jsonreader.cpp

 
// Name:        jsonreader.cpp
// Purpose:     the wxJSONReader class: a JSON text parser
// Author:      Luciano Cattani
// Created:     2007/10/14
// RCS-ID:      $Id: jsonreader.cpp,v 1.12 2008/03/12 10:48:19 luccat Exp $
// Copyright:   (c) 2007 Luciano Cattani
// Licence:     wxWidgets licence
 
#ifdef __GNUG__
#pragma implementation "jsonreader.cpp"
#endif
 
#ifdef NDEBUG
// make wxLogTrace a noop if no debug set, it's really slow
// must be defined before including wx/debug.h (also included by wx/wxprec.h)
#define wxDEBUG_LEVEL 0
#endif
 
#include "jsonreader.h"
 
#include <wx/mstream.h>
#include <wx/sstream.h>
#include <wx/debug.h>
#include <wx/log.h>
 
// if you have the debug build of wxWidgets and wxJSON you can see
// trace messages by setting the:
// WXTRACE=traceReader StoreComment
// environment variable
#if wxDEBUG_LEVEL > 0
static const wxChar* traceMask = _T("traceReader");
static const wxChar* storeTraceMask = _T("StoreComment");
#endif
 
 
wxJSONReader::wxJSONReader(int flags, int maxErrors) {
  m_flags = flags;
  m_maxErrors = maxErrors;
  m_noUtf8 = false;
#if !defined(wxJSON_USE_UNICODE)
  // in ANSI builds we can suppress UTF-8 conversion for both the writer and the
  // reader
  if (m_flags & wxJSONREADER_NOUTF8_STREAM) {
    m_noUtf8 = true;
  }
#endif
}
 
wxJSONReader::~wxJSONReader() {}
 
 
int wxJSONReader::Parse(const wxString& doc, wxJSONValue* val) {
#if !defined(wxJSON_USE_UNICODE)
  // in ANSI builds input from a string never use UTF-8 conversion
  bool noUtf8_bak = m_noUtf8;  // save the current setting
  m_noUtf8 = true;
#endif
 
  // convert the string to a UTF-8 / ANSI memory stream and calls overloaded
  // Parse()
  char* readBuff = 0;
  wxCharBuffer utf8CB = doc.ToUTF8();  // the UTF-8 buffer
#if !defined(wxJSON_USE_UNICODE)
  wxCharBuffer ansiCB(doc.c_str());  // the ANSI buffer
  if (m_noUtf8) {
    readBuff = ansiCB.data();
  } else {
    readBuff = utf8CB.data();
  }
#else
  readBuff = utf8CB.data();
#endif
 
  // now construct the temporary memory input stream
  size_t len = strlen(readBuff);
  wxMemoryInputStream is(readBuff, len);
 
  int numErr = Parse(is, val);
#if !defined(wxJSON_USE_UNICODE)
  m_noUtf8 = noUtf8_bak;
#endif
  return numErr;
}
 
int wxJSONReader::Parse(wxInputStream& is, wxJSONValue* val) {
  // if val == 0 the 'temp' JSON value will be passed to DoRead()
  wxJSONValue temp;
  m_level = 0;
  m_depth = 0;
  m_lineNo = 1;
  m_colNo = 1;
  m_peekChar = -1;
  m_errors.clear();
  m_warnings.clear();
 
  // if a wxJSONValue is not passed to the Parse function
  // we set the temparary object created on the stack
  // I know this will slow down the validation of input
  if (val == 0) {
    val = &temp;
  }
  wxASSERT(val);
 
  // set the wxJSONValue object's pointers for comment storage
  m_next = val;
  m_next->SetLineNo(-1);
  m_lastStored = 0;
  m_current = 0;
 
  int ch = GetStart(is);
  switch (ch) {
    case '{':
      val->SetType(wxJSONTYPE_OBJECT);
      break;
    case '[':
      val->SetType(wxJSONTYPE_ARRAY);
      break;
    default:
      AddError(_T("Cannot find a start object/array character" ));
      return m_errors.size();
      break;
  }
 
  // returning from DoRead() could be for EOF or for
  // the closing array-object character
  // if -1 is returned, it is as an error because the lack
  // of close-object/array characters
  // note that the missing close-chars error messages are
  // added by the DoRead() function
  ch = DoRead(is, *val);
  return m_errors.size();
}
 
 
int wxJSONReader::GetStart(wxInputStream& is) {
  int ch = 0;
  do {
    switch (ch) {
      case 0:
        ch = ReadChar(is);
        break;
      case '{':
        return ch;
        break;
      case '[':
        return ch;
        break;
      case '/':
        ch = SkipComment(is);
        StoreComment(0);
        break;
      default:
        ch = ReadChar(is);
        break;
    }
  } while (ch >= 0);
  return ch;
}
 
const wxArrayString& wxJSONReader::GetErrors() const { return m_errors; }
 
const wxArrayString& wxJSONReader::GetWarnings() const { return m_warnings; }
 
 
int wxJSONReader::GetDepth() const { return m_depth; }
 
int wxJSONReader::GetErrorCount() const { return m_errors.size(); }
 
int wxJSONReader::GetWarningCount() const { return m_warnings.size(); }
 
 
int wxJSONReader::ReadChar(wxInputStream& is) {
  if (is.Eof()) {
    return -1;
  }
 
  unsigned char ch = is.GetC();
  size_t last = is.LastRead();  // returns ZERO if EOF
  if (last == 0) {
    return -1;
  }
 
  // the function also converts CR in LF. only LF is returned
  // in the case of CR+LF
  int nextChar;
 
  if (ch == '\r') {
    m_colNo = 1;
    nextChar = PeekChar(is);
    if (nextChar == -1) {
      return -1;
    } else if (nextChar == '\n') {
      ch = is.GetC();
    }
  }
  if (ch == '\n') {
    ++m_lineNo;
    m_colNo = 1;
  } else {
    ++m_colNo;
  }
  return (int)ch;
}
 
 
int wxJSONReader::PeekChar(wxInputStream& is) {
  int ch = -1;
  unsigned char c;
  if (!is.Eof()) {
    c = is.Peek();
    ch = c;
  }
  return ch;
}
 
 
int wxJSONReader::DoRead(wxInputStream& is, wxJSONValue& parent) {
  ++m_level;
  if (m_depth < m_level) {
    m_depth = m_level;
  }
 
  // 'value' is the wxJSONValue structure that has to be
  // read. Data read from the JSON text input is stored
  // in the following object.
  wxJSONValue value(wxJSONTYPE_INVALID);
 
  // sets the pointers to the current, next and last-stored objects
  // in order to determine the value to which a comment refers to
  m_next = &value;
  m_current = &parent;
  m_current->SetLineNo(m_lineNo);
  m_lastStored = 0;
 
  // the 'key' string is stored from 'value' when a ':' is encontered
  wxString key;
 
  // the character read: -1=EOF, 0=to be read
  int ch = 0;
 
  do {  // we read until ch < 0
    switch (ch) {
      case 0:
        ch = ReadChar(is);
        break;
      case ' ':
      case '\t':
      case '\n':
      case '\r':
        ch = SkipWhiteSpace(is);
        break;
      case -1:  // the EOF
        break;
      case '/':
        ch = SkipComment(is);
        StoreComment(&parent);
        break;
 
      case '{':
        if (parent.IsObject()) {
          if (key.empty()) {
            AddError(_T("\'{\' is not allowed here (\'name\' is missing"));
          }
          if (value.IsValid()) {
            AddError(_T("\'{\' cannot follow a \'value\'"));
          }
        } else if (parent.IsArray()) {
          if (value.IsValid()) {
            AddError(_T("\'{\' cannot follow a \'value\' in JSON array"));
          }
        } else {
          wxJSON_ASSERT(0);  // always fails
        }
 
        // the openobject char cause the DoRead() to be called recursively
        value.SetType(wxJSONTYPE_OBJECT);
        ch = DoRead(is, value);
        break;
 
      case '}':
        if (!parent.IsObject()) {
          AddWarning(
              wxJSONREADER_MISSING,
              _T("Trying to close an array using the \'}\' (close-object) char" ));
        }
        // close-object: store the current value, if any
        StoreValue(ch, key, value, parent);
        m_current = &parent;
        m_next = 0;
        m_current->SetLineNo(m_lineNo);
        ch = ReadChar(is);
        return ch;
        break;
 
      case '[':
        if (parent.IsObject()) {
          if (key.empty()) {
            AddError(_T("\'[\' is not allowed here (\'name\' is missing"));
          }
          if (value.IsValid()) {
            AddError(_T("\'[\' cannot follow a \'value\' text"));
          }
        } else if (parent.IsArray()) {
          if (value.IsValid()) {
            AddError(_T("\'[\' cannot follow a \'value\'"));
          }
        } else {
          wxJSON_ASSERT(0);  // always fails
        }
        // open-array cause the DoRead() to be called recursively
        value.SetType(wxJSONTYPE_ARRAY);
        ch = DoRead(is, value);
        break;
 
      case ']':
        if (!parent.IsArray()) {
          // wrong close-array char (should be close-object)
          AddWarning(
              wxJSONREADER_MISSING,
              _T("Trying to close an object using the \']\' (close-array) char" ));
        }
        StoreValue(ch, key, value, parent);
        m_current = &parent;
        m_next = 0;
        m_current->SetLineNo(m_lineNo);
        return 0;  // returning ZERO for reading the next char
        break;
 
      case ',':
        // store the value, if any
        StoreValue(ch, key, value, parent);
        key.clear();
        ch = ReadChar(is);
        break;
 
      case '\"':
        ch = ReadString(is, value);  // read a JSON string type
        m_current = &value;
        m_next = 0;
        break;
 
      case '\'':
        ch = ReadMemoryBuff(is, value);  // read a memory buffer type
        m_current = &value;
        m_next = 0;
        break;
 
      case ':':  // key / value separator
        m_current = &value;
        m_current->SetLineNo(m_lineNo);
        m_next = 0;
        if (!parent.IsObject()) {
          AddError(_T( "\':\' can only used in object's values" ));
        } else if (!value.IsString()) {
          AddError(
              _T( "\':\' follows a value which is not of type \'string\'" ));
        } else if (!key.empty()) {
          AddError(
              _T( "\':\' not allowed where a \'name\' string was already available" ));
        } else {
          // the string in 'value' is set as the 'key'
          key = value.AsString();
          value.SetType(wxJSONTYPE_INVALID);
        }
        ch = ReadChar(is);
        break;
 
      default:
        // no special char: it is a literal or a number
        // errors are checked in the 'ReadValue()' function.
        m_current = &value;
        m_current->SetLineNo(m_lineNo);
        m_next = 0;
        ch = ReadValue(is, ch, value);
        break;
    }  // end switch
  } while (ch >= 0);
 
  // the DoRead() should return when the close-object/array char is encontered
  // if we are here, the EOF condition was encontered so one or more
  // close-something characters are missing
  if (parent.IsArray()) {
    AddWarning(wxJSONREADER_MISSING, _T("\']\' missing at end of file"));
  } else if (parent.IsObject()) {
    AddWarning(wxJSONREADER_MISSING, _T("\'}\' missing at end of file"));
  } else {
    wxJSON_ASSERT(0);
  }
 
  // we store the value, as there is a missing close-object/array char
  StoreValue(ch, key, value, parent);
 
  --m_level;
  return ch;
}
 
 
void wxJSONReader::StoreValue(int ch, const wxString& key, wxJSONValue& value,
                              wxJSONValue& parent) {
  // if 'ch' == } or ] than value AND key may be empty when a open object/array
  // is immediatly followed by a close object/array
  //
  // if 'ch' == , (comma) value AND key (for TypeMap) cannot be empty
  //
  wxLogTrace(traceMask, _T("(%s) ch=%d char=%c"), __PRETTY_FUNCTION__, ch,
             (char)ch);
  wxLogTrace(traceMask, _T("(%s) value=%s"), __PRETTY_FUNCTION__,
             value.AsString().c_str());
 
  m_current = 0;
  m_next = &value;
  m_lastStored = 0;
  m_next->SetLineNo(-1);
 
  if (!value.IsValid() && key.empty()) {
    // OK, if the char read is a close-object or close-array
    if (ch == '}' || ch == ']') {
      m_lastStored = 0;
      wxLogTrace(traceMask, _T("(%s) key and value are empty, returning"),
                 __PRETTY_FUNCTION__);
    } else {
      AddError(_T("key or value is missing for JSON value"));
    }
  } else {
    // key or value are not empty
    if (parent.IsObject()) {
      if (!value.IsValid()) {
        AddError(
            _T("cannot store the value: \'value\' is missing for JSON object ")
            _T("type"));
      } else if (key.empty()) {
        AddError(
            _T("cannot store the value: \'key\' is missing for JSON object ")
            _T("type"));
      } else {
        // OK, adding the value to parent key/value map
        wxLogTrace(traceMask, _T("(%s) adding value to key:%s"),
                   __PRETTY_FUNCTION__, key.c_str());
        parent[key] = value;
        m_lastStored = &(parent[key]);
        m_lastStored->SetLineNo(m_lineNo);
      }
    } else if (parent.IsArray()) {
      if (!value.IsValid()) {
        AddError(
            _T("cannot store the item: \'value\' is missing for JSON array ")
            _T("type"));
      }
      if (!key.empty()) {
        AddError(
            _T("cannot store the item: \'key\' (\'%s\') is not permitted in ")
            _T("JSON array type"),
            key);
      }
      wxLogTrace(traceMask, _T("(%s) appending value to parent array"),
                 __PRETTY_FUNCTION__);
      parent.Append(value);
      const wxJSONInternalArray* arr = parent.AsArray();
      wxJSON_ASSERT(arr);
      m_lastStored = &(arr->Last());
      m_lastStored->SetLineNo(m_lineNo);
    } else {
      wxJSON_ASSERT(0);  // should never happen
    }
  }
  value.SetType(wxJSONTYPE_INVALID);
  value.ClearComments();
}
 
 
void wxJSONReader::AddError(const wxString& msg) {
  wxString err;
  err.Printf(_T("Error: line %d, col %d - %s"), m_lineNo, m_colNo, msg.c_str());
 
  wxLogTrace(traceMask, _T("(%s) %s"), __PRETTY_FUNCTION__, err.c_str());
 
  if ((int)m_errors.size() < m_maxErrors) {
    m_errors.Add(err);
  } else if ((int)m_errors.size() == m_maxErrors) {
    m_errors.Add(
        _T("ERROR: too many error messages - ignoring further errors"));
  }
  // else if ( m_errors > m_maxErrors ) do nothing, thus ignore the error
  // message
}
 
void wxJSONReader::AddError(const wxString& fmt, const wxString& str) {
  wxString s;
  s.Printf(fmt.c_str(), str.c_str());
  AddError(s);
}
 
void wxJSONReader::AddError(const wxString& fmt, wxChar c) {
  wxString s;
  s.Printf(fmt.c_str(), c);
  AddError(s);
}
 
 
void wxJSONReader::AddWarning(int type, const wxString& msg) {
  // if 'type' AND 'm_flags' == 1 than the extension is
  // ON. Otherwise it is OFF anf the function calls AddError()
  if (type != 0) {
    if ((type & m_flags) == 0) {
      AddError(msg);
      return;
    }
  }
 
  wxString err;
  err.Printf(_T( "Warning: line %d, col %d - %s"), m_lineNo, m_colNo,
             msg.c_str());
 
  wxLogTrace(traceMask, _T("(%s) %s"), __PRETTY_FUNCTION__, err.c_str());
  if ((int)m_warnings.size() < m_maxErrors) {
    m_warnings.Add(err);
  } else if ((int)m_warnings.size() == m_maxErrors) {
    m_warnings.Add(
        _T("Error: too many warning messages - ignoring further warnings"));
  }
  // else do nothing, thus ignore the warning message
}
 
 
int wxJSONReader::SkipWhiteSpace(wxInputStream& is) {
  // just read one byte at a time and check for whitespaces
  int ch;
  do {
    ch = ReadChar(is);
    if (ch < 0) {
      break;
    }
  } while (ch == ' ' || ch == '\n' || ch == '\t');
  wxLogTrace(traceMask, _T("(%s) end whitespaces line=%d col=%d"),
             __PRETTY_FUNCTION__, m_lineNo, m_colNo);
  return ch;
}
 
 
int wxJSONReader::SkipComment(wxInputStream& is) {
  static const wxChar* warn =
      _T("Comments may be tolerated in JSON text but they are not part of ")
      _T("JSON syntax");
 
  // if it is a comment, then a warning is added to the array
  // otherwise it is an error: values cannot start with a '/'
  // read the char next to the first slash
  int ch = ReadChar(is);
  if (ch < 0) {
    return -1;
  }
 
  wxLogTrace(storeTraceMask, _T("(%s) start comment line=%d col=%d"),
             __PRETTY_FUNCTION__, m_lineNo, m_colNo);
 
  // the temporary UTF-8/ANSI buffer that holds the comment string. This will be
  // converted to a wxString object using wxString::FromUTF8() or From8BitData()
  wxMemoryBuffer utf8Buff;
  unsigned char c;
 
  if (ch == '/') {  // C++ comment, read until end-of-line
    // C++ comment strings are in UTF-8 format. we store all
    // UTF-8 code units until the first LF or CR+LF
    AddWarning(wxJSONREADER_ALLOW_COMMENTS, warn);
    m_commentLine = m_lineNo;
    utf8Buff.AppendData("//", 2);
 
    while (ch >= 0) {
      if (ch == '\n') {
        break;
      }
      if (ch == '\r') {
        ch = PeekChar(is);
        if (ch == '\n') {
          ch = ReadChar(is);
        }
        break;
      } else {
        // store the char in the UTF8 temporary buffer
        c = (unsigned char)ch;
        utf8Buff.AppendByte(c);
      }
      ch = ReadChar(is);
    }
    // now convert the temporary UTF-8 buffer
    m_comment = wxString::FromUTF8((const char*)utf8Buff.GetData(),
                                   utf8Buff.GetDataLen());
  }
 
  // check if a C-style comment
  else if (ch == '*') {  // C-style comment
    AddWarning(wxJSONREADER_ALLOW_COMMENTS, warn);
    m_commentLine = m_lineNo;
    utf8Buff.AppendData("/*", 2);
    while (ch >= 0) {
      // check the END-COMMENT chars ('*/')
      if (ch == '*') {
        ch = PeekChar(is);
        if (ch == '/') {
          ch = ReadChar(is);  // read the '/' char
          ch = ReadChar(is);  // read the next char that will be returned
          utf8Buff.AppendData("*/", 2);
          break;
        }
      }
      // store the char in the UTF8 temporary buffer
      c = (unsigned char)ch;
      utf8Buff.AppendByte(c);
      ch = ReadChar(is);
    }
    // now convert the temporary buffer in a wxString object
    if (m_noUtf8) {
      m_comment = wxString::From8BitData((const char*)utf8Buff.GetData(),
                                         utf8Buff.GetDataLen());
    } else {
      m_comment = wxString::FromUTF8((const char*)utf8Buff.GetData(),
                                     utf8Buff.GetDataLen());
    }
  }
 
  else {  // it is not a comment, return the character next the first '/'
    AddError(_T( "Strange '/' (did you want to insert a comment?)"));
    // we read until end-of-line OR end of C-style comment OR EOF
    // because a '/' should be a start comment
    while (ch >= 0) {
      ch = ReadChar(is);
      if (ch == '*' && PeekChar(is) == '/') {
        break;
      }
      if (ch == '\n') {
        break;
      }
    }
    // read the next char that will be returned
    ch = ReadChar(is);
  }
  wxLogTrace(traceMask, _T("(%s) end comment line=%d col=%d"),
             __PRETTY_FUNCTION__, m_lineNo, m_colNo);
  wxLogTrace(storeTraceMask, _T("(%s) end comment line=%d col=%d"),
             __PRETTY_FUNCTION__, m_lineNo, m_colNo);
  wxLogTrace(storeTraceMask, _T("(%s) comment=%s"), __PRETTY_FUNCTION__,
             m_comment.c_str());
  return ch;
}
 
 
int wxJSONReader::ReadString(wxInputStream& is, wxJSONValue& val) {
  // the char last read is the opening qoutes (")
 
  wxMemoryBuffer utf8Buff;
  char ues[8];  // stores a Unicode Escaped Esquence: \uXXXX
 
  int ch = 0;
  while (ch >= 0) {
    ch = ReadChar(is);
    unsigned char c = (unsigned char)ch;
    if (ch == '\\') {  // an escape sequence
      ch = ReadChar(is);
      switch (ch) {
        case -1:  // EOF
          break;
        case 't':
          utf8Buff.AppendByte('\t');
          break;
        case 'n':
          utf8Buff.AppendByte('\n');
          break;
        case 'b':
          utf8Buff.AppendByte('\b');
          break;
        case 'r':
          utf8Buff.AppendByte('\r');
          break;
        case '\"':
          utf8Buff.AppendByte('\"');
          break;
        case '\\':
          utf8Buff.AppendByte('\\');
          break;
        case '/':
          utf8Buff.AppendByte('/');
          break;
        case 'f':
          utf8Buff.AppendByte('\f');
          break;
        case 'u':
          ch = ReadUES(is, ues);
          if (ch < 0) {  // if EOF, returns
            return ch;
          }
          // append the escaped character to the UTF8 buffer
          AppendUES(utf8Buff, ues);
          // many thanks to Bryan Ashby who discovered this bug
          continue;
          // break;
        default:
          AddError(_T( "Unknow escaped character \'\\%c\'"), ch);
      }
    } else {
      // we have read a non-escaped character so we have to append it to
      // the temporary UTF-8 buffer until the next quote char
      if (ch == '\"') {
        break;
      }
      utf8Buff.AppendByte(c);
    }
  }
 
  // if UTF-8 conversion is disabled (ANSI builds only) we just copy the
  // bit data to a wxString object
  wxString s;
  if (m_noUtf8) {
    s = wxString::From8BitData((const char*)utf8Buff.GetData(),
                               utf8Buff.GetDataLen());
  } else {
    // perform UTF-8 conversion
    // first we check that the UTF-8 buffer is correct, i.e. it contains valid
    // UTF-8 code points.
    // this works in both ANSI and Unicode builds.
    size_t convLen =
        wxConvUTF8.ToWChar(0,  // wchar_t destination
                           0,  // size_t  destLenght
                           (const char*)utf8Buff.GetData(),  // char_t  source
                           utf8Buff.GetDataLen());  // size_t  sourceLenght
 
    if (convLen == wxCONV_FAILED) {
      AddError(_T( "String value: the UTF-8 stream is invalid"));
      s.append(_T( "<UTF-8 stream not valid>"));
    } else {
#if defined(wxJSON_USE_UNICODE)
      // in Unicode just convert to wxString
      s = wxString::FromUTF8((const char*)utf8Buff.GetData(),
                             utf8Buff.GetDataLen());
#else
      // in ANSI, the conversion may fail and an empty string is returned
      // in this case, the reader do a char-by-char conversion storing
      // unicode escaped sequences of unrepresentable characters
      s = wxString::FromUTF8((const char*)utf8Buff.GetData(),
                             utf8Buff.GetDataLen());
      if (s.IsEmpty()) {
        int r = ConvertCharByChar(
            s, utf8Buff);  // return number of escaped sequences
        if (r > 0) {
          AddWarning(
              0,
              _T( "The string value contains unrepresentable Unicode characters"));
        }
      }
#endif
    }
  }
  wxLogTrace(traceMask, _T("(%s) line=%d col=%d"), __PRETTY_FUNCTION__,
             m_lineNo, m_colNo);
  wxLogTrace(traceMask, _T("(%s) string read=%s"), __PRETTY_FUNCTION__,
             s.c_str());
  wxLogTrace(traceMask, _T("(%s) value=%s"), __PRETTY_FUNCTION__,
             val.AsString().c_str());
 
  // now assign the string to the JSON-value 'value'
  // must check that:
  //   'value'  is empty
  //   'value'  is a string; concatenate it but emit warning
  if (!val.IsValid()) {
    wxLogTrace(traceMask, _T("(%s) assigning the string to value"),
               __PRETTY_FUNCTION__);
    val = s;
  } else if (val.IsString()) {
    AddWarning(wxJSONREADER_MULTISTRING,
               _T("Multiline strings are not allowed by JSON syntax"));
    wxLogTrace(traceMask, _T("(%s) concatenate the string to value"),
               __PRETTY_FUNCTION__);
    val.Cat(s);
  } else {
    AddError(_T( "String value \'%s\' cannot follow another value"), s);
  }
 
  // store the input text's line number when the string was stored in 'val'
  val.SetLineNo(m_lineNo);
 
  // read the next char after the closing quotes and returns it
  if (ch >= 0) {
    ch = ReadChar(is);
  }
  return ch;
}
 
 
int wxJSONReader::ReadToken(wxInputStream& is, int ch, wxString& s) {
  int nextCh = ch;
  while (nextCh >= 0) {
    switch (nextCh) {
      case ' ':
      case ',':
      case ':':
      case '[':
      case ']':
      case '{':
      case '}':
      case '\t':
      case '\n':
      case '\r':
      case '\b':
        wxLogTrace(traceMask, _T("(%s) line=%d col=%d"), __PRETTY_FUNCTION__,
                   m_lineNo, m_colNo);
        wxLogTrace(traceMask, _T("(%s) token read=%s"), __PRETTY_FUNCTION__,
                   s.c_str());
        return nextCh;
        break;
      default:
        s.Append((unsigned char)nextCh, 1);
        break;
    }
    // read the next character
    nextCh = ReadChar(is);
  }
  wxLogTrace(traceMask, _T("(%s) EOF on line=%d col=%d"), __PRETTY_FUNCTION__,
             m_lineNo, m_colNo);
  wxLogTrace(traceMask, _T("(%s) EOF - token read=%s"), __PRETTY_FUNCTION__,
             s.c_str());
  return nextCh;
}
 
 
int wxJSONReader::ReadValue(wxInputStream& is, int ch, wxJSONValue& val) {
  wxString s;
  int nextCh = ReadToken(is, ch, s);
  wxLogTrace(traceMask, _T("(%s) value=%s"), __PRETTY_FUNCTION__,
             val.AsString().c_str());
 
  if (val.IsValid()) {
    AddError(_T( "Value \'%s\' cannot follow a value: \',\' or \':\' missing?"),
             s);
    return nextCh;
  }
 
  // variables used for converting numeric values
  bool r;
  double d;
#if defined(wxJSON_64BIT_INT)
  wxInt64 i64;
  wxUint64 ui64;
#else
  unsigned long int ul;
  long int l;
#endif
 
  // first try the literal strings lowercase and nocase
  if (s == _T("null")) {
    val.SetType(wxJSONTYPE_NULL);
    wxLogTrace(traceMask, _T("(%s) value = NULL"), __PRETTY_FUNCTION__);
    return nextCh;
  } else if (s.CmpNoCase(_T( "null" )) == 0) {
    wxLogTrace(traceMask, _T("(%s) value = NULL"), __PRETTY_FUNCTION__);
    AddWarning(wxJSONREADER_CASE,
               _T( "the \'null\' literal must be lowercase" ));
    val.SetType(wxJSONTYPE_NULL);
    return nextCh;
  } else if (s == _T("true")) {
    wxLogTrace(traceMask, _T("(%s) value = TRUE"), __PRETTY_FUNCTION__);
    val = true;
    return nextCh;
  } else if (s.CmpNoCase(_T( "true" )) == 0) {
    wxLogTrace(traceMask, _T("(%s) value = TRUE"), __PRETTY_FUNCTION__);
    AddWarning(wxJSONREADER_CASE,
               _T( "the \'true\' literal must be lowercase" ));
    val = true;
    return nextCh;
  } else if (s == _T("false")) {
    wxLogTrace(traceMask, _T("(%s) value = FALSE"), __PRETTY_FUNCTION__);
    val = false;
    return nextCh;
  } else if (s.CmpNoCase(_T( "false" )) == 0) {
    wxLogTrace(traceMask, _T("(%s) value = FALSE"), __PRETTY_FUNCTION__);
    AddWarning(wxJSONREADER_CASE,
               _T( "the \'false\' literal must be lowercase" ));
    val = false;
    return nextCh;
  }
 
  // try to convert to a number if the token starts with a digit, a plus or a
  // minus sign. The function first states what type of conversion are tested:
  //    1. first signed integer (not if 'ch' == '+')
  //    2. unsigned integer (not if 'ch' == '-')
  //    3. finally double
  bool tSigned = true, tUnsigned = true, tDouble = true;
  switch (ch) {
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
      // first try a signed integer, then a unsigned integer, then a double
      break;
 
    case '+':
      // the plus sign forces a unsigned integer
      tSigned = false;
      break;
 
    case '-':
      // try signed and double
      tUnsigned = false;
      break;
    default:
      AddError(_T( "Literal \'%s\' is incorrect (did you forget quotes?)"), s);
      return nextCh;
  }
 
  if (tSigned) {
#if defined(wxJSON_64BIT_INT)
    r = Strtoll(s, &i64);
    wxLogTrace(traceMask, _T("(%s) convert to wxInt64 result=%d"),
               __PRETTY_FUNCTION__, r);
    if (r) {
      // store the value
      val = i64;
      return nextCh;
    }
#else
    r = s.ToLong(&l);
    wxLogTrace(traceMask, _T("(%s) convert to int result=%d"),
               __PRETTY_FUNCTION__, r);
    if (r) {
      // store the value
      val = (int)l;
      return nextCh;
    }
#endif
  }
 
  if (tUnsigned) {
#if defined(wxJSON_64BIT_INT)
    r = Strtoull(s, &ui64);
    wxLogTrace(traceMask, _T("(%s) convert to wxUint64 result=%d"),
               __PRETTY_FUNCTION__, r);
    if (r) {
      // store the value
      val = ui64;
      return nextCh;
    }
#else
    r = s.ToULong(&ul);
    wxLogTrace(traceMask, _T("(%s) convert to int result=%d"),
               __PRETTY_FUNCTION__, r);
    if (r) {
      // store the value
      val = (unsigned int)ul;
      return nextCh;
    }
#endif
  }
 
  if (tDouble) {
    r = s.ToDouble(&d);
    wxLogTrace(traceMask, _T("(%s) convert to double result=%d"),
               __PRETTY_FUNCTION__, r);
    if (r) {
      // store the value
      val = d;
      return nextCh;
    }
  }
 
  // the value is not syntactically correct
  AddError(_T( "Literal \'%s\' is incorrect (did you forget quotes?)"), s);
  return nextCh;
  return nextCh;
}
 
 
int wxJSONReader::ReadUES(wxInputStream& is, char* uesBuffer) {
  int ch;
  for (int i = 0; i < 4; i++) {
    ch = ReadChar(is);
    if (ch < 0) {
      return ch;
    }
    uesBuffer[i] = (unsigned char)ch;
  }
  uesBuffer[4] = 0;  // makes a ASCIIZ string
 
  return 0;
}
 
 
int wxJSONReader::AppendUES(wxMemoryBuffer& utf8Buff, const char* uesBuffer) {
  unsigned long l;
  int r = sscanf(uesBuffer, "%lx", &l);  // r is the assigned items
  if (r != 1) {
    AddError(_T( "Invalid Unicode Escaped Sequence"));
    return -1;
  }
  wxLogTrace(traceMask, _T("(%s) unicode sequence=%s code=%ld"),
             __PRETTY_FUNCTION__, uesBuffer, l);
 
  wchar_t ch = (wchar_t)l;
  char buffer[16];
  size_t len = wxConvUTF8.FromWChar(buffer, 10, &ch, 1);
 
  // seems that the wxMBConv classes always appends a NULL byte to
  // the converted buffer
  if (len > 1) {
    len = len - 1;
  }
  utf8Buff.AppendData(buffer, len);
 
  // sould never fail
  wxASSERT(len != wxCONV_FAILED);
  return 0;
}
 
 
void wxJSONReader::StoreComment(const wxJSONValue* parent) {
  wxLogTrace(storeTraceMask, _T("(%s) m_comment=%s"), __PRETTY_FUNCTION__,
             m_comment.c_str());
  wxLogTrace(storeTraceMask, _T("(%s) m_flags=%d m_commentLine=%d"),
             __PRETTY_FUNCTION__, m_flags, m_commentLine);
  wxLogTrace(storeTraceMask, _T("(%s) m_current=%p"), __PRETTY_FUNCTION__,
             m_current);
  wxLogTrace(storeTraceMask, _T("(%s) m_next=%p"), __PRETTY_FUNCTION__, m_next);
  wxLogTrace(storeTraceMask, _T("(%s) m_lastStored=%p"), __PRETTY_FUNCTION__,
             m_lastStored);
 
  // first check if the 'store comment' bit is on
  if ((m_flags & wxJSONREADER_STORE_COMMENTS) == 0) {
    m_comment.clear();
    return;
  }
 
  // check if the comment is on the same line of one of the
  // 'current', 'next' or 'lastStored' value
  if (m_current != 0) {
    wxLogTrace(storeTraceMask, _T("(%s) m_current->lineNo=%d"),
               __PRETTY_FUNCTION__, m_current->GetLineNo());
    if (m_current->GetLineNo() == m_commentLine) {
      wxLogTrace(storeTraceMask,
                 _T("(%s) comment added to \'m_current\' INLINE"),
                 __PRETTY_FUNCTION__);
      m_current->AddComment(m_comment, wxJSONVALUE_COMMENT_INLINE);
      m_comment.clear();
      return;
    }
  }
  if (m_next != 0) {
    wxLogTrace(storeTraceMask, _T("(%s) m_next->lineNo=%d"),
               __PRETTY_FUNCTION__, m_next->GetLineNo());
    if (m_next->GetLineNo() == m_commentLine) {
      wxLogTrace(storeTraceMask, _T("(%s) comment added to \'m_next\' INLINE"),
                 __PRETTY_FUNCTION__);
      m_next->AddComment(m_comment, wxJSONVALUE_COMMENT_INLINE);
      m_comment.clear();
      return;
    }
  }
  if (m_lastStored != 0) {
    wxLogTrace(storeTraceMask, _T("(%s) m_lastStored->lineNo=%d"),
               __PRETTY_FUNCTION__, m_lastStored->GetLineNo());
    if (m_lastStored->GetLineNo() == m_commentLine) {
      wxLogTrace(storeTraceMask,
                 _T("(%s) comment added to \'m_lastStored\' INLINE"),
                 __PRETTY_FUNCTION__);
      m_lastStored->AddComment(m_comment, wxJSONVALUE_COMMENT_INLINE);
      m_comment.clear();
      return;
    }
  }
 
  // if comment is BEFORE, store the comment in the 'm_next'
  // or 'm_current' value
  // if comment is AFTER, store the comment in the 'm_lastStored'
  // or 'm_current' value
 
  if (m_flags & wxJSONREADER_COMMENTS_AFTER) {  // comment AFTER
    if (m_current) {
      if (m_current == parent || !m_current->IsValid()) {
        AddError(
            _T("Cannot find a value for storing the comment (flag AFTER)"));
      } else {
        wxLogTrace(storeTraceMask,
                   _T("(%s) comment added to m_current (AFTER)"),
                   __PRETTY_FUNCTION__);
        m_current->AddComment(m_comment, wxJSONVALUE_COMMENT_AFTER);
      }
    } else if (m_lastStored) {
      wxLogTrace(storeTraceMask,
                 _T("(%s) comment added to m_lastStored (AFTER)"),
                 __PRETTY_FUNCTION__);
      m_lastStored->AddComment(m_comment, wxJSONVALUE_COMMENT_AFTER);
    } else {
      wxLogTrace(storeTraceMask,
                 _T("(%s) cannot find a value for storing the AFTER comment"),
                 __PRETTY_FUNCTION__);
      AddError(_T("Cannot find a value for storing the comment (flag AFTER)"));
    }
  } else {  // comment BEFORE can only be added to the 'next' value
    if (m_next) {
      wxLogTrace(storeTraceMask, _T("(%s) comment added to m_next (BEFORE)"),
                 __PRETTY_FUNCTION__);
      m_next->AddComment(m_comment, wxJSONVALUE_COMMENT_BEFORE);
    } else {
      // cannot find a value for storing the comment
      AddError(_T("Cannot find a value for storing the comment (flag BEFORE)"));
    }
  }
  m_comment.clear();
}
 
 
int wxJSONReader::NumBytes(char ch) {
  int n = UTF8NumBytes(ch);
  return n;
}
 
 
int wxJSONReader::UTF8NumBytes(char ch) {
  int num = 0;  // the counter of '1' bits
  for (int i = 0; i < 8; i++) {
    if ((ch & 0x80) == 0) {
      break;
    }
    ++num;
    ch = ch << 1;
  }
 
  // note that if the char contains more than six '1' bits it is not
  // a valid UTF-8 encoded character
  if (num > 6) {
    num = -1;
  } else if (num == 0) {
    num = 1;
  }
  return num;
}
 
 
int wxJSONReader::ConvertCharByChar(wxString& s,
                                    const wxMemoryBuffer& utf8Buffer) {
  size_t len = utf8Buffer.GetDataLen();
  char* buff = (char*)utf8Buffer.GetData();
  char* buffEnd = buff + len;
 
  int result = 0;
  char temp[16];  // the UTF-8 code-point
 
  while (buff < buffEnd) {
    temp[0] = *buff;  // the first UTF-8 code-unit
    // compute the number of code-untis that make one UTF-8 code-point
    int numBytes = NumBytes(*buff);
    ++buff;
    for (int i = 1; i < numBytes; i++) {
      if (buff >= buffEnd) {
        break;
      }
      temp[i] = *buff;  // the first UTF-8 code-unit
      ++buff;
    }
    // if ( buff >= buffEnd )    {
    //    break;
    //}
    // now convert 'temp' to a wide-character
    wchar_t dst[10];
    size_t outLength = wxConvUTF8.ToWChar(dst, 10, temp, numBytes);
 
    // now convert the wide char to a locale dependent character
    // len = wxConvLocal.FromWChar( temp, 16, dst, outLength );
    // len = wxConviso8859_1.FromWChar( temp, 16, dst, outLength );
    len = wxConvLibc.FromWChar(temp, 16, dst, outLength);
    if (len == wxCONV_FAILED) {
      ++result;
      wxString t;
      t.Printf(_T( "\\u%04X"), (int)dst[0]);
      s.Append(t);
    } else {
      s.Append(temp[0], 1);
    }
  }  // end while
  return result;
}
 
 
// union byte
//{
//    unsigned char c[2];
//    short int b;
//};
 
int wxJSONReader::ReadMemoryBuff(wxInputStream& is, wxJSONValue& val) {
  static const wxChar* membuffError =
      _T("the \'memory buffer\' type contains %d invalid digits" );
 
  AddWarning(wxJSONREADER_MEMORYBUFF,
             _T( "the \'memory buffer\' type is not valid JSON text" ));
 
  wxMemoryBuffer buff;
  int ch = 0;
  int errors = 0;
  unsigned char byte = 0;
  while (ch >= 0) {
    ch = ReadChar(is);
    if (ch < 0) {
      break;
    }
    if (ch == '\'') {
      break;
    }
    // the conversion is done two chars at a time
    unsigned char c1 = (unsigned char)ch;
    ch = ReadChar(is);
    if (ch < 0) {
      break;
    }
    unsigned char c2 = (unsigned char)ch;
    c1 -= '0';
    c2 -= '0';
    if (c1 > 9) {
      c1 -= 7;
    }
    if (c2 > 9) {
      c2 -= 7;
    }
    if (c1 > 15) {
      ++errors;
    } else if (c2 > 15) {
      ++errors;
    } else {
      byte = (c1 * 16) + c2;
      buff.AppendByte(byte);
    }
  }  // end while
 
  if (errors > 0) {
    wxString err;
    err.Printf(membuffError, errors);
    AddError(err);
  }
 
  // now assign the memory buffer object to the JSON-value 'value'
  // must check that:
  //   'value'  is invalid OR
  //   'value'  is a memory buffer; concatenate it
  if (!val.IsValid()) {
    wxLogTrace(traceMask, _T("(%s) assigning the memory buffer to value"),
               __PRETTY_FUNCTION__);
    val = buff;
  } else if (val.IsMemoryBuff()) {
    wxLogTrace(traceMask, _T("(%s) concatenate memory buffer to value"),
               __PRETTY_FUNCTION__);
    val.Cat(buff);
  } else {
    AddError(_T( "Memory buffer value cannot follow another value"));
  }
 
  // store the input text's line number when the string was stored in 'val'
  val.SetLineNo(m_lineNo);
 
  // read the next char after the closing quotes and returns it
  if (ch >= 0) {
    ch = ReadChar(is);
  }
  return ch;
}
 
#if defined(wxJSON_64BIT_INT)
 
bool wxJSONReader::Strtoll(const wxString& str, wxInt64* i64) {
  wxChar sign = ' ';
  wxUint64 ui64;
  bool r = DoStrto_ll(str, &ui64, &sign);
 
  // check overflow for signed long long
  switch (sign) {
    case '-':
      if (ui64 > (wxUint64)LLONG_MAX + 1) {
        r = false;
      } else {
        *i64 = (wxInt64)(ui64 * -1);
      }
      break;
 
    // case '+' :
    default:
      if (ui64 > LLONG_MAX) {
        r = false;
      } else {
        *i64 = (wxInt64)ui64;
      }
      break;
  }
  return r;
}
 
 
bool wxJSONReader::Strtoull(const wxString& str, wxUint64* ui64) {
  wxChar sign = ' ';
  bool r = DoStrto_ll(str, ui64, &sign);
  if (sign == '-') {
    r = false;
  }
  return r;
}
 
 
bool wxJSONReader::DoStrto_ll(const wxString& str, wxUint64* ui64,
                              wxChar* sign) {
  // the conversion is done by multiplying the individual digits
  // in reverse order to the corresponding power of 10
  //
  //  10's power:  987654321.9876543210
  //
  // LLONG_MAX:     9223372036854775807
  // LLONG_MIN:    -9223372036854775808
  // ULLONG_MAX:   18446744073709551615
  //
  // the function does not take into account the sign: only a
  // unsigned long long int is returned
 
  int maxDigits = 20;  // 20 + 1 (for the sign)
 
  wxUint64 power10[] = {wxULL(1),
                        wxULL(10),
                        wxULL(100),
                        wxULL(1000),
                        wxULL(10000),
                        wxULL(100000),
                        wxULL(1000000),
                        wxULL(10000000),
                        wxULL(100000000),
                        wxULL(1000000000),
                        wxULL(10000000000),
                        wxULL(100000000000),
                        wxULL(1000000000000),
                        wxULL(10000000000000),
                        wxULL(100000000000000),
                        wxULL(1000000000000000),
                        wxULL(10000000000000000),
                        wxULL(100000000000000000),
                        wxULL(1000000000000000000),
                        wxULL(10000000000000000000)};
 
  wxUint64 temp1 = wxULL(0);  // the temporary converted integer
 
  int strLen = str.length();
  if (strLen == 0) {
    // an empty string is converted to a ZERO value: the function succeeds
    *ui64 = wxLL(0);
    return true;
  }
 
  int index = 0;
  wxChar ch = str[0];
  if (ch == '+' || ch == '-') {
    *sign = ch;
    ++index;
    ++maxDigits;
  }
 
  if (strLen > maxDigits) {
    return false;
  }
 
  // check the overflow: check the string length and the individual digits
  // of the string; the overflow is checked for unsigned long long
  if (strLen == maxDigits) {
    wxString uLongMax(_T("18446744073709551615"));
    int j = 0;
    for (int i = index; i < strLen - 1; i++) {
      ch = str[i];
      if (ch < '0' || ch > '9') {
        return false;
      }
      if (ch > uLongMax[j]) {
        return false;
      }
      if (ch < uLongMax[j]) {
        break;
      }
      ++j;
    }
  }
 
  // get the digits in the reverse order and multiply them by the
  // corresponding power of 10
  int exponent = 0;
  for (int i = strLen - 1; i >= index; i--) {
    wxChar ch = str[i];
    if (ch < '0' || ch > '9') {
      return false;
    }
    ch = ch - '0';
    // compute the new temporary value
    temp1 += ch * power10[exponent];
    ++exponent;
  }
  *ui64 = temp1;
  return true;
}
 
#endif  // defined( wxJSON_64BIT_INT )
 
/*
{
}
*/