Diff: jsoncpp/src/lib_json/json_writer.cpp

Revision:

0:2ee762ea11b3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jsoncpp/src/lib_json/json_writer.cpp	Fri Jan 26 06:05:31 2018 +0000
@@ -0,0 +1,1233 @@
+// Copyright 2011 Baptiste Lepilleur and The JsonCpp Authors
+// Distributed under MIT license, or public domain if desired and
+// recognized in your jurisdiction.
+// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
+
+#if !defined(JSON_IS_AMALGAMATION)
+#include <json/writer.h>
+#include "json_tool.h"
+#endif // if !defined(JSON_IS_AMALGAMATION)
+#include <iomanip>
+#include <memory>
+#include <sstream>
+#include <utility>
+#include <set>
+#include <cassert>
+#include <cstring>
+#include <cstdio>
+
+#if defined(_MSC_VER) && _MSC_VER >= 1200 && _MSC_VER < 1800 // Between VC++ 6.0 and VC++ 11.0
+#include <float.h>
+#define isfinite _finite
+#elif defined(__sun) && defined(__SVR4) //Solaris
+#if !defined(isfinite)
+#include <ieeefp.h>
+#define isfinite finite
+#endif
+#elif defined(_AIX)
+#if !defined(isfinite)
+#include <math.h>
+#define isfinite finite
+#endif
+#elif defined(__hpux)
+#if !defined(isfinite)
+#if defined(__ia64) && !defined(finite)
+#define isfinite(x) ((sizeof(x) == sizeof(float) ? \
+                     _Isfinitef(x) : _IsFinite(x)))
+#else
+#include <math.h>
+#define isfinite finite
+#endif
+#endif
+#else
+#include <cmath>
+#if !(defined(__QNXNTO__)) // QNX already defines isfinite
+#define isfinite std::isfinite
+#endif
+#endif
+
+#if defined(_MSC_VER)
+#if !defined(WINCE) && defined(__STDC_SECURE_LIB__) && _MSC_VER >= 1500 // VC++ 9.0 and above
+#define snprintf sprintf_s
+#elif _MSC_VER >= 1900 // VC++ 14.0 and above
+#define snprintf std::snprintf
+#else
+#define snprintf _snprintf
+#endif
+#elif defined(__ANDROID__) || defined(__QNXNTO__)
+#define snprintf snprintf
+#elif __cplusplus >= 201103L
+#if !defined(__MINGW32__) && !defined(__CYGWIN__)
+#define snprintf std::snprintf
+#endif
+#endif
+
+#if defined(__BORLANDC__)  
+#include <float.h>
+#define isfinite _finite
+#define snprintf _snprintf
+#endif
+
+#if defined(_MSC_VER) && _MSC_VER >= 1400 // VC++ 8.0
+// Disable warning about strdup being deprecated.
+#pragma warning(disable : 4996)
+#endif
+using namespace std;
+namespace Json {
+
+#if __cplusplus >= 201103L || (defined(_CPPLIB_VER) && _CPPLIB_VER >= 520)
+typedef std::unique_ptr<StreamWriter> StreamWriterPtr;
+#else
+typedef std::auto_ptr<StreamWriter>   StreamWriterPtr;
+#endif
+
+JSONCPP_STRING valueToString(LargestInt value) {
+  UIntToStringBuffer buffer;
+  char* current = buffer + sizeof(buffer);
+  if (value == Value::minLargestInt) {
+    uintToString(LargestUInt(Value::maxLargestInt) + 1, current);
+    *--current = '-';
+  } else if (value < 0) {
+    uintToString(LargestUInt(-value), current);
+    *--current = '-';
+  } else {
+    uintToString(LargestUInt(value), current);
+  }
+  assert(current >= buffer);
+  return current;
+}
+
+JSONCPP_STRING valueToString(LargestUInt value) {
+  UIntToStringBuffer buffer;
+  char* current = buffer + sizeof(buffer);
+  uintToString(value, current);
+  assert(current >= buffer);
+  return current;
+}
+
+#if defined(JSON_HAS_INT64)
+
+JSONCPP_STRING valueToString(Int value) {
+  return valueToString(LargestInt(value));
+}
+
+JSONCPP_STRING valueToString(UInt value) {
+  return valueToString(LargestUInt(value));
+}
+
+#endif // # if defined(JSON_HAS_INT64)
+
+namespace {
+JSONCPP_STRING valueToString(double value, bool useSpecialFloats, unsigned int precision) {
+  // Allocate a buffer that is more than large enough to store the 16 digits of
+  // precision requested below.
+  char buffer[36];
+  int len = -1;
+
+  char formatString[15];
+  snprintf(formatString, sizeof(formatString), "%%.%ug", precision);
+
+  // Print into the buffer. We need not request the alternative representation
+  // that always has a decimal point because JSON doesn't distinguish the
+  // concepts of reals and integers.
+  if (isfinite(value)) {
+    len = snprintf(buffer, sizeof(buffer), formatString, value);
+    fixNumericLocale(buffer, buffer + len);
+
+    // try to ensure we preserve the fact that this was given to us as a double on input
+    if (!strchr(buffer, '.') && !strchr(buffer, 'e')) {
+      strcat(buffer, ".0");
+    }
+
+  } else {
+    // IEEE standard states that NaN values will not compare to themselves
+    if (value != value) {
+      len = snprintf(buffer, sizeof(buffer), useSpecialFloats ? "NaN" : "null");
+    } else if (value < 0) {
+      len = snprintf(buffer, sizeof(buffer), useSpecialFloats ? "-Infinity" : "-1e+9999");
+    } else {
+      len = snprintf(buffer, sizeof(buffer), useSpecialFloats ? "Infinity" : "1e+9999");
+    }
+  }
+  assert(len >= 0);
+  return buffer;
+}
+}
+
+JSONCPP_STRING valueToString(double value) { return valueToString(value, false, 17); }
+
+JSONCPP_STRING valueToString(bool value) { return value ? "true" : "false"; }
+
+static bool isAnyCharRequiredQuoting(char const* s, size_t n) {
+  assert(s || !n);
+
+  char const* const end = s + n;
+  for (char const* cur = s; cur < end; ++cur) {
+    if (*cur == '\\' || *cur == '\"' || *cur < ' '
+      || static_cast<unsigned char>(*cur) < 0x80)
+      return true;
+  }
+  return false;
+}
+
+static unsigned int utf8ToCodepoint(const char*& s, const char* e) {
+  const unsigned int REPLACEMENT_CHARACTER = 0xFFFD;
+
+  unsigned int firstByte = static_cast<unsigned char>(*s);
+
+  if (firstByte < 0x80)
+    return firstByte;
+
+  if (firstByte < 0xE0) {
+    if (e - s < 2)
+      return REPLACEMENT_CHARACTER;
+
+    unsigned int calculated = ((firstByte & 0x1F) << 6)
+      | (static_cast<unsigned int>(s[1]) & 0x3F);
+    s += 1;
+    // oversized encoded characters are invalid
+    return calculated < 0x80 ? REPLACEMENT_CHARACTER : calculated;
+  }
+
+  if (firstByte < 0xF0) {
+    if (e - s < 3)
+      return REPLACEMENT_CHARACTER;
+
+    unsigned int calculated = ((firstByte & 0x0F) << 12)
+      | ((static_cast<unsigned int>(s[1]) & 0x3F) << 6)
+      |  (static_cast<unsigned int>(s[2]) & 0x3F);
+    s += 2;
+    // surrogates aren't valid codepoints itself
+    // shouldn't be UTF-8 encoded
+    if (calculated >= 0xD800 && calculated <= 0xDFFF)
+      return REPLACEMENT_CHARACTER;
+    // oversized encoded characters are invalid
+    return calculated < 0x800 ? REPLACEMENT_CHARACTER : calculated;
+  }
+
+  if (firstByte < 0xF8) {
+    if (e - s < 4)
+      return REPLACEMENT_CHARACTER;
+
+    unsigned int calculated = ((firstByte & 0x07) << 24)
+      | ((static_cast<unsigned int>(s[1]) & 0x3F) << 12)
+      | ((static_cast<unsigned int>(s[2]) & 0x3F) << 6)
+      |  (static_cast<unsigned int>(s[3]) & 0x3F);
+    s += 3;
+    // oversized encoded characters are invalid
+    return calculated < 0x10000 ? REPLACEMENT_CHARACTER : calculated;
+  }
+
+  return REPLACEMENT_CHARACTER;
+}
+
+static const char hex2[] =
+  "000102030405060708090a0b0c0d0e0f"
+  "101112131415161718191a1b1c1d1e1f"
+  "202122232425262728292a2b2c2d2e2f"
+  "303132333435363738393a3b3c3d3e3f"
+  "404142434445464748494a4b4c4d4e4f"
+  "505152535455565758595a5b5c5d5e5f"
+  "606162636465666768696a6b6c6d6e6f"
+  "707172737475767778797a7b7c7d7e7f"
+  "808182838485868788898a8b8c8d8e8f"
+  "909192939495969798999a9b9c9d9e9f"
+  "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
+  "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
+  "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
+  "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
+  "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
+  "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
+
+static JSONCPP_STRING toHex16Bit(unsigned int x) {
+  const unsigned int hi = (x >> 8) & 0xff;
+  const unsigned int lo = x & 0xff;
+  JSONCPP_STRING result(4, ' ');
+  result[0] = hex2[2 * hi];
+  result[1] = hex2[2 * hi + 1];
+  result[2] = hex2[2 * lo];
+  result[3] = hex2[2 * lo + 1];
+  return result;
+}
+
+static JSONCPP_STRING valueToQuotedStringN(const char* value, unsigned length) {
+  if (value == NULL)
+    return "";
+
+  if (!isAnyCharRequiredQuoting(value, length))
+    return JSONCPP_STRING("\"") + value + "\"";
+  // We have to walk value and escape any special characters.
+  // Appending to JSONCPP_STRING is not efficient, but this should be rare.
+  // (Note: forward slashes are *not* rare, but I am not escaping them.)
+  JSONCPP_STRING::size_type maxsize =
+      length * 2 + 3; // allescaped+quotes+NULL
+  JSONCPP_STRING result;
+  result.reserve(maxsize); // to avoid lots of mallocs
+  result += "\"";
+  char const* end = value + length;
+  for (const char* c = value; c != end; ++c) {
+    switch (*c) {
+    case '\"':
+      result += "\\\"";
+      break;
+    case '\\':
+      result += "\\\\";
+      break;
+    case '\b':
+      result += "\\b";
+      break;
+    case '\f':
+      result += "\\f";
+      break;
+    case '\n':
+      result += "\\n";
+      break;
+    case '\r':
+      result += "\\r";
+      break;
+    case '\t':
+      result += "\\t";
+      break;
+    // case '/':
+    // Even though \/ is considered a legal escape in JSON, a bare
+    // slash is also legal, so I see no reason to escape it.
+    // (I hope I am not misunderstanding something.)
+    // blep notes: actually escaping \/ may be useful in javascript to avoid </
+    // sequence.
+    // Should add a flag to allow this compatibility mode and prevent this
+    // sequence from occurring.
+    default: {
+        unsigned int cp = utf8ToCodepoint(c, end);
+        // don't escape non-control characters
+        // (short escape sequence are applied above)
+        if (cp < 0x80 && cp >= 0x20)
+          result += static_cast<char>(cp);
+        else if (cp < 0x10000) { // codepoint is in Basic Multilingual Plane
+          result += "\\u";
+          result += toHex16Bit(cp);
+        }
+        else { // codepoint is not in Basic Multilingual Plane
+               // convert to surrogate pair first
+          cp -= 0x10000;
+          result += "\\u";
+          result += toHex16Bit((cp >> 10) + 0xD800);
+          result += "\\u";
+          result += toHex16Bit((cp & 0x3FF) + 0xDC00);
+        }
+      }
+      break;
+    }
+  }
+  result += "\"";
+  return result;
+}
+
+JSONCPP_STRING valueToQuotedString(const char* value) {
+  return valueToQuotedStringN(value, static_cast<unsigned int>(strlen(value)));
+}
+
+// Class Writer
+// //////////////////////////////////////////////////////////////////
+Writer::~Writer() {}
+
+// Class FastWriter
+// //////////////////////////////////////////////////////////////////
+
+FastWriter::FastWriter()
+    : yamlCompatibilityEnabled_(false), dropNullPlaceholders_(false),
+      omitEndingLineFeed_(false) {}
+
+void FastWriter::enableYAMLCompatibility() { yamlCompatibilityEnabled_ = true; }
+
+void FastWriter::dropNullPlaceholders() { dropNullPlaceholders_ = true; }
+
+void FastWriter::omitEndingLineFeed() { omitEndingLineFeed_ = true; }
+
+JSONCPP_STRING FastWriter::write(const Value& root) {
+  document_.clear();
+  writeValue(root);
+  if (!omitEndingLineFeed_)
+    document_ += "\n";
+  return document_;
+}
+
+void FastWriter::writeValue(const Value& value) {
+  switch (value.type()) {
+  case nullValue:
+    if (!dropNullPlaceholders_)
+      document_ += "null";
+    break;
+  case intValue:
+    document_ += valueToString(value.asLargestInt());
+    break;
+  case uintValue:
+    document_ += valueToString(value.asLargestUInt());
+    break;
+  case realValue:
+    document_ += valueToString(value.asDouble());
+    break;
+  case stringValue:
+  {
+    // Is NULL possible for value.string_? No.
+    char const* str;
+    char const* end;
+    bool ok = value.getString(&str, &end);
+    if (ok) document_ += valueToQuotedStringN(str, static_cast<unsigned>(end-str));
+    break;
+  }
+  case booleanValue:
+    document_ += valueToString(value.asBool());
+    break;
+  case arrayValue: {
+    document_ += '[';
+    ArrayIndex size = value.size();
+    for (ArrayIndex index = 0; index < size; ++index) {
+      if (index > 0)
+        document_ += ',';
+      writeValue(value[index]);
+    }
+    document_ += ']';
+  } break;
+  case objectValue: {
+    Value::Members members(value.getMemberNames());
+    document_ += '{';
+    for (Value::Members::iterator it = members.begin(); it != members.end();
+         ++it) {
+      const JSONCPP_STRING& name = *it;
+      if (it != members.begin())
+        document_ += ',';
+      document_ += valueToQuotedStringN(name.data(), static_cast<unsigned>(name.length()));
+      document_ += yamlCompatibilityEnabled_ ? ": " : ":";
+      writeValue(value[name]);
+    }
+    document_ += '}';
+  } break;
+  }
+}
+
+// Class StyledWriter
+// //////////////////////////////////////////////////////////////////
+
+StyledWriter::StyledWriter()
+    : rightMargin_(74), indentSize_(3), addChildValues_() {}
+
+JSONCPP_STRING StyledWriter::write(const Value& root) {
+  document_.clear();
+  addChildValues_ = false;
+  indentString_.clear();
+  writeCommentBeforeValue(root);
+  writeValue(root);
+  writeCommentAfterValueOnSameLine(root);
+  document_ += "\n";
+  return document_;
+}
+
+void StyledWriter::writeValue(const Value& value) {
+  switch (value.type()) {
+  case nullValue:
+    pushValue("null");
+    break;
+  case intValue:
+    pushValue(valueToString(value.asLargestInt()));
+    break;
+  case uintValue:
+    pushValue(valueToString(value.asLargestUInt()));
+    break;
+  case realValue:
+    pushValue(valueToString(value.asDouble()));
+    break;
+  case stringValue:
+  {
+    // Is NULL possible for value.string_? No.
+    char const* str;
+    char const* end;
+    bool ok = value.getString(&str, &end);
+    if (ok) pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end-str)));
+    else pushValue("");
+    break;
+  }
+  case booleanValue:
+    pushValue(valueToString(value.asBool()));
+    break;
+  case arrayValue:
+    writeArrayValue(value);
+    break;
+  case objectValue: {
+    Value::Members members(value.getMemberNames());
+    if (members.empty())
+      pushValue("{}");
+    else {
+      writeWithIndent("{");
+      indent();
+      Value::Members::iterator it = members.begin();
+      for (;;) {
+        const JSONCPP_STRING& name = *it;
+        const Value& childValue = value[name];
+        writeCommentBeforeValue(childValue);
+        writeWithIndent(valueToQuotedString(name.c_str()));
+        document_ += " : ";
+        writeValue(childValue);
+        if (++it == members.end()) {
+          writeCommentAfterValueOnSameLine(childValue);
+          break;
+        }
+        document_ += ',';
+        writeCommentAfterValueOnSameLine(childValue);
+      }
+      unindent();
+      writeWithIndent("}");
+    }
+  } break;
+  }
+}
+
+void StyledWriter::writeArrayValue(const Value& value) {
+  unsigned size = value.size();
+  if (size == 0)
+    pushValue("[]");
+  else {
+    bool isArrayMultiLine = isMultilineArray(value);
+    if (isArrayMultiLine) {
+      writeWithIndent("[");
+      indent();
+      bool hasChildValue = !childValues_.empty();
+      unsigned index = 0;
+      for (;;) {
+        const Value& childValue = value[index];
+        writeCommentBeforeValue(childValue);
+        if (hasChildValue)
+          writeWithIndent(childValues_[index]);
+        else {
+          writeIndent();
+          writeValue(childValue);
+        }
+        if (++index == size) {
+          writeCommentAfterValueOnSameLine(childValue);
+          break;
+        }
+        document_ += ',';
+        writeCommentAfterValueOnSameLine(childValue);
+      }
+      unindent();
+      writeWithIndent("]");
+    } else // output on a single line
+    {
+      assert(childValues_.size() == size);
+      document_ += "[ ";
+      for (unsigned index = 0; index < size; ++index) {
+        if (index > 0)
+          document_ += ", ";
+        document_ += childValues_[index];
+      }
+      document_ += " ]";
+    }
+  }
+}
+
+bool StyledWriter::isMultilineArray(const Value& value) {
+  ArrayIndex const size = value.size();
+  bool isMultiLine = size * 3 >= rightMargin_;
+  childValues_.clear();
+  for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
+    const Value& childValue = value[index];
+    isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
+                        childValue.size() > 0);
+  }
+  if (!isMultiLine) // check if line length > max line length
+  {
+    childValues_.reserve(size);
+    addChildValues_ = true;
+    ArrayIndex lineLength = 4 + (size - 1) * 2; // '[ ' + ', '*n + ' ]'
+    for (ArrayIndex index = 0; index < size; ++index) {
+      if (hasCommentForValue(value[index])) {
+        isMultiLine = true;
+      }
+      writeValue(value[index]);
+      lineLength += static_cast<ArrayIndex>(childValues_[index].length());
+    }
+    addChildValues_ = false;
+    isMultiLine = isMultiLine || lineLength >= rightMargin_;
+  }
+  return isMultiLine;
+}
+
+void StyledWriter::pushValue(const JSONCPP_STRING& value) {
+  if (addChildValues_)
+    childValues_.push_back(value);
+  else
+    document_ += value;
+}
+
+void StyledWriter::writeIndent() {
+  if (!document_.empty()) {
+    char last = document_[document_.length() - 1];
+    if (last == ' ') // already indented
+      return;
+    if (last != '\n') // Comments may add new-line
+      document_ += '\n';
+  }
+  document_ += indentString_;
+}
+
+void StyledWriter::writeWithIndent(const JSONCPP_STRING& value) {
+  writeIndent();
+  document_ += value;
+}
+
+void StyledWriter::indent() { indentString_ += JSONCPP_STRING(indentSize_, ' '); }
+
+void StyledWriter::unindent() {
+  assert(indentString_.size() >= indentSize_);
+  indentString_.resize(indentString_.size() - indentSize_);
+}
+
+void StyledWriter::writeCommentBeforeValue(const Value& root) {
+  if (!root.hasComment(commentBefore))
+    return;
+
+  document_ += "\n";
+  writeIndent();
+  const JSONCPP_STRING& comment = root.getComment(commentBefore);
+  JSONCPP_STRING::const_iterator iter = comment.begin();
+  while (iter != comment.end()) {
+    document_ += *iter;
+    if (*iter == '\n' &&
+       ((iter+1) != comment.end() && *(iter + 1) == '/'))
+      writeIndent();
+    ++iter;
+  }
+
+  // Comments are stripped of trailing newlines, so add one here
+  document_ += "\n";
+}
+
+void StyledWriter::writeCommentAfterValueOnSameLine(const Value& root) {
+  if (root.hasComment(commentAfterOnSameLine))
+    document_ += " " + root.getComment(commentAfterOnSameLine);
+
+  if (root.hasComment(commentAfter)) {
+    document_ += "\n";
+    document_ += root.getComment(commentAfter);
+    document_ += "\n";
+  }
+}
+
+bool StyledWriter::hasCommentForValue(const Value& value) {
+  return value.hasComment(commentBefore) ||
+         value.hasComment(commentAfterOnSameLine) ||
+         value.hasComment(commentAfter);
+}
+
+// Class StyledStreamWriter
+// //////////////////////////////////////////////////////////////////
+
+StyledStreamWriter::StyledStreamWriter(JSONCPP_STRING indentation)
+    : document_(NULL), rightMargin_(74), indentation_(indentation),
+      addChildValues_() {}
+
+void StyledStreamWriter::write(JSONCPP_OSTREAM& out, const Value& root) {
+  document_ = &out;
+  addChildValues_ = false;
+  indentString_.clear();
+  indented_ = true;
+  writeCommentBeforeValue(root);
+  if (!indented_) writeIndent();
+  indented_ = true;
+  writeValue(root);
+  writeCommentAfterValueOnSameLine(root);
+  *document_ << "\n";
+  document_ = NULL; // Forget the stream, for safety.
+}
+
+void StyledStreamWriter::writeValue(const Value& value) {
+  switch (value.type()) {
+  case nullValue:
+    pushValue("null");
+    break;
+  case intValue:
+    pushValue(valueToString(value.asLargestInt()));
+    break;
+  case uintValue:
+    pushValue(valueToString(value.asLargestUInt()));
+    break;
+  case realValue:
+    pushValue(valueToString(value.asDouble()));
+    break;
+  case stringValue:
+  {
+    // Is NULL possible for value.string_? No.
+    char const* str;
+    char const* end;
+    bool ok = value.getString(&str, &end);
+    if (ok) pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end-str)));
+    else pushValue("");
+    break;
+  }
+  case booleanValue:
+    pushValue(valueToString(value.asBool()));
+    break;
+  case arrayValue:
+    writeArrayValue(value);
+    break;
+  case objectValue: {
+    Value::Members members(value.getMemberNames());
+    if (members.empty())
+      pushValue("{}");
+    else {
+      writeWithIndent("{");
+      indent();
+      Value::Members::iterator it = members.begin();
+      for (;;) {
+        const JSONCPP_STRING& name = *it;
+        const Value& childValue = value[name];
+        writeCommentBeforeValue(childValue);
+        writeWithIndent(valueToQuotedString(name.c_str()));
+        *document_ << " : ";
+        writeValue(childValue);
+        if (++it == members.end()) {
+          writeCommentAfterValueOnSameLine(childValue);
+          break;
+        }
+        *document_ << ",";
+        writeCommentAfterValueOnSameLine(childValue);
+      }
+      unindent();
+      writeWithIndent("}");
+    }
+  } break;
+  }
+}
+
+void StyledStreamWriter::writeArrayValue(const Value& value) {
+  unsigned size = value.size();
+  if (size == 0)
+    pushValue("[]");
+  else {
+    bool isArrayMultiLine = isMultilineArray(value);
+    if (isArrayMultiLine) {
+      writeWithIndent("[");
+      indent();
+      bool hasChildValue = !childValues_.empty();
+      unsigned index = 0;
+      for (;;) {
+        const Value& childValue = value[index];
+        writeCommentBeforeValue(childValue);
+        if (hasChildValue)
+          writeWithIndent(childValues_[index]);
+        else {
+          if (!indented_) writeIndent();
+          indented_ = true;
+          writeValue(childValue);
+          indented_ = false;
+        }
+        if (++index == size) {
+          writeCommentAfterValueOnSameLine(childValue);
+          break;
+        }
+        *document_ << ",";
+        writeCommentAfterValueOnSameLine(childValue);
+      }
+      unindent();
+      writeWithIndent("]");
+    } else // output on a single line
+    {
+      assert(childValues_.size() == size);
+      *document_ << "[ ";
+      for (unsigned index = 0; index < size; ++index) {
+        if (index > 0)
+          *document_ << ", ";
+        *document_ << childValues_[index];
+      }
+      *document_ << " ]";
+    }
+  }
+}
+
+bool StyledStreamWriter::isMultilineArray(const Value& value) {
+  ArrayIndex const size = value.size();
+  bool isMultiLine = size * 3 >= rightMargin_;
+  childValues_.clear();
+  for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
+    const Value& childValue = value[index];
+    isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
+                        childValue.size() > 0);
+  }
+  if (!isMultiLine) // check if line length > max line length
+  {
+    childValues_.reserve(size);
+    addChildValues_ = true;
+    ArrayIndex lineLength = 4 + (size - 1) * 2; // '[ ' + ', '*n + ' ]'
+    for (ArrayIndex index = 0; index < size; ++index) {
+      if (hasCommentForValue(value[index])) {
+        isMultiLine = true;
+      }
+      writeValue(value[index]);
+      lineLength += static_cast<ArrayIndex>(childValues_[index].length());
+    }
+    addChildValues_ = false;
+    isMultiLine = isMultiLine || lineLength >= rightMargin_;
+  }
+  return isMultiLine;
+}
+
+void StyledStreamWriter::pushValue(const JSONCPP_STRING& value) {
+  if (addChildValues_)
+    childValues_.push_back(value);
+  else
+    *document_ << value;
+}
+
+void StyledStreamWriter::writeIndent() {
+  // blep intended this to look at the so-far-written string
+  // to determine whether we are already indented, but
+  // with a stream we cannot do that. So we rely on some saved state.
+  // The caller checks indented_.
+  *document_ << '\n' << indentString_;
+}
+
+void StyledStreamWriter::writeWithIndent(const JSONCPP_STRING& value) {
+  if (!indented_) writeIndent();
+  *document_ << value;
+  indented_ = false;
+}
+
+void StyledStreamWriter::indent() { indentString_ += indentation_; }
+
+void StyledStreamWriter::unindent() {
+  assert(indentString_.size() >= indentation_.size());
+  indentString_.resize(indentString_.size() - indentation_.size());
+}
+
+void StyledStreamWriter::writeCommentBeforeValue(const Value& root) {
+  if (!root.hasComment(commentBefore))
+    return;
+
+  if (!indented_) writeIndent();
+  const JSONCPP_STRING& comment = root.getComment(commentBefore);
+  JSONCPP_STRING::const_iterator iter = comment.begin();
+  while (iter != comment.end()) {
+    *document_ << *iter;
+    if (*iter == '\n' &&
+       ((iter+1) != comment.end() && *(iter + 1) == '/'))
+      // writeIndent();  // would include newline
+      *document_ << indentString_;
+    ++iter;
+  }
+  indented_ = false;
+}
+
+void StyledStreamWriter::writeCommentAfterValueOnSameLine(const Value& root) {
+  if (root.hasComment(commentAfterOnSameLine))
+    *document_ << ' ' << root.getComment(commentAfterOnSameLine);
+
+  if (root.hasComment(commentAfter)) {
+    writeIndent();
+    *document_ << root.getComment(commentAfter);
+  }
+  indented_ = false;
+}
+
+bool StyledStreamWriter::hasCommentForValue(const Value& value) {
+  return value.hasComment(commentBefore) ||
+         value.hasComment(commentAfterOnSameLine) ||
+         value.hasComment(commentAfter);
+}
+
+//////////////////////////
+// BuiltStyledStreamWriter
+
+/// Scoped enums are not available until C++11.
+struct CommentStyle {
+  /// Decide whether to write comments.
+  enum Enum {
+    None,  ///< Drop all comments.
+    Most,  ///< Recover odd behavior of previous versions (not implemented yet).
+    All  ///< Keep all comments.
+  };
+};
+
+struct BuiltStyledStreamWriter : public StreamWriter
+{
+  BuiltStyledStreamWriter(
+      JSONCPP_STRING const& indentation,
+      CommentStyle::Enum cs,
+      JSONCPP_STRING const& colonSymbol,
+      JSONCPP_STRING const& nullSymbol,
+      JSONCPP_STRING const& endingLineFeedSymbol,
+      bool useSpecialFloats,
+      unsigned int precision);
+  int write(Value const& root, JSONCPP_OSTREAM* sout) JSONCPP_OVERRIDE;
+private:
+  void writeValue(Value const& value);
+  void writeArrayValue(Value const& value);
+  bool isMultilineArray(Value const& value);
+  void pushValue(JSONCPP_STRING const& value);
+  void writeIndent();
+  void writeWithIndent(JSONCPP_STRING const& value);
+  void indent();
+  void unindent();
+  void writeCommentBeforeValue(Value const& root);
+  void writeCommentAfterValueOnSameLine(Value const& root);
+  static bool hasCommentForValue(const Value& value);
+
+  typedef std::vector<JSONCPP_STRING> ChildValues;
+
+  ChildValues childValues_;
+  JSONCPP_STRING indentString_;
+  unsigned int rightMargin_;
+  JSONCPP_STRING indentation_;
+  CommentStyle::Enum cs_;
+  JSONCPP_STRING colonSymbol_;
+  JSONCPP_STRING nullSymbol_;
+  JSONCPP_STRING endingLineFeedSymbol_;
+  bool addChildValues_ : 1;
+  bool indented_ : 1;
+  bool useSpecialFloats_ : 1;
+  unsigned int precision_;
+};
+BuiltStyledStreamWriter::BuiltStyledStreamWriter(
+      JSONCPP_STRING const& indentation,
+      CommentStyle::Enum cs,
+      JSONCPP_STRING const& colonSymbol,
+      JSONCPP_STRING const& nullSymbol,
+      JSONCPP_STRING const& endingLineFeedSymbol,
+      bool useSpecialFloats,
+      unsigned int precision)
+  : rightMargin_(74)
+  , indentation_(indentation)
+  , cs_(cs)
+  , colonSymbol_(colonSymbol)
+  , nullSymbol_(nullSymbol)
+  , endingLineFeedSymbol_(endingLineFeedSymbol)
+  , addChildValues_(false)
+  , indented_(false)
+  , useSpecialFloats_(useSpecialFloats)
+  , precision_(precision)
+{
+}
+int BuiltStyledStreamWriter::write(Value const& root, JSONCPP_OSTREAM* sout)
+{
+  sout_ = sout;
+  addChildValues_ = false;
+  indented_ = true;
+  indentString_.clear();
+  writeCommentBeforeValue(root);
+  if (!indented_) writeIndent();
+  indented_ = true;
+  writeValue(root);
+  writeCommentAfterValueOnSameLine(root);
+  *sout_ << endingLineFeedSymbol_;
+  sout_ = NULL;
+  return 0;
+}
+void BuiltStyledStreamWriter::writeValue(Value const& value) {
+  switch (value.type()) {
+  case nullValue:
+    pushValue(nullSymbol_);
+    break;
+  case intValue:
+    pushValue(valueToString(value.asLargestInt()));
+    break;
+  case uintValue:
+    pushValue(valueToString(value.asLargestUInt()));
+    break;
+  case realValue:
+    pushValue(valueToString(value.asDouble(), useSpecialFloats_, precision_));
+    break;
+  case stringValue:
+  {
+    // Is NULL is possible for value.string_? No.
+    char const* str;
+    char const* end;
+    bool ok = value.getString(&str, &end);
+    if (ok) pushValue(valueToQuotedStringN(str, static_cast<unsigned>(end-str)));
+    else pushValue("");
+    break;
+  }
+  case booleanValue:
+    pushValue(valueToString(value.asBool()));
+    break;
+  case arrayValue:
+    writeArrayValue(value);
+    break;
+  case objectValue: {
+    Value::Members members(value.getMemberNames());
+    if (members.empty())
+      pushValue("{}");
+    else {
+      writeWithIndent("{");
+      indent();
+      Value::Members::iterator it = members.begin();
+      for (;;) {
+        JSONCPP_STRING const& name = *it;
+        Value const& childValue = value[name];
+        writeCommentBeforeValue(childValue);
+        writeWithIndent(valueToQuotedStringN(name.data(), static_cast<unsigned>(name.length())));
+        *sout_ << colonSymbol_;
+        writeValue(childValue);
+        if (++it == members.end()) {
+          writeCommentAfterValueOnSameLine(childValue);
+          break;
+        }
+        *sout_ << ",";
+        writeCommentAfterValueOnSameLine(childValue);
+      }
+      unindent();
+      writeWithIndent("}");
+    }
+  } break;
+  }
+}
+
+void BuiltStyledStreamWriter::writeArrayValue(Value const& value) {
+  unsigned size = value.size();
+  if (size == 0)
+    pushValue("[]");
+  else {
+    bool isMultiLine = (cs_ == CommentStyle::All) || isMultilineArray(value);
+    if (isMultiLine) {
+      writeWithIndent("[");
+      indent();
+      bool hasChildValue = !childValues_.empty();
+      unsigned index = 0;
+      for (;;) {
+        Value const& childValue = value[index];
+        writeCommentBeforeValue(childValue);
+        if (hasChildValue)
+          writeWithIndent(childValues_[index]);
+        else {
+          if (!indented_) writeIndent();
+          indented_ = true;
+          writeValue(childValue);
+          indented_ = false;
+        }
+        if (++index == size) {
+          writeCommentAfterValueOnSameLine(childValue);
+          break;
+        }
+        *sout_ << ",";
+        writeCommentAfterValueOnSameLine(childValue);
+      }
+      unindent();
+      writeWithIndent("]");
+    } else // output on a single line
+    {
+      assert(childValues_.size() == size);
+      *sout_ << "[";
+      if (!indentation_.empty()) *sout_ << " ";
+      for (unsigned index = 0; index < size; ++index) {
+        if (index > 0)
+          *sout_ << ((!indentation_.empty()) ? ", " : ",");
+        *sout_ << childValues_[index];
+      }
+      if (!indentation_.empty()) *sout_ << " ";
+      *sout_ << "]";
+    }
+  }
+}
+
+bool BuiltStyledStreamWriter::isMultilineArray(Value const& value) {
+  ArrayIndex const size = value.size();
+  bool isMultiLine = size * 3 >= rightMargin_;
+  childValues_.clear();
+  for (ArrayIndex index = 0; index < size && !isMultiLine; ++index) {
+    Value const& childValue = value[index];
+    isMultiLine = ((childValue.isArray() || childValue.isObject()) &&
+                        childValue.size() > 0);
+  }
+  if (!isMultiLine) // check if line length > max line length
+  {
+    childValues_.reserve(size);
+    addChildValues_ = true;
+    ArrayIndex lineLength = 4 + (size - 1) * 2; // '[ ' + ', '*n + ' ]'
+    for (ArrayIndex index = 0; index < size; ++index) {
+      if (hasCommentForValue(value[index])) {
+        isMultiLine = true;
+      }
+      writeValue(value[index]);
+      lineLength += static_cast<ArrayIndex>(childValues_[index].length());
+    }
+    addChildValues_ = false;
+    isMultiLine = isMultiLine || lineLength >= rightMargin_;
+  }
+  return isMultiLine;
+}
+
+void BuiltStyledStreamWriter::pushValue(JSONCPP_STRING const& value) {
+  if (addChildValues_)
+    childValues_.push_back(value);
+  else
+    *sout_ << value;
+}
+
+void BuiltStyledStreamWriter::writeIndent() {
+  // blep intended this to look at the so-far-written string
+  // to determine whether we are already indented, but
+  // with a stream we cannot do that. So we rely on some saved state.
+  // The caller checks indented_.
+
+  if (!indentation_.empty()) {
+    // In this case, drop newlines too.
+    *sout_ << '\n' << indentString_;
+  }
+}
+
+void BuiltStyledStreamWriter::writeWithIndent(JSONCPP_STRING const& value) {
+  if (!indented_) writeIndent();
+  *sout_ << value;
+  indented_ = false;
+}
+
+void BuiltStyledStreamWriter::indent() { indentString_ += indentation_; }
+
+void BuiltStyledStreamWriter::unindent() {
+  assert(indentString_.size() >= indentation_.size());
+  indentString_.resize(indentString_.size() - indentation_.size());
+}
+
+void BuiltStyledStreamWriter::writeCommentBeforeValue(Value const& root) {
+  if (cs_ == CommentStyle::None) return;
+  if (!root.hasComment(commentBefore))
+    return;
+
+  if (!indented_) writeIndent();
+  const JSONCPP_STRING& comment = root.getComment(commentBefore);
+  JSONCPP_STRING::const_iterator iter = comment.begin();
+  while (iter != comment.end()) {
+    *sout_ << *iter;
+    if (*iter == '\n' &&
+       ((iter+1) != comment.end() && *(iter + 1) == '/'))
+      // writeIndent();  // would write extra newline
+      *sout_ << indentString_;
+    ++iter;
+  }
+  indented_ = false;
+}
+
+void BuiltStyledStreamWriter::writeCommentAfterValueOnSameLine(Value const& root) {
+  if (cs_ == CommentStyle::None) return;
+  if (root.hasComment(commentAfterOnSameLine))
+    *sout_ << " " + root.getComment(commentAfterOnSameLine);
+
+  if (root.hasComment(commentAfter)) {
+    writeIndent();
+    *sout_ << root.getComment(commentAfter);
+  }
+}
+
+// static
+bool BuiltStyledStreamWriter::hasCommentForValue(const Value& value) {
+  return value.hasComment(commentBefore) ||
+         value.hasComment(commentAfterOnSameLine) ||
+         value.hasComment(commentAfter);
+}
+
+///////////////
+// StreamWriter
+
+StreamWriter::StreamWriter()
+    : sout_(NULL)
+{
+}
+StreamWriter::~StreamWriter()
+{
+}
+StreamWriter::Factory::~Factory()
+{}
+StreamWriterBuilder::StreamWriterBuilder()
+{
+  setDefaults(&settings_);
+}
+StreamWriterBuilder::~StreamWriterBuilder()
+{}
+StreamWriter* StreamWriterBuilder::newStreamWriter() const
+{
+  JSONCPP_STRING indentation = settings_["indentation"].asString();
+  JSONCPP_STRING cs_str = settings_["commentStyle"].asString();
+  bool eyc = settings_["enableYAMLCompatibility"].asBool();
+  bool dnp = settings_["dropNullPlaceholders"].asBool();
+  bool usf = settings_["useSpecialFloats"].asBool(); 
+  unsigned int pre = settings_["precision"].asUInt();
+  CommentStyle::Enum cs = CommentStyle::All;
+  if (cs_str == "All") {
+    cs = CommentStyle::All;
+  } else if (cs_str == "None") {
+    cs = CommentStyle::None;
+  } else {
+    throwRuntimeError("commentStyle must be 'All' or 'None'");
+  }
+  JSONCPP_STRING colonSymbol = " : ";
+  if (eyc) {
+    colonSymbol = ": ";
+  } else if (indentation.empty()) {
+    colonSymbol = ":";
+  }
+  JSONCPP_STRING nullSymbol = "null";
+  if (dnp) {
+    nullSymbol.clear();
+  }
+  if (pre > 17) pre = 17;
+  JSONCPP_STRING endingLineFeedSymbol;
+  return new BuiltStyledStreamWriter(
+      indentation, cs,
+      colonSymbol, nullSymbol, endingLineFeedSymbol, usf, pre);
+}
+static void getValidWriterKeys(std::set<JSONCPP_STRING>* valid_keys)
+{
+  valid_keys->clear();
+  valid_keys->insert("indentation");
+  valid_keys->insert("commentStyle");
+  valid_keys->insert("enableYAMLCompatibility");
+  valid_keys->insert("dropNullPlaceholders");
+  valid_keys->insert("useSpecialFloats");
+  valid_keys->insert("precision");
+}
+bool StreamWriterBuilder::validate(Json::Value* invalid) const
+{
+  Json::Value my_invalid;
+  if (!invalid) invalid = &my_invalid;  // so we do not need to test for NULL
+  Json::Value& inv = *invalid;
+  std::set<JSONCPP_STRING> valid_keys;
+  getValidWriterKeys(&valid_keys);
+  Value::Members keys = settings_.getMemberNames();
+  size_t n = keys.size();
+  for (size_t i = 0; i < n; ++i) {
+    JSONCPP_STRING const& key = keys[i];
+    if (valid_keys.find(key) == valid_keys.end()) {
+      inv[key] = settings_[key];
+    }
+  }
+  return 0u == inv.size();
+}
+Value& StreamWriterBuilder::operator[](JSONCPP_STRING key)
+{
+  return settings_[key];
+}
+// static
+void StreamWriterBuilder::setDefaults(Json::Value* settings)
+{
+  //! [StreamWriterBuilderDefaults]
+  (*settings)["commentStyle"] = "All";
+  (*settings)["indentation"] = "\t";
+  (*settings)["enableYAMLCompatibility"] = false;
+  (*settings)["dropNullPlaceholders"] = false;
+  (*settings)["useSpecialFloats"] = false;
+  (*settings)["precision"] = 17;
+  //! [StreamWriterBuilderDefaults]
+}
+
+JSONCPP_STRING writeString(StreamWriter::Factory const& builder, Value const& root) {
+  JSONCPP_OSTRINGSTREAM sout;
+  StreamWriterPtr const writer(builder.newStreamWriter());
+  writer->write(root, &sout);
+  return sout.str();
+}
+
+JSONCPP_OSTREAM& operator<<(JSONCPP_OSTREAM& sout, Value const& root) {
+  StreamWriterBuilder builder;
+  StreamWriterPtr const writer(builder.newStreamWriter());
+  writer->write(root, &sout);
+  return sout;
+}
+
+} // namespace Json