// Parse the rest of a UTF-8 sequence within an encoded URI.
private static int ParseRestOfUTF8(int utf8, string uri, ref int _index)
{
int index = _index;
int size;
int utf8Char;
if ((utf8 & 0xE0) == 0xC0)
{
size = 1;
utf8 &= 0x1F;
}
else if ((utf8 & 0xF0) == 0xE0)
{
size = 2;
utf8 &= 0x0F;
}
else if ((utf8 & 0xF8) == 0xF0)
{
size = 3;
utf8 &= 0x07;
}
else if ((utf8 & 0xFC) == 0xF8)
{
size = 4;
utf8 &= 0x03;
}
else
{
// Invalid UTF-8 start character.
throw new JScriptException(JSError.URIDecodeError);
}
while (size > 0)
{
if ((index + 2) >= uri.Length || uri[index] != '%' ||
!JSScanner.IsHexDigit(uri[index + 1]) ||
!JSScanner.IsHexDigit(uri[index + 2]))
{
throw new JScriptException(JSError.URIDecodeError);
}
utf8Char = (JSScanner.FromHex(uri[index + 1]) << 4) |
JSScanner.FromHex(uri[index + 2]);
if ((utf8Char & 0xC0) != 0x80)
{
// Invalid UTF-8 component character.
throw new JScriptException(JSError.URIDecodeError);
}
index += 3;
utf8 = (utf8 << 6) | (utf8Char & 0x3F);
--size;
}
_index = index;
if (utf8 < 0)
{
// Invalid UTF-8 character.
throw new JScriptException(JSError.URIDecodeError);
}
return(utf8);
}
public static string unescape(object str)
{
string s = Convert.ToString(str);
StringBuilder builder = new StringBuilder(s.Length);
int index = 0;
char ch;
while (index < s.Length)
{
ch = s[index++];
if (ch != '%')
{
builder.Append(ch);
}
else if ((index + 1) < s.Length &&
JSScanner.IsHexDigit(s[index]) &&
JSScanner.IsHexDigit(s[index + 1]))
{
ch = (char)((JSScanner.FromHex(s[index]) << 4) |
JSScanner.FromHex(s[index + 1]));
builder.Append(ch);
index += 2;
}
else if ((index + 4) < s.Length &&
s[index] == 'u' &&
JSScanner.IsHexDigit(s[index + 1]) &&
JSScanner.IsHexDigit(s[index + 2]) &&
JSScanner.IsHexDigit(s[index + 3]) &&
JSScanner.IsHexDigit(s[index + 4]))
{
ch = (char)((JSScanner.FromHex(s[index + 1]) << 12) |
(JSScanner.FromHex(s[index + 2]) << 8) |
(JSScanner.FromHex(s[index + 3]) << 4) |
JSScanner.FromHex(s[index + 4]));
builder.Append(ch);
index += 5;
}
else
{
builder.Append(ch);
}
}
return(builder.ToString());
}
// Internal URI decoding logic.
private static string InternalDecode(string uri, bool reserved)
{
StringBuilder builder = new StringBuilder(uri.Length);
int index = 0;
char ch;
int utf8Char;
int start;
while (index < uri.Length)
{
ch = uri[index++];
if (ch != '%')
{
builder.Append(ch);
}
else if ((index + 1) >= uri.Length ||
!JSScanner.IsHexDigit(uri[index]) ||
!JSScanner.IsHexDigit(uri[index + 1]))
{
// Invalid hexadecimal sequence.
throw new JScriptException(JSError.URIDecodeError);
}
else
{
start = index - 1;
utf8Char = (JSScanner.FromHex(uri[index]) << 4) |
JSScanner.FromHex(uri[index + 1]);
index += 2;
if (utf8Char >= 0x80)
{
// Parse the rest of the UTF-8 sequence.
utf8Char = ParseRestOfUTF8
(utf8Char, uri, ref index);
}
if (utf8Char < 0x10000)
{
// Single-character.
if (reserved && IsURIReserved((char)utf8Char))
{
builder.Append(uri, start, index - start);
}
else
{
builder.Append((char)utf8Char);
}
}
else if (utf8Char < 0x110000)
{
// Surrogate pair.
utf8Char -= 0x10000;
builder.Append((char)((utf8Char >> 10) + 0xD800));
builder.Append((char)((utf8Char & 0x3FF) + 0xDC00));
}
else
{
// UTF-8 character is out of range.
throw new JScriptException(JSError.URIDecodeError);
}
}
}
return(builder.ToString());
}
