public static ColorString Escape(string str, Func <char, ColorPair> exchange)
{
if (str == null)
{
return(null);
}
else if (str.Length == 0)
{
return(null);
}
char ch = str[0];
ColorPair current = exchange(ch);
StringBuilder sb = new StringBuilder(current.ToString());
sb.Append(current);
sb.Append(ch);
for (int i = 1; i < str.Length; i++)
{
ch = str[i];
ColorPair next = exchange(ch);
if (current != next)
{
sb.Append(next.ToString());
current = next;
}
sb.Append(ch);
}
return(new ColorString(sb.ToString()));
}
