/* // $Id: //guest/julian_hyde/saffron/src/main/saffron/rel/AggUnpickler.java#1 $ // Saffron preprocessor and data engine // Copyright (C) 2002 Julian Hyde <julian.hyde@mail.com> // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Library General Public // License as published by the Free Software Foundation; either // version 2 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Library General Public License for more details. // // You should have received a copy of the GNU Library General Public // License along with this library; if not, write to the // Free Software Foundation, Inc., 59 Temple Place - Suite 330, // Boston, MA 02111-1307, USA. // // See the COPYING file located in the top-level-directory of // the archive of this library for complete text of license. */ package saffron.rel; import openjava.ptree.Expression; import openjava.ptree.Variable; import openjava.ptree.util.EvaluationShuttle; import saffron.util.RelEnvironment; import saffron.util.Util; /** * Converts references to group items and aggregates (created by {@link * AggInternalTranslator}) into more conventional field accesses. **/ class AggUnpickler extends EvaluationShuttle { int groupCount; AggUnpickler(QueryInfo queryInfo, int groupCount) { super(queryInfo.env); this.groupCount = groupCount; } public Expression evaluateDown(Variable variable) { String name = variable.toString(); if (name.startsWith("$group")) { int i = Integer.parseInt(name.substring("$group".length())); return RelEnvironment.makeFieldAccess(0, i); } else if (name.startsWith("$agg")) { int i = Integer.parseInt(name.substring("$agg".length())); return RelEnvironment.makeFieldAccess(0, groupCount + i); } else if (name.startsWith("$input")) { throw Util.newInternal( "Expression " + variable + " is neither a constant nor " + "an aggregate function"); } else { // Other variables -- from the enclosing Java environment, or // correlating variables such as $corel2 -- are OK. return variable; } } }
# | Change | User | Description | Committed | |
---|---|---|---|---|---|
#1 | 1467 | Julian Hyde |
saffron: First saffron check-in; incorporate my changes to openjava. |