TokenSequence.java

/* Copyright (C) 2002 Univ. of Massachusetts Amherst, Computer Science Dept.
   This file is part of "MALLET" (MAchine Learning for LanguagE Toolkit).
   http://www.cs.umass.edu/~mccallum/mallet
   This software is provided under the terms of the Common Public License,
   version 1.0, as published by http://www.opensource.org.  For further
   information, see the file `LICENSE' included with this distribution. */




/**
 @author Andrew McCallum <a href="mailto:mccallum@cs.umass.edu">mccallum@cs.umass.edu</a>
 */

package cc.mallet.types;


import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;

import cc.mallet.util.PropertyList;

/**
 * A representation of a piece of text, usually a single word, to which we can attach properties.
 */

public class TokenSequence extends ArrayList<Token> implements Sequence, Serializable {
	//ArrayList tokens;
	PropertyList properties = null;				// for arbitrary properties

	public TokenSequence (Collection<Token> tokens) {
		super(tokens);
	}

	public TokenSequence () {
		super();
	}

	public TokenSequence (int capacity) {
		super (capacity);
	}

	public TokenSequence (Token[] tokens) {
		this (tokens.length);
		for (int i = 0; i < tokens.length; i++)
			this.add( tokens[i] );
	}

	public TokenSequence (Object[] tokens) {
		this( tokens.length );
		for (int i = 0; i < tokens.length; i++)
			this.add (new Token( tokens[i].toString()));
	}
	
	//public Token get (int i) {return this.get(i);	}

	public String toString () {
		StringBuffer sb = new StringBuffer();
		sb.append( "TokenSequence " + super.toString() + "\n" );
		for (int i = 0; i < this.size(); i++) {
			String tt = get(i).toString();
			sb.append( "Token#" + i + ":" );
			sb.append( tt );
			if (!tt.endsWith( "\n" ))
				sb.append( "\n" );
		}
		return sb.toString();
	}

	public String toStringShort () {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < this.size(); i++) {
			String tt = get(i).toString();
			tt.replaceAll("\n","");
			if (i > 0){
				sb.append(" ");
			}
			sb.append(tt);
		}
		return sb.toString();
	}

	// gdruck
	// This method causes a compiler error in Eclipse Helios.
	// Removed support for adding Objects other than String.
	/*
	public void add (Object o) {
		if (o instanceof Token)
			add( (Token)o );
		else if (o instanceof TokenSequence)
			add( (TokenSequence)o );
		else
			add( new Token( o.toString() ) );
	}
	*/
	
	public void add(String string) {
		add(new Token(string));
	}

	// added by Fuchun Peng, Oct. 24, 2003
	public Object removeLast () {
		if (this.size() > 0) 
			return this.remove (this.size() - 1);
		else
			return null;
	}


	public void addAll (Object[] objects) {
		for (int i = 0; i < objects.length; i++) {
			if (objects[i] instanceof Token)
				add( (Token)objects[i] );
			else
				add( new Token( objects[i].toString() ) );
		}
	}

	public FeatureSequence toFeatureSequence (Alphabet dict) {
		FeatureSequence fs = new FeatureSequence( dict, this.size() );
		for (int i = 0; i < this.size(); i++)
			fs.add (dict.lookupIndex( (this.get(i)).getText()));
		return fs;
	}

	public FeatureVector toFeatureVector (Alphabet dict) {
		return new FeatureVector( toFeatureSequence( dict ) );
	}

	public void setNumericProperty (String key, double value) {
		properties = PropertyList.add( key, value, properties );
	}

	public void setProperty (String key, Object value) {
		properties = PropertyList.add( key, value, properties );
	}

	public double getNumericProperty (String key) {
		return properties.lookupNumber( key );
	}

	public Object getProperty (String key) {
		return properties.lookupObject( key );
	}

	public boolean hasProperty (String key) {
		return properties.hasProperty( key );
	}

	// added gmann 8/30/2006
	public PropertyList getProperties () {
		return properties;
	}


	// Serialization

	private static final long serialVersionUID = 1;
	private static final int CURRENT_SERIAL_VERSION = 0;

	private void writeObject(ObjectOutputStream out) throws IOException {
		out.writeInt( CURRENT_SERIAL_VERSION );
		out.defaultWriteObject();
	}

	private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
		@SuppressWarnings("unused")
		int version = in.readInt();
		in.defaultReadObject();
	}


}