c) (vector-set! the-cdrs (cell-index c) x)))
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(display "number 7=") (display (make-number 7)) (newline)
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(define first (make-number 8)) (newline)
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(show-gc)
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(define second (make-number 9)) (newline)
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(show-gc)
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(define pair (gc-cons first second))
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(show-gc)
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(display "pair:") (display pair) (newline)
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(display "car:") (display (gc-car pair)) (newline)
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(display "cdr:") (display (gc-cdr pair)) (newline)
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(define (gc-null? x) (eq? (car x) 'e))
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(define gc-nil (make-cell 'e 0))
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(display "nil: ") (display gc-nil) (newline)
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(define (gc-list . rest)
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(if (null? rest) gc-nil
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(gc-cons (car rest) (apply gc-list (cdr rest)))))
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(define lst (gc-list (make-symbol 'a) (make-symbol 'b) (make-symbol 'c)))
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(display "lst:") (display lst) (newline)
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(show-gc)
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(define (gc-display x . cont?)
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(if (gc-pair? x) (begin (if (null? cont?) (display "("))
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(gc-display (gc-car x))
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(if (gc-pair? (gc-cdr x)) (display " "))
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(gc-display (gc-cdr x) #t)
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(if (null? cont?) (display ")")))
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(if (gc-null? x) (if (not cont?) (display "()"))
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(display (cell-value x)))))
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(display "gc-display lst=") (gc-display lst) (newline)
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(show-gc)
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