/*
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 Copyright (c) 2005-2009 Terence Parr
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package org.antlr.runtime.tree;

import org.antlr.runtime.Token;

A tree node that is wrapper for a Token object. After 3.0 release while building tree rewrite stuff, it became clear that computing parent and child index is very difficult and cumbersome. Better to spend the space in every tree node. If you don't want these extra fields, it's easy to cut them out in your own BaseTree subclass.
/** A tree node that is wrapper for a Token object. After 3.0 release * while building tree rewrite stuff, it became clear that computing * parent and child index is very difficult and cumbersome. Better to * spend the space in every tree node. If you don't want these extra * fields, it's easy to cut them out in your own BaseTree subclass. */
public class CommonTree extends BaseTree {
A single token is the payload
/** A single token is the payload */
public Token token;
What token indexes bracket all tokens associated with this node and below?
/** What token indexes bracket all tokens associated with this node * and below? */
protected int startIndex=-1, stopIndex=-1;
Who is the parent node of this node; if null, implies node is root
/** Who is the parent node of this node; if null, implies node is root */
public CommonTree parent;
What index is this node in the child list? Range: 0..n-1
/** What index is this node in the child list? Range: 0..n-1 */
public int childIndex = -1; public CommonTree() { } public CommonTree(CommonTree node) { super(node); this.token = node.token; this.startIndex = node.startIndex; this.stopIndex = node.stopIndex; } public CommonTree(Token t) { this.token = t; } public Token getToken() { return token; } @Override public Tree dupNode() { return new CommonTree(this); } @Override public boolean isNil() { return token==null; } @Override public int getType() { if ( token==null ) { return Token.INVALID_TOKEN_TYPE; } return token.getType(); } @Override public String getText() { if ( token==null ) { return null; } return token.getText(); } @Override public int getLine() { if ( token==null || token.getLine()==0 ) { if ( getChildCount()>0 ) { return getChild(0).getLine(); } return 0; } return token.getLine(); } @Override public int getCharPositionInLine() { if ( token==null || token.getCharPositionInLine()==-1 ) { if ( getChildCount()>0 ) { return getChild(0).getCharPositionInLine(); } return 0; } return token.getCharPositionInLine(); } @Override public int getTokenStartIndex() { if ( startIndex==-1 && token!=null ) { return token.getTokenIndex(); } return startIndex; } @Override public void setTokenStartIndex(int index) { startIndex = index; } @Override public int getTokenStopIndex() { if ( stopIndex==-1 && token!=null ) { return token.getTokenIndex(); } return stopIndex; } @Override public void setTokenStopIndex(int index) { stopIndex = index; }
For every node in this subtree, make sure it's start/stop token's are set. Walk depth first, visit bottom up. Only updates nodes with at least one token index < 0.
/** For every node in this subtree, make sure it's start/stop token's * are set. Walk depth first, visit bottom up. Only updates nodes * with at least one token index &lt; 0. */
public void setUnknownTokenBoundaries() { if ( children==null ) { if ( startIndex<0 || stopIndex<0 ) { startIndex = stopIndex = token.getTokenIndex(); } return; } for (int i=0; i<children.size(); i++) { ((CommonTree)children.get(i)).setUnknownTokenBoundaries(); } if ( startIndex>=0 && stopIndex>=0 ) return; // already set if ( children.size() > 0 ) { CommonTree firstChild = (CommonTree)children.get(0); CommonTree lastChild = (CommonTree)children.get(children.size()-1); startIndex = firstChild.getTokenStartIndex(); stopIndex = lastChild.getTokenStopIndex(); } } @Override public int getChildIndex() { return childIndex; } @Override public Tree getParent() { return parent; } @Override public void setParent(Tree t) { this.parent = (CommonTree)t; } @Override public void setChildIndex(int index) { this.childIndex = index; } @Override public String toString() { if ( isNil() ) { return "nil"; } if ( getType()==Token.INVALID_TOKEN_TYPE ) { return "<errornode>"; } if ( token==null ) { return null; } return token.getText(); } }