define-values stub

macro-testing.scm

@@ -66,6 +66,44 @@
         (lambda args (let ((len (length args))) (%case args len 0 () . clauses))))))
         ;(lambda args (let ((len (length* args))) (%case args len 0 () . clauses))))))
 
+;(define-syntax define-values
+;  (syntax-rules ()
+;    ((define-values () expr)
+;     (define dummy
+;       (call-with-values (lambda () expr)
+;         (lambda args #f))))
+;    ((define-values (var) expr)
+;     (define var expr))
+;    ((define-values (var0 var1 ... varn) expr)
+;     (begin
+;       (define var0
+;         (call-with-values (lambda () expr) list))
+;       (define var1
+;         (let ((v (cadr var0)))
+;           (set-cdr! var0 (cddr var0))
+;           v))
+;       ...
+;       (define varn
+;         (let ((v (cadr var0)))
+;           (set! var0 (car var0))
+;           v))))
+;    ((define-values (var0 var1 ... . var-dot) expr)
+;     (begin
+;       (define var0
+;         (call-with-values (lambda () expr) list))
+;       (define var1
+;         (let ((v (cadr var0)))
+;           (set-cdr! var0 (cddr var0))
+;           v))
+;       ...
+;       (define var-dot
+;         (let ((v (cdr var0)))
+;           (set! var0 (car var0))
+;           v))))
+;    ((define-values var expr)
+;     (define var
+;       (call-with-values (lambda () expr) list)))))
+
 (write
   (letrec* ((x 1)) x))
 
@@ -92,3 +130,11 @@
 (write
   (range 3 5)) ; => (3 4)
 
+;(define-values (x y) (integer-sqrt 17))
+;(write
+;  (list x y)) ; => (4 1)
+;
+;(write
+;  (let ()
+;    (define-values (x y) (values 1 2))
+;    (+ x y))) ;=> 3