JUCE/modules/juce_core/text/juce_CharacterFunctions.h

/*
  ==============================================================================

   This file is part of the JUCE library - "Jules' Utility Class Extensions"
   Copyright 2004-11 by Raw Material Software Ltd.

  ------------------------------------------------------------------------------

   JUCE can be redistributed and/or modified under the terms of the GNU General
   Public License (Version 2), as published by the Free Software Foundation.
   A copy of the license is included in the JUCE distribution, or can be found
   online at www.gnu.org/licenses.

   JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.rawmaterialsoftware.com/juce for more information.

  ==============================================================================
*/

#ifndef __JUCE_CHARACTERFUNCTIONS_JUCEHEADER__
#define __JUCE_CHARACTERFUNCTIONS_JUCEHEADER__


//==============================================================================
#if JUCE_WINDOWS && ! DOXYGEN
 #define JUCE_NATIVE_WCHAR_IS_UTF8      0
 #define JUCE_NATIVE_WCHAR_IS_UTF16     1
 #define JUCE_NATIVE_WCHAR_IS_UTF32     0
#else
 /** This macro will be set to 1 if the compiler's native wchar_t is an 8-bit type. */
 #define JUCE_NATIVE_WCHAR_IS_UTF8      0
 /** This macro will be set to 1 if the compiler's native wchar_t is a 16-bit type. */
 #define JUCE_NATIVE_WCHAR_IS_UTF16     0
 /** This macro will be set to 1 if the compiler's native wchar_t is a 32-bit type. */
 #define JUCE_NATIVE_WCHAR_IS_UTF32     1
#endif

#if JUCE_NATIVE_WCHAR_IS_UTF32 || DOXYGEN
 /** A platform-independent 32-bit unicode character type. */
 typedef wchar_t        juce_wchar;
#else
 typedef uint32         juce_wchar;
#endif

/** This macro is deprecated, but preserved for compatibility with old code. */
#define JUCE_T(stringLiteral)   (L##stringLiteral)

#if JUCE_DEFINE_T_MACRO
 /** The 'T' macro is an alternative for using the "L" prefix in front of a string literal.

     This macro is deprecated, but available for compatibility with old code if you set
     JUCE_DEFINE_T_MACRO = 1. The fastest, most portable and best way to write your string
     literals is as standard char strings, using escaped utf-8 character sequences for extended
     characters, rather than trying to store them as wide-char strings.
 */
 #define T(stringLiteral)   JUCE_T(stringLiteral)
#endif

#undef max
#undef min

//==============================================================================
/**
    A set of methods for manipulating characters and character strings.

    These are defined as wrappers around the basic C string handlers, to provide
    a clean, cross-platform layer, (because various platforms differ in the
    range of C library calls that they provide).

    @see String
*/
class JUCE_API  CharacterFunctions
{
public:
    //==============================================================================
    static juce_wchar toUpperCase (juce_wchar character) noexcept;
    static juce_wchar toLowerCase (juce_wchar character) noexcept;

    static bool isUpperCase (juce_wchar character) noexcept;
    static bool isLowerCase (juce_wchar character) noexcept;

    static bool isWhitespace (char character) noexcept;
    static bool isWhitespace (juce_wchar character) noexcept;

    static bool isDigit (char character) noexcept;
    static bool isDigit (juce_wchar character) noexcept;

    static bool isLetter (char character) noexcept;
    static bool isLetter (juce_wchar character) noexcept;

    static bool isLetterOrDigit (char character) noexcept;
    static bool isLetterOrDigit (juce_wchar character) noexcept;

    /** Returns 0 to 16 for '0' to 'F", or -1 for characters that aren't a legal hex digit. */
    static int getHexDigitValue (juce_wchar digit) noexcept;

    //==============================================================================
    template <typename CharPointerType>
    static double readDoubleValue (CharPointerType& text) noexcept
    {
        double result[3] = { 0 }, accumulator[2] = { 0 };
        int exponentAdjustment[2] = { 0 }, exponentAccumulator[2] = { -1, -1 };
        int exponent = 0, decPointIndex = 0, digit = 0;
        int lastDigit = 0, numSignificantDigits = 0;
        bool isNegative = false, digitsFound = false;
        const int maxSignificantDigits = 15 + 2;

        text = text.findEndOfWhitespace();
        juce_wchar c = *text;

        switch (c)
        {
            case '-':   isNegative = true; // fall-through..
            case '+':   c = *++text;
        }

        switch (c)
        {
            case 'n':
            case 'N':
                if ((text[1] == 'a' || text[1] == 'A') && (text[2] == 'n' || text[2] == 'N'))
                    return std::numeric_limits<double>::quiet_NaN();
                break;

            case 'i':
            case 'I':
                if ((text[1] == 'n' || text[1] == 'N') && (text[2] == 'f' || text[2] == 'F'))
                    return std::numeric_limits<double>::infinity();
                break;
        }

        for (;;)
        {
            if (text.isDigit())
            {
                lastDigit = digit;
                digit = (int) text.getAndAdvance() - '0';
                digitsFound = true;

                if (decPointIndex != 0)
                    exponentAdjustment[1]++;

                if (numSignificantDigits == 0 && digit == 0)
                    continue;

                if (++numSignificantDigits > maxSignificantDigits)
                {
                    if (digit > 5)
                        ++accumulator [decPointIndex];
                    else if (digit == 5 && (lastDigit & 1) != 0)
                        ++accumulator [decPointIndex];

                    if (decPointIndex > 0)
                        exponentAdjustment[1]--;
                    else
                        exponentAdjustment[0]++;

                    while (text.isDigit())
                    {
                        ++text;
                        if (decPointIndex == 0)
                            exponentAdjustment[0]++;
                    }
                }
                else
                {
                    const double maxAccumulatorValue = (double) ((std::numeric_limits<unsigned int>::max() - 9) / 10);
                    if (accumulator [decPointIndex] > maxAccumulatorValue)
                    {
                        result [decPointIndex] = mulexp10 (result [decPointIndex], exponentAccumulator [decPointIndex])
                                                    + accumulator [decPointIndex];
                        accumulator [decPointIndex] = 0;
                        exponentAccumulator [decPointIndex] = 0;
                    }

                    accumulator [decPointIndex] = accumulator[decPointIndex] * 10 + digit;
                    exponentAccumulator [decPointIndex]++;
                }
            }
            else if (decPointIndex == 0 && *text == '.')
            {
                ++text;
                decPointIndex = 1;

                if (numSignificantDigits > maxSignificantDigits)
                {
                    while (text.isDigit())
                        ++text;
                    break;
                }
            }
            else
            {
                break;
            }
        }

        result[0] = mulexp10 (result[0], exponentAccumulator[0]) + accumulator[0];

        if (decPointIndex != 0)
            result[1] = mulexp10 (result[1], exponentAccumulator[1]) + accumulator[1];

        c = *text;
        if ((c == 'e' || c == 'E') && digitsFound)
        {
            bool negativeExponent = false;

            switch (*++text)
            {
                case '-':   negativeExponent = true; // fall-through..
                case '+':   ++text;
            }

            while (text.isDigit())
                exponent = (exponent * 10) + ((int) text.getAndAdvance() - '0');

            if (negativeExponent)
                exponent = -exponent;
        }

        double r = mulexp10 (result[0], exponent + exponentAdjustment[0]);
        if (decPointIndex != 0)
            r += mulexp10 (result[1], exponent - exponentAdjustment[1]);

        return isNegative ? -r : r;
    }

    template <typename CharPointerType>
    static double getDoubleValue (const CharPointerType& text) noexcept
    {
        CharPointerType t (text);
        return readDoubleValue (t);
    }

    //==============================================================================
    template <typename IntType, typename CharPointerType>
    static IntType getIntValue (const CharPointerType& text) noexcept
    {
        IntType v = 0;
        CharPointerType s (text.findEndOfWhitespace());

        const bool isNeg = *s == '-';
        if (isNeg)
            ++s;

        for (;;)
        {
            const juce_wchar c = s.getAndAdvance();

            if (c >= '0' && c <= '9')
                v = v * 10 + (IntType) (c - '0');
            else
                break;
        }

        return isNeg ? -v : v;
    }

    //==============================================================================
    template <typename CharPointerType>
    static size_t lengthUpTo (CharPointerType text, const size_t maxCharsToCount) noexcept
    {
        size_t len = 0;

        while (len < maxCharsToCount && text.getAndAdvance() != 0)
            ++len;

        return len;
    }

    template <typename CharPointerType>
    static size_t lengthUpTo (CharPointerType start, const CharPointerType& end) noexcept
    {
        size_t len = 0;

        while (start < end && start.getAndAdvance() != 0)
            ++len;

        return len;
    }

    template <typename DestCharPointerType, typename SrcCharPointerType>
    static void copyAll (DestCharPointerType& dest, SrcCharPointerType src) noexcept
    {
        for (;;)
        {
            const juce_wchar c = src.getAndAdvance();

            if (c == 0)
                break;

            dest.write (c);
        }

        dest.writeNull();
    }

    template <typename DestCharPointerType, typename SrcCharPointerType>
    static int copyWithDestByteLimit (DestCharPointerType& dest, SrcCharPointerType src, int maxBytes) noexcept
    {
        typename DestCharPointerType::CharType const* const startAddress = dest.getAddress();
        maxBytes -= sizeof (typename DestCharPointerType::CharType); // (allow for a terminating null)

        for (;;)
        {
            const juce_wchar c = src.getAndAdvance();
            const int bytesNeeded = (int) DestCharPointerType::getBytesRequiredFor (c);

            maxBytes -= bytesNeeded;
            if (c == 0 || maxBytes < 0)
                break;

            dest.write (c);
        }

        dest.writeNull();

        return (int) (getAddressDifference (dest.getAddress(), startAddress) + sizeof (typename DestCharPointerType::CharType));
    }

    template <typename DestCharPointerType, typename SrcCharPointerType>
    static void copyWithCharLimit (DestCharPointerType& dest, SrcCharPointerType src, int maxChars) noexcept
    {
        while (--maxChars > 0)
        {
            const juce_wchar c = src.getAndAdvance();
            if (c == 0)
                break;

            dest.write (c);
        }

        dest.writeNull();
    }

    template <typename CharPointerType1, typename CharPointerType2>
    static int compare (CharPointerType1 s1, CharPointerType2 s2) noexcept
    {
        for (;;)
        {
            const int c1 = (int) s1.getAndAdvance();
            const int c2 = (int) s2.getAndAdvance();

            const int diff = c1 - c2;
            if (diff != 0)
                return diff < 0 ? -1 : 1;
            else if (c1 == 0)
                break;
        }

        return 0;
    }

    template <typename CharPointerType1, typename CharPointerType2>
    static int compareUpTo (CharPointerType1 s1, CharPointerType2 s2, int maxChars) noexcept
    {
        while (--maxChars >= 0)
        {
            const int c1 = (int) s1.getAndAdvance();
            const int c2 = (int) s2.getAndAdvance();

            const int diff = c1 - c2;
            if (diff != 0)
                return diff < 0 ? -1 : 1;
            else if (c1 == 0)
                break;
        }

        return 0;
    }

    template <typename CharPointerType1, typename CharPointerType2>
    static int compareIgnoreCase (CharPointerType1 s1, CharPointerType2 s2) noexcept
    {
        for (;;)
        {
            int c1 = (int) s1.toUpperCase();
            int c2 = (int) s2.toUpperCase();
            ++s1;
            ++s2;

            const int diff = c1 - c2;
            if (diff != 0)
                return diff < 0 ? -1 : 1;
            else if (c1 == 0)
                break;
        }

        return 0;
    }

    template <typename CharPointerType1, typename CharPointerType2>
    static int compareIgnoreCaseUpTo (CharPointerType1 s1, CharPointerType2 s2, int maxChars) noexcept
    {
        while (--maxChars >= 0)
        {
            int c1 = s1.toUpperCase();
            int c2 = s2.toUpperCase();
            ++s1;
            ++s2;

            const int diff = c1 - c2;
            if (diff != 0)
                return diff < 0 ? -1 : 1;
            else if (c1 == 0)
                break;
        }

        return 0;
    }

    template <typename CharPointerType1, typename CharPointerType2>
    static int indexOf (CharPointerType1 haystack, const CharPointerType2& needle) noexcept
    {
        int index = 0;
        const int needleLength = (int) needle.length();

        for (;;)
        {
            if (haystack.compareUpTo (needle, needleLength) == 0)
                return index;

            if (haystack.getAndAdvance() == 0)
                return -1;

            ++index;
        }
    }

    template <typename CharPointerType1, typename CharPointerType2>
    static int indexOfIgnoreCase (CharPointerType1 haystack, const CharPointerType2& needle) noexcept
    {
        int index = 0;
        const int needleLength = (int) needle.length();

        for (;;)
        {
            if (haystack.compareIgnoreCaseUpTo (needle, needleLength) == 0)
                return index;

            if (haystack.getAndAdvance() == 0)
                return -1;

            ++index;
        }
    }

    template <typename Type>
    static int indexOfChar (Type text, const juce_wchar charToFind) noexcept
    {
        int i = 0;

        while (! text.isEmpty())
        {
            if (text.getAndAdvance() == charToFind)
                return i;

            ++i;
        }

        return -1;
    }

    template <typename Type>
    static int indexOfCharIgnoreCase (Type text, juce_wchar charToFind) noexcept
    {
        charToFind = CharacterFunctions::toLowerCase (charToFind);
        int i = 0;

        while (! text.isEmpty())
        {
            if (text.toLowerCase() == charToFind)
                return i;

            ++text;
            ++i;
        }

        return -1;
    }

    template <typename Type>
    static Type findEndOfWhitespace (const Type& text) noexcept
    {
        Type p (text);

        while (p.isWhitespace())
            ++p;

        return p;
    }

    template <typename Type>
    static Type findEndOfToken (const Type& text, const Type& breakCharacters, const Type& quoteCharacters)
    {
        Type t (text);
        juce_wchar currentQuoteChar = 0;

        while (! t.isEmpty())
        {
            const juce_wchar c = t.getAndAdvance();

            if (currentQuoteChar == 0 && breakCharacters.indexOf (c) >= 0)
            {
                --t;
                break;
            }

            if (quoteCharacters.indexOf (c) >= 0)
            {
                if (currentQuoteChar == 0)
                    currentQuoteChar = c;
                else if (currentQuoteChar == c)
                    currentQuoteChar = 0;
            }
        }

        return t;
    }

private:
    static double mulexp10 (const double value, int exponent) noexcept;
};


#endif   // __JUCE_CHARACTERFUNCTIONS_JUCEHEADER__