Support expressions of the form 'scalar op ANY (array)' and

'scalar op ALL (array)', where the operator is applied between the
lefthand scalar and each element of the array.  The operator must
yield boolean; the result of the construct is the OR or AND of the
per-element results, respectively.

Original coding by Joe Conway, after an idea of Peter's.  Rewritten
by Tom to keep the implementation strictly separate from subqueries.

1 files changed, 91 insertions, 1 deletions

diff --git a/src/backend/parser/parse_oper.c b/src/backend/parser/parse_oper.c
index 983041eb45b..72327243310 100644
--- a/src/backend/parser/parse_oper.c
+++ b/src/backend/parser/parse_oper.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.67 2003/06/27 00:33:25 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.68 2003/06/29 00:33:43 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -737,6 +737,96 @@ make_op(ParseState *pstate, List *opname, Node *ltree, Node *rtree)
 	return result;
 }
 
+/*
+ * make_scalar_array_op()
+ *		Build expression tree for "scalar op ANY/ALL (array)" construct.
+ */
+Expr *
+make_scalar_array_op(ParseState *pstate, List *opname,
+					 bool useOr,
+					 Node *ltree, Node *rtree)
+{
+	Oid			ltypeId,
+				rtypeId,
+				atypeId,
+				res_atypeId;
+	Operator	tup;
+	Form_pg_operator opform;
+	Oid			actual_arg_types[2];
+	Oid			declared_arg_types[2];
+	List	   *args;
+	Oid			rettype;
+	ScalarArrayOpExpr *result;
+
+	ltypeId = exprType(ltree);
+	atypeId = exprType(rtree);
+	/*
+	 * The right-hand input of the operator will be the element type of
+	 * the array.  However, if we currently have just an untyped literal
+	 * on the right, stay with that and hope we can resolve the operator.
+	 */
+	if (atypeId == UNKNOWNOID)
+		rtypeId = UNKNOWNOID;
+	else
+	{
+		rtypeId = get_element_type(atypeId);
+		if (!OidIsValid(rtypeId))
+			elog(ERROR, "op ANY/ALL (array) requires array on right side");
+	}
+
+	/* Now resolve the operator */
+	tup = oper(opname, ltypeId, rtypeId, false);
+	opform = (Form_pg_operator) GETSTRUCT(tup);
+
+	args = makeList2(ltree, rtree);
+	actual_arg_types[0] = ltypeId;
+	actual_arg_types[1] = rtypeId;
+	declared_arg_types[0] = opform->oprleft;
+	declared_arg_types[1] = opform->oprright;
+
+	/*
+	 * enforce consistency with ANYARRAY and ANYELEMENT argument and
+	 * return types, possibly adjusting return type or declared_arg_types
+	 * (which will be used as the cast destination by make_fn_arguments)
+	 */
+	rettype = enforce_generic_type_consistency(actual_arg_types,
+											   declared_arg_types,
+											   2,
+											   opform->oprresult);
+
+	/*
+	 * Check that operator result is boolean
+	 */
+	if (rettype != BOOLOID)
+		elog(ERROR, "op ANY/ALL (array) requires operator to yield boolean");
+	if (get_func_retset(opform->oprcode))
+		elog(ERROR, "op ANY/ALL (array) requires operator not to return a set");
+
+	/*
+	 * Now switch back to the array type on the right, arranging for
+	 * any needed cast to be applied.
+	 */
+	res_atypeId = get_array_type(declared_arg_types[1]);
+	if (!OidIsValid(res_atypeId))
+		elog(ERROR, "unable to find datatype for array of %s",
+			 format_type_be(declared_arg_types[1]));
+	actual_arg_types[1] = atypeId;
+	declared_arg_types[1] = res_atypeId;
+
+	/* perform the necessary typecasting of arguments */
+	make_fn_arguments(pstate, args, actual_arg_types, declared_arg_types);
+
+	/* and build the expression node */
+	result = makeNode(ScalarArrayOpExpr);
+	result->opno = oprid(tup);
+	result->opfuncid = InvalidOid;
+	result->useOr = useOr;
+	result->args = args;
+
+	ReleaseSysCache(tup);
+
+	return (Expr *) result;
+}
 
 /*
  * make_op_expr()