default Stream<T> tokens() {
		return Stream.generate(this::next).takeWhile(Objects::nonNull);
	}
Return a stream of tokens, generated by {@code this} tokenizer. The
returned stream terminates, when the {@code null}-token is encountered.

@return a new tokens stream of {@code this} tokenizer
jenetics.ext/src/main/java/io/jenetics/ext/internal/parser/Tokenizer.java