/* 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. */
package cc.mallet.pipe;
import java.io.*;
import java.net.URI;
import java.util.regex.*;
import java.util.logging.Logger;
import cc.mallet.extract.StringSpan;
import cc.mallet.extract.StringTokenization;
import cc.mallet.types.Instance;
import cc.mallet.types.Token;
import cc.mallet.types.TokenSequence;
import cc.mallet.util.CharSequenceLexer;
import cc.mallet.util.Lexer;
import cc.mallet.util.MalletLogger;
/**
Converts a string containing simple SGML tags into a dta TokenSequence of words,
paired with a target TokenSequence containing the SGML tags in effect for each word.
It does not handle nested SGML tags, nor gracefully handle malformed SGML.
@author Andrew McCallum <a href="mailto:mccallum@cs.umass.edu">mccallum@cs.umass.edu</a>
*/
public class SGML2TokenSequence extends Pipe implements Serializable
{
private static Logger logger = MalletLogger.getLogger (SGML2TokenSequence.class.getName());
Pattern sgmlPattern = Pattern.compile ("</?([^>]*)>");
CharSequenceLexer lexer;
String backgroundTag;
private boolean saveSource = true;
public SGML2TokenSequence (CharSequenceLexer lexer, String backgroundTag, boolean saveSource)
{
this.lexer = lexer;
this.backgroundTag = backgroundTag;
this.saveSource = saveSource;
}
public SGML2TokenSequence (CharSequenceLexer lexer, String backgroundTag)
{
this.lexer = lexer;
this.backgroundTag = backgroundTag;
}
public SGML2TokenSequence (String regex, String backgroundTag)
{
this.lexer = new CharSequenceLexer (regex);
this.backgroundTag = backgroundTag;
}
public SGML2TokenSequence ()
{
this (new CharSequenceLexer(), "O");
}
public Instance pipe (Instance carrier)
{
CharSequence string = (CharSequence) carrier.getData();
StringTokenization dataTokens = new StringTokenization (string);
TokenSequence targetTokens = new TokenSequence ();
String tag = backgroundTag;
String nextTag = backgroundTag;
Matcher m = sgmlPattern.matcher (string);
int textStart = 0;
int textEnd = 0;
int nextStart = 0;
boolean done = false;
logger.fine(sgmlPattern.pattern());
logger.finer(string.toString());
while (!done) {
done = !(m.find());
if (done)
textEnd = string.length(); // culotta: changed from string.length()-1
else {
String sgml = m.group();
logger.finer ("SGML = "+sgml);
int groupCount = m.groupCount();
logger.finer(Integer.toString (groupCount));
if (sgml.charAt(1) == '/')
nextTag = backgroundTag;
else{
//nextTag = m.group(0);
nextTag = sgml.substring(1, sgml.length()-1);
}
logger.finer("nextTag: " + nextTag);
nextStart = m.end(); // m.end returns one beyond index of last match char
textEnd = m.start(); // String.subtring does not include index end
logger.finer ("Text start/end "+textStart+" "+textEnd);
}
if (textEnd - textStart > 0) {
logger.finer ("Tag = "+tag);
logger.finer ("Target = "+string.subSequence (textStart, textEnd));
lexer.setCharSequence (string.subSequence (textStart, textEnd));
while (lexer.hasNext()) {
lexer.next ();
int tokStart = textStart + lexer.getStartOffset ();
int tokEnd = textStart + lexer.getEndOffset ();
dataTokens.add (new StringSpan (string, tokStart, tokEnd));
targetTokens.add (new Token (tag));
}
}
textStart = nextStart;
tag = nextTag;
}
carrier.setData(dataTokens);
carrier.setTarget(targetTokens);
if (saveSource)
carrier.setSource(dataTokens);
return carrier;
}
public static void main (String[] args)
{
try {
Pipe p = new SerialPipes (new Pipe[] {
new Input2CharSequence (),
new SGML2TokenSequence()
// new SGML2TokenSequence (new CharSequenceLexer (Pattern.compile (".")), "O")
});
for (int i = 0; i < args.length; i++) {
Instance carrier = p.instanceFrom(new Instance (new File(args[i]), null, null, null));
TokenSequence data = (TokenSequence) carrier.getData();
TokenSequence target = (TokenSequence) carrier.getTarget();
logger.finer ("===");
logger.info (args[i]);
for (int j = 0; j < data.size(); j++)
logger.info (target.get(j).getText()+" "+data.get(j).getText());
}
} catch (Exception e) {
System.out.println (e);
e.printStackTrace();
}
}
// Serialization
private static final long serialVersionUID = 1;
// Version history
// 1: add save source
private static final int CURRENT_SERIAL_VERSION = 1;
private void writeObject (ObjectOutputStream out) throws IOException {
out.writeInt(CURRENT_SERIAL_VERSION);
out.writeObject(sgmlPattern);
out.writeObject(lexer);
out.writeObject(backgroundTag);
out.writeBoolean(saveSource);
}
private void readObject (ObjectInputStream in) throws IOException, ClassNotFoundException {
int version = in.readInt ();
sgmlPattern = (Pattern) in.readObject();
lexer = (CharSequenceLexer) in.readObject();
backgroundTag = (String) in.readObject();
if (version == 0) saveSource = true;
}
}