/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.hql.ast.util;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Map;
import org.hibernate.hql.ast.tree.DisplayableNode;
import org.hibernate.util.StringHelper;
import antlr.collections.AST;
/**
* Utility for generating pretty "ASCII art" representations of syntax trees.
*
* @author Joshua Davis
* @author Steve Ebersole
*/
public class ASTPrinter {
private final Map tokenTypeNameCache;
private final boolean showClassNames;
/**
* Constructs a printer.
* <p/>
* Delegates to {@link #ASTPrinter(Class, boolean)} with {@link #isShowClassNames showClassNames} as <tt>true</tt>
*
* @param tokenTypeConstants The token types to use during printing; typically the {vocabulary}TokenTypes.java
* interface generated by ANTLR.
*/
public ASTPrinter(Class tokenTypeConstants) {
this( ASTUtil.generateTokenNameCache( tokenTypeConstants ), true );
}
public ASTPrinter(boolean showClassNames) {
this( ( Map ) null, showClassNames );
}
/**
* Constructs a printer.
*
* @param tokenTypeConstants The token types to use during printing; typically the {vocabulary}TokenTypes.java
* interface generated by ANTLR.
* @param showClassNames Should the AST class names be shown.
*/
public ASTPrinter(Class tokenTypeConstants, boolean showClassNames) {
this( ASTUtil.generateTokenNameCache( tokenTypeConstants ), showClassNames );
}
private ASTPrinter(Map tokenTypeNameCache, boolean showClassNames) {
this.tokenTypeNameCache = tokenTypeNameCache;
this.showClassNames = showClassNames;
}
/**
* Getter for property 'showClassNames'.
*
* @return Value for property 'showClassNames'.
*/
public boolean isShowClassNames() {
return showClassNames;
}
/**
* Renders the AST into 'ASCII art' form and returns that string representation.
*
* @param ast The AST to display.
* @param header The header for the display.
*
* @return The AST in 'ASCII art' form, as a string.
*/
public String showAsString(AST ast, String header) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream ps = new PrintStream( baos );
ps.println( header );
showAst( ast, ps );
ps.flush();
return new String( baos.toByteArray() );
}
/**
* Prints the AST in 'ASCII art' form to the specified print stream.
*
* @param ast The AST to print.
* @param out The print stream to which the AST should be printed.
*/
public void showAst(AST ast, PrintStream out) {
showAst( ast, new PrintWriter( out ) );
}
/**
* Prints the AST in 'ASCII art' tree form to the specified print writer.
*
* @param ast The AST to print.
* @param pw The print writer to which the AST should be written.
*/
public void showAst(AST ast, PrintWriter pw) {
ArrayList parents = new ArrayList();
showAst( parents, pw, ast );
pw.flush();
}
/**
* Returns the token type name for the given token type.
*
* @param type The token type.
* @return String - The token type name from the token type constant class,
* or just the integer as a string if none exists.
*/
public String getTokenTypeName(int type) {
final Integer typeInteger = new Integer( type );
String value = null;
if ( tokenTypeNameCache != null ) {
value = ( String ) tokenTypeNameCache.get( typeInteger );
}
if ( value == null ) {
value = typeInteger.toString();
}
return value;
}
private void showAst(ArrayList parents, PrintWriter pw, AST ast) {
if ( ast == null ) {
pw.println( "AST is null!" );
return;
}
for ( int i = 0; i < parents.size(); i++ ) {
AST parent = ( AST ) parents.get( i );
if ( parent.getNextSibling() == null ) {
pw.print( " " );
}
else {
pw.print( " | " );
}
}
if ( ast.getNextSibling() == null ) {
pw.print( " \\-" );
}
else {
pw.print( " +-" );
}
showNode( pw, ast );
ArrayList newParents = new ArrayList( parents );
newParents.add( ast );
for ( AST child = ast.getFirstChild(); child != null; child = child.getNextSibling() ) {
showAst( newParents, pw, child );
}
newParents.clear();
}
private void showNode(PrintWriter pw, AST ast) {
String s = nodeToString( ast, isShowClassNames() );
pw.println( s );
}
public String nodeToString(AST ast, boolean showClassName) {
if ( ast == null ) {
return "{node:null}";
}
StringBuffer buf = new StringBuffer();
buf.append( "[" ).append( getTokenTypeName( ast.getType() ) ).append( "] " );
if ( showClassName ) {
buf.append( StringHelper.unqualify( ast.getClass().getName() ) ).append( ": " );
}
buf.append( "'" );
String text = ast.getText();
if ( text == null ) {
text = "{text:null}";
}
appendEscapedMultibyteChars(text, buf);
buf.append( "'" );
if ( ast instanceof DisplayableNode ) {
DisplayableNode displayableNode = ( DisplayableNode ) ast;
// Add a space before the display text.
buf.append( " " ).append( displayableNode.getDisplayText() );
}
return buf.toString();
}
public static void appendEscapedMultibyteChars(String text, StringBuffer buf) {
char[] chars = text.toCharArray();
for (int i = 0; i < chars.length; i++) {
char aChar = chars[i];
if (aChar > 256) {
buf.append("\\u");
buf.append(Integer.toHexString(aChar));
}
else
buf.append(aChar);
}
}
public static String escapeMultibyteChars(String text) {
StringBuffer buf = new StringBuffer();
appendEscapedMultibyteChars(text,buf);
return buf.toString();
}
}