package org.codehaus.plexus.util.cli;
   
   /*
    * Copyright The Codehaus Foundation.
    *
    * Licensed 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.
   */
  
  import java.util.StringTokenizer;
  
  /**
   * The java.util.StringTokenizer is horribly broken. Given the string 1,,,3,,4 (, delim) It will return 1,3,4 Which is
   * clearly wrong - 1,EMPTY,EMPTY,3,EMPTY,4 is what it should return
   *
   *
   */
  public final class EnhancedStringTokenizer {
      private StringTokenizer cst = null;
  
      String cdelim;
  
      final boolean cdelimSingleChar;
  
      final char cdelimChar;
  
      boolean creturnDelims;
  
      String lastToken = null;
  
      boolean delimLast = true;
  
      public EnhancedStringTokenizer(String str) {
          this(str, " \t\n\r\f", false);
      }
  
      public EnhancedStringTokenizer(String str, String delim) {
          this(str, delim, false);
      }
  
      public EnhancedStringTokenizer(String str, String delim, boolean returnDelims) {
          cst = new StringTokenizer(str, delim, true);
          cdelim = delim;
          creturnDelims = returnDelims;
          cdelimSingleChar = (delim.length() == 1);
          cdelimChar = delim.charAt(0);
      }
  
      public boolean hasMoreTokens() {
          return cst.hasMoreTokens();
      }
  
      private String internalNextToken() {
          if (lastToken != null) {
              String last = lastToken;
              lastToken = null;
              return last;
          }
  
          String token = cst.nextToken();
          if (isDelim(token)) {
              if (delimLast) {
                  lastToken = token;
                  return "";
              } else {
                  delimLast = true;
                  return token;
              }
          } else {
              delimLast = false;
              return token;
          }
      }
  
      public String nextToken() {
          String token = internalNextToken();
          if (creturnDelims) {
              return token;
          }
          if (isDelim(token)) {
              return hasMoreTokens() ? internalNextToken() : "";
          } else {
              return token;
          }
      }
  
      private boolean isDelim(String str) {
          if (str.length() == 1) {
              char ch = str.charAt(0);
              if (cdelimSingleChar) {
                 if (cdelimChar == ch) {
                     return true;
                 }
             } else {
                 if (cdelim.indexOf(ch) >= 0) {
                     return true;
                 }
             }
         }
         return false;
     }
 }