4.1

1 files changed, 336 insertions, 0 deletions

diff --git a/zen/utf8.h b/zen/utf8.h
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+// **************************************************************************
+// * This file is part of the zenXML project. It is distributed under the   *
+// * Boost Software License, Version 1.0. See accompanying file             *
+// * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.       *
+// * Copyright (C) 2011 ZenJu (zhnmju123 AT gmx.de)                         *
+// **************************************************************************
+
+#ifndef STRING_UTF8_HEADER_01832479146991573473545
+#define STRING_UTF8_HEADER_01832479146991573473545
+
+#include <iterator>
+#include "string_tools.h"
+//#include "type_tools.h"
+//#include "string_traits.h"
+
+namespace zen
+{
+//convert any(!) "string-like" object into target string by applying a UTF8 conversion (but only if necessary!)
+template <class TargetString, class SourceString> TargetString utf8CvrtTo(const SourceString& str);
+
+//convert wide to utf8 string; example: std::string tmp = toUtf8<std::string>(L"abc");
+template <class CharString, class WideString>
+CharString wideToUtf8(const WideString& str);
+
+//convert utf8 string to wide; example: std::wstring tmp = utf8To<std::wstring>("abc");
+template <class WideString, class CharString>
+WideString utf8ToWide(const CharString& str);
+
+const char BYTE_ORDER_MARK_UTF8[] = "\xEF\xBB\xBF";
+
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+
+//----------------------- implementation ----------------------------------
+namespace implementation
+{
+typedef unsigned int CodePoint;
+
+const CodePoint CODE_POINT_MAX     = 0x10ffff;
+
+const CodePoint HIGH_SURROGATE     = 0xd800;
+const CodePoint HIGH_SURROGATE_MAX = 0xdbff;
+
+const CodePoint LOW_SURROGATE      = 0xdc00;
+const CodePoint LOW_SURROGATE_MAX  = 0xdfff;
+
+
+template <class OutputIterator> inline
+OutputIterator codePointToUtf16(CodePoint cp, OutputIterator result) //http://en.wikipedia.org/wiki/UTF-16
+{
+    typedef unsigned short Char16; //this isn't necessarily 16 bit, but all we need is an unsigned type
+
+    assert(cp < HIGH_SURROGATE || LOW_SURROGATE_MAX < cp); //code points [0xd800, 0xdfff] are not allowed for UTF-16
+    assert(cp <= CODE_POINT_MAX);
+
+    if (cp < 0x10000)
+        *result++ = static_cast<Char16>(cp);
+    else
+    {
+        cp -= 0x10000;
+        *result++ = static_cast<Char16>((cp >> 10) + HIGH_SURROGATE);
+        *result++ = static_cast<Char16>((cp & 0x3ff) + LOW_SURROGATE);
+    }
+    return result;
+}
+
+
+template <class CharIterator, class Function> inline
+Function utf16ToCodePoint(CharIterator first, CharIterator last, Function f) //f is a unary function taking a CodePoint as single parameter
+{
+    assert_static(sizeof(typename std::iterator_traits<CharIterator>::value_type) == 2);
+    typedef unsigned short Char16; //this isn't necessarily 16 bit, but all we need is an unsigned type
+
+    for ( ; first != last; ++first)
+    {
+        CodePoint cp = static_cast<Char16>(*first);
+        if (HIGH_SURROGATE <= cp && cp <= HIGH_SURROGATE_MAX)
+        {
+            if (++first == last)
+            {
+                assert(false); //low surrogate expected
+                break;
+            }
+            assert(LOW_SURROGATE <= static_cast<Char16>(*first) && static_cast<Char16>(*first) <= LOW_SURROGATE_MAX); //low surrogate expected
+            cp = ((cp - HIGH_SURROGATE) << 10) + static_cast<Char16>(*first) - LOW_SURROGATE + 0x10000;
+        }
+        else
+            assert(cp < LOW_SURROGATE || LOW_SURROGATE_MAX < cp); //NO low surrogate expected
+
+        f(cp);
+    }
+    return f;
+}
+
+
+template <class OutputIterator> inline
+OutputIterator codePointToUtf8(CodePoint cp, OutputIterator result) //http://en.wikipedia.org/wiki/UTF-8
+{
+    typedef unsigned char Char8;
+
+    assert(cp <= CODE_POINT_MAX);
+
+    if (cp < 0x80)
+        *result++ = static_cast<Char8>(cp);
+    else if (cp < 0x800)
+    {
+        *result++ = static_cast<Char8>((cp >> 6  ) | 0xc0);
+        *result++ = static_cast<Char8>((cp & 0x3f) | 0x80);
+    }
+    else if (cp < 0x10000)
+    {
+        *result++ = static_cast<Char8>((cp >> 12        ) | 0xe0);
+        *result++ = static_cast<Char8>(((cp >> 6) & 0x3f) | 0x80);
+        *result++ = static_cast<Char8>((cp & 0x3f       ) | 0x80);
+    }
+    else
+    {
+        *result++ = static_cast<Char8>((cp >> 18         ) | 0xf0);
+        *result++ = static_cast<Char8>(((cp >> 12) & 0x3f) | 0x80);
+        *result++ = static_cast<Char8>(((cp >> 6)  & 0x3f) | 0x80);
+        *result++ = static_cast<Char8>((cp & 0x3f        ) | 0x80);
+    }
+    return result;
+}
+
+
+inline
+size_t getUtf8Len(unsigned char ch)
+{
+    if (ch < 0x80)
+        return 1;
+    if (ch >> 5 == 0x6)
+        return 2;
+    if (ch >> 4 == 0xe)
+        return 3;
+    if (ch >> 3 == 0x1e)
+        return 4;
+
+    assert(false); //no valid begin of UTF8 encoding
+    return 1;
+}
+
+
+template <class CharIterator, class Function> inline
+Function utf8ToCodePoint(CharIterator first, CharIterator last, Function f) //f is a unary function taking a CodePoint as single parameter
+{
+    assert_static(sizeof(typename std::iterator_traits<CharIterator>::value_type) == 1);
+    typedef unsigned char Char8;
+
+    for ( ; first != last; ++first)
+    {
+        auto getChar = [&](Char8 & ch) -> bool
+        {
+            if (++first == last)
+            {
+                assert(false); //low surrogate expected
+                return false;
+            }
+            ch = static_cast<Char8>(*first);
+            assert(ch >> 6 == 0x2);
+            return true;
+        };
+
+        CodePoint cp = static_cast<Char8>(*first);
+        switch (getUtf8Len(static_cast<Char8>(cp)))
+        {
+            case 1:
+                break;
+            case 2:
+            {
+                cp = (cp & 0x1f) << 6;
+                Char8 ch;
+                if (!getChar(ch)) continue;
+                cp += ch & 0x3f;
+            }
+            break;
+            case 3:
+            {
+                cp = (cp & 0xf) << 12;
+                Char8 ch;
+                if (!getChar(ch)) continue;
+                cp += (ch & 0x3f) << 6;
+                if (!getChar(ch)) continue;
+                cp += ch & 0x3f;
+
+            }
+            break;
+            case 4:
+            {
+                cp = (cp & 0x7) << 18;
+                Char8 ch;
+                if (!getChar(ch)) continue;
+                cp += (ch & 0x3f) << 12;
+                if (!getChar(ch)) continue;
+                cp += (ch & 0x3f) << 6;
+                if (!getChar(ch)) continue;
+                cp += ch & 0x3f;
+            }
+            break;
+            default:
+                assert(false);
+        }
+        f(cp);
+    }
+    return f;
+}
+
+
+template <class String>
+class AppendStringIterator: public std::iterator<std::output_iterator_tag, void, void, void, void>
+{
+public:
+    explicit AppendStringIterator (String& x) : str(&x) {}
+    AppendStringIterator& operator= (typename String::value_type value) { *str += value; return *this; }
+    AppendStringIterator& operator*  ()    { return *this; }
+    AppendStringIterator& operator++ ()    { return *this; }
+    AppendStringIterator  operator++ (int) { return *this; }
+private:
+    String* str;
+};
+
+
+template <class WideString, class CharString> inline
+WideString utf8ToWide(const CharString& str, Int2Type<2>) //windows: convert utf8 to utf16 wchar_t
+{
+    WideString output;
+    utf8ToCodePoint(strBegin(str), strBegin(str) + strLength(str),
+    [&](CodePoint cp) { codePointToUtf16(cp, AppendStringIterator<WideString>(output)); });
+    return output;
+}
+
+
+template <class WideString, class CharString> inline
+WideString utf8ToWide(const CharString& str, Int2Type<4>) //other OS: convert utf8 to utf32 wchar_t
+{
+    WideString output;
+    utf8ToCodePoint(strBegin(str), strBegin(str) + strLength(str),
+    [&](CodePoint cp) { output += cp; });
+    return output;
+}
+
+
+template <class CharString, class WideString> inline
+CharString wideToUtf8(const WideString& str, Int2Type<2>) //windows: convert utf16-wchar_t to utf8
+{
+    CharString output;
+    utf16ToCodePoint(strBegin(str), strBegin(str) + strLength(str),
+    [&](CodePoint cp) { codePointToUtf8(cp, AppendStringIterator<CharString>(output)); });
+    return output;
+}
+
+
+template <class CharString, class WideString> inline
+CharString wideToUtf8(const WideString& str, Int2Type<4>) //other OS: convert utf32-wchar_t to utf8
+{
+    CharString output;
+    std::for_each(strBegin(str), strBegin(str) + strLength(str),
+    [&](CodePoint cp) { codePointToUtf8(cp, AppendStringIterator<CharString>(output)); });
+    return output;
+}
+}
+
+
+template <class WideString, class CharString> inline
+WideString utf8ToWide(const CharString& str)
+{
+    assert_static((IsSameType<typename StringTraits<CharString>::CharType, char   >::result));
+    assert_static((IsSameType<typename StringTraits<WideString>::CharType, wchar_t>::result));
+
+    return implementation::utf8ToWide<WideString>(str, Int2Type<sizeof(wchar_t)>());
+}
+
+
+template <class CharString, class WideString> inline
+CharString wideToUtf8(const WideString& str)
+{
+    assert_static((IsSameType<typename StringTraits<CharString>::CharType, char   >::result));
+    assert_static((IsSameType<typename StringTraits<WideString>::CharType, wchar_t>::result));
+
+    return implementation::wideToUtf8<CharString>(str, Int2Type<sizeof(wchar_t)>());
+}
+
+
+//-------------------------------------------------------------------------------------------
+template <class TargetString, class SourceString> inline
+TargetString utf8CvrtTo(const SourceString& str, char, wchar_t) { return utf8ToWide<TargetString>(str); }
+
+template <class TargetString, class SourceString> inline
+TargetString utf8CvrtTo(const SourceString& str, wchar_t, char) { return wideToUtf8<TargetString>(str); }
+
+template <class TargetString, class SourceString> inline
+TargetString utf8CvrtTo(const SourceString& str, char, char) { return cvrtString<TargetString>(str); }
+
+template <class TargetString, class SourceString> inline
+TargetString utf8CvrtTo(const SourceString& str, wchar_t, wchar_t) { return cvrtString<TargetString>(str); }
+
+template <class TargetString, class SourceString> inline
+TargetString utf8CvrtTo(const SourceString& str)
+{
+    return utf8CvrtTo<TargetString>(str,
+                                    typename StringTraits<SourceString>::CharType(),
+                                    typename StringTraits<TargetString>::CharType());
+}
+}
+
+#endif //STRING_UTF8_HEADER_01832479146991573473545