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);
}
public static object Parse(CharReader reader)
{
_SkipWhitespace(reader);
char startChar;
startChar = reader.Peek();
if (startChar == '{')
{
return(_ParseJObject(reader));
}
else if (startChar == '[')
{
return(_ParseJArray(reader));
}
else
{
throw new ArgumentException("Invalid JSON input");
}
}
private static object _GetValue(CharReader reader)
{
char c;
string token;
c = reader.Peek();
switch (c)
{
case 'n':
token = _GetToken(reader);
if (token != "null")
{
throw new ArgumentException($"Invalid token: {token}");
}
return(null);
case 'f':
token = _GetToken(reader);
if (token != "false")
{
throw new ArgumentException($"Invalid token: {token}");
}
return(false);
case 't':
token = _GetToken(reader);
if (token != "true")
{
throw new ArgumentException($"Invalid token: {token}");
}
return(true);
case '\"':
return(_GetStringValue(reader));
case '[':
return(_ParseJArray(reader));
case '{':
return(_ParseJObject(reader));
case '-':
case '+':
case '.':
case 'e':
case 'E':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return(_GetNumeric(reader));
default:
throw new ArgumentException($"Unexpected character: {c}");
}
}
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;
}
}
