public override void Visit(CodePoint expression)
{
terminal.Peek().Append(expression.Match);
}
public override void Visit(CodePoint expression)
{
String matchtext = expression.Match;
_matchStack.Push(
delegate(IInputIterator iterator)
{
if (matchtext.StartsWith("#x"))
{
//hexadecimal evaluation
String hexinput = matchtext.Substring(2);
if (hexinput == String.Empty)
throw new ArgumentException("Hex value specified is empty.");
if (hexinput.Length % 2 != 0)
hexinput = "0" + hexinput; // on incomplete byte boundaries shift right
int total_compare_bytes = hexinput.Length / 2;
for (int i = 0; i < total_compare_bytes; i++)
{
if (iterator.Current() == -1)
return false;
var compareWith = (Byte)iterator.Current();
for (Int32 j = 0; j < 2; j++)
{
// low nibble comparison
Int32 nibbleOffset = 0;
if (j == 0)
{
// high nibble comparison
nibbleOffset = 4;
}
// j == 0 == high nibble
// j == 1 == low nibble
var tmp = (Byte)hexinput[i * 2 + j];
if (tmp >= (Byte)'0' && tmp <= (Byte)'9')
{
tmp = (Byte)((tmp - (Byte)'0') << nibbleOffset);
}
else if (tmp >= (Byte)'a' && tmp <= (Byte)'f')
{
tmp = (Byte)((tmp - (Byte)'A' + 10) << nibbleOffset);
}
else if (tmp >= (Byte)'A' && tmp <= (Byte)'F')
{
tmp = (Byte)((tmp - (Byte)'A' + 10) << nibbleOffset);
}
else if (tmp == (Byte)'x' || tmp == (Byte)'X')
{
// don't care ignore nibble comparison
}
else
{
throw new ArgumentException("Hex value specified contains invalid characters.");
}
if (!(tmp == (Byte)'x' || tmp == (Byte)'X'))
{
if (
((compareWith & (1 << (nibbleOffset + 3))) >> (nibbleOffset + 3)) !=
((tmp & (1 << (nibbleOffset + 3))) >> (nibbleOffset + 3)) ||
((compareWith & (1 << (nibbleOffset + 2))) >> (nibbleOffset + 2)) !=
((tmp & (1 << (nibbleOffset + 2))) >> (nibbleOffset + 2)) ||
((compareWith & (1 << (nibbleOffset + 1))) >> (nibbleOffset + 1)) !=
((tmp & (1 << (nibbleOffset + 1))) >> (nibbleOffset + 1)) ||
((compareWith & (1 << nibbleOffset)) >> nibbleOffset) !=
((tmp & (1 << nibbleOffset)) >> nibbleOffset)
)
{
return false;
}
}
}
iterator.Next();
}
}
else if (matchtext.StartsWith("#b"))
{
// binary evaluation
String binaryinput = matchtext.Substring(2);
if (binaryinput == String.Empty)
throw new ArgumentException("Binary value specified is empty.");
if (binaryinput.Length % 8 != 0)
binaryinput = "".PadLeft(8 - (binaryinput.Length % 8), '0') + binaryinput;
// on incomplete byte boundaries shift right
int total_compare_bytes = binaryinput.Length / 8;
for (int i = 0; i < total_compare_bytes; i++)
{
if (iterator.Current() == -1)
return false;
var compareWith = (Byte)iterator.Current();
for (Int32 j = 0; j < 8; j++)
{
var tmp = (Byte)binaryinput[i * 8 + j];
if (tmp == (Byte)'0')
{
tmp = 0x00;
}
else if (tmp == (Byte)'1')
{
tmp = 0x01;
}
else if (tmp == (Byte)'x' || tmp == (Byte)'X')
{
// don't care ignore nibble comparison
}
else
{
throw new ArgumentException(
"Binary value specified contains invalid characters.");
}
if (!(tmp == (Byte)'x' || tmp == (Byte)'X'))
{
Int32 bit2compare = 7 - j;
if (
((compareWith & (1 << bit2compare)) >> bit2compare) != tmp
)
{
return false;
}
}
}
iterator.Next();
}
}
else
{
// decimal codepoint evaluation
String decimalinput = matchtext.Substring(1);
if (decimalinput == String.Empty)
throw new ArgumentException("Decimal codepoint value specified is empty.");
if (!Regex.IsMatch(decimalinput, @"^[0-9]+$"))
throw new ArgumentException(
"Decimal codepoint value specified contains invalid characters.");
if (decimalinput.Length > 10) // 4,294,967,295
throw new ArgumentException(
"Decimal codepoint value exceeds 4 byte maximum length. Largest decimal value possible 2^32");
UInt32 codepoint = UInt32.Parse(decimalinput);
var c4 = (Byte)(codepoint >> 24);
var c3 = (Byte)(codepoint >> 16);
var c2 = (Byte)(codepoint >> 8);
var c1 = (Byte)(codepoint);
if (c4 != 0x00)
{
// consumes 4 bytes
if (iterator.Current() == -1 || iterator.Current() != c1)
{
return false;
}
iterator.Next();
if (iterator.Current() == -1 || iterator.Current() != c2)
{
return false;
}
iterator.Next();
if (iterator.Current() == -1 || iterator.Current() != c3)
{
return false;
}
iterator.Next();
if (iterator.Current() == -1 || iterator.Current() != c4)
{
return false;
}
iterator.Next();
}
else if (c3 != 0x00)
{
// consumes 3 bytes
if (iterator.Current() == -1 || iterator.Current() != c1)
{
return false;
}
iterator.Next();
if (iterator.Current() == -1 || iterator.Current() != c2)
{
return false;
}
iterator.Next();
if (iterator.Current() == -1 || iterator.Current() != c3)
{
return false;
}
iterator.Next();
}
else if (c2 != 0x00)
{
// consumes 2 bytes
if (iterator.Current() == -1 || iterator.Current() != c1)
{
return false;
}
iterator.Next();
if (iterator.Current() == -1 || iterator.Current() != c2)
{
return false;
}
iterator.Next();
}
else
{
// user must want to match null \0
// (c1 != 0x00)
// consumes 1 byte
if (iterator.Current() == -1 || iterator.Current() != c1)
{
return false;
}
iterator.Next();
}
}
return true;
}
);
}
public abstract void Visit(CodePoint expression);
