/// <summary>
/// 获取字符类中包含的所有字符。
/// </summary>
/// <param name="charClass">要获取所有字符的字符类。</param>
/// <returns>字符类中包含的所有字符。</returns>
private static CharSet GetCharClassSet(string charClass)
{
CharSet set = new CharSet();
if (RegexCharClass.IsSubtraction(charClass) || RegexCharClass.ContainsCategory(charClass))
{
for (int i = 0; i <= char.MaxValue; i++)
{
if (RegexCharClass.CharInClass((char)i, charClass))
{
set.Add((char)i);
}
}
}
else
{
// 如果不包含差集和 Unicode 字符分类的话，可以更快。
string ranges = RegexCharClass.GetCharClassRanges(charClass);
if (RegexCharClass.IsNegated(charClass))
{
int s = 0;
for (int i = 0; i < ranges.Length; i++)
{
for (int j = s; j < ranges[i]; j++)
{
set.Add((char)j);
}
i++;
s = i < ranges.Length ? ranges[i] : char.MaxValue + 1;
}
for (int j = s; j <= char.MaxValue; j++)
{
set.Add((char)j);
}
}
else
{
for (int i = 0; i < ranges.Length; i++)
{
int j = ranges[i++];
int end = i < ranges.Length ? ranges[i] : char.MaxValue + 1;
for (; j < end; j++)
{
set.Add((char)j);
}
}
}
}
return(set);
}