/* // $Id: //guest/julian_hyde/saffron/src/main/saffron/opt/Operand.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.opt; import saffron.util.Walkable; /** * An <code>Operand</code> determines whether a {@link VolcanoPlanner.Rule} * can be applied to a particular expression. * * <p>For example, the rule to pull a filter up from the left side of a * join takes operands: <code>(Join (Filter) (Any))</code>.</p> * * <p>Note that <code>children</code> means different things if it is empty * or it is <code>null</code>: <code>(Join (Filter <b>()</b>) (Any))</code> * means that, to match the rule, <code>Filter</code> must have no * operands. **/ public class Operand implements Walkable { Class clazz; Operand[] children; Operand parent; int ordinalInParent; Rule rule; int ordinalInRule; int[] solveOrder; public Operand(Class clazz, Operand[] children) { this.clazz = clazz; this.children = children; if (children != null) { for (int i = 0; i < this.children.length; i++) { this.children[i].parent = this; } } } // implement Walkable public Object[] getChildren() { return children; } }
# | Change | User | Description | Committed | |
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#2 | 1474 | Julian Hyde |
saffron: Aggregations are working. Renamed 'aggregator' to 'aggregation'. |
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#1 | 1467 | Julian Hyde |
saffron: First saffron check-in; incorporate my changes to openjava. |