+/*
+ * Copyright © 2016 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <ao_lisp.h>
+
+ao_poly
+ao_lisp_save(struct ao_lisp_cons *cons)
+{
+#ifdef AO_LISP_SAVE
+ struct ao_lisp_os_save *os = (struct ao_lisp_os_save *) &ao_lisp_pool[AO_LISP_POOL];
+
+ ao_lisp_collect();
+ os->ao_lisp_atoms = ao_lisp_atom_poly(ao_lisp_atoms);
+ os->ao_lisp_globals = ao_lisp_frame_poly(ao_lisp_frame_global);
+ if (ao_lisp_os_save())
+ return _ao_lisp_atom_t;
+#endif
+ return AO_LISP_NIL;
+}
+
+ao_poly
+ao_lisp_restore(struct ao_lisp_cons *cons)
+{
+#ifdef AO_LISP_SAVE
+ struct ao_lisp_os_save *os = (struct ao_lisp_os_save *) &ao_lisp_pool[AO_LISP_POOL];
+
+ if (ao_lisp_os_restore()) {
+
+ ao_lisp_atoms = ao_lisp_poly_atom(os->ao_lisp_atoms);
+ ao_lisp_frame_global = ao_lisp_poly_frame(os->ao_lisp_globals);
+
+ /* Clear the eval global variabls */
+ ao_lisp_eval_clear_globals();
+
+ /* Reset the allocator */
+ ao_lisp_top = AO_LISP_POOL;
+ ao_lisp_collect();
+
+ /* Re-create the evaluator stack */
+ if (!ao_lisp_eval_restart())
+ return AO_LISP_NIL;
+ return _ao_lisp_atom_t;
+ }
+#endif
+ return AO_LISP_NIL;
+}