/* Copyright Paul James Mutton, 2001-2004, http://www.jibble.org/This file is part of JMegaHal.This software is dual-licensed, allowing you to choose between the GNUGeneral Public License (GPL) and the www.jibble.org Commercial License.Since the GPL may be too restrictive for use in a proprietary application,a commercial license is also provided. Full license information can befound at http://www.jibble.org/licenses/$Author: pjm2 $$Id: JMegaHal.java,v 1.4 2004/02/01 13:24:06 pjm2 Exp $*/package org.jibble.jmegahal;import java.util.*;import java.net.*;import java.io.*;public class JMegaHal implements Serializable { // These are valid chars for words. Anything else is treated as punctuation. public static final String WORD_CHARS = "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "0123456789"; public static final String END_CHARS = ".!?"; /** * Construct an instance of JMegaHal with an empty brain. */ public JMegaHal() { } /** * Adds an entire documents to the 'brain'. Useful for feeding in * stray theses, but be careful not to put too much in, or you may * run out of memory! */ public void addDocument(String uri) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(new URL(uri).openStream())); StringBuffer buffer = new StringBuffer(); int ch = 0; while ((ch = reader.read()) != -1) { buffer.append((char) ch); if (END_CHARS.indexOf((char) ch) >= 0) { String sentence = buffer.toString(); sentence = sentence.replace('\r', ' '); sentence = sentence.replace('\n', ' '); add(sentence); buffer = new StringBuffer(); } } add(buffer.toString()); reader.close(); } /** * Adds a new sentence to the 'brain' */ public void add(String sentence) { sentence = sentence.trim(); ArrayList parts = new ArrayList(); char[] chars = sentence.toCharArray(); int i = 0; boolean punctuation = false; StringBuffer buffer = new StringBuffer(); while (i < chars.length) { char ch = chars[i]; if ((WORD_CHARS.indexOf(ch) >= 0) == punctuation) { punctuation = !punctuation; String token = buffer.toString(); if (token.length() > 0) { parts.add(token); } buffer = new StringBuffer(); //i++; continue; } buffer.append(ch); i++; } String lastToken = buffer.toString(); if (lastToken.length() > 0) { parts.add(lastToken); } if (parts.size() >= 4) { for (i = 0; i < parts.size() - 3; i++) { //System.out.println("\"" + parts.get(i) + "\""); Quad quad = new Quad((String) parts.get(i), (String) parts.get(i + 1), (String)parts.get(i + 2), (String) parts.get(i + 3)); if (quads.containsKey(quad)) { quad = (Quad) quads.get(quad); } else { quads.put(quad, quad); } if (i == 0) { quad.setCanStart(true); } //else if (i == parts.size() - 4) { if (i == parts.size() - 4) { quad.setCanEnd(true); } for (int n = 0; n < 4; n++) { String token = (String) parts.get(i + n); if (!words.containsKey(token)) { words.put(token, new HashSet(1)); } HashSet set = (HashSet) words.get(token); set.add(quad); } if (i > 0) { String previousToken = (String) parts.get(i - 1); if (!previous.containsKey(quad)) { previous.put(quad, new HashSet(1)); } HashSet set = (HashSet) previous.get(quad); set.add(previousToken); } if (i < parts.size() - 4) { String nextToken = (String) parts.get(i + 4); if (!next.containsKey(quad)) { next.put(quad, new HashSet(1)); } HashSet set = (HashSet) next.get(quad); set.add(nextToken); } } } else { // Didn't learn anything. } } /** * Generate a random sentence from the brain. */ public String getSentence() { return getSentence(null); } /** * Generate a sentence that includes (if possible) the specified word. */ public String getSentence(String word) { LinkedList parts = new LinkedList(); Quad[] quads; if (words.containsKey(word)) { quads = (Quad[]) ((HashSet) words.get(word)).toArray(new Quad[0]); } else { quads = (Quad[]) this.quads.keySet().toArray(new Quad[0]); } if (quads.length == 0) { return ""; } Quad middleQuad = quads[rand.nextInt(quads.length)]; Quad quad = middleQuad; for (int i = 0; i < 4; i++) { parts.add(quad.getToken(i)); } while (quad.canEnd() == false) { String[] nextTokens = (String[]) ((HashSet) next.get(quad)).toArray(new String[0]); String nextToken = nextTokens[rand.nextInt(nextTokens.length)]; quad = (Quad) this.quads.get(new Quad(quad.getToken(1), quad.getToken(2), quad.getToken(3), nextToken)); parts.add(nextToken); } quad = middleQuad; while (quad.canStart() == false) { String[] previousTokens = (String[]) ((HashSet) previous.get(quad)).toArray(new String[0]); String previousToken = previousTokens[rand.nextInt(previousTokens.length)]; quad = (Quad) this.quads.get(new Quad(previousToken, quad.getToken(0), quad.getToken(1), quad.getToken(2))); parts.addFirst(previousToken); } StringBuffer sentence = new StringBuffer(); Iterator it = parts.iterator(); while (it.hasNext()) { String token = (String) it.next(); sentence.append(token); } return sentence.toString(); } // This maps a single word to a HashSet of all the Quads it is in. private HashMap words = new HashMap(); // A self-referential HashMap of Quads. private HashMap quads = new HashMap(); // This maps a Quad onto a Set of Strings that may come next. private HashMap next = new HashMap(); // This maps a Quad onto a Set of Strings that may come before it. private HashMap previous = new HashMap(); private Random rand = new Random();}