Languages such as Chinese do not have word boundaries. For example, 木卫三是围绕木星运转的一颗卫星，公转周期约为7天 from Wikipedia is a sentence in Chinese that translates roughly into "Ganymede is running around Jupiter's moons, orbital period of about seven days" as done by the machine translation service at https://translate.google.com. Notice the absence of white spaces.

Finding tokens in this sort of data requires a very different approach that is based on character-language models and our spell-checking class. This recipe encodes finding words by treating untokenized text as misspelled text, where the correction inserts a space to delimit tokens. Of course, there is nothing misspelled about Chinese, Japanese, Vietnamese, and other non-word delimiting orthographies, but we have encoded it in our spelling-correction class.