content: package com.dbflow5.config;
  
  /*
   NaturalOrderComparator.java -- Perform 'natural order' comparisons of strings in Java.
   Copyright (C) 2003 by Pierre-Luc Paour <natorder@paour.com>
  
   Based on the C version by Martin Pool, of which this is more or less a straight conversion.
   Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>
  
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
   arising from the use of this software.
  
   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:
  
   1. The origin of this software must not be misrepresented; you must not
   claim that you wrote the original software. If you use this software
   in a product, an acknowledgment in the product documentation would be
   appreciated but is not required.
   2. Altered source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.
   3. This notice may not be removed or altered from any source distribution.
   */
  
  import java.util.Comparator;
  
  public class NaturalOrderComparator implements Comparator<Object> {
      static char charAt(String s, int i) {
          if (i >= s.length()) {
              return 0;
          } else {
              return s.charAt(i);
          }
      }
  
      public int compare(Object o1, Object o2) {
          String a = o1.toString();
          String b = o2.toString();
  
          int ia = 0, ib = 0;
          int nza = 0, nzb = 0;
          char ca, cb;
          int result;
  
          while (true) {
              // only count the number of zeroes leading the last number compared
              nza = nzb = 0;
  
              ca = charAt(a, ia);
              cb = charAt(b, ib);
  
              // skip over leading spaces or zeros
              while (Character.isSpaceChar(ca) || ca == '0') {
                  if (ca == '0') {
                      nza++;
                  } else {
                      // only count consecutive zeroes
                      nza = 0;
                  }
  
                  ca = charAt(a, ++ia);
              }
  
              while (Character.isSpaceChar(cb) || cb == '0') {
                  if (cb == '0') {
                      nzb++;
                  } else {
                      // only count consecutive zeroes
                      nzb = 0;
                  }
  
                  cb = charAt(b, ++ib);
              }
  
              // process run of digits
              if (Character.isDigit(ca) && Character.isDigit(cb)) {
                  if ((result = compareRight(a.substring(ia), b.substring(ib))) != 0) {
                      return result;
                  }
              }
  
              if (ca == 0 && cb == 0) {
                  // The strings compare the same. Perhaps the caller
                  // will want to call strcmp to break the tie.
                  return nza - nzb;
              }
  
              if (ca < cb) {
                  return -1;
              } else if (ca > cb) {
                  return +1;
              }
  
              ++ia;
              ++ib;
          }
      }
  
      int compareRight(String a, String b) {
          int bias = 0;
          int ia = 0;
          int ib = 0;
  
          // The longest run of digits wins. That aside, the greatest
          // name wins, but we can't know that it will until we've scanned
          // both numbers to know that they have the same magnitude, so we
          // remember it in BIAS.
          for (; ; ia++, ib++) {
              char ca = charAt(a, ia);
              char cb = charAt(b, ib);
  
              if (!Character.isDigit(ca) && !Character.isDigit(cb)) {
                  return bias;
              } else if (!Character.isDigit(ca)) {
                  return -1;
              } else if (!Character.isDigit(cb)) {
                  return +1;
              } else if (ca < cb) {
                  if (bias == 0) {
                      bias = -1;
                  }
              } else if (ca > cb) {
                  if (bias == 0) {
                      bias = +1;
                  }
              } else if (ca == 0 && cb == 0) {
                  return bias;
              }
          }
      }
  }
  