New function: clear-struct.

* struct.c (clear_struct): New function.
(struct_init): Register clear-struct intrinsic.

* struct.h (struct_init): Declared.

* txr.1: documented clear-struct.

1 files changed, 15 insertions, 0 deletions

diff --git a/struct.c b/struct.c
index 4ff01a74..43a30a65 100644
--- a/struct.c
+++ b/struct.c
@@ -111,6 +111,7 @@ void struct_init(void)
   reg_fun(intern(lit("super"), user_package), func_n1(super));
   reg_fun(intern(lit("make-struct"), user_package), func_n2v(make_struct));
   reg_fun(intern(lit("copy-struct"), user_package), func_n1(copy_struct));
+  reg_fun(intern(lit("clear-struct"), user_package), func_n2o(clear_struct, 1));
   reg_fun(intern(lit("slot"), user_package), func_n2(slot));
   reg_fun(intern(lit("slotset"), user_package), func_n3(slotset));
   reg_fun(intern(lit("static-slot"), user_package), func_n2(static_slot));
@@ -393,6 +394,20 @@ val copy_struct(val strct)
   return copy;
 }
 
+val clear_struct(val strct, val value)
+{
+  const val self = lit("clear-struct");
+  struct struct_inst *si = struct_handle(strct, self);
+  struct struct_type *st = coerce(struct struct_type *, si->type->co.handle);
+  val clear_val = default_bool_arg(value);
+  cnum i;
+
+  for (i = 0; i < st->nslots; i++)
+    si->slot[i] = clear_val;
+
+  return strct;
+}
+
 static int cache_set_lookup(slot_cache_entry_t *set, cnum id)
 {
   if (set[0].id == id)