Token.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 edu.nd.nina.types;

import edu.nd.nina.util.PropertyList;

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

public class Token implements PropertyHolder {

	private String text;
	PropertyList properties = null; // for arbitrary properties
	PropertyList features = null; // numeric, to turn into a FeatureVector

	public Token(String s) {
		text = s;
	}

	public String getText() {
		return text;
	}

	public void setText(String t) {
		text = t;
	}

	// xxx This implementation may change in the future!
	// If you really just want the text, you should use Token.getText() instead.
	public String toString() {
		StringBuffer sb = new StringBuffer();
		sb.append(getText());
		if (features != null) {
			PropertyList.Iterator iter = features.iterator();
			while (iter.hasNext()) {
				iter.next();
				sb.append(" feature(" + iter.getKey() + ")="
						+ iter.getNumericValue());
			}
		}
		if (properties != null) {
			PropertyList.Iterator iter = properties.iterator();
			while (iter.hasNext()) {
				iter.next();
				if (iter.isNumeric())
					sb.append(" property(" + iter.getKey() + ")="
							+ iter.getNumericValue());
				else
					sb.append(" property(" + iter.getKey() + ")="
							+ iter.getObjectValue());
			}
		}
		return sb.toString();
	}

	public String toStringWithFeatureNames() {
		StringBuffer sb = new StringBuffer();
		sb.append(getText());
		if (features != null) {
			PropertyList.Iterator iter = features.iterator();
			while (iter.hasNext()) {
				iter.next();
				sb.append(" " + iter.getKey());
			}
		}
		return sb.toString();
	}

	public FeatureVector toFeatureVector(Alphabet dict, boolean binary) {
		return new FeatureVector(dict, features, binary);
	}

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

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

	public PropertyList getProperties() {
		return properties;
	}

	public void setProperties(PropertyList newProperties) {
		properties = newProperties;
	}

	public Object getProperty(String key) {
		return properties == null ? null : properties.lookupObject(key);
	}

	public double getNumericProperty(String key) {
		return (properties == null ? 0.0 : properties.lookupNumber(key));
	}

	public boolean hasProperty(String key) {
		return (properties != null && properties.hasProperty(key));
	}

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

	public double getFeatureValue(String key) {
		return (features == null ? 0.0 : features.lookupNumber(key));
	}

	public PropertyList getFeatures() {
		return features;
	}

	public void setFeatures(PropertyList pl) {
		features = pl;
	}

}