args: new args reversing function.

* args.c (args_copy_reverse): New function.

* args.h (args_copy_reverse): Declared.

2 files changed, 12 insertions, 0 deletions

diff --git a/args.c b/args.c
index aa2139a7..c93d8108 100644
--- a/args.c
+++ b/args.c
@@ -117,6 +117,17 @@ struct args *args_cat_zap_from(struct args *to, struct args *from, cnum index)
   return to;
 }
 
+struct args *args_copy_reverse(struct args *to, struct args *from, cnum nargs)
+{
+  cnum i, index = 0;
+
+  for (i = nargs - 1; i >= 0; i--)
+    to->arg[i] = args_get(from, &index);
+
+  to->fill = nargs;
+  return to;
+}
+
 val args_copy_to_list(struct args *args)
 {
   list_collect_decl (out, ptail);
diff --git a/args.h b/args.h
index 76aa10a1..df244e3b 100644
--- a/args.h
+++ b/args.h
@@ -187,6 +187,7 @@ struct args *args_copy(struct args *to, struct args *from);
 struct args *args_copy_zap(struct args *to, struct args *from);
 struct args *args_cat_zap(struct args *to, struct args *from);
 struct args *args_cat_zap_from(struct args *to, struct args *from, cnum index);
+struct args *args_copy_reverse(struct args *to, struct args *from, cnum nargs);
 val args_copy_to_list(struct args *args);
 void args_for_each(struct args *args,
                    int (*fn)(val arg, int ix, mem_t *ctx),