| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.pig.tutorial; |
| |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Set; |
| |
| public class TutorialUtil { |
| |
| /** |
| * This function splits a search query string into a set |
| * of non-empty words |
| */ |
| protected static String[] splitToWords(String query) { |
| List<String> res = new LinkedList<String>(); |
| String[] words = query.split("\\W"); |
| for (String word : words) { |
| if (!word.equals("")) { |
| res.add(word); |
| } |
| } |
| return res.toArray(new String[res.size()]); |
| } |
| |
| /** |
| * This is a simple utility function that make word-level |
| * ngrams from a set of words |
| * @param words |
| * @param ngrams |
| * @param size |
| */ |
| protected static void makeNGram(String[] words, Set<String> ngrams, int size) { |
| int stop = words.length - size + 1; |
| for (int i = 0; i < stop; i++) { |
| StringBuilder sb = new StringBuilder(); |
| for (int j = 0; j < size; j++) { |
| sb.append(words[i + j]).append(" "); |
| } |
| sb.deleteCharAt(sb.length() - 1); |
| ngrams.add(sb.toString()); |
| } |
| if (size > 1) { |
| makeNGram(words, ngrams, size - 1); |
| } |
| } |
| |
| } |