Finished the Between patch Christopher started.

Implements between (symmetric / asymmetric) as a node.

Executes the left or right expression once, makes a Const out of the
resulting Datum and executes the >=, <= portions out of the Const sets.

Of course, the parser does a fair amount of preparatory work for this to
happen.

Rod Taylor

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.187 2002/07/16 22:12:20 tgl Exp $
+ * $Id: parsenodes.h,v 1.188 2002/07/18 04:41:45 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -173,6 +173,25 @@ typedef struct A_Const
 	TypeName   *typename;		/* typecast */
 } A_Const;
 
+/*
+ * BetweenExpr - an SQL99 BETWEEN expression
+ */
+
+typedef struct BetweenExpr
+{
+	NodeTag		type;
+	Node	   *expr;			/* Expression to check */
+	Node	   *lexpr;			/* First bound */
+	Node	   *rexpr;			/* Second bound */
+	bool		not;			/* Do we want inverse? */
+	bool		symmetric;		/* True if SYMMETRIC, false if ASYMMETRIC */
+	Oid			typeId;			/* Information abotu common type */
+	int16		typeLen;
+	bool		typeByVal;
+	Expr	   *gthan;
+	Expr	   *lthan;
+} BetweenExpr;
+
 /*
  * TypeCast - a CAST expression
  *