Lisp method process

Question

Can you help me? I don't understand this code's part

(lambda (this &rest args) ;; Adds The THIS Argument
  (apply (get-slot this 
           method-name)
     (append (list this)
         args))))

Rewrite Method

;;;; This Function Add The Argument This To The Method
(defun rewrite-method (method-spec)
   (list 'lambda (append (list 'this) ;; Add The THIS Argument
               (second method-spec))
    (cons 'progn (rest (rest method-spec))))) ;; Eval All The Method's Body




;;;; Method-Process
;;;; Function Used To Process Methods, Rewriting Them To
;;;; Lisp Functions 
(defun method-process (method-name method-spec)
  (setf (fdefinition method-name) ;; Associate The Lambda To The Method's Name
    (lambda (this &rest args) ;; Adds The THIS Argument
      (apply (get-slot this 
               method-name)
         (append (list this)
             args))))   
  (eval (rewrite-method method-spec))) ;; Returned Value

It would be nice it you could format the code. It's impossible to read it. — JustAnotherCurious
– JustAnotherCurious, Commented Jan 23, 2015 at 11:20

Rainer Joswig · Accepted Answer · 2015-01-23 12:23:25Z

3

It takes an arglist (foo bar baz) and adds a this parameter: (this foo bar baz).

Thus a function (lambda (foo bar baz) ...) then is (lambda (this foo bar baz) ...).

This is useful in implementation of single-inheritance object-oriented languages where the first argument is the object which receives a message and other arguments. Here the parameter this is the receiving object.

Note that the call to APPLY could be improved. (apply function (append (list this) args)) is just (apply function this args).

answered Jan 23, 2015 at 12:23

Rainer Joswig

140k11 gold badges230 silver badges357 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Lisp method process

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related