1/* 2 [The "BSD licence"] 3 Copyright (c) 2005-2006 Terence Parr 4 All rights reserved. 5 6 Redistribution and use in source and binary forms, with or without 7 modification, are permitted provided that the following conditions 8 are met: 9 1. Redistributions of source code must retain the above copyright 10 notice, this list of conditions and the following disclaimer. 11 2. Redistributions in binary form must reproduce the above copyright 12 notice, this list of conditions and the following disclaimer in the 13 documentation and/or other materials provided with the distribution. 14 3. The name of the author may not be used to endorse or promote products 15 derived from this software without specific prior written permission. 16 17 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27*/ 28package org.antlr.runtime.tree { 29 import org.antlr.runtime.Token; 30 import org.antlr.runtime.TokenConstants; 31 32 /** A tree node that is wrapper for a Token object. After 3.0 release 33 * while building tree rewrite stuff, it became clear that computing 34 * parent and child index is very difficult and cumbersome. Better to 35 * spend the space in every tree node. If you don't want these extra 36 * fields, it's easy to cut them out in your own BaseTree subclass. 37 */ 38 public class CommonTree extends BaseTree { 39 /** A single token is the payload */ 40 protected var _token:Token; 41 42 /** What token indexes bracket all tokens associated with this node 43 * and below? 44 */ 45 public var startIndex:int=-1, stopIndex:int=-1; 46 47 /** Who is the parent node of this node; if null, implies node is root */ 48 protected var _parent:CommonTree; 49 50 /** What index is this node in the child list? Range: 0..n-1 */ 51 protected var _childIndex:int = -1; 52 53 public function CommonTree(node:CommonTree = null) { 54 if (node != null) { 55 super(node); 56 this._token = node._token; 57 this.startIndex = node.startIndex; 58 this.stopIndex = node.stopIndex; 59 } 60 } 61 62 public static function createFromToken(t:Token):CommonTree { 63 var ct:CommonTree = new CommonTree(); 64 ct._token = t; 65 return ct; 66 } 67 68 public function get token():Token { 69 return _token; 70 } 71 72 public override function dupNode():Tree { 73 return new CommonTree(this); 74 } 75 76 public override function get isNil():Boolean { 77 return _token==null; 78 } 79 80 public override function get type():int { 81 if ( _token==null ) { 82 return TokenConstants.INVALID_TOKEN_TYPE; 83 } 84 return _token.type; 85 } 86 87 public override function get text():String { 88 if ( _token==null ) { 89 return null; 90 } 91 return _token.text; 92 } 93 94 public override function get line():int { 95 if ( _token==null || _token.line==0 ) { 96 if ( childCount >0 ) { 97 return getChild(0).line; 98 } 99 return 0; 100 } 101 return _token.line; 102 } 103 104 public override function get charPositionInLine():int { 105 if ( _token==null || _token.charPositionInLine==-1 ) { 106 if ( childCount>0 ) { 107 return getChild(0).charPositionInLine; 108 } 109 return 0; 110 } 111 return _token.charPositionInLine; 112 } 113 114 public override function get tokenStartIndex():int { 115 if ( startIndex==-1 && _token!=null ) { 116 return _token.tokenIndex; 117 } 118 return startIndex; 119 } 120 121 public override function set tokenStartIndex(index:int):void { 122 startIndex = index; 123 } 124 125 public override function get tokenStopIndex():int { 126 if ( stopIndex==-1 && _token!=null ) { 127 return _token.tokenIndex; 128 } 129 return stopIndex; 130 } 131 132 public override function set tokenStopIndex(index:int):void { 133 stopIndex = index; 134 } 135 136 public override function get childIndex():int { 137 return _childIndex; 138 } 139 140 public override function get parent():Tree { 141 return _parent; 142 } 143 144 public override function set parent(t:Tree):void { 145 this._parent = CommonTree(t); 146 } 147 148 public override function set childIndex(index:int):void { 149 this._childIndex = index; 150 } 151 152 public function toString():String { 153 if ( isNil ) { 154 return "nil"; 155 } 156 if ( type==TokenConstants.INVALID_TOKEN_TYPE ) { 157 return "<errornode>"; 158 } 159 if ( token==null ) { 160 return null; 161 } 162 return _token.text; 163 } 164 } 165 166} 167