srfi-16 just re-exports psyntax's case-lambda

* module/srfi/srfi-16.scm (case-lambda): Just re-export the core's
  case-lambda, it's semantically the same but faster and better
  integrated.

module/srfi/srfi-16.scm

@@ -46,81 +46,8 @@
 ;;; Code:
 
 (define-module (srfi srfi-16)
-  #:replace (case-lambda))
+  #:re-export (case-lambda))
+
+;; Case-lambda is now provided by code psyntax.
 
 (cond-expand-provide (current-module) '(srfi-16))
-
-(define-macro (case-lambda . clauses)
-
-  ;; Return the length of the list @var{l}, but allow dotted list.
-  ;;
-  (define (alength l)
-    (cond ((null? l) 0)
-	  ((pair? l) (+ 1 (alength (cdr l))))
-	  (else 0)))
-
-  ;; Return @code{#t} if @var{l} is a dotted list, @code{#f} if it is
-  ;; a normal list.
-  ;;
-  (define (dotted? l)
-    (cond ((null? l) #f)
-	  ((pair? l) (dotted? (cdr l)))
-	  (else #t)))
-
-  ;; Return the expression for accessing the @var{index}th element of
-  ;; the list called @var{args-name}.  If @var{tail?} is true, code
-  ;; for accessing the list-tail is generated, otherwise for accessing
-  ;; the list element itself.
-  ;;
-  (define (accessor args-name index tail?)
-    (if tail?
-	(case index
-	  ((0) `,args-name)
-	  ((1) `(cdr ,args-name))
-	  ((2) `(cddr ,args-name))
-	  ((3) `(cdddr ,args-name))
-	  ((4) `(cddddr ,args-name))
-	  (else `(list-tail ,args-name ,index)))
-	(case index
-	  ((0) `(car ,args-name))
-	  ((1) `(cadr ,args-name))
-	  ((2) `(caddr ,args-name))
-	  ((3) `(cadddr ,args-name))
-	  (else `(list-ref ,args-name ,index)))))
-
-  ;; Generate the binding lists of the variables of one case-lambda
-  ;; clause.  @var{vars} is the (possibly dotted) list of variables
-  ;; and @var{args-name} is the generated name used for the argument
-  ;; list.
-  ;;
-  (define (gen-temps vars args-name)
-    (let lp ((v vars) (i 0))
-      (cond ((null? v) '())
-	    ((pair? v)
-	     (cons `(,(car v) ,(accessor args-name i #f))
-		   (lp (cdr v) (+ i 1))))
-	    (else `((,v ,(accessor args-name i #t)))))))
-
-  ;; Generate the cond clauses for each of the clauses of case-lambda,
-  ;; including the parameter count check, binding of the parameters
-  ;; and the code of the corresponding body.
-  ;;
-  (define (gen-clauses l length-name args-name)
-    (cond ((null? l) (list '(else (error "too few arguments"))))
-	  (else
-	   (cons
-	    `((,(if (dotted? (caar l)) '>= '=)
-	       ,length-name ,(alength (caar l)))
-	      (let ,(gen-temps (caar l) args-name)
-	      ,@(cdar l)))
-	    (gen-clauses (cdr l) length-name args-name)))))
-
-  (let ((args-name (gensym))
-	(length-name (gensym)))
-    (let ((proc
-	   `(lambda ,args-name
-	      (let ((,length-name (length ,args-name)))
-		(cond ,@(gen-clauses clauses length-name args-name))))))
-      proc)))
-
-;;; srfi-16.scm ends here