/Users/parrt/antlr/code/antlr/main/runtime/Java/src/main/java/org/antlr/runtime/tree/BufferedTreeNodeStream.java

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/*
 [The "BSD license"]
 Copyright (c) 2005-2009 Terence Parr
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
 2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
 3. The name of the author may not be used to endorse or promote products
     derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.antlr.runtime.tree;

import org.antlr.runtime.Token;
import org.antlr.runtime.TokenStream;
import org.antlr.runtime.misc.IntArray;
import java.util.*;

public class BufferedTreeNodeStream implements TreeNodeStream {
        public static final int DEFAULT_INITIAL_BUFFER_SIZE = 100;
        public static final int INITIAL_CALL_STACK_SIZE = 10;

    protected class StreamIterator implements Iterator {
                int i = 0;
                public boolean hasNext() {
                        return i<nodes.size();
                }

                public Object next() {
                        int current = i;
                        i++;
                        if ( current < nodes.size() ) {
                                return nodes.get(current);
                        }
                        return eof;
                }

                public void remove() {
                        throw new RuntimeException("cannot remove nodes from stream");
                }
        }

        // all these navigation nodes are shared and hence they
        // cannot contain any line/column info

        protected Object down;
        protected Object up;
        protected Object eof;

        protected List nodes;

        protected Object root;

        protected TokenStream tokens;

        TreeAdaptor adaptor;

        protected boolean uniqueNavigationNodes = false;

        protected int p = -1;

        protected int lastMarker;

        protected IntArray calls;

        public BufferedTreeNodeStream(Object tree) {
                this(new CommonTreeAdaptor(), tree);
        }

        public BufferedTreeNodeStream(TreeAdaptor adaptor, Object tree) {
                this(adaptor, tree, DEFAULT_INITIAL_BUFFER_SIZE);
        }

        public BufferedTreeNodeStream(TreeAdaptor adaptor, Object tree, int initialBufferSize) {
                this.root = tree;
                this.adaptor = adaptor;
                nodes = new ArrayList(initialBufferSize);
                down = adaptor.create(Token.DOWN, "DOWN");
                up = adaptor.create(Token.UP, "UP");
                eof = adaptor.create(Token.EOF, "EOF");
        }

        protected void fillBuffer() {
                fillBuffer(root);
                //System.out.println("revIndex="+tokenTypeToStreamIndexesMap);
                p = 0; // buffer of nodes intialized now
        }

        public void fillBuffer(Object t) {
                boolean nil = adaptor.isNil(t);
                if ( !nil ) {
                        nodes.add(t); // add this node
                }
                // add DOWN node if t has children
                int n = adaptor.getChildCount(t);
                if ( !nil && n>0 ) {
                        addNavigationNode(Token.DOWN);
                }
                // and now add all its children
                for (int c=0; c<n; c++) {
                        Object child = adaptor.getChild(t,c);
                        fillBuffer(child);
                }
                // add UP node if t has children
                if ( !nil && n>0 ) {
                        addNavigationNode(Token.UP);
                }
        }

        protected int getNodeIndex(Object node) {
                if ( p==-1 ) {
                        fillBuffer();
                }
                for (int i = 0; i < nodes.size(); i++) {
                        Object t = (Object) nodes.get(i);
                        if ( t==node ) {
                                return i;
                        }
                }
                return -1;
        }

        protected void addNavigationNode(final int ttype) {
                Object navNode = null;
                if ( ttype==Token.DOWN ) {
                        if ( hasUniqueNavigationNodes() ) {
                                navNode = adaptor.create(Token.DOWN, "DOWN");
                        }
                        else {
                                navNode = down;
                        }
                }
                else {
                        if ( hasUniqueNavigationNodes() ) {
                                navNode = adaptor.create(Token.UP, "UP");
                        }
                        else {
                                navNode = up;
                        }
                }
                nodes.add(navNode);
        }

        public Object get(int i) {
                if ( p==-1 ) {
                        fillBuffer();
                }
                return nodes.get(i);
        }

        public Object LT(int k) {
                if ( p==-1 ) {
                        fillBuffer();
                }
                if ( k==0 ) {
                        return null;
                }
                if ( k<0 ) {
                        return LB(-k);
                }
                //System.out.print("LT(p="+p+","+k+")=");
                if ( (p+k-1) >= nodes.size() ) {
                        return eof;
                }
                return nodes.get(p+k-1);
        }

        public Object getCurrentSymbol() { return LT(1); }

/*
        public Object getLastTreeNode() {
                int i = index();
                if ( i>=size() ) {
                        i--; // if at EOF, have to start one back
                }
                System.out.println("start last node: "+i+" size=="+nodes.size());
                while ( i>=0 &&
                        (adaptor.getType(get(i))==Token.EOF ||
                         adaptor.getType(get(i))==Token.UP ||
                         adaptor.getType(get(i))==Token.DOWN) )
                {
                        i--;
                }
                System.out.println("stop at node: "+i+" "+nodes.get(i));
                return nodes.get(i);
        }
*/
        
        protected Object LB(int k) {
                if ( k==0 ) {
                        return null;
                }
                if ( (p-k)<0 ) {
                        return null;
                }
                return nodes.get(p-k);
        }

        public Object getTreeSource() {
                return root;
        }

        public String getSourceName() {
                return getTokenStream().getSourceName();
        }

        public TokenStream getTokenStream() {
                return tokens;
        }

        public void setTokenStream(TokenStream tokens) {
                this.tokens = tokens;
        }

        public TreeAdaptor getTreeAdaptor() {
                return adaptor;
        }

        public void setTreeAdaptor(TreeAdaptor adaptor) {
                this.adaptor = adaptor;
        }

        public boolean hasUniqueNavigationNodes() {
                return uniqueNavigationNodes;
        }

        public void setUniqueNavigationNodes(boolean uniqueNavigationNodes) {
                this.uniqueNavigationNodes = uniqueNavigationNodes;
        }

        public void consume() {
                if ( p==-1 ) {
                        fillBuffer();
                }
                p++;
        }

        public int LA(int i) {
                return adaptor.getType(LT(i));
        }

        public int mark() {
                if ( p==-1 ) {
                        fillBuffer();
                }
                lastMarker = index();
                return lastMarker;
        }

        public void release(int marker) {
                // no resources to release
        }

        public int index() {
                return p;
        }

        public void rewind(int marker) {
                seek(marker);
        }

        public void rewind() {
                seek(lastMarker);
        }

        public void seek(int index) {
                if ( p==-1 ) {
                        fillBuffer();
                }
                p = index;
        }

        public void push(int index) {
                if ( calls==null ) {
                        calls = new IntArray();
                }
                calls.push(p); // save current index
                seek(index);
        }

        public int pop() {
                int ret = calls.pop();
                seek(ret);
                return ret;
        }

        public void reset() {
                p = 0;
                lastMarker = 0;
        if (calls != null) {
            calls.clear();
        }
    }

        public int size() {
                if ( p==-1 ) {
                        fillBuffer();
                }
                return nodes.size();
        }

        public Iterator iterator() {
                if ( p==-1 ) {
                        fillBuffer();
                }
                return new StreamIterator();
        }

        // TREE REWRITE INTERFACE

        public void replaceChildren(Object parent, int startChildIndex, int stopChildIndex, Object t) {
                if ( parent!=null ) {
                        adaptor.replaceChildren(parent, startChildIndex, stopChildIndex, t);
                }
        }

        public String toTokenTypeString() {
                if ( p==-1 ) {
                        fillBuffer();
                }
                StringBuffer buf = new StringBuffer();
                for (int i = 0; i < nodes.size(); i++) {
                        Object t = (Object) nodes.get(i);
                        buf.append(" ");
                        buf.append(adaptor.getType(t));
                }
                return buf.toString();
        }

        public String toTokenString(int start, int stop) {
                if ( p==-1 ) {
                        fillBuffer();
                }
                StringBuffer buf = new StringBuffer();
                for (int i = start; i < nodes.size() && i <= stop; i++) {
                        Object t = (Object) nodes.get(i);
                        buf.append(" ");
                        buf.append(adaptor.getToken(t));
                }
                return buf.toString();
        }

        public String toString(Object start, Object stop) {
                System.out.println("toString");
                if ( start==null || stop==null ) {
                        return null;
                }
                if ( p==-1 ) {
                        fillBuffer();
                }
                //System.out.println("stop: "+stop);
                if ( start instanceof CommonTree )
                        System.out.print("toString: "+((CommonTree)start).getToken()+", ");
                else
                        System.out.println(start);
                if ( stop instanceof CommonTree )
                        System.out.println(((CommonTree)stop).getToken());
                else
                        System.out.println(stop);
                // if we have the token stream, use that to dump text in order
                if ( tokens!=null ) {
                        int beginTokenIndex = adaptor.getTokenStartIndex(start);
                        int endTokenIndex = adaptor.getTokenStopIndex(stop);
                        // if it's a tree, use start/stop index from start node
                        // else use token range from start/stop nodes
                        if ( adaptor.getType(stop)==Token.UP ) {
                                endTokenIndex = adaptor.getTokenStopIndex(start);
                        }
                        else if ( adaptor.getType(stop)==Token.EOF ) {
                                endTokenIndex = size()-2; // don't use EOF
                        }
                        return tokens.toString(beginTokenIndex, endTokenIndex);
                }
                // walk nodes looking for start
                Object t = null;
                int i = 0;
                for (; i < nodes.size(); i++) {
                        t = nodes.get(i);
                        if ( t==start ) {
                                break;
                        }
                }
                // now walk until we see stop, filling string buffer with text
                 StringBuffer buf = new StringBuffer();
                t = nodes.get(i);
                while ( t!=stop ) {
                        String text = adaptor.getText(t);
                        if ( text==null ) {
                                text = " "+String.valueOf(adaptor.getType(t));
                        }
                        buf.append(text);
                        i++;
                        t = nodes.get(i);
                }
                // include stop node too
                String text = adaptor.getText(stop);
                if ( text==null ) {
                        text = " "+String.valueOf(adaptor.getType(stop));
                }
                buf.append(text);
                return buf.toString();
        }
}

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