private static DataNode ReadNode(string contents, ref int index, string name)
{
DataNode result = null;
var state = State.Type;
char c;
var mode = InputMode.None;
StringBuilder name_content = new StringBuilder();
StringBuilder value_content = new StringBuilder();
int rewind_index = index;
bool is_escaped = false;
do
{
bool isWhiteSpace;
bool next = false;
do
{
if (index >= contents.Length)
{
if (state == State.Next)
{
return(result);
}
throw new Exception($"JSON parsing exception, unexpected end of data");
}
c = contents[index];
isWhiteSpace = Char.IsWhiteSpace(c);
if (!isWhiteSpace)
{
rewind_index = index;
}
index++;
next = (mode == InputMode.None) ? isWhiteSpace : false;
} while (next);
switch (state)
{
case State.Type:
{
switch (c)
{
case '{':
{
result = DataNode.CreateObject(name);
state = State.Name;
break;
}
case '[':
{
result = DataNode.CreateArray(name);
state = State.Value;
break;
}
default:
{
throw new Exception($"JSON parsing exception at, unexpected character");
//throw new Exception($"JSON parsing exception at {ParserUtils.GetOffsetError(contents, index)}, unexpected character");
}
}
break;
}
case State.Name:
{
if (c == '}' && result.Kind == NodeKind.Object)
{
return(result);
}
switch (c)
{
case '"':
{
if (mode == InputMode.None)
{
mode = InputMode.Text;
name_content.Length = 0;
}
else
{
mode = InputMode.None;
state = State.Colon;
}
break;
}
default:
{
if (mode == InputMode.Text)
{
name_content.Append(c);
}
else
{
throw new Exception($"JSON parsing exception at, unexpected character");
//throw new Exception($"JSON parsing exception at {ParserUtils.GetOffsetError(contents, index)}, unexpected character");
}
break;
}
}
break;
}
case State.Colon:
{
switch (c)
{
case ':':
{
state = State.Value;
break;
}
default:
{
throw new Exception($"JSON parsing exception at, expected collon");
//throw new Exception($"JSON parsing exception at {ParserUtils.GetOffsetError(contents, index)}, expected collon");
}
}
break;
}
case State.Value:
{
if (c == '\\' && !is_escaped)
{
is_escaped = true;
}
else
if (is_escaped)
{
is_escaped = false;
if (c == 'n') // Newline
{
value_content.Append('\n');
}
else if (c == 'r') // Carriage return
{
value_content.Append('\r');
}
else if (c == 't') // Tab
{
value_content.Append('\t');
}
else if (c == 'b') // Backspace
{
value_content.Append('\b');
}
else if (c == 'f') // Form feed
{
value_content.Append('\f');
}
else
{
if (c == 'u')
{
var hex = "";
for (int i = 0; i < 4; i++)
{
if (index >= contents.Length)
{
throw new Exception($"JSON parsing exception, unexpected end of data");
}
hex += contents[index]; index++;
}
ushort unicode_val;
unicode_val = ushort.Parse(hex, System.Globalization.NumberStyles.HexNumber);
c = (char)unicode_val;
}
value_content.Append(c);
}
}
else
if (c == 'n' && mode == InputMode.None)
{
ReadString("null", contents, ref index);
result.AddField(name_content.Length == 0 ? null : name_content.ToString(), null);
state = State.Next;
}
else
if (c == 'f' && mode == InputMode.None)
{
ReadString("false", contents, ref index);
result.AddField(name_content.Length == 0 ? null : name_content.ToString(), false);
state = State.Next;
}
else
if (c == 't' && mode == InputMode.None)
{
ReadString("true", contents, ref index);
result.AddField(name_content.Length == 0 ? null : name_content.ToString(), true);
state = State.Next;
}
else
if (c == ']' && mode == InputMode.None && result.Kind == NodeKind.Array)
{
return(result);
}
else
{
switch (c)
{
case '"':
{
if (mode == InputMode.None)
{
mode = InputMode.Text;
value_content.Length = 0;
}
else
{
object value;
var str = value_content.ToString();
if (mode == InputMode.Number)
{
if (str.Contains("e"))
{
// TODO
}
value = str;
}
else
{
value = str;
}
mode = InputMode.None;
result.AddField(name_content.Length == 0 ? null : name_content.ToString(), value);
state = State.Next;
}
break;
}
case '[':
case '{':
{
if (mode == InputMode.Text)
{
value_content.Append(c);
}
else
{
index = rewind_index;
var node = ReadNode(contents, ref index, name_content.Length == 0 ? null : name_content.ToString());
result.AddNode(node);
state = State.Next;
}
break;
}
default:
{
if (mode == InputMode.Text)
{
value_content.Append(c);
}
else
if (char.IsNumber(c) || (c == '.' || c == 'e' || c == 'E' || c == '-' || c == '+'))
{
if (mode != InputMode.Number)
{
value_content.Length = 0;
mode = InputMode.Number;
}
if (c == 'E')
{
c = 'e';
}
value_content.Append(c);
}
else
{
if (mode == InputMode.Number)
{
mode = InputMode.None;
var numStr = value_content.ToString();
if (numStr.Contains("e"))
{
var num = double.Parse(numStr, NumberStyles.Any, CultureInfo.InvariantCulture);
result.AddField(name_content.Length == 0 ? null : name_content.ToString(), num);
}
else
{
var num = decimal.Parse(numStr, NumberStyles.Any, CultureInfo.InvariantCulture);
result.AddField(name_content.Length == 0 ? null : name_content.ToString(), num);
}
state = State.Next;
if (c == ',' || c == ']' || c == '}')
{
index = rewind_index;
}
}
else
{
//throw new Exception($"JSON parsing exception at {ParserUtils.GetOffsetError(contents, index)}, unexpected character");
}
}
break;
}
}
}
break;
}
case State.Next:
{
switch (c)
{
case ',':
{
state = result.Kind == NodeKind.Array ? State.Value : State.Name;
break;
}
case '}':
{
if (result.Kind != NodeKind.Object)
{
//throw new Exception($"JSON parsing exception at {ParserUtils.GetOffsetError(contents, index)}, unexpected }}");
}
return(result);
}
case ']':
{
if (result.Kind != NodeKind.Array)
{
//throw new Exception($"JSON parsing exception at {ParserUtils.GetOffsetError(contents, index)}, unexpected ]");
}
return(result);
}
default:
{
throw new Exception($"JSON parsing exception at, expected collon");
//throw new Exception($"JSON parsing exception at {ParserUtils.GetOffsetError(contents, index)}, expected collon");
}
}
break;
}
}
} while (true);
}
public static DataNode ReadFromString(string contents)
{
var root = DataNode.CreateArray(null);
//Console.WriteLine(contents);
var header = new List <string>();
int index = 0;
var state = State.Header;
char c;
int fieldIndex = 0;
bool isEscaped = false;
var content = new StringBuilder();
DataNode currentNode = null;
while (index < contents.Length)
{
c = contents[index];
index++;
switch (state)
{
case State.Header:
{
if (c == ',' || c == '\n')
{
header.Add(content.ToString().Trim());
content.Length = 0;
}
switch (c)
{
case ',': { break; }
case '\n':
{
state = State.Content;
break;
}
default:
{
content.Append(c);
break;
}
}
break;
}
case State.Content:
{
if (!isEscaped && (c == ',' || c == '\n'))
{
if (fieldIndex < header.Count)
{
currentNode.AddField(header[fieldIndex], content.ToString());
}
content.Length = 0;
fieldIndex++;
if (c == '\n')
{
fieldIndex = 0;
currentNode = null;
}
break;
}
if (c == '"')
{
if (isEscaped && index < contents.Length && contents[index] == '"')
{
index++;
}
else
{
isEscaped = !isEscaped;
break;
}
}
if (currentNode == null)
{
currentNode = DataNode.CreateObject(null);
root.AddNode(currentNode);
}
content.Append(c);
break;
}
}
}
if (currentNode != null && fieldIndex < header.Count)
{
currentNode.AddField(header[fieldIndex], content.ToString());
}
return(root);
}
