// Tencent is pleased to support the open source community by making RapidJSON available.

//

// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip.

//

// Licensed under the MIT License (the "License"); you may not use this file except

// in compliance with the License. You may obtain a copy of the License at

//

// http://opensource.org/licenses/MIT

//

// Unless required by applicable law or agreed to in writing, software distributed

// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR

// CONDITIONS OF ANY KIND, either express or implied. See the License for the

// specific language governing permissions and limitations under the License.

#ifndef RAPIDJSON_READER_H_

#define RAPIDJSON_READER_H_

/*! \file reader.h */

#include "allocators.h"

#include "stream.h"

#include "encodedstream.h"

#include "internal/clzll.h"

#include "internal/meta.h"

#include "internal/stack.h"

#include "internal/strtod.h"

#include <limits>

#if defined(RAPIDJSON_SIMD) && defined(_MSC_VER)

#include <intrin.h>

#pragma intrinsic(_BitScanForward)

#endif

#ifdef RAPIDJSON_SSE42

#include <nmmintrin.h>

#elif defined(RAPIDJSON_SSE2)

#include <emmintrin.h>

#elif defined(RAPIDJSON_NEON)

#include <arm_neon.h>

#endif

#ifdef __clang__

RAPIDJSON_DIAG_PUSH

RAPIDJSON_DIAG_OFF(old-style-cast)

RAPIDJSON_DIAG_OFF(padded)

RAPIDJSON_DIAG_OFF(switch-enum)

#elif defined(_MSC_VER)

RAPIDJSON_DIAG_PUSH

RAPIDJSON_DIAG_OFF(4127)  // conditional expression is constant

RAPIDJSON_DIAG_OFF(4702)  // unreachable code

#endif

#ifdef __GNUC__

RAPIDJSON_DIAG_PUSH

RAPIDJSON_DIAG_OFF(effc++)

#endif

//!@cond RAPIDJSON_HIDDEN_FROM_DOXYGEN

#define RAPIDJSON_NOTHING /* deliberately empty */

#ifndef RAPIDJSON_PARSE_ERROR_EARLY_RETURN

#define RAPIDJSON_PARSE_ERROR_EARLY_RETURN(value) \

    RAPIDJSON_MULTILINEMACRO_BEGIN \

    if (RAPIDJSON_UNLIKELY(HasParseError())) { return value; } \

    RAPIDJSON_MULTILINEMACRO_END

#endif

#define RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID \

    RAPIDJSON_PARSE_ERROR_EARLY_RETURN(RAPIDJSON_NOTHING)

//!@endcond

/*! \def RAPIDJSON_PARSE_ERROR_NORETURN

    \ingroup RAPIDJSON_ERRORS

    \brief Macro to indicate a parse error.

    \param parseErrorCode \ref rapidjson::ParseErrorCode of the error

    \param offset  position of the error in JSON input (\c size_t)

    This macros can be used as a customization point for the internal

    error handling mechanism of RapidJSON.

    A common usage model is to throw an exception instead of requiring the

    caller to explicitly check the \ref rapidjson::GenericReader::Parse's

    return value:

    \code

    #define RAPIDJSON_PARSE_ERROR_NORETURN(parseErrorCode,offset) \

       throw ParseException(parseErrorCode, #parseErrorCode, offset)

    #include <stdexcept>               // std::runtime_error

    #include "rapidjson/error/error.h" // rapidjson::ParseResult

    struct ParseException : std::runtime_error, rapidjson::ParseResult {

      ParseException(rapidjson::ParseErrorCode code, const char* msg, size_t offset)

        : std::runtime_error(msg), ParseResult(code, offset) {}

    };

    #include "rapidjson/reader.h"

    \endcode

    \see RAPIDJSON_PARSE_ERROR, rapidjson::GenericReader::Parse

 */

#ifndef RAPIDJSON_PARSE_ERROR_NORETURN

#define RAPIDJSON_PARSE_ERROR_NORETURN(parseErrorCode, offset) \

    RAPIDJSON_MULTILINEMACRO_BEGIN \

    RAPIDJSON_ASSERT(!HasParseError()); /* Error can only be assigned once */ \

    SetParseError(parseErrorCode, offset); \

    RAPIDJSON_MULTILINEMACRO_END

#endif

/*! \def RAPIDJSON_PARSE_ERROR

    \ingroup RAPIDJSON_ERRORS

    \brief (Internal) macro to indicate and handle a parse error.

    \param parseErrorCode \ref rapidjson::ParseErrorCode of the error

    \param offset  position of the error in JSON input (\c size_t)

    Invokes RAPIDJSON_PARSE_ERROR_NORETURN and stops the parsing.

    \see RAPIDJSON_PARSE_ERROR_NORETURN

    \hideinitializer

 */

#ifndef RAPIDJSON_PARSE_ERROR

#define RAPIDJSON_PARSE_ERROR(parseErrorCode, offset) \

    RAPIDJSON_MULTILINEMACRO_BEGIN \

    RAPIDJSON_PARSE_ERROR_NORETURN(parseErrorCode, offset); \

    RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; \

    RAPIDJSON_MULTILINEMACRO_END

#endif

#include "error/error.h" // ParseErrorCode, ParseResult

RAPIDJSON_NAMESPACE_BEGIN

///////////////////////////////////////////////////////////////////////////////

// ParseFlag

/*! \def RAPIDJSON_PARSE_DEFAULT_FLAGS

    \ingroup RAPIDJSON_CONFIG

    \brief User-defined kParseDefaultFlags definition.

    User can define this as any \c ParseFlag combinations.

*/

#ifndef RAPIDJSON_PARSE_DEFAULT_FLAGS

#define RAPIDJSON_PARSE_DEFAULT_FLAGS kParseNoFlags

#endif

//! Combination of parseFlags

/*! \see Reader::Parse, Document::Parse, Document::ParseInsitu, Document::ParseStream

 */

enum ParseFlag {

    kParseNoFlags = 0,              //!< No flags are set.

    kParseInsituFlag = 1,           //!< In-situ(destructive) parsing.

    kParseValidateEncodingFlag = 2, //!< Validate encoding of JSON strings.

    kParseIterativeFlag = 4,        //!< Iterative(constant complexity in terms of function call stack size) parsing.

    kParseStopWhenDoneFlag = 8,     //!< After parsing a complete JSON root from stream, stop further processing the rest of stream. When this flag is used, parser will not generate kParseErrorDocumentRootNotSingular error.

    kParseFullPrecisionFlag = 16,   //!< Parse number in full precision (but slower).

    kParseCommentsFlag = 32,        //!< Allow one-line (//) and multi-line (/**/) comments.

    kParseNumbersAsStringsFlag = 64,    //!< Parse all numbers (ints/doubles) as strings.

    kParseTrailingCommasFlag = 128, //!< Allow trailing commas at the end of objects and arrays.

    kParseNanAndInfFlag = 256,      //!< Allow parsing NaN, Inf, Infinity, -Inf and -Infinity as doubles.

    kParseEscapedApostropheFlag = 512,  //!< Allow escaped apostrophe in strings.

    kParseDefaultFlags = RAPIDJSON_PARSE_DEFAULT_FLAGS  //!< Default parse flags. Can be customized by defining RAPIDJSON_PARSE_DEFAULT_FLAGS

};

///////////////////////////////////////////////////////////////////////////////

// Handler

/*! \class rapidjson::Handler

    \brief Concept for receiving events from GenericReader upon parsing.

    The functions return true if no error occurs. If they return false,

    the event publisher should terminate the process.

\code

concept Handler {

    typename Ch;

    bool Null();

    bool Bool(bool b);

    bool Int(int i);

    bool Uint(unsigned i);

    bool Int64(int64_t i);

    bool Uint64(uint64_t i);

    bool Double(double d);

    /// enabled via kParseNumbersAsStringsFlag, string is not null-terminated (use length)

    bool RawNumber(const Ch* str, SizeType length, bool copy);

    bool String(const Ch* str, SizeType length, bool copy);

    bool StartObject();

    bool Key(const Ch* str, SizeType length, bool copy);

    bool EndObject(SizeType memberCount);

    bool StartArray();

    bool EndArray(SizeType elementCount);

};

\endcode

*/

///////////////////////////////////////////////////////////////////////////////

// BaseReaderHandler

//! Default implementation of Handler.

/*! This can be used as base class of any reader handler.

    \note implements Handler concept

*/

template<typename Encoding = UTF8<>, typename Derived = void>

struct BaseReaderHandler {

    typedef typename Encoding::Ch Ch;

    typedef typename internal::SelectIf<internal::IsSame<Derived, void>, BaseReaderHandler, Derived>::Type Override;

    bool Default() { return true; }

    bool Null() { return static_cast<Override&>(*this).Default(); }

    bool Bool(bool) { return static_cast<Override&>(*this).Default(); }

    bool Int(int) { return static_cast<Override&>(*this).Default(); }

    bool Uint(unsigned) { return static_cast<Override&>(*this).Default(); }

    bool Int64(int64_t) { return static_cast<Override&>(*this).Default(); }

    bool Uint64(uint64_t) { return static_cast<Override&>(*this).Default(); }

    bool Double(double) { return static_cast<Override&>(*this).Default(); }

    /// enabled via kParseNumbersAsStringsFlag, string is not null-terminated (use length)

    bool RawNumber(const Ch* str, SizeType len, bool copy) { return static_cast<Override&>(*this).String(str, len, copy); }

    bool String(const Ch*, SizeType, bool) { return static_cast<Override&>(*this).Default(); }

    bool StartObject() { return static_cast<Override&>(*this).Default(); }

    bool Key(const Ch* str, SizeType len, bool copy) { return static_cast<Override&>(*this).String(str, len, copy); }

    bool EndObject(SizeType) { return static_cast<Override&>(*this).Default(); }

    bool StartArray() { return static_cast<Override&>(*this).Default(); }

    bool EndArray(SizeType) { return static_cast<Override&>(*this).Default(); }

};

///////////////////////////////////////////////////////////////////////////////

// StreamLocalCopy

namespace internal {

template<typename Stream, int = StreamTraits<Stream>::copyOptimization>

class StreamLocalCopy;

//! Do copy optimization.

template<typename Stream>

class StreamLocalCopy<Stream, 1> {

public:

    StreamLocalCopy(Stream& original) : s(original), original_(original) {}

    ~StreamLocalCopy() { original_ = s; }

    Stream s;

private:

    StreamLocalCopy& operator=(const StreamLocalCopy&) /* = delete */;

    Stream& original_;

};

//! Keep reference.

template<typename Stream>

class StreamLocalCopy<Stream, 0> {

public:

    StreamLocalCopy(Stream& original) : s(original) {}

    Stream& s;

private:

    StreamLocalCopy& operator=(const StreamLocalCopy&) /* = delete */;

};

} // namespace internal

///////////////////////////////////////////////////////////////////////////////

// SkipWhitespace

//! Skip the JSON white spaces in a stream.

/*! \param is A input stream for skipping white spaces.

    \note This function has SSE2/SSE4.2 specialization.

*/

template<typename InputStream>

void SkipWhitespace(InputStream& is) {

    internal::StreamLocalCopy<InputStream> copy(is);

    InputStream& s(copy.s);

    typename InputStream::Ch c;

    while ((c = s.Peek()) == ' ' || c == '\n' || c == '\r' || c == '\t')

        s.Take();

}

inline const char* SkipWhitespace(const char* p, const char* end) {

    while (p != end && (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t'))

        ++p;

    return p;

}

#ifdef RAPIDJSON_SSE42

//! Skip whitespace with SSE 4.2 pcmpistrm instruction, testing 16 8-byte characters at once.

inline const char *SkipWhitespace_SIMD(const char* p) {

    // Fast return for single non-whitespace

    if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t')

        ++p;

    else

        return p;

    // 16-byte align to the next boundary

    const char* nextAligned = reinterpret_cast<const char*>((reinterpret_cast<size_t>(p) + 15) & static_cast<size_t>(~15));

    while (p != nextAligned)

        if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t')

            ++p;

        else

            return p;

    // The rest of string using SIMD

    static const char whitespace[16] = " \n\r\t";

    const __m128i w = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespace[0]));

    for (;; p += 16) {

        const __m128i s = _mm_load_si128(reinterpret_cast<const __m128i *>(p));

        const int r = _mm_cmpistri(w, s, _SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_ANY | _SIDD_LEAST_SIGNIFICANT | _SIDD_NEGATIVE_POLARITY);

        if (r != 16)    // some of characters is non-whitespace

            return p + r;

    }

}

inline const char *SkipWhitespace_SIMD(const char* p, const char* end) {

    // Fast return for single non-whitespace

    if (p != end && (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t'))

        ++p;

    else

        return p;

    // The middle of string using SIMD

    static const char whitespace[16] = " \n\r\t";

    const __m128i w = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespace[0]));

    for (; p <= end - 16; p += 16) {

        const __m128i s = _mm_loadu_si128(reinterpret_cast<const __m128i *>(p));

        const int r = _mm_cmpistri(w, s, _SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_ANY | _SIDD_LEAST_SIGNIFICANT | _SIDD_NEGATIVE_POLARITY);

        if (r != 16)    // some of characters is non-whitespace

            return p + r;

    }

    return SkipWhitespace(p, end);

}

#elif defined(RAPIDJSON_SSE2)

//! Skip whitespace with SSE2 instructions, testing 16 8-byte characters at once.

inline const char *SkipWhitespace_SIMD(const char* p) {

    // Fast return for single non-whitespace

    if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t')

        ++p;

    else

        return p;

    // 16-byte align to the next boundary

    const char* nextAligned = reinterpret_cast<const char*>((reinterpret_cast<size_t>(p) + 15) & static_cast<size_t>(~15));

    while (p != nextAligned)

        if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t')

            ++p;

        else

            return p;

    // The rest of string

    #define C16(c) { c, c, c, c, c, c, c, c, c, c, c, c, c, c, c, c }

    static const char whitespaces[4][16] = { C16(' '), C16('\n'), C16('\r'), C16('\t') };

    #undef C16

    const __m128i w0 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[0][0]));

    const __m128i w1 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[1][0]));

    const __m128i w2 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[2][0]));

    const __m128i w3 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[3][0]));

    for (;; p += 16) {

        const __m128i s = _mm_load_si128(reinterpret_cast<const __m128i *>(p));

        __m128i x = _mm_cmpeq_epi8(s, w0);

        x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w1));

        x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w2));

        x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w3));

        unsigned short r = static_cast<unsigned short>(~_mm_movemask_epi8(x));

        if (r != 0) {   // some of characters may be non-whitespace

#ifdef _MSC_VER         // Find the index of first non-whitespace

            unsigned long offset;

            _BitScanForward(&offset, r);

            return p + offset;

#else

            return p + __builtin_ffs(r) - 1;

#endif

        }

    }

}

inline const char *SkipWhitespace_SIMD(const char* p, const char* end) {

    // Fast return for single non-whitespace

    if (p != end && (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t'))

        ++p;

    else

        return p;

    // The rest of string

    #define C16(c) { c, c, c, c, c, c, c, c, c, c, c, c, c, c, c, c }

    static const char whitespaces[4][16] = { C16(' '), C16('\n'), C16('\r'), C16('\t') };

    #undef C16

    const __m128i w0 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[0][0]));

    const __m128i w1 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[1][0]));

    const __m128i w2 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[2][0]));

    const __m128i w3 = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&whitespaces[3][0]));

    for (; p <= end - 16; p += 16) {

        const __m128i s = _mm_loadu_si128(reinterpret_cast<const __m128i *>(p));

        __m128i x = _mm_cmpeq_epi8(s, w0);

        x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w1));

        x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w2));

        x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w3));

        unsigned short r = static_cast<unsigned short>(~_mm_movemask_epi8(x));

        if (r != 0) {   // some of characters may be non-whitespace

#ifdef _MSC_VER         // Find the index of first non-whitespace

            unsigned long offset;

            _BitScanForward(&offset, r);

            return p + offset;

#else

            return p + __builtin_ffs(r) - 1;

#endif

        }

    }

    return SkipWhitespace(p, end);

}

#elif defined(RAPIDJSON_NEON)

//! Skip whitespace with ARM Neon instructions, testing 16 8-byte characters at once.

inline const char *SkipWhitespace_SIMD(const char* p) {

    // Fast return for single non-whitespace

    if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t')

        ++p;

    else

        return p;

    // 16-byte align to the next boundary

    const char* nextAligned = reinterpret_cast<const char*>((reinterpret_cast<size_t>(p) + 15) & static_cast<size_t>(~15));

    while (p != nextAligned)

        if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t')

            ++p;

        else

            return p;

    const uint8x16_t w0 = vmovq_n_u8(' ');

    const uint8x16_t w1 = vmovq_n_u8('\n');

    const uint8x16_t w2 = vmovq_n_u8('\r');

    const uint8x16_t w3 = vmovq_n_u8('\t');

    for (;; p += 16) {

        const uint8x16_t s = vld1q_u8(reinterpret_cast<const uint8_t *>(p));

        uint8x16_t x = vceqq_u8(s, w0);

        x = vorrq_u8(x, vceqq_u8(s, w1));

        x = vorrq_u8(x, vceqq_u8(s, w2));

        x = vorrq_u8(x, vceqq_u8(s, w3));

        x = vmvnq_u8(x);                       // Negate

        x = vrev64q_u8(x);                     // Rev in 64

        uint64_t low = vgetq_lane_u64(vreinterpretq_u64_u8(x), 0);   // extract

        uint64_t high = vgetq_lane_u64(vreinterpretq_u64_u8(x), 1);  // extract

        if (low == 0) {

            if (high != 0) {

                uint32_t lz = internal::clzll(high);

                return p + 8 + (lz >> 3);

            }

        } else {

            uint32_t lz = internal::clzll(low);

            return p + (lz >> 3);

        }

    }

}

inline const char *SkipWhitespace_SIMD(const char* p, const char* end) {

    // Fast return for single non-whitespace

    if (p != end && (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t'))

        ++p;

    else

        return p;

    const uint8x16_t w0 = vmovq_n_u8(' ');

    const uint8x16_t w1 = vmovq_n_u8('\n');

    const uint8x16_t w2 = vmovq_n_u8('\r');

    const uint8x16_t w3 = vmovq_n_u8('\t');

    for (; p <= end - 16; p += 16) {

        const uint8x16_t s = vld1q_u8(reinterpret_cast<const uint8_t *>(p));

        uint8x16_t x = vceqq_u8(s, w0);

        x = vorrq_u8(x, vceqq_u8(s, w1));

        x = vorrq_u8(x, vceqq_u8(s, w2));

        x = vorrq_u8(x, vceqq_u8(s, w3));

        x = vmvnq_u8(x);                       // Negate

        x = vrev64q_u8(x);                     // Rev in 64

        uint64_t low = vgetq_lane_u64(vreinterpretq_u64_u8(x), 0);   // extract

        uint64_t high = vgetq_lane_u64(vreinterpretq_u64_u8(x), 1);  // extract

        if (low == 0) {

            if (high != 0) {

                uint32_t lz = internal::clzll(high);

                return p + 8 + (lz >> 3);

            }

        } else {

            uint32_t lz = internal::clzll(low);

            return p + (lz >> 3);

        }

    }

    return SkipWhitespace(p, end);

}

#endif // RAPIDJSON_NEON

#ifdef RAPIDJSON_SIMD

//! Template function specialization for InsituStringStream

template<> inline void SkipWhitespace(InsituStringStream& is) {

    is.src_ = const_cast<char*>(SkipWhitespace_SIMD(is.src_));

}

//! Template function specialization for StringStream

template<> inline void SkipWhitespace(StringStream& is) {

    is.src_ = SkipWhitespace_SIMD(is.src_);

}

template<> inline void SkipWhitespace(EncodedInputStream<UTF8<>, MemoryStream>& is) {

    is.is_.src_ = SkipWhitespace_SIMD(is.is_.src_, is.is_.end_);

}

#endif // RAPIDJSON_SIMD

///////////////////////////////////////////////////////////////////////////////

// GenericReader

//! SAX-style JSON parser. Use \ref Reader for UTF8 encoding and default allocator.

/*! GenericReader parses JSON text from a stream, and send events synchronously to an

    object implementing Handler concept.

    It needs to allocate a stack for storing a single decoded string during

    non-destructive parsing.

    For in-situ parsing, the decoded string is directly written to the source

    text string, no temporary buffer is required.

    A GenericReader object can be reused for parsing multiple JSON text.

    \tparam SourceEncoding Encoding of the input stream.

    \tparam TargetEncoding Encoding of the parse output.

    \tparam StackAllocator Allocator type for stack.

*/

template <typename SourceEncoding, typename TargetEncoding, typename StackAllocator = CrtAllocator>

class GenericReader {

public:

    typedef typename SourceEncoding::Ch Ch; //!< SourceEncoding character type

    //! Constructor.

    /*! \param stackAllocator Optional allocator for allocating stack memory. (Only use for non-destructive parsing)

        \param stackCapacity stack capacity in bytes for storing a single decoded string.  (Only use for non-destructive parsing)

    */

    GenericReader(StackAllocator* stackAllocator = 0, size_t stackCapacity = kDefaultStackCapacity) :

        stack_(stackAllocator, stackCapacity), parseResult_(), state_(IterativeParsingStartState) {}

    //! Parse JSON text.

    /*! \tparam parseFlags Combination of \ref ParseFlag.

        \tparam InputStream Type of input stream, implementing Stream concept.

        \tparam Handler Type of handler, implementing Handler concept.

        \param is Input stream to be parsed.

        \param handler The handler to receive events.

        \return Whether the parsing is successful.

    */

    template <unsigned parseFlags, typename InputStream, typename Handler>

    ParseResult Parse(InputStream& is, Handler& handler) {

        if (parseFlags & kParseIterativeFlag)

            return IterativeParse<parseFlags>(is, handler);

        parseResult_.Clear();

        ClearStackOnExit scope(*this);

        SkipWhitespaceAndComments<parseFlags>(is);

        RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_);

        if (RAPIDJSON_UNLIKELY(is.Peek() == '\0')) {

            RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorDocumentEmpty, is.Tell());

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_);

        }

        else {

            ParseValue<parseFlags>(is, handler);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_);

            if (!(parseFlags & kParseStopWhenDoneFlag)) {

                SkipWhitespaceAndComments<parseFlags>(is);

                RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_);

                if (RAPIDJSON_UNLIKELY(is.Peek() != '\0')) {

                    RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorDocumentRootNotSingular, is.Tell());

                    RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_);

                }

            }

        }

        return parseResult_;

    }

    //! Parse JSON text (with \ref kParseDefaultFlags)

    /*! \tparam InputStream Type of input stream, implementing Stream concept

        \tparam Handler Type of handler, implementing Handler concept.

        \param is Input stream to be parsed.

        \param handler The handler to receive events.

        \return Whether the parsing is successful.

    */

    template <typename InputStream, typename Handler>

    ParseResult Parse(InputStream& is, Handler& handler) {

        return Parse<kParseDefaultFlags>(is, handler);

    }

    //! Initialize JSON text token-by-token parsing

    /*!

     */

    void IterativeParseInit() {

        parseResult_.Clear();

        state_ = IterativeParsingStartState;

    }

    //! Parse one token from JSON text

    /*! \tparam InputStream Type of input stream, implementing Stream concept

        \tparam Handler Type of handler, implementing Handler concept.

        \param is Input stream to be parsed.

        \param handler The handler to receive events.

        \return Whether the parsing is successful.

     */

    template <unsigned parseFlags, typename InputStream, typename Handler>

    bool IterativeParseNext(InputStream& is, Handler& handler) {

        while (RAPIDJSON_LIKELY(is.Peek() != '\0')) {

            SkipWhitespaceAndComments<parseFlags>(is);

            Token t = Tokenize(is.Peek());

            IterativeParsingState n = Predict(state_, t);

            IterativeParsingState d = Transit<parseFlags>(state_, t, n, is, handler);

            // If we've finished or hit an error...

            if (RAPIDJSON_UNLIKELY(IsIterativeParsingCompleteState(d))) {

                // Report errors.

                if (d == IterativeParsingErrorState) {

                    HandleError(state_, is);

                    return false;

                }

                // Transition to the finish state.

                RAPIDJSON_ASSERT(d == IterativeParsingFinishState);

                state_ = d;

                // If StopWhenDone is not set...

                if (!(parseFlags & kParseStopWhenDoneFlag)) {

                    // ... and extra non-whitespace data is found...

                    SkipWhitespaceAndComments<parseFlags>(is);

                    if (is.Peek() != '\0') {

                        // ... this is considered an error.

                        HandleError(state_, is);

                        return false;

                    }

                }

                // Success! We are done!

                return true;

            }

            // Transition to the new state.

            state_ = d;

            // If we parsed anything other than a delimiter, we invoked the handler, so we can return true now.

            if (!IsIterativeParsingDelimiterState(n))

                return true;

        }

        // We reached the end of file.

        stack_.Clear();

        if (state_ != IterativeParsingFinishState) {

            HandleError(state_, is);

            return false;

        }

        return true;

    }

    //! Check if token-by-token parsing JSON text is complete

    /*! \return Whether the JSON has been fully decoded.

     */

    RAPIDJSON_FORCEINLINE bool IterativeParseComplete() const {

        return IsIterativeParsingCompleteState(state_);

    }

    //! Whether a parse error has occurred in the last parsing.

    bool HasParseError() const { return parseResult_.IsError(); }

    //! Get the \ref ParseErrorCode of last parsing.

    ParseErrorCode GetParseErrorCode() const { return parseResult_.Code(); }

    //! Get the position of last parsing error in input, 0 otherwise.

    size_t GetErrorOffset() const { return parseResult_.Offset(); }

protected:

    void SetParseError(ParseErrorCode code, size_t offset) { parseResult_.Set(code, offset); }

private:

    // Prohibit copy constructor & assignment operator.

    GenericReader(const GenericReader&);

    GenericReader& operator=(const GenericReader&);

    void ClearStack() { stack_.Clear(); }

    // clear stack on any exit from ParseStream, e.g. due to exception

    struct ClearStackOnExit {

        explicit ClearStackOnExit(GenericReader& r) : r_(r) {}

        ~ClearStackOnExit() { r_.ClearStack(); }

    private:

        GenericReader& r_;

        ClearStackOnExit(const ClearStackOnExit&);

        ClearStackOnExit& operator=(const ClearStackOnExit&);

    };

    template<unsigned parseFlags, typename InputStream>

    void SkipWhitespaceAndComments(InputStream& is) {

        SkipWhitespace(is);

        if (parseFlags & kParseCommentsFlag) {

            while (RAPIDJSON_UNLIKELY(Consume(is, '/'))) {

                if (Consume(is, '*')) {

                    while (true) {

                        if (RAPIDJSON_UNLIKELY(is.Peek() == '\0'))

                            RAPIDJSON_PARSE_ERROR(kParseErrorUnspecificSyntaxError, is.Tell());

                        else if (Consume(is, '*')) {

                            if (Consume(is, '/'))

                                break;

                        }

                        else

                            is.Take();

                    }

                }

                else if (RAPIDJSON_LIKELY(Consume(is, '/')))

                    while (is.Peek() != '\0' && is.Take() != '\n') {}

                else

                    RAPIDJSON_PARSE_ERROR(kParseErrorUnspecificSyntaxError, is.Tell());

                SkipWhitespace(is);

            }

        }

    }

    // Parse object: { string : value, ... }

    template<unsigned parseFlags, typename InputStream, typename Handler>

    void ParseObject(InputStream& is, Handler& handler) {

        RAPIDJSON_ASSERT(is.Peek() == '{');

        is.Take();  // Skip '{'

        if (RAPIDJSON_UNLIKELY(!handler.StartObject()))

            RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

        SkipWhitespaceAndComments<parseFlags>(is);

        RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

        if (Consume(is, '}')) {

            if (RAPIDJSON_UNLIKELY(!handler.EndObject(0)))  // empty object

                RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

            return;

        }

        for (SizeType memberCount = 0;;) {

            if (RAPIDJSON_UNLIKELY(is.Peek() != '"'))

                RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissName, is.Tell());

            ParseString<parseFlags>(is, handler, true);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            SkipWhitespaceAndComments<parseFlags>(is);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            if (RAPIDJSON_UNLIKELY(!Consume(is, ':')))

                RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissColon, is.Tell());

            SkipWhitespaceAndComments<parseFlags>(is);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            ParseValue<parseFlags>(is, handler);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            SkipWhitespaceAndComments<parseFlags>(is);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            ++memberCount;

            switch (is.Peek()) {

                case ',':

                    is.Take();

                    SkipWhitespaceAndComments<parseFlags>(is);

                    RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

                    break;

                case '}':

                    is.Take();

                    if (RAPIDJSON_UNLIKELY(!handler.EndObject(memberCount)))

                        RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

                    return;

                default:

                    RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissCommaOrCurlyBracket, is.Tell()); break; // This useless break is only for making warning and coverage happy

            }

            if (parseFlags & kParseTrailingCommasFlag) {

                if (is.Peek() == '}') {

                    if (RAPIDJSON_UNLIKELY(!handler.EndObject(memberCount)))

                        RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

                    is.Take();

                    return;

                }

            }

        }

    }

    // Parse array: [ value, ... ]

    template<unsigned parseFlags, typename InputStream, typename Handler>

    void ParseArray(InputStream& is, Handler& handler) {

        RAPIDJSON_ASSERT(is.Peek() == '[');

        is.Take();  // Skip '['

        if (RAPIDJSON_UNLIKELY(!handler.StartArray()))

            RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

        SkipWhitespaceAndComments<parseFlags>(is);

        RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

        if (Consume(is, ']')) {

            if (RAPIDJSON_UNLIKELY(!handler.EndArray(0))) // empty array

                RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

            return;

        }

        for (SizeType elementCount = 0;;) {

            ParseValue<parseFlags>(is, handler);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            ++elementCount;

            SkipWhitespaceAndComments<parseFlags>(is);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            if (Consume(is, ',')) {

                SkipWhitespaceAndComments<parseFlags>(is);

                RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            }

            else if (Consume(is, ']')) {

                if (RAPIDJSON_UNLIKELY(!handler.EndArray(elementCount)))

                    RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

                return;

            }

            else

                RAPIDJSON_PARSE_ERROR(kParseErrorArrayMissCommaOrSquareBracket, is.Tell());

            if (parseFlags & kParseTrailingCommasFlag) {

                if (is.Peek() == ']') {

                    if (RAPIDJSON_UNLIKELY(!handler.EndArray(elementCount)))

                        RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

                    is.Take();

                    return;

                }

            }

        }

    }

    template<unsigned parseFlags, typename InputStream, typename Handler>

    void ParseNull(InputStream& is, Handler& handler) {

        RAPIDJSON_ASSERT(is.Peek() == 'n');

        is.Take();

        if (RAPIDJSON_LIKELY(Consume(is, 'u') && Consume(is, 'l') && Consume(is, 'l'))) {

            if (RAPIDJSON_UNLIKELY(!handler.Null()))

                RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

        }

        else

            RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, is.Tell());

    }

    template<unsigned parseFlags, typename InputStream, typename Handler>

    void ParseTrue(InputStream& is, Handler& handler) {

        RAPIDJSON_ASSERT(is.Peek() == 't');

        is.Take();

        if (RAPIDJSON_LIKELY(Consume(is, 'r') && Consume(is, 'u') && Consume(is, 'e'))) {

            if (RAPIDJSON_UNLIKELY(!handler.Bool(true)))

                RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

        }

        else

            RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, is.Tell());

    }

    template<unsigned parseFlags, typename InputStream, typename Handler>

    void ParseFalse(InputStream& is, Handler& handler) {

        RAPIDJSON_ASSERT(is.Peek() == 'f');

        is.Take();

        if (RAPIDJSON_LIKELY(Consume(is, 'a') && Consume(is, 'l') && Consume(is, 's') && Consume(is, 'e'))) {

            if (RAPIDJSON_UNLIKELY(!handler.Bool(false)))

                RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell());

        }

        else

            RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, is.Tell());

    }

    template<typename InputStream>

    RAPIDJSON_FORCEINLINE static bool Consume(InputStream& is, typename InputStream::Ch expect) {

        if (RAPIDJSON_LIKELY(is.Peek() == expect)) {

            is.Take();

            return true;

        }

        else

            return false;

    }

    // Helper function to parse four hexadecimal digits in \uXXXX in ParseString().

    template<typename InputStream>

    unsigned ParseHex4(InputStream& is, size_t escapeOffset) {

        unsigned codepoint = 0;

        for (int i = 0; i < 4; i++) {

            Ch c = is.Peek();

            codepoint <<= 4;

            codepoint += static_cast<unsigned>(c);

            if (c >= '0' && c <= '9')

                codepoint -= '0';

            else if (c >= 'A' && c <= 'F')

                codepoint -= 'A' - 10;

            else if (c >= 'a' && c <= 'f')

                codepoint -= 'a' - 10;

            else {

                RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorStringUnicodeEscapeInvalidHex, escapeOffset);

                RAPIDJSON_PARSE_ERROR_EARLY_RETURN(0);

            }

            is.Take();

        }

        return codepoint;

    }

    template <typename CharType>

    class StackStream {

    public:

        typedef CharType Ch;

        StackStream(internal::Stack<StackAllocator>& stack) : stack_(stack), length_(0) {}

        RAPIDJSON_FORCEINLINE void Put(Ch c) {

            *stack_.template Push<Ch>() = c;

            ++length_;

        }

        RAPIDJSON_FORCEINLINE void* Push(SizeType count) {

            length_ += count;

            return stack_.template Push<Ch>(count);

        }

        size_t Length() const { return length_; }

        Ch* Pop() {

            return stack_.template Pop<Ch>(length_);

        }

    private:

        StackStream(const StackStream&);

        StackStream& operator=(const StackStream&);

        internal::Stack<StackAllocator>& stack_;

        SizeType length_;

    };

    // Parse string and generate String event. Different code paths for kParseInsituFlag.

    template<unsigned parseFlags, typename InputStream, typename Handler>

    void ParseString(InputStream& is, Handler& handler, bool isKey = false) {

        internal::StreamLocalCopy<InputStream> copy(is);

        InputStream& s(copy.s);

        RAPIDJSON_ASSERT(s.Peek() == '\"');

        s.Take();  // Skip '\"'

        bool success = false;

        if (parseFlags & kParseInsituFlag) {

            typename InputStream::Ch *head = s.PutBegin();

            ParseStringToStream<parseFlags, SourceEncoding, SourceEncoding>(s, s);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            size_t length = s.PutEnd(head) - 1;

            RAPIDJSON_ASSERT(length <= 0xFFFFFFFF);

            const typename TargetEncoding::Ch* const str = reinterpret_cast<typename TargetEncoding::Ch*>(head);

            success = (isKey ? handler.Key(str, SizeType(length), false) : handler.String(str, SizeType(length), false));

        }

        else {

            StackStream<typename TargetEncoding::Ch> stackStream(stack_);

            ParseStringToStream<parseFlags, SourceEncoding, TargetEncoding>(s, stackStream);

            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

            SizeType length = static_cast<SizeType>(stackStream.Length()) - 1;

            const typename TargetEncoding::Ch* const str = stackStream.Pop();

            success = (isKey ? handler.Key(str, length, true) : handler.String(str, length, true));

        }

        if (RAPIDJSON_UNLIKELY(!success))

            RAPIDJSON_PARSE_ERROR(kParseErrorTermination, s.Tell());

    }

    // Parse string to an output is

    // This function handles the prefix/suffix double quotes, escaping, and optional encoding validation.

    template<unsigned parseFlags, typename SEncoding, typename TEncoding, typename InputStream, typename OutputStream>

    RAPIDJSON_FORCEINLINE void ParseStringToStream(InputStream& is, OutputStream& os) {

//!@cond RAPIDJSON_HIDDEN_FROM_DOXYGEN

#define Z16 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0

        static const char escape[256] = {

            Z16, Z16, 0, 0,'\"', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, '/',

            Z16, Z16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'\\', 0, 0, 0,

            0, 0,'\b', 0, 0, 0,'\f', 0, 0, 0, 0, 0, 0, 0,'\n', 0,

            0, 0,'\r', 0,'\t', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

            Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16

        };

#undef Z16

//!@endcond

        for (;;) {

            // Scan and copy string before "\\\"" or < 0x20. This is an optional optimzation.

            if (!(parseFlags & kParseValidateEncodingFlag))

                ScanCopyUnescapedString(is, os);

            Ch c = is.Peek();

            if (RAPIDJSON_UNLIKELY(c == '\\')) {    // Escape

                size_t escapeOffset = is.Tell();    // For invalid escaping, report the initial '\\' as error offset

                is.Take();

                Ch e = is.Peek();

                if ((sizeof(Ch) == 1 || unsigned(e) < 256) && RAPIDJSON_LIKELY(escape[static_cast<unsigned char>(e)])) {

                    is.Take();

                    os.Put(static_cast<typename TEncoding::Ch>(escape[static_cast<unsigned char>(e)]));

                }

                else if ((parseFlags & kParseEscapedApostropheFlag) && RAPIDJSON_LIKELY(e == '\'')) { // Allow escaped apostrophe

                    is.Take();

                    os.Put('\'');

                }

                else if (RAPIDJSON_LIKELY(e == 'u')) {    // Unicode

                    is.Take();

                    unsigned codepoint = ParseHex4(is, escapeOffset);

                    RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

                    if (RAPIDJSON_UNLIKELY(codepoint >= 0xD800 && codepoint <= 0xDFFF)) {

                        // high surrogate, check if followed by valid low surrogate

                        if (RAPIDJSON_LIKELY(codepoint <= 0xDBFF)) {

                            // Handle UTF-16 surrogate pair

                            if (RAPIDJSON_UNLIKELY(!Consume(is, '\\') || !Consume(is, 'u')))

                                RAPIDJSON_PARSE_ERROR(kParseErrorStringUnicodeSurrogateInvalid, escapeOffset);

                            unsigned codepoint2 = ParseHex4(is, escapeOffset);

                            RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

                            if (RAPIDJSON_UNLIKELY(codepoint2 < 0xDC00 || codepoint2 > 0xDFFF))

                                RAPIDJSON_PARSE_ERROR(kParseErrorStringUnicodeSurrogateInvalid, escapeOffset);

                            codepoint = (((codepoint - 0xD800) << 10) | (codepoint2 - 0xDC00)) + 0x10000;

                        }

                        // single low surrogate

                        else

                        {

                            RAPIDJSON_PARSE_ERROR(kParseErrorStringUnicodeSurrogateInvalid, escapeOffset);

                        }

                    }

                    TEncoding::Encode(os, codepoint);

                }

                else

                    RAPIDJSON_PARSE_ERROR(kParseErrorStringEscapeInvalid, escapeOffset);

            }

            else if (RAPIDJSON_UNLIKELY(c == '"')) {    // Closing double quote

                is.Take();

                os.Put('\0');   // null-terminate the string

                return;

            }

            else if (RAPIDJSON_UNLIKELY(static_cast<unsigned>(c) < 0x20)) { // RFC 4627: unescaped = %x20-21 / %x23-5B / %x5D-10FFFF

                if (c == '\0')

                    RAPIDJSON_PARSE_ERROR(kParseErrorStringMissQuotationMark, is.Tell());

                else

                    RAPIDJSON_PARSE_ERROR(kParseErrorStringInvalidEncoding, is.Tell());

            }

            else {

                size_t offset = is.Tell();

                if (RAPIDJSON_UNLIKELY((parseFlags & kParseValidateEncodingFlag ?

                    !Transcoder<SEncoding, TEncoding>::Validate(is, os) :

                    !Transcoder<SEncoding, TEncoding>::Transcode(is, os))))

                    RAPIDJSON_PARSE_ERROR(kParseErrorStringInvalidEncoding, offset);

            }

        }

    }

    template<typename InputStream, typename OutputStream>

    static RAPIDJSON_FORCEINLINE void ScanCopyUnescapedString(InputStream&, OutputStream&) {

            // Do nothing for generic version

    }

#if defined(RAPIDJSON_SSE2) || defined(RAPIDJSON_SSE42)

    // StringStream -> StackStream<char>

    static RAPIDJSON_FORCEINLINE void ScanCopyUnescapedString(StringStream& is, StackStream<char>& os) {

        const char* p = is.src_;

        // Scan one by one until alignment (unaligned load may cross page boundary and cause crash)

        const char* nextAligned = reinterpret_cast<const char*>((reinterpret_cast<size_t>(p) + 15) & static_cast<size_t>(~15));

        while (p != nextAligned)

            if (RAPIDJSON_UNLIKELY(*p == '\"') || RAPIDJSON_UNLIKELY(*p == '\\') || RAPIDJSON_UNLIKELY(static_cast<unsigned>(*p) < 0x20)) {

                is.src_ = p;

                return;

            }

            else

                os.Put(*p++);

        // The rest of string using SIMD

        static const char dquote[16] = { '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"', '\"' };

        static const char bslash[16] = { '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\', '\\' };

        static const char space[16]  = { 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F };

        const __m128i dq = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&dquote[0]));

        const __m128i bs = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&bslash[0]));

        const __m128i sp = _mm_loadu_si128(reinterpret_cast<const __m128i *>(&space[0]));

        for (;; p += 16) {

            const __m128i s = _mm_load_si128(reinterpret_cast<const __m128i *>(p));

            const __m128i t1 = _mm_cmpeq_epi8(s, dq);

            const __m128i t2 = _mm_cmpeq_epi8(s, bs);

            const __m128i t3 = _mm_cmpeq_epi8(_mm_max_epu8(s, sp), sp); // s < 0x20 <=> max(s, 0x1F) == 0x1F

            const __m128i x = _mm_or_si128(_mm_or_si128(t1, t2), t3);

            unsigned short r = static_cast<unsigned short>(_mm_movemask_epi8(x));

            if (RAPIDJSON_UNLIKELY(r != 0)) {   // some of characters is escaped

                SizeType length;

    #ifdef _MSC_VER         // Find the index of first escaped

                unsigned long offset;

                _BitScanForward(&offset, r);

                length = offset;

    #else

                length = static_cast<SizeType>(__builtin_ffs(r) - 1);

    #endif

                if (length != 0) {

                    char* q = reinterpret_cast<char*>(os.Push(length));

                    for (size_t i = 0; i < length; i++)

                        q[i] = p[i];

                    p += length;

                }

                break;

            }

            _mm_storeu_si128(reinterpret_cast<__m128i *>(os.Push(16)), s);

        }

        is.src_ = p;

    }

    // InsituStringStream -> InsituStringStream

    static RAPIDJSON_FORCEINLINE void ScanCopyUnescapedString(InsituStringStream& is, InsituStringStream& os) {

        RAPIDJSON_ASSERT(&is == &os);

        (void)os;

        if (is.src_ == is.dst_) {

            SkipUnescapedString(is);

            return;

        }

        char* p = is.src_;