code: /* LanguageTool, a natural language style checker
   * Copyright (C) 2015 Daniel Naber (http://www.danielnaber.de)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
   * USA
   */
  package org.languagetool.dev.dumpcheck;
  
  import org.languagetool.Language;
  
  import java.io.InputStream;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.NoSuchElementException;
  import java.util.Scanner;
  import java.util.regex.Pattern;
  
  /**
   * Provides access to the relevant sentences of a plain text file
   * with one sentence per line.
   * @since 3.0
   */
  public class PlainTextSentenceSource extends SentenceSource {
  
    private final List<String> sentences;
    private final Scanner scanner;
  
    // Each sentence is one article, but count anyway so it's coherent with what the Wikipedia code does:
    private int articleCount = 0;
    private String currentUrl = null;
  
    public PlainTextSentenceSource(InputStream textInput, Language language) {
      this(textInput, language, null);
    }
    
    /** @since 3.0 */
    public PlainTextSentenceSource(InputStream textInput, Language language, Pattern filter) {
      super(language, filter);
      scanner = new Scanner(textInput);
      sentences = new ArrayList<>();
    }
  
    @Override
    public boolean hasNext() {
      fillSentences();
      return sentences.size() > 0;
    }
  
    @Override
    public Sentence next() {
      fillSentences();
      if (sentences.isEmpty()) {
        throw new NoSuchElementException();
      }
      return new Sentence(sentences.remove(0), getSource(), "<plaintext>", null, ++articleCount);
    }
  
    @Override
    public String getSource() {
      return currentUrl;
    }
  
    private void fillSentences() {
      while (sentences.isEmpty() && scanner.hasNextLine()) {
        String line = scanner.nextLine();
        if (line.isEmpty()) {
          continue;
        }
        if (line.startsWith("# source:")) {
          currentUrl = line.substring("# source: ".length());
          continue;
        }
        if (acceptSentence(line)) {
          sentences.add(line);
        }
      }
    }
  
  }
  