diff: std_util.m: remove obsolete XXX comments

[Fergus Henderson]

library/std_util.m:
	Remove some old `XXX' comments that are obsolete now that
	type_name/1 etc. handle higher-order types correctly.

Index: std_util.m
===================================================================
RCS file: /home/staff/zs/imp/mercury/library/std_util.m,v
retrieving revision 1.98
diff -u -r1.98 std_util.m
--- std_util.m	1997/07/27 15:07:17	1.98
+++ std_util.m	1997/07/27 15:29:11
@@ -189,10 +189,6 @@
 	% A type_info represents a type, e.g. `list(int)'.
 	% A type_ctor_info represents a type constructor, e.g. `list/1'.
 
-	% XXX The facilities here don't yet work for higher-order types.
-	%     If you try, there is a good chance that you will get a core
-	%     dump or worse.
- 
 :- type type_info.
 :- type type_ctor_info.
 
@@ -1164,10 +1160,9 @@
 ").
 
 
-	% A type_ctor_info is represented as a pointer to a base_type_info.
-	% XXX what about higher-order types?
-	%     For them the type_ctor_info should include the arity, but
-	%     the arity is stored in the type_info, not the base_type_info.
+	% A type_ctor_info is represented as a pointer to a base_type_info,
+	% except for higher-order types, which are represented using
+	% small integers.  See runtime/type_info.h.
 :- type type_ctor_info == c_pointer.  
 
 :- pragma c_code(type_of(Value::unused) = (TypeInfo::out),
@@ -1759,10 +1754,8 @@
 	Word base_type_info;
 
 	/*
-	** XXX: do we need to treat higher-order predicates as
-	**      a special case here?
+	** We need to treat higher-order predicates as a special case here.
 	*/
-
 	if (MR_TYPECTOR_IS_HIGHER_ORDER(type_ctor)) {
 		base_type_info = MR_TYPECTOR_GET_HOT_BASE_TYPE_INFO(type_ctor);
 		extra_args = 2;

-- 
Fergus Henderson <fjh at cs.mu.oz.au>   |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
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