public string ToString(char first, char last, bool complement)
{
if (first > last)
//throw new ArgumentException(CoreResources.GetString("last_is_less_than_first"));
throw new NotImplementedException();
int modf = first & 0x1f;
int modl = last & 0x1f;
int f = first >> 5;
int l = last >> 5;
// an optimization:
if (l > lastDirty && !complement)
{
// sets upper bound to the last bit in the lastDirty block:
l = lastDirty;
modl = 31;
// the whole interval is beyond the last set bit:
if (f > l) return String.Empty;
}
// if complementary set is required, we xor each item of the "flags" array by the "invert_equality"
// and so invert the result of comparison with zero in the following if statement:
uint invert_inequality = (complement) ? 0xffffffffU : 0U;
uint flg;
char c = first;
StringBuilder result = new StringBuilder();
if (f == l)
{
// the "first" and the "last" points to the same block:
flg = flags[f] ^ invert_inequality;
for (uint mask = (0x80000000U >> modf); mask > (0x80000000U >> modl); mask >>= 1)
{
if ((flg & mask) != 0) result.Append(c);
c++;
}
}
else
{
// the first block:
flg = flags[f] ^ invert_inequality;
for (uint mask = 0x80000000U >> modf; mask != 0; mask >>= 1)
{
if ((flg & mask) != 0) result.Append(c);
c++;
}
// middle blocks (if any):
for (int i = f + 1; i < l; i++)
{
flg = flags[i] ^ invert_inequality;
for (uint mask = 0x80000000U; mask != 0; mask >>= 1)
{
if ((flg & mask) != 0) result.Append(c);
c++;
}
}
// the last block:
flg = flags[l] ^ invert_inequality;
for (uint mask = 0x80000000U; mask >= (0x80000000U >> modl); mask >>= 1)
{
if ((flg & mask) != 0) result.Append(c);
c++;
}
}
return result.ToString();
}
}
