protected static JObject _ParseJObject(CharReader reader)
{
JObject result = new JObject();
char c;
try
{
_SkipWhitespace(reader);
if (reader.Read() != '{')
{
throw new SystemException("Begining brace expected");
}
string key;
object value;
_SkipWhitespace(reader);
while (reader.Peek() != '}')
{
_SkipWhitespace(reader);
if (reader.Peek() == ',')
{
// allow extraneous commas
reader.Read(); // gobble char
_SkipWhitespace(reader);
continue;
}
if (reader.Peek() != '\"')
{
throw new SystemException("Quote char expected");
}
key = _GetStringValue(reader);
_SkipWhitespace(reader);
if (reader.Read() != ':')
{
throw new SystemException("Colon char expected");
}
_SkipWhitespace(reader);
value = _GetValue(reader);
result.Add(key, value);
_SkipWhitespace(reader);
c = reader.Peek();
if (c != ',' && c != '}')
{
throw new SystemException("Comma or end brace expected");
}
if (c == ',')
{
reader.Read(); // gobble comma char
_SkipWhitespace(reader);
}
}
reader.Read(); // gobble } char
}
catch (Exception ex)
{
throw new ArgumentException($"Invalid JObject input\r\n{ex.Message}");
}
return(result);
}
protected static JArray _ParseJArray(CharReader reader)
{
JArray result = new JArray();
char c;
try
{
_SkipWhitespace(reader);
c = reader.Read();
if (c != '[')
{
throw new SystemException("Begining bracket expected");
}
object value;
_SkipWhitespace(reader);
while (reader.Peek() != ']')
{
_SkipWhitespace(reader);
if (reader.Peek() == ',')
{
// allow extraneous commas
reader.Read(); // gobble char
_SkipWhitespace(reader);
continue;
}
value = _GetValue(reader);
result.Add(value);
_SkipWhitespace(reader);
c = reader.Peek();
if (c != ',' && c != ']')
{
throw new SystemException("Comma or end bracket expected");
}
if (c == ',')
{
reader.Read(); // gobble comma char
_SkipWhitespace(reader);
}
}
reader.Read(); // gobble end bracket char
}
catch (Exception ex)
{
throw new ArgumentException($"Invalid JArray input\r\n{ex.Message}");
}
return(result);
}
private static string _GetToken(CharReader reader)
{
StringBuilder result = new StringBuilder();
char c;
while (true)
{
c = reader.Read();
if (char.IsLetterOrDigit(c) || c == '-' || c == '+' || c == '.')
{
result.Append(c);
continue;
}
reader.Push(c);
break;
}
return(result.ToString());
}
private static string _GetStringValue(CharReader reader)
{
// reader must be on starting quote char
if (reader.Read() != '\"')
{
throw new ArgumentException("Invalid JSON string");
}
StringBuilder result = new StringBuilder();
bool escaped = false;
char c;
while (true)
{
c = reader.Read();
if (escaped)
{
switch (c)
{
case '\"':
case '\\':
case '/':
result.Append(c);
break;
case 'b':
result.Append('\b');
break;
case 'f':
result.Append('\f');
break;
case 'n':
result.Append('\n');
break;
case 'r':
result.Append('\r');
break;
case 't':
result.Append('\t');
break;
case 'u':
string unicodeValue = $"{reader.Read()}{reader.Read()}{reader.Read()}{reader.Read()}";
result.Append(Convert.ToChar(Convert.ToUInt16(unicodeValue, 16)));
break;
default:
throw new ArgumentException($"Invalid escaped char in string: {c}");
}
escaped = false;
continue;
}
// escape next char
if (c == '\\')
{
escaped = true;
continue;
}
// ending quote, done
if (c == '\"')
{
break;
}
// normal char
result.Append(c);
}
return(result.ToString());
}
protected static void _SkipWhitespace(CharReader reader)
{
char currChar;
while (true)
{
if (reader.EOF())
{
break;
}
currChar = reader.Peek();
// use c# definition of whitespace
if (char.IsWhiteSpace(currChar))
{
reader.Read(); // gobble char
continue;
}
// check for comments
if (currChar == '/')
{
reader.Read(); // gobble char
char nextChar = reader.Read();
if (nextChar == '/') // to EOF
{
while (true)
{
// not error if EOF before CR-LF
if (reader.EOF())
{
break;
}
currChar = reader.Read();
if (currChar == '\r' || currChar == '\n')
{
break;
}
}
continue;
}
else if (nextChar == '*') /* to */
{
nextChar = ' '; // clear for comparison
while (true)
{
// will throw an error if EOF before '*/' is found
currChar = nextChar;
nextChar = reader.Read();
if (currChar == '*' && nextChar == '/')
{
break;
}
}
continue;
}
else // not a comment
{
// push back in reverse order
reader.Push(nextChar);
reader.Push(currChar);
break;
}
}
break;
}
}