srfi-1 append-reverse: move from C to Scheme

* libguile/srfi-1.c (scm_srfi1_append_reverse): delete.
* libguile/srfi-1.h (scm_srfi1_append_reverse): delete.
* module/srfi/srfi-1.scm: add append-reverse.

libguile/srfi-1.c

@@ -86,31 +86,6 @@ list_copy_part (SCM lst, int count, SCM *dst)
 #undef FUNC_NAME
 
 
-SCM_DEFINE (scm_srfi1_append_reverse, "append-reverse", 2, 0, 0,
-            (SCM revhead, SCM tail),
-	    "Reverse @var{rev-head}, append @var{tail} to it, and return the\n"
-	    "result.  This is equivalent to @code{(append (reverse\n"
-	    "@var{rev-head}) @var{tail})}, but its implementation is more\n"
-	    "efficient.\n"
-	    "\n"
-	    "@example\n"
-	    "(append-reverse '(1 2 3) '(4 5 6)) @result{} (3 2 1 4 5 6)\n"
-	    "@end example")
-#define FUNC_NAME s_scm_srfi1_append_reverse
-{
-  while (scm_is_pair (revhead))
-    {
-      /* copy first element of revhead onto front of tail */
-      tail = scm_cons (SCM_CAR (revhead), tail);
-      revhead = SCM_CDR (revhead);
-    }
-  SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (revhead), revhead, SCM_ARG1, FUNC_NAME,
-                   "list");
-  return tail;
-}
-#undef FUNC_NAME
-
-
 SCM_DEFINE (scm_srfi1_append_reverse_x, "append-reverse!", 2, 0, 0,
             (SCM revhead, SCM tail),
 	    "Reverse @var{rev-head}, append @var{tail} to it, and return the\n"

libguile/srfi-1.h

@@ -24,7 +24,6 @@
 
 #include "libguile/scm.h"
 
-SCM_INTERNAL SCM scm_srfi1_append_reverse (SCM revhead, SCM tail);
 SCM_INTERNAL SCM scm_srfi1_append_reverse_x (SCM revhead, SCM tail);
 SCM_INTERNAL SCM scm_srfi1_count (SCM pred, SCM list1, SCM rest);
 SCM_INTERNAL SCM scm_srfi1_delete_duplicates (SCM lst, SCM pred);

module/srfi/srfi-1.scm

@@ -464,6 +464,23 @@ of arguments a function takes, which the @code{apply} might exceed.  In
 Guile there is no such limit."
   (apply append! lists))
 
+(define (append-reverse rev-head tail)
+  "Reverse @var{rev-head}, append @var{tail} to it, and return the
+result.  This is equivalent to @code{(append (reverse @var{rev-head})
+@var{tail})}, but its implementation is more efficient.
+
+@example
+(append-reverse '(1 2 3) '(4 5 6)) @result{} (3 2 1 4 5 6)
+@end example"
+  (let lp ((rh rev-head)
+           (result tail))
+    (if (pair? rh)
+        (lp (cdr rh) (cons (car rh) result))
+        (begin
+          (unless (null? rh)
+            (wrong-type-arg 'append-reverse rev-head))
+          result))))
+
 (define (zip clist1 . rest)
   (let lp ((l (cons clist1 rest)) (acc '()))
     (if (any null? l)