charsequence2tokensequence.java

常用机器学习算法,java编写源代码,内含常用分类算法,包括说明文档

/* 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:[e-mail]">[e-mail]</a>
 */

package edu.umass.cs.mallet.base.pipe;

import edu.umass.cs.mallet.base.types.TokenSequence;
import edu.umass.cs.mallet.base.types.Token;
import edu.umass.cs.mallet.base.types.Instance;
import edu.umass.cs.mallet.base.util.Lexer;
import edu.umass.cs.mallet.base.util.CharSequenceLexer;
import java.io.*;
import java.net.URI;

/**
 *  Pipe that tokenizes a character sequence.  Expects a CharSequence
 *   in the Instance data, and converts the sequence into a token
 *   sequence using the given regex or CharSequenceLexer.  
 *   (The regex / lexer should specify what counts as a token.)
 */
public class CharSequence2TokenSequence extends Pipe implements Serializable
{
	CharSequenceLexer lexer;
	
	public CharSequence2TokenSequence (CharSequenceLexer lexer)
	{
		this.lexer = lexer;
	}

	public CharSequence2TokenSequence (String regex)
	{
		this.lexer = new CharSequenceLexer (regex);
	}

	public CharSequence2TokenSequence ()
	{
		this (new CharSequenceLexer());
	}

	public Instance pipe (Instance carrier)
	{
		CharSequence string = (CharSequence) carrier.getData();
		lexer.setCharSequence (string);
		TokenSequence ts = new TokenSequence ();
		while (lexer.hasNext())
			ts.add (new Token ((String) lexer.next()));
		carrier.setData(ts);
		return carrier;
	}

	public static void main (String[] args)
	{
		try {
			for (int i = 0; i < args.length; i++) {
				Instance carrier = new Instance (new File(args[i]), null, null, null);
				Pipe p = new SerialPipes (new Pipe[] {
					new Input2CharSequence (),
					new CharSequence2TokenSequence(new CharSequenceLexer())});
				carrier = p.pipe (carrier);
				TokenSequence ts = (TokenSequence) carrier.getData();
				System.out.println ("===");
				System.out.println (args[i]);
				System.out.println (ts.toString());
			}
		} catch (Exception e) {
			System.out.println (e);
			e.printStackTrace();
		}
	}

	// 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.writeObject(lexer);
	}
	
	private void readObject (ObjectInputStream in) throws IOException, ClassNotFoundException {
		int version = in.readInt ();
		lexer = (CharSequenceLexer) in.readObject();
	}


	
}