pointertype.java

WordNet is an extensive database developed by Princeton University faculty and students over the las

/*
 * WordNet-Java
 *
 * Copyright 1998 by Oliver Steele.  You can use this software freely so long as you preserve
 * the copyright notice and this restriction, and label your changes.
 */
package edu.gwu.wordnet;
import  edu.gwu.wordnet.util.*;
import java.util.NoSuchElementException;

/** Instances of this class enumerate the possible WordNet pointer types, and are used to label <code>PointerType</code>s.
 * Each <code>PointerType</code> carries additional information:
 * a human-readable label, an optional reflexive type that labels links pointing the opposite direction,
 * an encoding of parts-of-speech that it applies to, and a short string that represents it in the dictionary files.
 *
 * @see Pointer
 * @see POS
 * @author Oliver Steele, [e-mail]
 * @version 1.0
 */
public class PointerType {
	// Flags for tagging a pointer type with the POS types it apples to.
	protected static final int N = 1;
	protected static final int V = 2;
	protected static final int ADJ = 4;
	protected static final int ADV = 8;
	protected static final int LEXICAL = 16;
	
	protected static final POS[] CATS = {POS.NOUN, POS.VERB, POS.ADJ, POS.ADV};
	protected static final int[] POS_MASK = {N, V, ADJ, ADV};
	
	// All categories
	public static final PointerType ANTONYM = new PointerType("antonym", "!", N | V | ADJ | ADV | LEXICAL);

	// Nouns and Verbs
	public static final PointerType HYPERNYM = new PointerType("hypernym", "@", N | V);
	public static final PointerType HYPONYM = new PointerType("hyponym", "~", N | V);

	// Nouns and Adjectives
	public static final PointerType ATTRIBUTE = new PointerType("attribute", "=", N | ADJ);
	public static final PointerType SEE_ALSO = new PointerType("also see", "^", N | ADJ | LEXICAL);

	// Verbs
	public static final PointerType ENTAILMENT = new PointerType("entailment", "*", V);
	public static final PointerType CAUSE = new PointerType("cause", ">", V);
	public static final PointerType VERB_GROUP = new PointerType("verb group", "$", V);

	// Nouns
	public static final PointerType MEMBER_MERONYM = new PointerType("member meronym", "#m", N);
	public static final PointerType SUBSTANCE_MERONYM = new PointerType("substance meronym", "#s", N);
	public static final PointerType PART_MERONYM = new PointerType("part meronym", "#p", N);
	public static final PointerType MEMBER_HOLONYM = new PointerType("member holonym", "%m", N);
	public static final PointerType SUBSTANCE_HOLONYM = new PointerType("substance holonym", "%s", N);
	public static final PointerType PART_HOLONYM = new PointerType("part holonym", "%p", N);
	
	// Adjectives
	public static final PointerType SIMILAR_TO = new PointerType("similar", "&", ADJ);
	public static final PointerType PARTICIPLE_OF = new PointerType("participle of", "<", ADJ | LEXICAL);
	public static final PointerType PERTAINYM = new PointerType("pertainym", "\\", ADJ | LEXICAL);

	// Adverbs
	public static final PointerType DERIVED = new PointerType("derived from", "\\", ADV);	// from adjective

	/** A list of all <code>PointerType</code>s. */
	public static final PointerType[] TYPES = {ANTONYM, HYPERNYM, HYPONYM, ATTRIBUTE, SEE_ALSO,
						    ENTAILMENT, CAUSE, VERB_GROUP,
						    MEMBER_MERONYM, SUBSTANCE_MERONYM, PART_MERONYM,
						    MEMBER_HOLONYM, SUBSTANCE_HOLONYM, PART_HOLONYM,
						    SIMILAR_TO, PARTICIPLE_OF, PERTAINYM, DERIVED};
	
	static protected void setSymmetric(PointerType a, PointerType b) {
		a.symmetricType = b;
		b.symmetricType = a;
	}
	
	static {
		setSymmetric(ANTONYM, ANTONYM);
		setSymmetric(HYPERNYM, HYPONYM);
		setSymmetric(MEMBER_MERONYM, MEMBER_HOLONYM);
		setSymmetric(SUBSTANCE_MERONYM, SUBSTANCE_HOLONYM);
		setSymmetric(PART_MERONYM, PART_HOLONYM);
		setSymmetric(SIMILAR_TO, SIMILAR_TO);
	}
	
	/** Return the <code>PointerType</code> whose key matches <var>key</var>.
	 * @exception NoSuchElementException If <var>key</var> doesn't name any <code>PointerType</code>.
	 */
	static PointerType parseKey(String key) {
		for (int i = 0; i < TYPES.length; ++i) {
			PointerType type = TYPES[i];
			if (type.key.equals(key)) {
				return type;
			}
		}
                // Need to make exception for these symbols that will be used in wordnet 2.0
                if (key.equals("+")) {
                    return null;
                }
		throw new NoSuchElementException("unknown link type " + key);
	}
	
	/*
	 * Instance Interface
	 */
	protected String label;
	protected String key;
	protected int flags;
	protected PointerType symmetricType;
	
	protected PointerType(String label, String key, int flags) {
		this.label = label;
		this.key = key;
		this.flags = flags;
	}
	
	public String getLabel() {
		return label;
	}
	
	public boolean appliesTo(POS pos) {
		return (flags & POS_MASK[ArrayUtilities.indexOf(CATS, pos)]) != 0;
	}
	
	public boolean symmetricTo(PointerType type) {
		return symmetricType != null && symmetricType.equals(type);
	}
}