lisp-syntax-transformer

[hello <kxn30 at po dot cwru dot edu>]

Hello,

(define-class <lisp-variable> ()
  (sym #:accessor sym #:init-keyword #:symbol)
  (var #:allocation #:virtual
       #:slot-ref (lambda (i) (%lisp-eval (sym i)))
       #:slot-set! (lambda (i v)
		     (%lisp-eval `(setq ,(sym i) ',v))
		     *unspecified*)
       #:accessor lisp-value))

(define-method (write (obj <lisp-variable>) port)
  (display "#<lisp-variable " port)
  (display (sym obj) port)
  (display ">" port))

(define user-full-name (make <lisp-variable> #:symbol 'user-full-name))

user-full-name              => #<lisp-variable user-full-name>
(lisp-value user-full-name) => #<foreign-object <emacs-string> 4047e070>


(define (transformer x)
  (let ((lisp-symbol? (lambda (o) (eq? (string-ref o 0) #\$)))
	(lisp-value (lambda (o) (list 'lisp-value
				      (string->symbol (substring o 1))))))
    (if (and (symbol? x) (lisp-symbol? x))
	(lisp-value x)
	(letrec ((trans! (lambda (x)
			   (cond ((pair? x)
				  (if (symbol? (car x))
				      (if (lisp-symbol? (car x))
					  (set-car! x (lisp-value (car x))))
				      (trans! (car x)))
				  (trans! (cdr x)))))))
	  (trans! x)
	  x))))

(transformer '$foo)            => (lisp-value foo)
(transformer '(set! $foo #t))  => (set! (lisp-value foo) #t)

(use-syntax transformer)

(set! $user-full-name "hello")
$user-full-name                 => #<foreign-object <emacs-string> 4042a298>
(%lisp->scheme $user-full-name) => "hello"


Any comment?

-- Kei