obviously there's 'better' ways of doing this, but use it an a contrived example:

    string inputpath = "/a/b";

    auto parts = splitter(inputpath, "/");
    // parts is ["", "a", "b"]
    parts.popFront; // get rid of empty leading part
    auto file = parts.back;
    parts.popBack;
    writefln("file = %s", file);
    auto path = reduce!(q{a ~= "/" ~ b})("", parts);
    writefln("path = %s", path);

Problem: Splitter is strictly a forward range currently.