Function make_scalar_array_op

src/backend/parser/parse_oper.c:782–906

* make_scalar_array_op() * Build expression tree for "scalar op ANY/ALL (array)" construct. */

 *		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,
					 int location)
{
	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_base_element_type(atypeId);
		if (!OidIsValid(rtypeId))
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("op ANY/ALL (array) requires array on right side"),
					 parser_errposition(pstate, location)));
	}

	/* Now resolve the operator */
	tup = oper(pstate, opname, ltypeId, rtypeId, false, location);
	opform = (Form_pg_operator) GETSTRUCT(tup);

	/* Check it's not a shell */
	if (!RegProcedureIsValid(opform->oprcode))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("operator is only a shell: %s",
						op_signature_string(opname,
											opform->oprkind,
											opform->oprleft,
											opform->oprright)),
				 parser_errposition(pstate, location)));

	args = list_make2(ltree, rtree);
	actual_arg_types[0] = ltypeId;
	actual_arg_types[1] = rtypeId;
	declared_arg_types[0] = opform->oprleft;
	declared_arg_types[1] = opform->oprright;