3db4056e22
I hope. I finally realized that we were going at it backwards: when there are excess parentheses, they need to be treated as part of the sub-SELECT, not as part of the surrounding expression. Although either choice yields an unambiguous grammar, only this way produces a grammar that is LALR(1). With the old approach we were guaranteed to fail on either 'SELECT (((SELECT 2)) + 3)' or 'SELECT (((SELECT 2)) UNION SELECT 2)' depending on which way we resolve the initial shift/reduce conflict. With the new way, the same reduction track can be followed in both cases until we have advanced far enough to know whether we are done with the sub-SELECT or not.
PostgreSQL Data Base Management System (formerly known as Postgres, then as Postgres95). This directory contains the development version of 7.1 of the PostgreSQL database server. The server is not ANSI SQL compliant, but it gets closer with every release. After you unzip and untar the distribution file, look at file INSTALL for the installation notes and file HISTORY for the changes. The latest version of this software may be obtained at ftp://ftp.postgresql.org/pub/. For more information look at our WWW home page located at http://www.postgreSQL.org/. PostgreSQL is not public domain software. It is copyrighted by the University of California but may be used according to the licensing terms of the the copyright below: ------------------------------------------------------------------------ POSTGRES95 Data Base Management System (formerly known as Postgres, then as Postgres95). Copyright (c) 1994-7 Regents of the University of California Permission to use, copy, modify, and distribute this software and its documentation for any purpose, without fee, and without a written agreement is hereby granted, provided that the above copyright notice and this paragraph and the following two paragraphs appear in all copies. IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.