Add a bunch of pseudo-types to replace the behavior formerly associated

with OPAQUE, as per recent pghackers discussion.  I still want to do some
more work on the 'cstring' pseudo-type, but I'm going to commit the bulk
of the changes now before the tree starts shifting under me ...

contrib/lo/lo.sql.in

@@ -1,21 +1,21 @@
 --
 --	PostgreSQL code for LargeObjects
 --
---	$Id: lo.sql.in,v 1.6 2000/11/21 21:51:58 tgl Exp $
+--	$Id: lo.sql.in,v 1.7 2002/08/22 00:01:39 tgl Exp $
 --
 --
 --	Create the data type
 --
 
 -- used by the lo type, it takes an oid and returns an lo object
-create function lo_in(opaque)
-	returns opaque
+create function lo_in(cstring)
+	returns lo
 	as 'MODULE_PATHNAME'
 	language 'c';
 
 -- used by the lo type, it returns the oid of the object
-create function lo_out(opaque)
-	returns opaque
+create function lo_out(lo)
+	returns cstring
 	as 'MODULE_PATHNAME'
 	language 'c';
 
@@ -51,6 +51,6 @@ create function lo(oid)
 
 -- This is used in triggers
 create function lo_manage()
-	returns opaque
+	returns trigger
 	as 'MODULE_PATHNAME'
 	language 'c';

contrib/lo/lo_drop.sql

@@ -6,16 +6,10 @@
 -- remove our test table
 drop table a;
 
--- now drop any sql based functions associated with the lo type
-drop function oid(lo);
+-- now drop the type and associated C functions
+drop type lo CASCADE;
 
--- now drop the type
-drop type lo;
-
--- as the type is gone, remove the C based functions
-drop function lo_in(opaque);
-drop function lo_out(opaque);
-drop function lo(oid);
+-- the trigger function has no dependency on the type, so drop separately
 drop function lo_manage();
 
 -- the lo stuff is now removed from the system