Utils.java

/**
 * 
 * Copyright 1999-2012 Carnegie Mellon University.  
 * Portions Copyright 2002 Sun Microsystems, Inc.  
 * Portions Copyright 2002 Mitsubishi Electric Research Laboratories.
 * All Rights Reserved.  Use is subject to license terms.
 * 
 * See the file "license.terms" for information on usage and
 * redistribution of this file, and for a DISCLAIMER OF ALL 
 * WARRANTIES.
 *
 */

package edu.cmu.sphinx.fst.utils;

import java.util.ArrayList;
import java.util.HashMap;

/**
 * Several general use utility functions needed by the fst framework
 * 
 * @author John Salatas
 */
public class Utils {

    /**
     * Searches an ArrayList of Strings starting from a specific position for a
     * pattern
     * 
     * @param src the input ArrayList of Strings
     * @param pattern the pattern to search for
     * @param start the starting position
     * @return the index of the first occurrence or -1 if no matches found
     */
    public static int search(ArrayList<String> src, ArrayList<String> pattern,
            int start) {
        int index = -1;
        int pos = -1;
        int startpos = 0;
        if (start > src.size() - pattern.size()) {
            return -1;
        }

        do {
            pos = src
                    .subList(startpos + start, src.size() - pattern.size() + 1)
                    .indexOf(pattern.get(0));
            if (pos == -1) {
                return pos;
            }

            boolean flag = true;
            for (int i = 1; i < pattern.size(); i++) {
                if (!src.get(startpos + start + pos + i).equals(pattern.get(i))) {
                    index = -1;
                    flag = false;
                    break;
                }
            }

            if (flag) {
                index = startpos + pos;
                break;
            } else {
                startpos += pos + 1;
            }
        } while (startpos + start < src.size());

        return index;
    }

    /**
     * Get the position (index) of a particular string in a Strings array.
     * 
     * The search is case insensitive.
     * 
     * @param strings the Strings array
     * @param string the string to search
     * @return the index of the first occurrence or -1 if no matches found
     */
    public static int getIndex(String[] strings, String string) {
        for (int i = 0; i < strings.length; i++) {
            if (string.toLowerCase().equals(strings[i].toLowerCase())) {
                return i;
            }
        }
        return -1;
    }

    /**
     * Convert a HashMap to string array
     * 
     * @param syms the input HashMap
     * @return the strings array
     */
    public static String[] toStringArray(HashMap<String, Integer> syms) {
        String[] res = new String[syms.size()];
        for (String sym : syms.keySet()) {
            res[syms.get(sym)] = sym;
        }
        return res;
    }
}