Promote row expressions to full-fledged citizens of the expression syntax,

rather than allowing them only in a few special cases as before.  In
particular you can now pass a ROW() construct to a function that accepts
a rowtype parameter.  Internal generation of RowExprs fixes a number of
corner cases that used to not work very well, such as referencing the
whole-row result of a JOIN or subquery.  This represents a further step in
the work I started a month or so back to make rowtype values into
first-class citizens.

src/backend/nodes/makefuncs.c

@@ -9,12 +9,13 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/makefuncs.c,v 1.42 2003/11/29 19:51:49 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/makefuncs.c,v 1.43 2004/05/10 22:44:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
+#include "catalog/pg_type.h"
 #include "nodes/makefuncs.h"
 #include "utils/lsyscache.h"
 
@@ -170,6 +171,17 @@ makeNullConst(Oid consttype)
 					 typByVal);
 }
 
+/*
+ * makeBoolConst -
+ *	  creates a Const node representing a boolean value (can be NULL too)
+ */
+Node *
+makeBoolConst(bool value, bool isnull)
+{
+	/* note that pg_type.h hardwires size of bool as 1 ... duplicate it */
+	return (Node *) makeConst(BOOLOID, 1, BoolGetDatum(value), isnull, true);
+}
+
 /*
  * makeBoolExpr -
  *	  creates a BoolExpr node