The GOOPS "unbound" value is a unique pair

* libguile/goops.c (SCM_GOOPS_UNBOUND, SCM_GOOPS_UNBOUNDP): Remove
  internal macros.
  (scm_make_unbound, scm_unbound_p): Remove internal functions.
  (scm_sys_clear_fields_x): Add "unbound" parameter, for the init
  value.

* module/oop/goops.scm (*unbound*): Define in Scheme as a simple
  heap-allocated value.
  (unbound?): New definition.
  (%allocate-instance): Pass *unbound* to %clear-fields!.
  (make-class, slot-definition-init-value)
  (slot-definition-init-form, make-closure-variable): Use *unbound*
  instead of (make-unbound), which is now gone.

* module/oop/goops/active-slot.scm (compute-get-n-set): Use *unbound*
  instead of make-unbound.  This module uses the GOOPS internals module;
  perhaps we should export make-unbound or something...

* module/oop/goops/save.scm (make-unbound): Export our own make-unbound
  definition, for use by residualized save code.

* module/language/ecmascript/base.scm (<undefined>, *undefined*): Use a
  unique object kind and instance for the undefined value.

* libguile/vm.c (scm_i_vm_mark_stack): Fill the stack with
  SCM_UNSPECIFIED instead of SCM_UNBOUND.

1 files changed, 4 insertions, 30 deletions

diff --git a/libguile/goops.c b/libguile/goops.c
index c7e775c86..286f3c7dc 100644
--- a/libguile/goops.c
+++ b/libguile/goops.c
@@ -55,9 +55,6 @@
 #define SCM_OUT_PCLASS_INDEX      SCM_I_MAX_PORT_TYPE_COUNT
 #define SCM_INOUT_PCLASS_INDEX    (2 * SCM_I_MAX_PORT_TYPE_COUNT)
 
-#define SCM_GOOPS_UNBOUND SCM_UNBOUND
-#define SCM_GOOPS_UNBOUNDP(x) (scm_is_eq (x, SCM_GOOPS_UNBOUND))
-
 /* Objects have identity, so references to classes and instances are by
    value, not by reference.  Redefinition of a class or modification of
    an instance causes in-place update; you can think of GOOPS as
@@ -149,11 +146,9 @@ SCM scm_i_smob_class[SCM_I_MAX_SMOB_TYPE_COUNT];
 
 SCM scm_module_goops;
 
-static SCM scm_make_unbound (void);
-static SCM scm_unbound_p (SCM obj);
 static SCM scm_sys_make_vtable_vtable (SCM layout);
 static SCM scm_sys_init_layout_x (SCM class, SCM layout);
-static SCM scm_sys_clear_fields_x (SCM obj);
+static SCM scm_sys_clear_fields_x (SCM obj, SCM unbound);
 static SCM scm_sys_goops_early_init (void);
 static SCM scm_sys_goops_loaded (void);
 
@@ -428,27 +423,6 @@ scm_method_procedure (SCM obj)
 
 
 
-SCM_DEFINE (scm_make_unbound, "make-unbound", 0, 0, 0,
-	    (),
-	    "Return the unbound value.")
-#define FUNC_NAME s_scm_make_unbound
-{
-  return SCM_GOOPS_UNBOUND;
-}
-#undef FUNC_NAME
-
-SCM_DEFINE (scm_unbound_p, "unbound?", 1, 0, 0,
-	    (SCM obj),
-	    "Return @code{#t} if @var{obj} is unbound.")
-#define FUNC_NAME s_scm_unbound_p
-{
-  return SCM_GOOPS_UNBOUNDP (obj) ? SCM_BOOL_T : SCM_BOOL_F;
-}
-#undef FUNC_NAME
-
-
-
-
 SCM
 scm_slot_ref (SCM obj, SCM slot_name)
 {
@@ -476,8 +450,8 @@ scm_slot_exists_p (SCM obj, SCM slot_name)
 
 
 
-SCM_DEFINE (scm_sys_clear_fields_x, "%clear-fields!", 1, 0, 0,
-	    (SCM obj),
+SCM_DEFINE (scm_sys_clear_fields_x, "%clear-fields!", 2, 0, 0,
+	    (SCM obj, SCM unbound),
             "")
 #define FUNC_NAME s_scm_sys_clear_fields_x
 {
@@ -493,7 +467,7 @@ SCM_DEFINE (scm_sys_clear_fields_x, "%clear-fields!", 1, 0, 0,
   /* Set all SCM-holding slots to the GOOPS unbound value.  */
   for (i = 0; i < n; i++)
     if (scm_i_symbol_ref (layout, i*2) == 'p')
-      SCM_STRUCT_SLOT_SET (obj, i, SCM_GOOPS_UNBOUND);
+      SCM_STRUCT_SLOT_SET (obj, i, unbound);
 
   return SCM_UNSPECIFIED;
 }