1324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver/* 2324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * [The "BSD licence"] 3324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Copyright (c) 2005-2008 Terence Parr 4324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * All rights reserved. 5324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 6324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Conversion to C#: 7324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc. 8324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * All rights reserved. 9324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 10324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Redistribution and use in source and binary forms, with or without 11324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * modification, are permitted provided that the following conditions 12324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * are met: 13324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 1. Redistributions of source code must retain the above copyright 14324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * notice, this list of conditions and the following disclaimer. 15324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 2. Redistributions in binary form must reproduce the above copyright 16324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * notice, this list of conditions and the following disclaimer in the 17324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * documentation and/or other materials provided with the distribution. 18324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 3. The name of the author may not be used to endorse or promote products 19324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * derived from this software without specific prior written permission. 20324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 21324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 32324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 33324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruvernamespace Antlr.Runtime.Tree 34324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver{ 35324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** <summary>Do a depth first walk of a tree, applying pre() and post() actions as we go.</summary> */ 36324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public class TreeVisitor 37324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 38324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected ITreeAdaptor adaptor; 39324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 40324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public TreeVisitor(ITreeAdaptor adaptor) 41324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 42324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver this.adaptor = adaptor; 43324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 44324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public TreeVisitor() 45324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver : this(new CommonTreeAdaptor()) 46324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 47324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 48324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 49324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** <summary> 50324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Visit every node in tree t and trigger an action for each node 51324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * before/after having visited all of its children. Bottom up walk. 52324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Execute both actions even if t has no children. Ignore return 53324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * results from transforming children since they will have altered 54324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * the child list of this node (their parent). Return result of 55324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * applying post action to this node. 56324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * </summary> 57324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 58324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public object Visit(object t, ITreeVisitorAction action) 59324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 60324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // System.out.println("visit "+((Tree)t).toStringTree()); 61324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver bool isNil = adaptor.IsNil(t); 62324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (action != null && !isNil) 63324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 64324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver t = action.Pre(t); // if rewritten, walk children of new t 65324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 66324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver for (int i = 0; i < adaptor.GetChildCount(t); i++) 67324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 68324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver object child = adaptor.GetChild(t, i); 69324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Visit(child, action); 70324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 71324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (action != null && !isNil) 72324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver t = action.Post(t); 73324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return t; 74324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 75324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 76324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public object Visit(object t, Func<object, object> preAction, Func<object, object> postAction) 77324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver { 78324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return Visit(t, new TreeVisitorAction(preAction, postAction)); 79324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 80324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 81324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver} 82