1 /* 2 [The "BSD license"] 3 Copyright (c) 2005-2009 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 */ 28 package org.antlr.runtime.tree; 29 30 import org.antlr.runtime.Token; 31 import org.antlr.runtime.CommonToken; 32 33 public class TreePatternParser { 34 protected TreePatternLexer tokenizer; 35 protected int ttype; 36 protected TreeWizard wizard; 37 protected TreeAdaptor adaptor; 38 TreePatternParser(TreePatternLexer tokenizer, TreeWizard wizard, TreeAdaptor adaptor)39 public TreePatternParser(TreePatternLexer tokenizer, TreeWizard wizard, TreeAdaptor adaptor) { 40 this.tokenizer = tokenizer; 41 this.wizard = wizard; 42 this.adaptor = adaptor; 43 ttype = tokenizer.nextToken(); // kickstart 44 } 45 pattern()46 public Object pattern() { 47 if ( ttype==TreePatternLexer.BEGIN ) { 48 return parseTree(); 49 } 50 else if ( ttype==TreePatternLexer.ID ) { 51 Object node = parseNode(); 52 if ( ttype==TreePatternLexer.EOF ) { 53 return node; 54 } 55 return null; // extra junk on end 56 } 57 return null; 58 } 59 parseTree()60 public Object parseTree() { 61 if ( ttype != TreePatternLexer.BEGIN ) { 62 throw new RuntimeException("no BEGIN"); 63 } 64 ttype = tokenizer.nextToken(); 65 Object root = parseNode(); 66 if ( root==null ) { 67 return null; 68 } 69 while ( ttype==TreePatternLexer.BEGIN || 70 ttype==TreePatternLexer.ID || 71 ttype==TreePatternLexer.PERCENT || 72 ttype==TreePatternLexer.DOT ) 73 { 74 if ( ttype==TreePatternLexer.BEGIN ) { 75 Object subtree = parseTree(); 76 adaptor.addChild(root, subtree); 77 } 78 else { 79 Object child = parseNode(); 80 if ( child==null ) { 81 return null; 82 } 83 adaptor.addChild(root, child); 84 } 85 } 86 if ( ttype != TreePatternLexer.END ) { 87 throw new RuntimeException("no END"); 88 } 89 ttype = tokenizer.nextToken(); 90 return root; 91 } 92 parseNode()93 public Object parseNode() { 94 // "%label:" prefix 95 String label = null; 96 if ( ttype == TreePatternLexer.PERCENT ) { 97 ttype = tokenizer.nextToken(); 98 if ( ttype != TreePatternLexer.ID ) { 99 return null; 100 } 101 label = tokenizer.sval.toString(); 102 ttype = tokenizer.nextToken(); 103 if ( ttype != TreePatternLexer.COLON ) { 104 return null; 105 } 106 ttype = tokenizer.nextToken(); // move to ID following colon 107 } 108 109 // Wildcard? 110 if ( ttype == TreePatternLexer.DOT ) { 111 ttype = tokenizer.nextToken(); 112 Token wildcardPayload = new CommonToken(0, "."); 113 TreeWizard.TreePattern node = 114 new TreeWizard.WildcardTreePattern(wildcardPayload); 115 if ( label!=null ) { 116 node.label = label; 117 } 118 return node; 119 } 120 121 // "ID" or "ID[arg]" 122 if ( ttype != TreePatternLexer.ID ) { 123 return null; 124 } 125 String tokenName = tokenizer.sval.toString(); 126 ttype = tokenizer.nextToken(); 127 if ( tokenName.equals("nil") ) { 128 return adaptor.nil(); 129 } 130 String text = tokenName; 131 // check for arg 132 String arg = null; 133 if ( ttype == TreePatternLexer.ARG ) { 134 arg = tokenizer.sval.toString(); 135 text = arg; 136 ttype = tokenizer.nextToken(); 137 } 138 139 // create node 140 int treeNodeType = wizard.getTokenType(tokenName); 141 if ( treeNodeType==Token.INVALID_TOKEN_TYPE ) { 142 return null; 143 } 144 Object node; 145 node = adaptor.create(treeNodeType, text); 146 if ( label!=null && node.getClass()==TreeWizard.TreePattern.class ) { 147 ((TreeWizard.TreePattern)node).label = label; 148 } 149 if ( arg!=null && node.getClass()==TreeWizard.TreePattern.class ) { 150 ((TreeWizard.TreePattern)node).hasTextArg = true; 151 } 152 return node; 153 } 154 } 155