code: package pl.sdadas.fstlexicon.command;
  
  import org.apache.commons.lang3.StringUtils;
  import pl.sdadas.fstlexicon.fst.FSTSearch;
  
  import java.util.Map;
  import java.util.stream.Collectors;
  
  /**
   * @author Sławomir Dadas
   */
  public class ListDictionaries implements Command {
  
      @Override
      public boolean readable(String input) {
          return StringUtils.strip(input).equalsIgnoreCase("--list");
      }
  
      @Override
      public void read(String input, Map<String, FSTSearch<Long>> dictionaries) {
          String output = dictionaries.keySet().stream().sorted().collect(Collectors.joining(" "));
          System.err.println(output);
      }
  }
  