old-autovect-branch/libjava/gnu/gcj/convert/Input_JavaSrc.java

   1 /* Copyright (C) 1999  Free Software Foundation
   2
   3    This file is part of libgcj.
   4
   5 This software is copyrighted work licensed under the terms of the
   6 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   7 details.  */
   8
   9 package gnu.gcj.convert;
  10
  11 /**
  12  * Convert Ascii with \ u XXXX-escapes to Unicode.
  13  * @author Per Bothner <bothner@cygnus.com>
  14  * @date April 1999.
  15  */
  16
  17 public class Input_JavaSrc extends BytesToUnicode
  18 {
  19   public String getName() { return "JavaSrc"; }
  20
  21   // 0: normal
  22   // 1: seen '\\'
  23   // 2: seen '\\' and 'u'
  24   // 3: seen '\\' and need to emit value.
  25   // 4, 5, 6, 7:  seen '\\u', 'u' and (state-3) hex digits.
  26   int state = 0;
  27
  28   int value;
  29
  30   public int read (char[] outbuffer, int outpos, int count)
  31   {
  32     int origpos = outpos;
  33     for (;;)
  34       {
  35         if (inpos >= inlength)
  36           break;
  37         if (outpos - origpos >= count)
  38           break;
  39         char b = (char) (inbuffer[inpos++] & 0xFF);
  40         switch (state)
  41           {
  42           case 0:
  43             if (b == '\\')
  44               {
  45                 state = 1;
  46                 continue;
  47               }
  48             break;
  49           case 1:
  50             if (b == 'u')
  51               {
  52                 state = 2;
  53                 continue;
  54               }
  55             if (b != '\\')
  56               {
  57                 value = b;
  58                 b = '\\';
  59                 state = 3;
  60               }
  61             break;
  62           case 3:
  63             b = (char) value;
  64             break;
  65           default:  //  case 4:  case 5:  case 6:  case 7:
  66             int digit = Character.digit(b, 16);
  67             if (digit < 0)
  68               {
  69                 b = '\uFFFD';
  70                 state = 0;
  71               }
  72             else
  73               {
  74                 value = value * 16 + digit;
  75                 if (state < 7)
  76                   {
  77                     state++;
  78                     continue;
  79                   }
  80                 b = (char) value;
  81               }
  82             state = 0;
  83           }
  84         outbuffer[outpos++] = b;
  85       }
  86     return outpos - origpos;
  87   }
  88 }
  89