subtypep: handle COBJ inheritance.

* lib.c (class_from_sym): New static function.
(subtypep): Remove special case handling of stream versus
stdio-stream. If the two types are not both structures, then
check whether they are both cobj classes. If so, check if they
are in an inheritance relationship via the cobj_hash.
(cobj_populate_hash): Map each symbol to a fixnum integer
which gives class handle'position in the cobj_class table.
(cobj_class_exists): Style: compare to nil instead of 0.
(obj_init): Do not call cobj_populate_hash here, it is far too
early: only a couple of COBJ types exist at this point.
Moreover, hash_init has not been called so hash_cls and
hash_iter_cls still have null symbols.
(init): Call obj_populate_hash here, as the last step.

* tests/012/type.tl: New file.

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/012/type.tl b/tests/012/type.tl
new file mode 100644
index 00000000..0cac2581
--- /dev/null
+++ b/tests/012/type.tl
@@ -0,0 +1,20 @@
+(load "../common")
+
+(mtest
+  (subtypep 'a 'a) t
+  (subtypep t t) t
+  (subtypep nil t) t
+  (subtypep t nil) nil
+  (subtypep nil nil) t
+  (subtypep 'null nil) nil
+  (subtypep nil 'null) t
+  (subtypep 'null t) t
+  (subtypep 'null 'a) nil
+  (subtypep 'a 'null) nil
+  (subtypep nil 'a) t
+  (subtypep 'a nil) nil
+  (subtypep 'a t) t)
+
+(mtest
+  (subtypep 'stream 'stdio-stream) nil
+  (subtypep 'stdio-stream 'stream) t)