private char UnEscapeUnicode()
{
var code = 0;
for (var i = 0; i < 4; i++)
{
Consume();
var ch = _nextChar;
code <<= 4;
if ('0' <= ch && ch <= '9')
{
code += ch - '0';
}
else if ('a' <= ch && ch <= 'f')
{
code += 10 + ch - 'a';
}
else if ('A' <= ch && ch <= 'F')
{
code += 10 + ch - 'A';
}
else
{
throw JsonParserException.InvalidError(string.Format("unicode escape '{0}'", ch), _position);
}
}
return((char)code);
}
private string GetString()
{
Consume();
var start = _position;
var len = 0;
while (true)
{
if (_isEnd)
{
throw JsonParserException.UnexpectedEnd(start + len);
}
var ch = _nextChar;
if (ch == '"')
{
Consume();
return(new string(_charBuffer, 0, len));
}
if (ch == '\\')
{
ch = UnEscape();
}
else if (ch < ' ')
{
throw JsonParserException.UnexpectedError(ch, _position);
}
if (len >= _charBuffer.Length)
{
Array.Resize(ref _charBuffer, _charBuffer.Length * 2);
}
_charBuffer[len++] = ch;
Consume();
}
}
private double GetNumber()
{
var result = 0d;
var sign = 1;
if (_nextChar == '-')
{
sign = -1;
Consume();
if (!IsNumber())
{
throw JsonParserException.ExpectingError("digit", _position);
}
}
do
{
result = result * 10.0 + (_nextChar - '0');
Consume();
} while (IsNumber());
if (_nextChar == '.')
{
Consume();
if (!IsNumber())
{
throw JsonParserException.ExpectingError("digit", _position);
}
var exp = 0.1;
do
{
result += (_nextChar - '0') * exp;
exp *= 0.1;
Consume();
} while (IsNumber());
}
if (_nextChar == 'e' || _nextChar == 'E')
{
Consume();
var expSign = 1;
var exp = 0;
if (_nextChar == '-' || _nextChar == '+')
{
if (_nextChar == '-')
{
expSign = -1;
}
Consume();
}
if (!IsNumber())
{
throw JsonParserException.ExpectingError("digit", _position);
}
do
{
exp = exp * 10 + (_nextChar - '0');
Consume();
} while (IsNumber());
result = result * Math.Pow(10, expSign * exp);
}
return(sign * result);
}
private void CheckToken(string s)
{
Consume();
foreach (var ch in s)
{
if (ch != _nextChar)
{
throw JsonParserException.ExpectingError(string.Format("'{0}'", ch), _position);
}
Consume();
}
}
private char UnEscape()
{
Consume();
var ch = _nextChar;
switch (ch)
{
case '\\':
case '/':
case '"':
break;
case 'b':
ch = '\b';
break;
case 'f':
ch = '\f';
break;
case 'n':
ch = '\n';
break;
case 'r':
ch = '\r';
break;
case 't':
ch = '\t';
break;
case 'u':
ch = UnEscapeUnicode();
break;
default:
throw JsonParserException.InvalidError(string.Format("escape character '{0}'", ch), _position);
}
return(ch);
}
private object ParseInternal(TextReader reader, int maxDepth)
{
Setup(reader);
var stack = new Context[maxDepth];
var depth = 0;
var context = new Context();
SkipWhiteSpaces();
while (true)
{
var value = new InternalObject();
switch (_nextChar)
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '-':
value.Number = GetNumber();
break;
case 'n':
CheckToken("ull");
value.Type = JsonType.Null;
break;
case 't':
CheckToken("rue");
value.Type = JsonType.True;
break;
case 'f':
// ReSharper disable once StringLiteralTypo
CheckToken("alse");
value.Type = JsonType.False;
break;
case '"':
value.Type = JsonType.String;
value.String = GetString();
break;
case '[':
if (depth == maxDepth)
{
throw JsonParserException.TooDeepNesting(depth, _position);
}
Consume();
stack[depth++] = context;
context = new Context
{
Array = new JsonArray()
};
SkipWhiteSpaces();
continue;
case ']':
if (context.Array == null)
{
throw JsonParserException.UnexpectedError(_nextChar, _position);
}
Consume();
value.Type = JsonType.Array;
value.Array = context.Array;
context = stack[--depth];
break;
case '{':
if (depth == maxDepth)
{
throw JsonParserException.TooDeepNesting(depth, _position);
}
Consume();
stack[depth++] = context;
context = new Context
{
Dictionary = new JsonDictionary()
};
goto GetKey;
case '}':
if (context.Dictionary == null)
{
throw JsonParserException.UnexpectedError(_nextChar, _position);
}
Consume();
value.Type = JsonType.Object;
value.Dictionary = context.Dictionary;
context = stack[--depth];
break;
default:
if (_isEnd)
{
throw JsonParserException.UnexpectedEnd(_position);
}
throw JsonParserException.UnexpectedError(_nextChar, _position);
}
SkipWhiteSpaces();
// Start
if (depth == 0)
{
if (_isEnd)
{
return(JsonObject.ToValue(value));
}
throw JsonParserException.UnexpectedError(_nextChar, _position);
}
// Array
if (context.Key == null)
{
context.Array.Add(value);
if (_nextChar == ']')
{
continue;
}
if (_nextChar != ',')
{
throw JsonParserException.ExpectingError("',' or ']'", _position);
}
Consume();
SkipWhiteSpaces();
continue;
}
// Object
context.Dictionary.Add(context.Key, value);
if (_nextChar == '}')
{
continue;
}
if (_nextChar != ',')
{
throw JsonParserException.ExpectingError("',' or '}'", _position);
}
Consume();
GetKey:
SkipWhiteSpaces();
if (_nextChar == '}')
{
continue;
}
if (_nextChar != '"')
{
throw JsonParserException.ExpectingError("string", _position);
}
context.Key = GetString();
SkipWhiteSpaces();
if (_nextChar != ':')
{
throw JsonParserException.ExpectingError("':'", _position);
}
Consume();
SkipWhiteSpaces();
}
}