juce_CharPointer_UTF8.h

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/*
  ==============================================================================
 
   This file is part of the juce_core module of the JUCE library.
   Copyright (c) 2015 - ROLI Ltd.
 
   Permission to use, copy, modify, and/or distribute this software for any purpose with
   or without fee is hereby granted, provided that the above copyright notice and this
   permission notice appear in all copies.
 
   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
   NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
   DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
   IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
   ------------------------------------------------------------------------------
 
   NOTE! This permissive ISC license applies ONLY to files within the juce_core module!
   All other JUCE modules are covered by a dual GPL/commercial license, so if you are
   using any other modules, be sure to check that you also comply with their license.
 
   For more details, visit www.juce.com
 
  ==============================================================================
*/
 
#ifndef JUCE_CHARPOINTER_UTF8_H_INCLUDED
#define JUCE_CHARPOINTER_UTF8_H_INCLUDED
 
//==============================================================================
class CharPointer_UTF8
{
public:
    typedef char CharType;
 
    inline explicit CharPointer_UTF8 (const CharType* const rawPointer) noexcept
        : data (const_cast <CharType*> (rawPointer))
    {
    }
 
    inline CharPointer_UTF8 (const CharPointer_UTF8& other) noexcept
        : data (other.data)
    {
    }
 
    inline CharPointer_UTF8 operator= (CharPointer_UTF8 other) noexcept
    {
        data = other.data;
        return *this;
    }
 
    inline CharPointer_UTF8 operator= (const CharType* text) noexcept
    {
        data = const_cast <CharType*> (text);
        return *this;
    }
 
    inline bool operator== (CharPointer_UTF8 other) const noexcept      { return data == other.data; }
    inline bool operator!= (CharPointer_UTF8 other) const noexcept      { return data != other.data; }
    inline bool operator<= (CharPointer_UTF8 other) const noexcept      { return data <= other.data; }
    inline bool operator<  (CharPointer_UTF8 other) const noexcept      { return data <  other.data; }
    inline bool operator>= (CharPointer_UTF8 other) const noexcept      { return data >= other.data; }
    inline bool operator>  (CharPointer_UTF8 other) const noexcept      { return data >  other.data; }
 
    inline CharType* getAddress() const noexcept        { return data; }
 
    inline operator const CharType*() const noexcept    { return data; }
 
    inline bool isEmpty() const noexcept                { return *data == 0; }
 
    juce_wchar operator*() const noexcept
    {
        const signed char byte = (signed char) *data;
 
        if (byte >= 0)
            return (juce_wchar) (uint8) byte;
 
        uint32 n = (uint32) (uint8) byte;
        uint32 mask = 0x7f;
        uint32 bit = 0x40;
        size_t numExtraValues = 0;
 
        while ((n & bit) != 0 && bit > 0x10)
        {
            mask >>= 1;
            ++numExtraValues;
            bit >>= 1;
        }
 
        n &= mask;
 
        for (size_t i = 1; i <= numExtraValues; ++i)
        {
            const uint8 nextByte = (uint8) data [i];
 
            if ((nextByte & 0xc0) != 0x80)
                break;
 
            n <<= 6;
            n |= (nextByte & 0x3f);
        }
 
        return (juce_wchar) n;
    }
 
    CharPointer_UTF8& operator++() noexcept
    {
        jassert (*data != 0); // trying to advance past the end of the string?
        const signed char n = (signed char) *data++;
 
        if (n < 0)
        {
            juce_wchar bit = 0x40;
 
            while ((n & bit) != 0 && bit > 0x8)
            {
                ++data;
                bit >>= 1;
            }
        }
 
        return *this;
    }
 
    CharPointer_UTF8 operator--() noexcept
    {
        int count = 0;
 
        while ((*--data & 0xc0) == 0x80 && ++count < 4)
        {}
 
        return *this;
    }
 
    juce_wchar getAndAdvance() noexcept
    {
        const signed char byte = (signed char) *data++;
 
        if (byte >= 0)
            return (juce_wchar) (uint8) byte;
 
        uint32 n = (uint32) (uint8) byte;
        uint32 mask = 0x7f;
        uint32 bit = 0x40;
        int numExtraValues = 0;
 
        while ((n & bit) != 0 && bit > 0x8)
        {
            mask >>= 1;
            ++numExtraValues;
            bit >>= 1;
        }
 
        n &= mask;
 
        while (--numExtraValues >= 0)
        {
            const uint32 nextByte = (uint32) (uint8) *data;
 
            if ((nextByte & 0xc0) != 0x80)
                break;
 
            ++data;
            n <<= 6;
            n |= (nextByte & 0x3f);
        }
 
        return (juce_wchar) n;
    }
 
    CharPointer_UTF8 operator++ (int) noexcept
    {
        CharPointer_UTF8 temp (*this);
        ++*this;
        return temp;
    }
 
    void operator+= (int numToSkip) noexcept
    {
        if (numToSkip < 0)
        {
            while (++numToSkip <= 0)
                --*this;
        }
        else
        {
            while (--numToSkip >= 0)
                ++*this;
        }
    }
 
    void operator-= (int numToSkip) noexcept
    {
        operator+= (-numToSkip);
    }
 
    juce_wchar operator[] (int characterIndex) const noexcept
    {
        CharPointer_UTF8 p (*this);
        p += characterIndex;
        return *p;
    }
 
    CharPointer_UTF8 operator+ (int numToSkip) const noexcept
    {
        CharPointer_UTF8 p (*this);
        p += numToSkip;
        return p;
    }
 
    CharPointer_UTF8 operator- (int numToSkip) const noexcept
    {
        CharPointer_UTF8 p (*this);
        p += -numToSkip;
        return p;
    }
 
    size_t length() const noexcept
    {
        const CharType* d = data;
        size_t count = 0;
 
        for (;;)
        {
            const uint32 n = (uint32) (uint8) *d++;
 
            if ((n & 0x80) != 0)
            {
                while ((*d & 0xc0) == 0x80)
                    ++d;
            }
            else if (n == 0)
                break;
 
            ++count;
        }
 
        return count;
    }
 
    size_t lengthUpTo (const size_t maxCharsToCount) const noexcept
    {
        return CharacterFunctions::lengthUpTo (*this, maxCharsToCount);
    }
 
    size_t lengthUpTo (const CharPointer_UTF8 end) const noexcept
    {
        return CharacterFunctions::lengthUpTo (*this, end);
    }
 
    size_t sizeInBytes() const noexcept
    {
        jassert (data != nullptr);
        return strlen (data) + 1;
    }
 
    static size_t getBytesRequiredFor (const juce_wchar charToWrite) noexcept
    {
        size_t num = 1;
        const uint32 c = (uint32) charToWrite;
 
        if (c >= 0x80)
        {
            ++num;
            if (c >= 0x800)
            {
                ++num;
                if (c >= 0x10000)
                    ++num;
            }
        }
 
        return num;
    }
 
    template <class CharPointer>
    static size_t getBytesRequiredFor (CharPointer text) noexcept
    {
        size_t count = 0;
        juce_wchar n;
 
        while ((n = text.getAndAdvance()) != 0)
            count += getBytesRequiredFor (n);
 
        return count;
    }
 
    CharPointer_UTF8 findTerminatingNull() const noexcept
    {
        return CharPointer_UTF8 (data + strlen (data));
    }
 
    void write (const juce_wchar charToWrite) noexcept
    {
        const uint32 c = (uint32) charToWrite;
 
        if (c >= 0x80)
        {
            int numExtraBytes = 1;
            if (c >= 0x800)
            {
                ++numExtraBytes;
                if (c >= 0x10000)
                    ++numExtraBytes;
            }
 
            *data++ = (CharType) ((uint32) (0xff << (7 - numExtraBytes)) | (c >> (numExtraBytes * 6)));
 
            while (--numExtraBytes >= 0)
                *data++ = (CharType) (0x80 | (0x3f & (c >> (numExtraBytes * 6))));
        }
        else
        {
            *data++ = (CharType) c;
        }
    }
 
    inline void writeNull() const noexcept
    {
        *data = 0;
    }
 
    template <typename CharPointer>
    void writeAll (const CharPointer src) noexcept
    {
        CharacterFunctions::copyAll (*this, src);
    }
 
    void writeAll (const CharPointer_UTF8 src) noexcept
    {
        const CharType* s = src.data;
 
        while ((*data = *s) != 0)
        {
            ++data;
            ++s;
        }
    }
 
    template <typename CharPointer>
    size_t writeWithDestByteLimit (const CharPointer src, const size_t maxDestBytes) noexcept
    {
        return CharacterFunctions::copyWithDestByteLimit (*this, src, maxDestBytes);
    }
 
    template <typename CharPointer>
    void writeWithCharLimit (const CharPointer src, const int maxChars) noexcept
    {
        CharacterFunctions::copyWithCharLimit (*this, src, maxChars);
    }
 
    template <typename CharPointer>
    int compare (const CharPointer other) const noexcept
    {
        return CharacterFunctions::compare (*this, other);
    }
 
    template <typename CharPointer>
    int compareUpTo (const CharPointer other, const int maxChars) const noexcept
    {
        return CharacterFunctions::compareUpTo (*this, other, maxChars);
    }
 
    template <typename CharPointer>
    int compareIgnoreCase (const CharPointer other) const noexcept
    {
        return CharacterFunctions::compareIgnoreCase (*this, other);
    }
 
    int compareIgnoreCase (const CharPointer_UTF8 other) const noexcept
    {
       #if JUCE_MSVC
        return stricmp (data, other.data);
       #elif JUCE_MINGW
        return CharacterFunctions::compareIgnoreCase (*this, other);
       #else
        return strcasecmp (data, other.data);
       #endif
    }
 
    template <typename CharPointer>
    int compareIgnoreCaseUpTo (const CharPointer other, const int maxChars) const noexcept
    {
        return CharacterFunctions::compareIgnoreCaseUpTo (*this, other, maxChars);
    }
 
    template <typename CharPointer>
    int indexOf (const CharPointer stringToFind) const noexcept
    {
        return CharacterFunctions::indexOf (*this, stringToFind);
    }
 
    int indexOf (const juce_wchar charToFind) const noexcept
    {
        return CharacterFunctions::indexOfChar (*this, charToFind);
    }
 
    int indexOf (const juce_wchar charToFind, const bool ignoreCase) const noexcept
    {
        return ignoreCase ? CharacterFunctions::indexOfCharIgnoreCase (*this, charToFind)
                          : CharacterFunctions::indexOfChar (*this, charToFind);
    }
 
    bool isWhitespace() const noexcept      { const CharType c = *data; return c == ' ' || (c <= 13 && c >= 9); }
    bool isDigit() const noexcept           { const CharType c = *data; return c >= '0' && c <= '9'; }
    bool isLetter() const noexcept          { return CharacterFunctions::isLetter (operator*()) != 0; }
    bool isLetterOrDigit() const noexcept   { return CharacterFunctions::isLetterOrDigit (operator*()) != 0; }
    bool isUpperCase() const noexcept       { return CharacterFunctions::isUpperCase (operator*()) != 0; }
    bool isLowerCase() const noexcept       { return CharacterFunctions::isLowerCase (operator*()) != 0; }
 
    juce_wchar toUpperCase() const noexcept { return CharacterFunctions::toUpperCase (operator*()); }
    juce_wchar toLowerCase() const noexcept { return CharacterFunctions::toLowerCase (operator*()); }
 
    int getIntValue32() const noexcept      { return atoi (data); }
 
    int64 getIntValue64() const noexcept
    {
       #if JUCE_LINUX || JUCE_ANDROID || JUCE_MINGW
        return atoll (data);
       #elif JUCE_WINDOWS
        return _atoi64 (data);
       #else
        return CharacterFunctions::getIntValue <int64, CharPointer_UTF8> (*this);
       #endif
    }
 
    double getDoubleValue() const noexcept  { return CharacterFunctions::getDoubleValue (*this); }
 
    CharPointer_UTF8 findEndOfWhitespace() const noexcept   { return CharacterFunctions::findEndOfWhitespace (*this); }
 
    static bool canRepresent (juce_wchar character) noexcept
    {
        return ((unsigned int) character) < (unsigned int) 0x10ffff;
    }
 
    static bool isValidString (const CharType* dataToTest, int maxBytesToRead)
    {
        while (--maxBytesToRead >= 0 && *dataToTest != 0)
        {
            const signed char byte = (signed char) *dataToTest++;
 
            if (byte < 0)
            {
                int bit = 0x40;
                int numExtraValues = 0;
 
                while ((byte & bit) != 0)
                {
                    if (bit < 8)
                        return false;
 
                    ++numExtraValues;
                    bit >>= 1;
 
                    if (bit == 8 && (numExtraValues > maxBytesToRead
                                       || *CharPointer_UTF8 (dataToTest - 1) > 0x10ffff))
                        return false;
                }
 
                maxBytesToRead -= numExtraValues;
                if (maxBytesToRead < 0)
                    return false;
 
                while (--numExtraValues >= 0)
                    if ((*dataToTest++ & 0xc0) != 0x80)
                        return false;
            }
        }
 
        return true;
    }
 
    CharPointer_UTF8 atomicSwap (const CharPointer_UTF8 newValue)
    {
        return CharPointer_UTF8 (reinterpret_cast <Atomic<CharType*>&> (data).exchange (newValue.data));
    }
 
    enum
    {
        byteOrderMark1 = 0xef,
        byteOrderMark2 = 0xbb,
        byteOrderMark3 = 0xbf
    };
 
    static bool isByteOrderMark (const void* possibleByteOrder) noexcept
    {
        jassert (possibleByteOrder != nullptr);
        const uint8* const c = static_cast<const uint8*> (possibleByteOrder);
 
        return c[0] == (uint8) byteOrderMark1
            && c[1] == (uint8) byteOrderMark2
            && c[2] == (uint8) byteOrderMark3;
    }
 
private:
    CharType* data;
};
 
#endif   // JUCE_CHARPOINTER_UTF8_H_INCLUDED