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author | Bryan Newbold <bnewbold@robocracy.org> | 2017-02-20 00:05:25 -0800 |
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committer | Bryan Newbold <bnewbold@robocracy.org> | 2017-02-20 00:05:25 -0800 |
commit | 8ffbc2df0fde83082610149d24e594c1cd879f4a (patch) | |
tree | a2be9aad5101c5e450ad141d15c514bc9c2a2963 /object.scm | |
download | slib-8ffbc2df0fde83082610149d24e594c1cd879f4a.tar.gz slib-8ffbc2df0fde83082610149d24e594c1cd879f4a.zip |
Import Upstream version 2a6upstream/2a6
Diffstat (limited to 'object.scm')
-rw-r--r-- | object.scm | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/object.scm b/object.scm new file mode 100644 index 0000000..4ba28fb --- /dev/null +++ b/object.scm @@ -0,0 +1,97 @@ +;;; "object.scm" Macroless Object System +;;;From: whumeniu@datap.ca (Wade Humeniuk) + +;;;Date: February 15, 1994 + +;; Object Construction: +;; 0 1 2 3 4 +;; #(object-tag get-method make-method! unmake-method! get-all-methods) + +(define object:tag "object") + +;;; This might be better done using COMLIST:DELETE-IF. +(define (object:removeq obj alist) + (if (null? alist) + alist + (if (eq? (caar alist) obj) + (cdr alist) + (cons (car alist) (object:removeq obj (cdr alist)))))) + +(define (get-all-methods obj) + (if (object? obj) + ((vector-ref obj 4)) + (slib:error "Cannot get methods on non-object: " obj))) + +(define (object? obj) + (and (vector? obj) + (eq? object:tag (vector-ref obj 0)))) + +(define (make-method! obj generic-method method) + (if (object? obj) + (if (procedure? method) + (begin + ((vector-ref obj 2) generic-method method) + method) + (slib:error "Method must be a procedure: " method)) + (slib:error "Cannot make method on non-object: " obj))) + +(define (get-method obj generic-method) + (if (object? obj) + ((vector-ref obj 1) generic-method) + (slib:error "Cannot get method on non-object: " obj))) + +(define (unmake-method! obj generic-method) + (if (object? obj) + ((vector-ref obj 3) generic-method) + (slib:error "Cannot unmake method on non-object: " obj))) + +(define (make-predicate! obj generic-predicate) + (if (object? obj) + ((vector-ref obj 2) generic-predicate (lambda (self) #t)) + (slib:error "Cannot make predicate on non-object: " obj))) + +(define (make-generic-method . exception-procedure) + (define generic-method + (lambda (obj . operands) + (if (object? obj) + (let ((object-method ((vector-ref obj 1) generic-method))) + (if object-method + (apply object-method (cons obj operands)) + (slib:error "Method not supported: " obj))) + (apply exception-procedure (cons obj operands))))) + + (if (not (null? exception-procedure)) + (if (procedure? (car exception-procedure)) + (set! exception-procedure (car exception-procedure)) + (slib:error "Exception Handler Not Procedure:")) + (set! exception-procedure + (lambda (obj . params) + (slib:error "Operation not supported: " obj)))) + generic-method) + +(define (make-generic-predicate) + (define generic-predicate + (lambda (obj) + (if (object? obj) + (if ((vector-ref obj 1) generic-predicate) + #t + #f) + #f))) + generic-predicate) + +(define (make-object . ancestors) + (define method-list + (apply append (map (lambda (obj) (get-all-methods obj)) ancestors))) + (define (make-method! generic-method method) + (set! method-list (cons (cons generic-method method) method-list)) + method) + (define (unmake-method! generic-method) + (set! method-list (object:removeq generic-method method-list)) + #t) + (define (all-methods) method-list) + (define (get-method generic-method) + (let ((method-def (assq generic-method method-list))) + (if method-def (cdr method-def) #f))) + (vector object:tag get-method make-method! unmake-method! all-methods)) + + |