workbench/libs/codesetslib/src/convertUTF.h

   1 /*
   2  * Copyright 2001-2004 Unicode, Inc.
   3  *
   4  * Disclaimer
   5  *
   6  * This source code is provided as is by Unicode, Inc. No claims are
   7  * made as to fitness for any particular purpose. No warranties of any
   8  * kind are expressed or implied. The recipient agrees to determine
   9  * applicability of information provided. If this file has been
  10  * purchased on magnetic or optical media from Unicode, Inc., the
  11  * sole remedy for any claim will be exchange of defective media
  12  * within 90 days of receipt.
  13  *
  14  * Limitations on Rights to Redistribute This Code
  15  *
  16  * Unicode, Inc. hereby grants the right to freely use the information
  17  * supplied in this file in the creation of products supporting the
  18  * Unicode Standard, and to make copies of this file in any form
  19  * for internal or external distribution as long as this notice
  20  * remains attached.
  21  */
  22
  23 /* ---------------------------------------------------------------------
  24
  25     Conversions between UTF32, UTF-16, and UTF-8.  Header file.
  26
  27     Several funtions are included here, forming a complete set of
  28     conversions between the three formats.  UTF-7 is not included
  29     here, but is handled in a separate source file.
  30
  31     Each of these routines takes pointers to input buffers and output
  32     buffers.  The input buffers are const.
  33
  34     Each routine converts the text between *sourceStart and sourceEnd,
  35     putting the result into the buffer between *targetStart and
  36     targetEnd. Note: the end pointers are *after* the last item: e.g.
  37     *(sourceEnd - 1) is the last item.
  38
  39     The return result indicates whether the conversion was successful,
  40     and if not, whether the problem was in the source or target buffers.
  41     (Only the first encountered problem is indicated.)
  42
  43     After the conversion, *sourceStart and *targetStart are both
  44     updated to point to the end of last text successfully converted in
  45     the respective buffers.
  46
  47     Input parameters:
  48         sourceStart - pointer to a pointer to the source buffer.
  49                 The contents of this are modified on return so that
  50                 it points at the next thing to be converted.
  51         targetStart - similarly, pointer to pointer to the target buffer.
  52         sourceEnd, targetEnd - respectively pointers to the ends of the
  53                 two buffers, for overflow checking only.
  54
  55     These conversion functions take a ConversionFlags argument. When this
  56     flag is set to strict, both irregular sequences and isolated surrogates
  57     will cause an error.  When the flag is set to lenient, both irregular
  58     sequences and isolated surrogates are converted.
  59
  60     Whether the flag is strict or lenient, all illegal sequences will cause
  61     an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,
  62     or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code
  63     must check for illegal sequences.
  64
  65     When the flag is set to lenient, characters over 0x10FFFF are converted
  66     to the replacement character; otherwise (when the flag is set to strict)
  67     they constitute an error.
  68
  69     Output parameters:
  70         The value "sourceIllegal" is returned from some routines if the input
  71         sequence is malformed.  When "sourceIllegal" is returned, the source
  72         value will point to the illegal value that caused the problem. E.g.,
  73         in UTF-8 when a sequence is malformed, it points to the start of the
  74         malformed sequence.
  75
  76     Author: Mark E. Davis, 1994.
  77     Rev History: Rick McGowan, fixes & updates May 2001.
  78                  Fixes & updates, Sept 2001.
  79
  80 ------------------------------------------------------------------------ */
  81
  82 /***********************************************************************
  83
  84     The following 4 definitions are compiler-specific.
  85     The C standard does not guarantee that wchar_t has at least
  86     16 bits, so wchar_t is no less portable than unsigned short!
  87     All should be unsigned values to avoid sign extension during
  88     bit mask & shift operations.
  89
  90 ***********************************************************************/
  91
  92 /* Some fundamental constants */
  93 #define UNI_REPLACEMENT_CHAR    ((UTF32)0x0000FFFD)
  94 #define UNI_MAX_BMP             ((UTF32)0x0000FFFF)
  95 #define UNI_MAX_UTF16           ((UTF32)0x0010FFFF)
  96 #define UNI_MAX_UTF32           ((UTF32)0x7FFFFFFF)
  97 #define UNI_MAX_LEGAL_UTF32     ((UTF32)0x0010FFFF)
  98
  99 /***********************************************************************/
 100
 101 extern const char trailingBytesForUTF8[];
 102
 103 /***********************************************************************/