Implementation of static slots for structures.

* share/txr/stdlib/struct.tl (sys:bad-slot-syntax): New helper function.
(defstruct): Macro revamped with new slot specifier syntax for
writing static slots as well as methods.

* struct.c (STATIC_SLOT_BASE): New preprocessor symbol.
(struct struct_type): New members, nstslots, stinitfun, stslot.
(make_struct_type_compat): New static function.
(struct_init): Register make-struct-type to make_struct_type_compat
if compatibility is 117 or lower.
Register new intrinsics static-slot, static-slot-set, call-super-method,
call-super-fun, slot-p and static-slot-p.
(call_stinitfun_chain): New static function.
(make_struct_type): Two new arguments for specifying static slots and
an initialization function for them. Logic added for setting
up static slots and handling inheritance.
(struct_type_destroy): New static function.
(struct_type_mark): Mark the new stinitfun member of struct type.
Also iterate over the static slots in the new stslot array and
mark them.
(lookup_slot): Altered to return a loc instead of a raw pointer,
and also to accept the instance object as a member.
Now resolves static slots: it can return a loc which references
a static slot in the structure type, or an instance slot in
the structure.
(lookup_static_slot): New static function.
(slot, slotset): Implementation adjusted due to new lookup_slot interface.
(static_slot, static_slot_set, slot_p, static_slot_p): New functions.
(call_super_method, call_super_fun): New static functions.
(struct_inst_print): This function can no longer assume that the slots
list lines up with the array of slots, since it contains a mixture of
static and instance slots. Earnest slot lookup has to be performed.
(struct_type_ops): Point the destroy function to struct_type_destroy
instead of cobj_destroy_free_op. A structure type now has an array
of static slots to free.

* struct.h (make_struct_type): Declaration updated.
(static_slot, static_slot_set, slot_p, static_slot_p): Declared.

* lib.c (time_init): Update call to make_struct_type with new
arguments.

* sysif.c (sysif_init): Likewise.

* tests/012/struct.tl: Update defstruct macro expansion test.

* txr.1: Documented static slots and new functions.

1 files changed, 7 insertions, 1 deletions

diff --git a/struct.h b/struct.h
index 193c605d..d0bc9c85 100644
--- a/struct.h
+++ b/struct.h
@@ -25,7 +25,9 @@
  */
 
 extern val struct_type_s;
-val make_struct_type(val name, val super, val slots, val initfun, val boactor);
+val make_struct_type(val name, val super,
+                     val static_slots, val slots,
+                     val static_initfun, val initfun, val boactor);
 val struct_type_p(val obj);
 val super(val type);
 val make_struct(val type, val plist, struct args *);
@@ -33,6 +35,10 @@ val copy_struct(val strct);
 val find_struct_type(val sym);
 val slot(val strct, val sym);
 val slotset(val strct, val sym, val newval);
+val static_slot(val stype, val sym);
+val static_slot_set(val stype, val sym, val newval);
+val slot_p(val type, val sym);
+val static_slot_p(val type, val sym);
 val structp(val obj);
 val struct_type(val strct);
 val method(val strct, val obj);