text: /*
   * Copyright (C) 2007 Apple Inc.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
   */
  
  #ifndef WTF_UTF8_h
  #define WTF_UTF8_h
  
  #include <unicode/utypes.h>
  #include <wtf/text/LChar.h>
  
  namespace WTF {
  namespace Unicode {
  
      // Given a first byte, gives the length of the UTF-8 sequence it begins.
      // Returns 0 for bytes that are not legal starts of UTF-8 sequences.
      // Only allows sequences of up to 4 bytes, since that works for all Unicode characters (U-00000000 to U-0010FFFF).
      WTF_EXPORT_PRIVATE int UTF8SequenceLength(char);
  
      // Takes a null-terminated C-style string with a UTF-8 sequence in it and converts it to a character.
      // Only allows Unicode characters (U-00000000 to U-0010FFFF).
      // Returns -1 if the sequence is not valid (including presence of extra bytes).
      WTF_EXPORT_PRIVATE int decodeUTF8Sequence(const char*);
  
      typedef enum {
              conversionOK,       // conversion successful
              sourceExhausted,    // partial character in source, but hit end
              targetExhausted,    // insuff. room in target for conversion
              sourceIllegal       // source sequence is illegal/malformed
      } ConversionResult;
  
      // These conversion functions take a "strict" argument. When this
      // flag is set to strict, both irregular sequences and isolated surrogates
      // will cause an error.  When the flag is set to lenient, both irregular
      // sequences and isolated surrogates are converted.
      // 
      // Whether the flag is strict or lenient, all illegal sequences will cause
      // an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,
      // or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code
      // must check for illegal sequences.
      // 
      // When the flag is set to lenient, characters over 0x10FFFF are converted
      // to the replacement character; otherwise (when the flag is set to strict)
      // they constitute an error.
  
      WTF_EXPORT_PRIVATE ConversionResult convertUTF8ToUTF16(
                      const char** sourceStart, const char* sourceEnd, 
                      UChar** targetStart, UChar* targetEnd, bool* isSourceAllASCII = 0, bool strict = true);
  
      WTF_EXPORT_PRIVATE ConversionResult convertLatin1ToUTF8(
                      const LChar** sourceStart, const LChar* sourceEnd, 
                      char** targetStart, char* targetEnd);
  
      WTF_EXPORT_PRIVATE ConversionResult convertUTF16ToUTF8(
                      const UChar** sourceStart, const UChar* sourceEnd, 
                      char** targetStart, char* targetEnd, bool strict = true);
  
      WTF_EXPORT_PRIVATE unsigned calculateStringHashAndLengthFromUTF8MaskingTop8Bits(const char* data, const char* dataEnd, unsigned& dataLength, unsigned& utf16Length);
  
      // The caller of these functions already knows that the lengths are the same, so we omit an end argument for UTF-16 and Latin-1.
      bool equalUTF16WithUTF8(const UChar* stringInUTF16, const char* stringInUTF8, const char* stringInUTF8End);
      bool equalLatin1WithUTF8(const LChar* stringInLatin1, const char* stringInUTF8, const char* stringInUTF8End);
  
  } // namespace Unicode
  } // namespace WTF
  
  #endif // WTF_UTF8_h
  