static LS lambdaMapLike singlePredTok(ICharPred isPartOfToken, S s) {
  new ArrayList<S> tok;
  int l = s == null ? 0 : s.length();
  
  int i = 0, n = 0;
  while (i < l) {
    int j = i;
    char c;
    
    // scan for whitespace
    while (j < l) {
      c = s.charAt(j);
      if (isPartOfToken.get(c))
        break;
      else
        ++j;
    }
    
    tok.add(substring(s, i, j));
    i = j;
    if (i >= l) break;

    // scan for non-whitespace
    
    do
      ++j;
    while (j < l && isPartOfToken.get(s.charAt(j)));

    tok.add(substring(s, i, j));
    i = j;
  }
  
  if ((tok.size() % 2) == 0) tok.add("");
  ret tok;
}