Java ultra fast split(String, String)

/**
 * Splits the given string by the given splitter string, keeping empty strings
 * if there are zero characters between splits
 * @param string The input string to split
 * @param split  The splitter value
 * @return A list of split elements
 * @author REghZy
 */
@Nonnull
public static ArrayList<String> splitAsList(@Nullable String string, @Nullable String split) {
    int srcLen, tarLen;
    if (string == null || (srcLen = string.length()) == 0)
        return new ArrayList<String>();
    if (split == null || (tarLen = split.length()) == 0)
        return Linq.of(charToStringArray(string.toCharArray())).toList();
    ArrayList<String> list = new ArrayList<String>();
    int i = -tarLen, last = 0;
    while ((i = string.indexOf(split, i + tarLen)) != -1) {
        list.add(string.substring(last, i));
        last = i + tarLen;
    }
    // using '<=' instead of '<' to keep the empty string element if the split is
    // at the very end of the string (because 'last' will be equal to 'srcLen' in this case)
    // e.g. splitAsList("hi__lol__") with '<=' gives ["hi", "lol", ""], whereas '<' gives ["hi", "lol"]
    // Could add a "keepTrailingSplits" parameter, and replace below with (keepTrailingSplits ? (last <= srcLen) : (last < srcLen))
    if (last <= srcLen) {
        list.add(string.substring(last));
    }
    return list;
}