New functions for manipulating attribute lists: obj_prepend_attr()

[libucw.git] / lib / object.c

diff --git a/lib/object.c b/lib/object.c
index d12461527a4a24889e38cf900b1ecbaf65745e14..0a0686540ab36aa3a6cdebfeae6c088e83cf3bf7 100644 (file)
--- a/lib/object.c
+++ b/lib/object.c
@@ -220,5 +220,41 @@ obj_add_attr(struct odes *o, struct oattr *a, uns x, byte *v)
   b = oa_new(o, x, v);
   a->last_same->same = b;
   a->last_same = b;
+  return a;
+}
+
+struct oattr *
+obj_prepend_attr(struct odes *o, uns x, byte *v)
+{
+  struct oattr *a, *b, **z;
+
+  b = oa_new(o, x, v);
+  z = &o->attrs;
+  while (a = *z)
+    {
+      if (a->attr == x)
+       {
+         b->same = a;
+         *z = b;
+         b->last_same = a->last_same;
+         return b;
+       }
+      z = &a->next;
+    }
+  b->next = o->attrs;
+  o->attrs = b;
+  return b;
+}
+
+struct oattr *
+obj_insert_attr(struct odes *o, struct oattr *first, struct oattr *after, byte *v)
+{
+  struct oattr *b;
+
+  b = oa_new(o, first->attr, v);
+  b->same = after->same;
+  after->same = b;
+  if (first->last_same == after)
+    first->last_same = b;
   return b;
 }