/// <summary>
/// Parse a JSON string to generate objects.
/// </summary>
/// <param name="json">The JSON string</param>
/// <returns>A .NET object</returns>
public static JNode Parse(string json)
{
int rp = 0;
int rmax = json.Length;
int[] istack = new int[32];
int isp = 0;
object[] ostack = new object[32];
int osp = 0;
int state = ROOT;
string key = null;
JArray list = null;
JObject hash = null;
JNode item = null;
StringBuilder sb;
char ctmp;
int itmp, jtmp;
while (true)
{
while (rp < rmax && char.IsWhiteSpace(json [rp]))
{
rp++;
}
if (rp == rmax)
{
throw new JSONParseException("unexpected EOF at " + rp);
}
switch (json [rp])
{
case '[':
if (isp + 2 > istack.Length)
{
Array.Resize(ref istack, isp * 2);
}
if (osp + 2 > ostack.Length)
{
Array.Resize(ref ostack, osp * 2);
}
istack [isp++] = state;
ostack [osp++] = list;
list = new JArray();
state = LIST_START;
rp++;
break;
case '{':
if (isp + 2 > istack.Length)
{
Array.Resize(ref istack, isp * 2);
}
if (osp + 2 > ostack.Length)
{
Array.Resize(ref ostack, osp * 2);
}
istack [isp++] = state;
ostack [osp++] = key;
ostack [osp++] = hash;
hash = new JObject();
state = HASH_START;
rp++;
break;
case ']':
if (state == LIST_START || state == LIST_ITEM)
{
rp++;
item = list;
list = (JArray)ostack [--osp];
state = istack [--isp];
goto add_item;
}
else
{
throw new JSONParseException("unexpected CLOSE BRACKET at " + rp);
}
case '}':
if (state == HASH_START || state == HASH_ITEM)
{
rp++;
item = hash;
hash = (JObject)ostack [--osp];
key = (string)ostack [--osp];
state = istack [--isp];
goto add_item;
}
else
{
throw new JSONParseException("unexpected CLOSE BRACE at " + rp);
}
case ':':
if (state == HASH_KEY)
{
state = HASH_COLON;
}
else
{
throw new JSONParseException("unexpected COLON at " + rp);
}
rp++;
break;
case ',':
if (state == HASH_ITEM)
{
state = HASH_COMMA;
}
else if (state == LIST_ITEM)
{
state = LIST_COMMA;
}
else
{
throw new JSONParseException("unexpected COMMA at " + rp);
}
rp++;
break;
case 't':
if (rp + 4 <= rmax && json.Substring(rp, 4) == "true")
{
item = true;
rp += 4;
goto add_item;
}
goto default;
case 'f':
if (rp + 5 <= rmax && json.Substring(rp, 5) == "false")
{
item = false;
rp += 5;
goto add_item;
}
goto default;
case 'n':
if (rp + 4 <= rmax && json.Substring(rp, 4) == "null")
{
item = null;
rp += 4;
goto add_item;
}
goto default;
case '"':
rp++;
sb = new StringBuilder();
while (true)
{
if (rp == rmax)
{
throw new JSONParseException("unexpected EOF in string at " + rp);
}
ctmp = json [rp];
if (char.IsControl(ctmp))
{
throw new JSONParseException("control character in string at " + rp);
}
rp++;
if (ctmp == '"')
{
break;
}
if (ctmp != '\\')
{
sb.Append(ctmp);
continue;
}
if (rp == rmax)
{
throw new JSONParseException("unexpected EOF in string at " + rp);
}
switch (json [rp++])
{
case '"':
sb.Append('"');
break;
case '\\':
sb.Append('\\');
break;
case '/':
sb.Append('/');
break;
case 'b':
sb.Append('\b');
break;
case 'f':
sb.Append('\f');
break;
case 'n':
sb.Append('\n');
break;
case 'r':
sb.Append('\r');
break;
case 't':
sb.Append('\t');
break;
case 'u':
if (rp + 4 > rmax)
{
throw new JSONParseException("unexpected EOF in hex escape at " + rp);
}
jtmp = 0;
for (itmp = 0; itmp < 4; itmp++)
{
ctmp = json [rp++];
jtmp = (jtmp << 4) + (int)ctmp;
if (ctmp >= '0' && ctmp <= '9')
{
jtmp -= (int)'0';
}
else if (ctmp >= 'a' && ctmp <= 'f')
{
jtmp -= ((int)'a' - 10);
}
else if (ctmp >= 'A' && ctmp <= 'F')
{
jtmp -= ((int)'A' - 10);
}
else
{
throw new JSONParseException("invalid hex digit at " + rp);
}
}
sb.Append((char)jtmp);
break;
default:
throw new JSONParseException("unknown backslash escape at " + rp);
}
}
item = sb.ToString();
goto add_item;
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
itmp = rp;
if (rp < rmax && json [rp] == '-')
{
rp++;
}
if (rp < rmax && json [rp] == '0')
{
rp++;
}
else if (rp < rmax && json [rp] >= '1' && json [rp] <= '9')
{
rp++;
while (rp < rmax && json [rp] >= '0' && json [rp] <= '9')
{
rp++;
}
}
else
{
throw new JSONParseException("malformed number at " + rp);
}
if (rp < rmax && json [rp] == '.')
{
rp++;
if (rp < rmax && json [rp] >= '0' && json [rp] <= '9')
{
rp++;
}
else
{
throw new JSONParseException("malformed number at " + rp);
}
while (rp < rmax && json [rp] >= '0' && json [rp] <= '9')
{
rp++;
}
}
if (rp < rmax && (json [rp] == 'e' || json [rp] == 'E'))
{
rp++;
if (rp < rmax && (json [rp] == '+' || json [rp] == '-'))
{
rp++;
}
if (rp < rmax && json [rp] >= '0' && json [rp] <= '9')
{
rp++;
}
else
{
throw new JSONParseException("malformed number at " + rp);
}
while (rp < rmax && json [rp] >= '0' && json [rp] <= '9')
{
rp++;
}
}
item = double.Parse(json.Substring(itmp, rp - itmp), NumberFormatInfo.InvariantInfo);
goto add_item;
default:
throw new JSONParseException("unrecognized token at " + rp);
}
continue;
add_item:
if (state == HASH_START || state == HASH_COMMA)
{
JString js = item as JString;
if (js == null)
{
throw new JSONParseException("non-string hash key at " + rp);
}
js.TryString(out key);
state = HASH_KEY;
}
else if (state == HASH_COLON)
{
hash [key] = item;
state = HASH_ITEM;
}
else if (state == LIST_START || state == LIST_COMMA)
{
list.Add(item);
state = LIST_ITEM;
}
else if (state == ROOT)
{
while (rp < rmax && char.IsWhiteSpace(json [rp]))
{
rp++;
}
if (rp < rmax)
{
throw new JSONParseException("trailing garbage at " + rp);
}
return(item);
}
else
{
throw new JSONParseException("unexpected ITEM at " + rp);
}
continue;
}
}
