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 using System.Collections.Generic; 35324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 36324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** Return a node stream from a doubly-linked tree whose nodes 37324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * know what child index they are. No remove() is supported. 38324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 39324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Emit navigation nodes (DOWN, UP, and EOF) to let show tree structure. 40324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 41324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public class TreeIterator : IEnumerator<object> { 42324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected ITreeAdaptor adaptor; 43324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected object root; 44324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected object tree; 45324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected bool firstTime = true; 46324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 47324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // navigation nodes to return during walk and at end 48324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public object up; 49324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public object down; 50324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public object eof; 51324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 52324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** If we emit UP/DOWN nodes, we need to spit out multiple nodes per 53324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * next() call. 54324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 55324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected Queue<object> nodes; 56324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 57324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public TreeIterator(object tree) 58324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver : this(new CommonTreeAdaptor(), tree) { 59324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 60324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 61324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public TreeIterator(ITreeAdaptor adaptor, object tree) { 62324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver this.adaptor = adaptor; 63324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver this.tree = tree; 64324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver this.root = tree; 65324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver nodes = new Queue<object>(); 66324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver down = adaptor.Create(TokenTypes.Down, "DOWN"); 67324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver up = adaptor.Create(TokenTypes.Up, "UP"); 68324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver eof = adaptor.Create(TokenTypes.EndOfFile, "EOF"); 69324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 70324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 71324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver #region IEnumerator<object> Members 72324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 73324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public object Current { 74324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver get; 75324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver private set; 76324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 77324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 78324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver #endregion 79324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 80324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver #region IDisposable Members 81324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 82324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public void Dispose() { 83324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 84324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 85324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver #endregion 86324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 87324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver #region IEnumerator Members 88324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 89324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public bool MoveNext() { 90324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (firstTime) { 91324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // initial condition 92324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver firstTime = false; 93324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (adaptor.GetChildCount(tree) == 0) { 94324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // single node tree (special) 95324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver nodes.Enqueue(eof); 96324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 97324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Current = tree; 98324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } else { 99324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // if any queued up, use those first 100324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (nodes != null && nodes.Count > 0) { 101324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Current = nodes.Dequeue(); 102324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } else { 103324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // no nodes left? 104324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (tree == null) { 105324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Current = eof; 106324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } else { 107324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // next node will be child 0 if any children 108324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (adaptor.GetChildCount(tree) > 0) { 109324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver tree = adaptor.GetChild(tree, 0); 110324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver nodes.Enqueue(tree); // real node is next after DOWN 111324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Current = down; 112324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } else { 113324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // if no children, look for next sibling of tree or ancestor 114324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver object parent = adaptor.GetParent(tree); 115324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // while we're out of siblings, keep popping back up towards root 116324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver while (parent != null && 117324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver adaptor.GetChildIndex(tree) + 1 >= adaptor.GetChildCount(parent)) { 118324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver nodes.Enqueue(up); // we're moving back up 119324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver tree = parent; 120324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver parent = adaptor.GetParent(tree); 121324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 122324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 123324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // no nodes left? 124324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (parent == null) { 125324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver tree = null; // back at root? nothing left then 126324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver nodes.Enqueue(eof); // add to queue, might have UP nodes in there 127324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Current = nodes.Dequeue(); 128324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } else { 129324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // must have found a node with an unvisited sibling 130324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // move to it and return it 131324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver int nextSiblingIndex = adaptor.GetChildIndex(tree) + 1; 132324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver tree = adaptor.GetChild(parent, nextSiblingIndex); 133324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver nodes.Enqueue(tree); // add to queue, might have UP nodes in there 134324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Current = nodes.Dequeue(); 135324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 136324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 137324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 138324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 139324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 140324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 141324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return Current != eof; 142324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 143324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 144324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public void Reset() { 145324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver firstTime = true; 146324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver tree = root; 147324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver nodes.Clear(); 148324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 149324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 150324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver #endregion 151324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 152324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver} 153