private bool EvalChar(Mode mode, ref int ptr, ref int pc, bool multi)
{
bool consumed = false;
char c = '\0';
bool negate;
bool ignore;
do
{
ushort word = program[pc];
OpCode op = (OpCode)(word & 0x00ff);
OpFlags flags = (OpFlags)(word & 0xff00);
++pc;
ignore = (flags & OpFlags.IgnoreCase) != 0;
// consume character: the direction of an In construct is
// determined by the direction of its first op
if (!consumed)
{
if ((flags & OpFlags.RightToLeft) != 0)
{
if ((substring_mode && ptr <= (regex_rtl ? text_end : text_start)) || (!substring_mode && ptr <= 0))
{
return(false);
}
c = text[--ptr];
}
else
{
if ((!regex_rtl && ptr >= text_end) || (regex_rtl && ptr >= text_start))
{
return(false);
}
c = text[ptr++];
}
if (ignore)
{
c = Char.ToLower(c);
}
consumed = true;
}
// negate flag
negate = (flags & OpFlags.Negate) != 0;
// execute op
switch (op)
{
case OpCode.True:
return(true);
case OpCode.False:
return(false);
case OpCode.Character: {
if (c == (char)program[pc++])
{
return(!negate);
}
break;
}
case OpCode.Category: {
if (CategoryUtils.IsCategory((Category)program[pc++], c))
{
return(!negate);
}
break;
}
case OpCode.NotCategory: {
if (!CategoryUtils.IsCategory((Category)program[pc++], c))
{
return(!negate);
}
break;
}
case OpCode.Range: {
int lo = (char)program[pc++];
int hi = (char)program[pc++];
if (lo <= c && c <= hi)
{
return(!negate);
}
break;
}
case OpCode.Set: {
int lo = (char)program[pc++];
int len = (char)program[pc++];
int bits = pc;
pc += len;
int i = (int)c - lo;
if (i < 0 || i >= len << 4)
{
break;
}
if ((program[bits + (i >> 4)] & (1 << (i & 0xf))) != 0)
{
return(!negate);
}
break;
}
}
} while (multi);
return(negate);
}
private bool IsWordChar(char c)
{
return(CategoryUtils.IsCategory(Category.Word, c));
}