;;; objects.lsp — record types, closures as objects, hash tables ;;; Run: python3 uncommonlisp.py examples/objects.lsp ;; Record types with inheritance (define-record-type (make-point x y) point? (x point-x) (y point-y)) (define-record-type (inherit ) (make-point3d x y z) point3d? (x point3d-x) (y point3d-y) (z point3d-z)) (define p (make-point 3 4)) (define p3 (make-point3d 1 2 3)) (display "point: ") (display (point-x p)) (display ",") (display (point-y p)) (newline) (display "point3d: ") (display (point3d-x p3)) (display ",") (display (point3d-y p3)) (display ",") (display (point3d-z p3)) (newline) (display "point3d is point? ") (display (point? p3)) (newline) ;; Closure-based counter (define (make-counter) (let ((n 0)) (lambda (msg . args) (cond ((eq? msg 'inc) (set! n (+ n 1)) n) ((eq? msg 'dec) (set! n (- n 1)) n) ((eq? msg 'get) n) ((eq? msg 'reset) (set! n 0) n) (else (error "unknown message" msg)))))) (define c (make-counter)) (c 'inc) (c 'inc) (c 'inc) (display "Counter after 3 increments: ") (display (c 'get)) (newline) (c 'dec) (display "Counter after decrement: ") (display (c 'get)) (newline) ;; Hash table (define ht (make-hash-table)) (hash-table-set! ht 'name "uncommonlisp") (hash-table-set! ht 'version "1.0.0") (hash-table-set! ht 'features '(bytecode continuations macros)) (display "Name: ") (display (hash-table-ref ht 'name)) (newline) (display "Features: ") (display (hash-table-ref ht 'features)) (newline)