New function: args_cat_zap_from.

* args.c (args_cat_zap): New function.

* args.c (args_cat_zap): Declared.

2 files changed, 11 insertions, 0 deletions

diff --git a/args.c b/args.c
index 7c62baee..9377d357 100644
--- a/args.c
+++ b/args.c
@@ -97,6 +97,16 @@ struct args *args_cat_zap(struct args *to, struct args *from)
   return to;
 }
 
+struct args *args_cat_zap_from(struct args *to, struct args *from, cnum index)
+{
+  size_t size = sizeof *from->arg * (from->fill - index);
+  to->list = from->list;
+  memcpy(to->arg + to->fill, from->arg + index, size);
+  to->fill += from->fill - index;
+  memset(from->arg, 0, size);
+  return to;
+}
+
 val args_copy_to_list(struct args *args)
 {
   list_collect_decl (out, ptail);
diff --git a/args.h b/args.h
index c9f6bd9a..68d301b8 100644
--- a/args.h
+++ b/args.h
@@ -185,4 +185,5 @@ val args_get_checked(val name, struct args *args, cnum *arg_index);
 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);
 val args_copy_to_list(struct args *args);