simple-pandoric.scm

pandtest.scm

(define-syntax pandoric-let
  (syntax-rules ()
     ((_ ((var val) ...) body ... retval)
       (let ((this #f) (var val) ...)
         (set! this retval)
         body ...
         (lambda args
           (case (car args)
             ((__pandoric-set)
               (case (cadr args)
                 ((var) (set! var (caddr args))) ...))
             ((__pandoric-get)
               (case (cadr args)
                 ((var) var) ...))
             (else
               (apply this args))))))))

 (define p-get
   (cut <> '__pandoric-get <>))

 (define p-set!
   (cut <> '__pandoric-set <> <>))

 (define pandtest
   (pandoric-let ((acc 0))
     (lambda (n)
       (set! acc (+ n acc))
       acc)))

 (pandtest 1)
 (pandtest 2)
 (p-get pandtest 'acc)
 (p-set! pandtest 'acc 0)
 (pandtest 1)
 (p-get pandtest 'acc)