jsonwriter.cpp

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// Name:        jsonwriter.cpp
// Purpose:     the wxJSONWriter class: a JSON text generator
// Author:      Luciano Cattani
// Created:     2007/10/12
// RCS-ID:      $Id: jsonwriter.cpp,v 1.6 2008/03/03 19:05:47 luccat Exp $
// Copyright:   (c) 2007 Luciano Cattani
// Licence:     wxWidgets licence
 
#ifdef NDEBUG
// make wxLogTrace a noop if no debug set, it's really slow
// must be defined before including debug.h
#define wxDEBUG_LEVEL 0
#endif
 
#include <wx/jsonwriter.h>
 
#include <wx/sstream.h>
#include <wx/mstream.h>
#include <wx/debug.h>
#include <wx/log.h>
 
#if wxDEBUG_LEVEL > 0
static const wxChar* writerTraceMask = _T("traceWriter");
#endif
 
 
wxJSONWriter::wxJSONWriter(int style, int indent, int step) {
  m_indent = indent;
  m_step = step;
  m_style = style;
  m_noUtf8 = false;
  if (m_style == wxJSONWRITER_NONE) {
    m_indent = 0;
    m_step = 0;
  }
  // set the default format string for doubles as
  // 10 significant digits and suppress trailing ZEROes
  SetDoubleFmtString("%.10g");
 
#if !defined(wxJSON_USE_UNICODE)
  // in ANSI builds we can suppress UTF-8 conversion for both the writer and the
  // reader
  if (m_style == wxJSONWRITER_NOUTF8_STREAM) {
    m_noUtf8 = true;
  }
#endif
}
 
wxJSONWriter::~wxJSONWriter() {}
 
 
void wxJSONWriter::Write(const wxJSONValue& value, wxString& str) {
#if !defined(wxJSON_USE_UNICODE)
  // in ANSI builds output to a string never use UTF-8 conversion
  bool noUtf8_bak = m_noUtf8;  // save the current setting
  m_noUtf8 = true;
#endif
 
  wxMemoryOutputStream os;
  Write(value, os);
 
  // get the address of the buffer
  wxFileOffset len = os.GetLength();
  wxStreamBuffer* osBuff = os.GetOutputStreamBuffer();
  void* buffStart = osBuff->GetBufferStart();
 
  if (m_noUtf8) {
    str = wxString::From8BitData((const char*)buffStart, len);
  } else {
    str = wxString::FromUTF8((const char*)buffStart, len);
  }
#if !defined(wxJSON_USE_UNICODE)
  m_noUtf8 = noUtf8_bak;  // restore the old setting
#endif
}
 
void wxJSONWriter::Write(const wxJSONValue& value, wxOutputStream& os) {
  m_level = 0;
  DoWrite(os, value, 0, false);
}
 
 
void wxJSONWriter::SetDoubleFmtString(const char* fmt) { m_fmt = (char*)fmt; }
 
 
int wxJSONWriter::DoWrite(wxOutputStream& os, const wxJSONValue& value,
                          const wxString* key, bool comma) {
  // note that this function is recursive
 
  // some variables that cannot be allocated in the switch statement
  const wxJSONInternalMap* map = nullptr;
  int size;
  m_colNo = 1;
  m_lineNo = 1;
  // determine the comment position; it is one of:
  //
  //  wxJSONVALUE_COMMENT_BEFORE
  //  wxJSONVALUE_COMMENT_AFTER
  //  wxJSONVALUE_COMMENT_INLINE
  //
  // or -1 if comments have not to be written
  int commentPos = -1;
  if (value.GetCommentCount() > 0 && (m_style & wxJSONWRITER_WRITE_COMMENTS)) {
    commentPos = value.GetCommentPos();
    if ((m_style & wxJSONWRITER_COMMENTS_BEFORE) != 0) {
      commentPos = wxJSONVALUE_COMMENT_BEFORE;
    } else if ((m_style & wxJSONWRITER_COMMENTS_AFTER) != 0) {
      commentPos = wxJSONVALUE_COMMENT_AFTER;
    }
  }
 
  int lastChar = 0;  // check if WriteComment() writes the last LF char
 
  // first write the comment if it is BEFORE
  if (commentPos == wxJSONVALUE_COMMENT_BEFORE) {
    lastChar = WriteComment(os, value, true);
    if (lastChar < 0) {
      return lastChar;
    } else if (lastChar != '\n') {
      WriteSeparator(os);
    }
  }
 
  lastChar = WriteIndent(os);
  if (lastChar < 0) {
    return lastChar;
  }
 
  // now write the key if it is not nullptr
  if (key) {
    lastChar = WriteKey(os, *key);
  }
  if (lastChar < 0) {
    return lastChar;
  }
 
  // now write the value
  wxJSONInternalMap::const_iterator it;  // declare the map object
  long int count = 0;
 
  wxJSONType t = value.GetType();
  switch (t) {
    case wxJSONTYPE_INVALID:
      WriteInvalid(os);
      wxFAIL_MSG(
          _T("wxJSONWriter::WriteEmpty() cannot be called (not a valid JSON ")
          _T("text"));
      break;
 
    case wxJSONTYPE_INT:
    case wxJSONTYPE_SHORT:
    case wxJSONTYPE_LONG:
    case wxJSONTYPE_INT64:
      lastChar = WriteIntValue(os, value);
      break;
 
    case wxJSONTYPE_UINT:
    case wxJSONTYPE_USHORT:
    case wxJSONTYPE_ULONG:
    case wxJSONTYPE_UINT64:
      lastChar = WriteUIntValue(os, value);
      break;
 
    case wxJSONTYPE_NULL:
      lastChar = WriteNullValue(os);
      break;
    case wxJSONTYPE_BOOL:
      lastChar = WriteBoolValue(os, value);
      break;
 
    case wxJSONTYPE_DOUBLE:
      lastChar = WriteDoubleValue(os, value);
      break;
 
    case wxJSONTYPE_STRING:
    case wxJSONTYPE_CSTRING:
      lastChar = WriteStringValue(os, value.AsString());
      break;
 
    case wxJSONTYPE_MEMORYBUFF:
      lastChar = WriteMemoryBuff(os, value.AsMemoryBuff());
      break;
 
    case wxJSONTYPE_ARRAY:
      ++m_level;
      os.PutC('[');
      // the inline comment for objects and arrays are printed in the open char
      if (commentPos == wxJSONVALUE_COMMENT_INLINE) {
        commentPos = -1;  // we have already written the comment
        lastChar = WriteComment(os, value, false);
        if (lastChar < 0) {
          return lastChar;
        }
        if (lastChar != '\n') {
          lastChar = WriteSeparator(os);
        }
      } else {  // comment is not to be printed inline, so write a LF
        lastChar = WriteSeparator(os);
        if (lastChar < 0) {
          return lastChar;
        }
      }
 
      // now iterate through all sub-items and call DoWrite() recursively
      size = value.Size();
      for (int i = 0; i < size; i++) {
        bool comma = false;
        if (i < size - 1) {
          comma = true;
        }
        wxJSONValue v = value.ItemAt(i);
        lastChar = DoWrite(os, v, 0, comma);
        if (lastChar < 0) {
          return lastChar;
        }
      }
      --m_level;
      lastChar = WriteIndent(os);
      if (lastChar < 0) {
        return lastChar;
      }
      os.PutC(']');
      break;
 
    case wxJSONTYPE_OBJECT:
      ++m_level;
 
      os.PutC('{');
      // the inline comment for objects and arrays are printed in the open char
      if (commentPos == wxJSONVALUE_COMMENT_INLINE) {
        commentPos = -1;  // we have already written the comment
        lastChar = WriteComment(os, value, false);
        if (lastChar < 0) {
          return lastChar;
        }
        if (lastChar != '\n') {
          WriteSeparator(os);
        }
      } else {
        lastChar = WriteSeparator(os);
      }
 
      map = value.AsMap();
      size = value.Size();
      count = 0;
      for (it = map->begin(); it != map->end(); ++it) {
        // get the key and the value
        wxString key = it->first;
        const wxJSONValue& v = it->second;
        bool comma = false;
        if (count < size - 1) {
          comma = true;
        }
        lastChar = DoWrite(os, v, &key, comma);
        if (lastChar < 0) {
          return lastChar;
        }
        count++;
      }
      --m_level;
      lastChar = WriteIndent(os);
      if (lastChar < 0) {
        return lastChar;
      }
      os.PutC('}');
      break;
 
    default:
      // a not yet defined wxJSONType: we FAIL
      wxFAIL_MSG(_T("wxJSONWriter::DoWrite() undefined wxJSONType type"));
      break;
  }
 
  // writes the comma character before the inline comment
  if (comma) {
    os.PutC(',');
  }
 
  if (commentPos == wxJSONVALUE_COMMENT_INLINE) {
    lastChar = WriteComment(os, value, false);
    if (lastChar < 0) {
      return lastChar;
    }
  } else if (commentPos == wxJSONVALUE_COMMENT_AFTER) {
    WriteSeparator(os);
    lastChar = WriteComment(os, value, true);
    if (lastChar < 0) {
      return lastChar;
    }
  }
  if (lastChar != '\n') {
    lastChar = WriteSeparator(os);
  }
  return lastChar;
}
 
int wxJSONWriter::WriteComment(wxOutputStream& os, const wxJSONValue& value,
                               bool indent) {
  // the function returns the last character written which should be
  // a LF char or -1 in case of errors
  // if nothing is written, returns ZERO
  int lastChar = 0;
 
  // only write comments if the style include the WRITE_COMMENTS flag
  if ((m_style & wxJSONWRITER_WRITE_COMMENTS) == 0) {
    return lastChar;
  }
 
  const wxArrayString cmt = value.GetCommentArray();
  int cmtSize = cmt.GetCount();
  for (int i = 0; i < cmtSize; i++) {
    if (indent) {
      WriteIndent(os);
    } else {
      os.PutC('\t');
    }
    WriteString(os, cmt[i]);
    lastChar = cmt[i].Last();
    if (lastChar != '\n') {
      os.PutC('\n');
      lastChar = '\n';
    }
  }
  return lastChar;
}
 
 
int wxJSONWriter::WriteIndent(wxOutputStream& os) {
  int lastChar = WriteIndent(os, m_level);
  return lastChar;
}
 
 
int wxJSONWriter::WriteIndent(wxOutputStream& os, int num) {
  int lastChar = 0;
  if (!(m_style & wxJSONWRITER_STYLED) ||
      (m_style & wxJSONWRITER_NO_INDENTATION)) {
    return lastChar;
  }
 
  int numChars = m_indent + (m_step * num);
  char c = ' ';
  if (m_style & wxJSONWRITER_TAB_INDENT) {
    c = '\t';
    numChars = num;
  }
 
  for (int i = 0; i < numChars; i++) {
    os.PutC(c);
    if (os.GetLastError() != wxSTREAM_NO_ERROR) {
      return -1;
    }
  }
  return c;
}
 
 
int wxJSONWriter::WriteStringValue(wxOutputStream& os, const wxString& str) {
  // JSON values of type STRING are written by converting the whole string
  // to UTF-8 and then copying the UTF-8 buffer to the 'os' stream
  // one byte at a time and processing them
  os.PutC('\"');  // open quotes
 
  // the buffer that has to be written is either UTF-8 or ANSI c_str() depending
  // on the 'm_noUtf8' flag
  char* writeBuff = 0;
  wxCharBuffer utf8CB = str.ToUTF8();  // the UTF-8 buffer
#if !defined(wxJSON_USE_UNICODE)
  wxCharBuffer ansiCB(str.c_str());  // the ANSI buffer
  if (m_noUtf8) {
    writeBuff = ansiCB.data();
  } else {
    writeBuff = utf8CB.data();
  }
#else
  writeBuff = utf8CB.data();
#endif
 
  // NOTE: in ANSI builds UTF-8 conversion may fail (see samples/test5.cpp,
  // test 7.3) although I do not know why
  if (writeBuff == nullptr) {
    const char* err =
        "<wxJSONWriter::WriteStringValue(): error converting the string to a "
        "UTF8 buffer>";
    os.Write(err, strlen(err));
    return 0;
  }
  size_t len = strlen(writeBuff);
  int lastChar = 0;
 
  // store the column at which the string starts
  // splitting strings only happen if the string starts within
  // column wxJSONWRITER_LAST_COL (default 50)
  // see 'include/wx/json_defs.h' for the defines
  int tempCol = m_colNo;
 
  // now write the UTF8 buffer processing the bytes
  size_t i;
  for (i = 0; i < len; i++) {
    bool shouldEscape = false;
    unsigned char ch = *writeBuff;
    ++writeBuff;  // point to the next byte
 
    // the escaped character
    char escCh = 0;
 
    // for every character we have to check if it is a character that
    // needs to be escaped: note that characters that should be escaped
    // may be not if some writer's flags are specified
    switch (ch) {
      case '\"':  // quotes
        shouldEscape = true;
        escCh = '\"';
        break;
      case '\\':  // reverse solidus
        shouldEscape = true;
        escCh = '\\';
        break;
      case '/':  // solidus
        shouldEscape = true;
        escCh = '/';
        break;
      case '\b':  // backspace
        shouldEscape = true;
        escCh = 'b';
        break;
      case '\f':  // formfeed
        shouldEscape = true;
        escCh = 'f';
        break;
      case '\n':  // newline
        shouldEscape = true;
        escCh = 'n';
        break;
      case '\r':  // carriage-return
        shouldEscape = true;
        escCh = 'r';
        break;
      case '\t':  // horizontal tab
        shouldEscape = true;
        escCh = 't';
        break;
      default:
        shouldEscape = false;
        break;
    }  // end switch
 
    // if the character is a control character that is not identified by a
    // lowercase letter, we should escape it
    if (!shouldEscape && ch < 32) {
      char b[8];
      snprintf(b, 8, "\\u%04X", (int)ch);
      os.Write(b, 6);
      if (os.GetLastError() != wxSTREAM_NO_ERROR) {
        return -1;
      }
    }
 
    // the char is not a control character
    else {
      // some characters that should be escaped are not escaped
      // if the writer was constructed with some flags
      if (shouldEscape && !(m_style & wxJSONWRITER_ESCAPE_SOLIDUS)) {
        if (ch == '/') {
          shouldEscape = false;
        }
      }
      if (shouldEscape && (m_style & wxJSONWRITER_MULTILINE_STRING)) {
        if (ch == '\n' || ch == '\t') {
          shouldEscape = false;
        }
      }
 
      // now write the character prepended by ESC if it should be escaped
      if (shouldEscape) {
        os.PutC('\\');
        os.PutC(escCh);
        if (os.GetLastError() != wxSTREAM_NO_ERROR) {
          return -1;
        }
      } else {
        //  a normal char or a UTF-8 units: write the character
        os.PutC(ch);
        if (os.GetLastError() != wxSTREAM_NO_ERROR) {
          return -1;
        }
      }
    }
 
    // check if SPLIT_STRING flag is set and if the string has to
    // be splitted
    if ((m_style & wxJSONWRITER_STYLED) &&
        (m_style & wxJSONWRITER_SPLIT_STRING)) {
      // split the string if the character written is LF
      if (ch == '\n') {
        // close quotes and CR
        os.Write("\"\n", 2);
        lastChar = WriteIndent(os, m_level + 2);  // write indentation
        os.PutC('\"');                            // reopen quotes
        if (lastChar < 0) {
          return lastChar;
        }
      }
      // split the string only if there is at least wxJSONWRITER_MIN_LENGTH
      // character to write and the character written is a punctuation or space
      // BUG: the following does not work because the columns are not counted
      else if ((m_colNo >= wxJSONWRITER_SPLIT_COL) &&
               (tempCol <= wxJSONWRITER_LAST_COL)) {
        if (IsSpace(ch) || IsPunctuation(ch)) {
          if (len - i > wxJSONWRITER_MIN_LENGTH) {
            // close quotes and CR
            os.Write("\"\n", 2);
            lastChar = WriteIndent(os, m_level + 2);  // write indentation
            os.PutC('\"');                            // reopen quotes
            if (lastChar < 0) {
              return lastChar;
            }
          }
        }
      }
    }
  }  // end for
  os.PutC('\"');  // close quotes
  return 0;
}
 
 
int wxJSONWriter::WriteString(wxOutputStream& os, const wxString& str) {
  wxLogTrace(writerTraceMask, _T("(%s) string to write=%s"),
             __PRETTY_FUNCTION__, str.c_str());
  int lastChar = 0;
  char* writeBuff = nullptr;
 
  // the buffer that has to be written is either UTF-8 or ANSI c_str() depending
  // on the 'm_noUtf8' flag
  wxCharBuffer utf8CB = str.ToUTF8();  // the UTF-8 buffer
#if !defined(wxJSON_USE_UNICODE)
  wxCharBuffer ansiCB(str.c_str());  // the ANSI buffer
 
  if (m_noUtf8) {
    writeBuff = ansiCB.data();
  } else {
    writeBuff = utf8CB.data();
  }
#else
  writeBuff = utf8CB.data();
#endif
 
  // NOTE: in ANSI builds UTF-8 conversion may fail (see samples/test5.cpp,
  // test 7.3) although I do not know why
  if (writeBuff == nullptr) {
    const char* err =
        "<wxJSONWriter::WriteComment(): error converting the string to UTF-8>";
    os.Write(err, strlen(err));
    return 0;
  }
  size_t len = strlen(writeBuff);
 
  os.Write(writeBuff, len);
  if (os.GetLastError() != wxSTREAM_NO_ERROR) {
    return -1;
  }
 
  wxLogTrace(writerTraceMask, _T("(%s) result=%d"), __PRETTY_FUNCTION__,
             lastChar);
  return lastChar;
}
 
 
int wxJSONWriter::WriteNullValue(wxOutputStream& os) {
  os.Write("null", 4);
  if (os.GetLastError() != wxSTREAM_NO_ERROR) {
    return -1;
  }
  return 0;
}
 
 
int wxJSONWriter::WriteIntValue(wxOutputStream& os, const wxJSONValue& value) {
  int r = 0;
  char buffer[32];  // need to store 64-bits integers (max 20 digits)
  size_t len;
 
  wxJSONRefData* data = value.GetRefData();
  wxASSERT(data);
 
#if defined(wxJSON_64BIT_INT)
#if wxCHECK_VERSION(2, 9, 0) || !defined(wxJSON_USE_UNICODE)
  // this is fine for wxW 2.9 and for wxW 2.8 ANSI
  snprintf(buffer, 32, "%" wxLongLongFmtSpec "d", data->m_value.m_valInt64);
#else
  // this is for wxW 2.8 Unicode: in order to use the cross-platform
  // format specifier, we use the wxString's sprintf() function and then
  // convert to UTF-8 before writing to the stream
  wxString s;
  s.Printf(_T("%") wxLongLongFmtSpec _T("d"), data->m_value.m_valInt64);
  wxCharBuffer cb = s.ToUTF8();
  const char* cbData = cb.data();
  len = strlen(cbData);
  wxASSERT(len < 32);
  memcpy(buffer, cbData, len);
  buffer[len] = 0;
#endif
#else
  snprintf(buffer, 32, "%ld", data->m_value.m_valLong);
#endif
  len = strlen(buffer);
  os.Write(buffer, len);
  if (os.GetLastError() != wxSTREAM_NO_ERROR) {
    r = -1;
  }
  return r;
}
 
 
int wxJSONWriter::WriteUIntValue(wxOutputStream& os, const wxJSONValue& value) {
  int r = 0;
  size_t len;
 
  // prepend a plus sign if the style specifies that unsigned integers
  // have to be recognized by the JSON reader
  if (m_style & wxJSONWRITER_RECOGNIZE_UNSIGNED) {
    os.PutC('+');
  }
 
  char buffer[32];  // need to store 64-bits integers (max 20 digits)
  wxJSONRefData* data = value.GetRefData();
  wxASSERT(data);
 
#if defined(wxJSON_64BIT_INT)
#if wxCHECK_VERSION(2, 9, 0) || !defined(wxJSON_USE_UNICODE)
  // this is fine for wxW 2.9 and for wxW 2.8 ANSI
  snprintf(buffer, 32, "%" wxLongLongFmtSpec "u", data->m_value.m_valUInt64);
#else
  // this is for wxW 2.8 Unicode: in order to use the cross-platform
  // format specifier, we use the wxString's sprintf() function and then
  // convert to UTF-8 before writing to the stream
  wxString s;
  s.Printf(_T("%") wxLongLongFmtSpec _T("u"), data->m_value.m_valInt64);
  wxCharBuffer cb = s.ToUTF8();
  const char* cbData = cb.data();
  len = strlen(cbData);
  wxASSERT(len < 32);
  memcpy(buffer, cbData, len);
  buffer[len] = 0;
#endif
#else
  snprintf(buffer, 32, "%lu", data->m_value.m_valULong);
#endif
  len = strlen(buffer);
  os.Write(buffer, len);
  if (os.GetLastError() != wxSTREAM_NO_ERROR) {
    r = -1;
  }
  return r;
}
 
 
int wxJSONWriter::WriteDoubleValue(wxOutputStream& os,
                                   const wxJSONValue& value) {
  int r = 0;
 
  char buffer[32];
  wxJSONRefData* data = value.GetRefData();
  wxASSERT(data);
  snprintf(buffer, 32, m_fmt, data->m_value.m_valDouble);
  size_t len = strlen(buffer);
  os.Write(buffer, len);
  if (os.GetLastError() != wxSTREAM_NO_ERROR) {
    r = -1;
  }
  return r;
}
 
 
int wxJSONWriter::WriteBoolValue(wxOutputStream& os, const wxJSONValue& value) {
  int r = 0;
  const char* f = "false";
  const char* t = "true";
  wxJSONRefData* data = value.GetRefData();
  wxASSERT(data);
 
  const char* c = f;  // defaults to FALSE
 
  if (data->m_value.m_valBool) {
    c = t;
  }
 
  size_t len = strlen(c);
  os.Write(c, len);
  if (os.GetLastError() != wxSTREAM_NO_ERROR) {
    r = -1;
  }
  return r;
}
 
int wxJSONWriter::WriteKey(wxOutputStream& os, const wxString& key) {
  wxLogTrace(writerTraceMask, _T("(%s) key write=%s"), __PRETTY_FUNCTION__,
             key.c_str());
 
  int lastChar = WriteStringValue(os, key);
  os.Write(" : ", 3);
  return lastChar;
}
 
 
int wxJSONWriter::WriteInvalid(wxOutputStream& os) {
  wxFAIL_MSG(
      _T("wxJSONWriter::WriteInvalid() cannot be called (not a valid JSON ")
      _T("text"));
  int lastChar = 0;
  os.Write("<invalid JSON value>", 9);
  return lastChar;
}
 
 
int wxJSONWriter::WriteMemoryBuff(wxOutputStream& os,
                                  const wxMemoryBuffer& buff) {
#define MAX_BYTES_PER_ROW 20
  char str[16];
 
  // if STYLED and SPLIT_STRING flags are set, the function writes 20 bytes on
  // every row the following is the counter of bytes written. the string is
  // splitted only for the special meory buffer type, not for array of INTs
  int bytesWritten = 0;
  bool splitString = false;
  if ((m_style & wxJSONWRITER_STYLED) &&
      (m_style & wxJSONWRITER_SPLIT_STRING)) {
    splitString = true;
  }
 
  size_t buffLen = buff.GetDataLen();
  unsigned char* ptr = (unsigned char*)buff.GetData();
  wxASSERT(ptr);
  char openChar = '\'';
  char closeChar = '\'';
  bool asArray = false;
 
  if ((m_style & wxJSONWRITER_MEMORYBUFF) == 0) {
    // if the special flag is not specified, write as an array of INTs
    openChar = '[';
    closeChar = ']';
    asArray = true;
  }
  // write the open character
  os.PutC(openChar);
 
  for (size_t i = 0; i < buffLen; i++) {
    unsigned char c = *ptr;
    ++ptr;
 
    if (asArray) {
      snprintf(str, 14, "%d", c);
      size_t len = strlen(str);
      wxASSERT(len <= 3);
      wxASSERT(len >= 1);
      str[len] = ',';
      // do not write the comma char for the last element
      if (i < buffLen - 1) {
        ++len;
      }
      os.Write(str, len);
      if (os.GetLastError() != wxSTREAM_NO_ERROR) {
        return -1;
      }
    } else {
      // now convert the byte in two hex digits
      char c1 = c / 16;
      char c2 = c % 16;
      c1 += '0';
      c2 += '0';
      if (c1 > '9') {
        c1 += 7;
      }
      if (c2 > '9') {
        c2 += 7;
      }
      os.PutC(c1);
      os.PutC(c2);
      if (os.GetLastError() != wxSTREAM_NO_ERROR) {
        return -1;
      }
      if (splitString) {
        ++bytesWritten;
      }
 
      if ((bytesWritten >= MAX_BYTES_PER_ROW) && ((buffLen - i) >= 5)) {
        // split the string if we wrote 20 bytes, but only is we have to
        // write at least 5 bytes
        os.Write("\'\n", 2);
        int lastChar = WriteIndent(os, m_level + 2);  // write indentation
        os.PutC('\'');                                // reopen quotes
        if (lastChar < 0) {
          return lastChar;
        }
        bytesWritten = 0;
      }
    }
  }
 
  // write the close character
  os.PutC(closeChar);
  return closeChar;
}
 
 
int wxJSONWriter::WriteSeparator(wxOutputStream& os) {
  int lastChar = '\n';
  if ((m_style & wxJSONWRITER_STYLED) &&
      !(m_style & wxJSONWRITER_NO_LINEFEEDS)) {
    os.PutC('\n');
  }
  return lastChar;
}
 
bool wxJSONWriter::IsSpace(wxChar ch) {
  bool r = false;
  switch (ch) {
    case ' ':
    case '\t':
    case '\r':
    case '\f':
    case '\n':
      r = true;
      break;
    default:
      break;
  }
  return r;
}
 
bool wxJSONWriter::IsPunctuation(wxChar ch) {
  bool r = false;
  switch (ch) {
    case '.':
    case ',':
    case ';':
    case ':':
    case '!':
    case '?':
      r = true;
      break;
    default:
      break;
  }
  return r;
}
 
/*
{
}
*/